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Issues pulling repo #3

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kraoof opened this issue Apr 15, 2017 · 1 comment
Closed

Issues pulling repo #3

kraoof opened this issue Apr 15, 2017 · 1 comment

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@kraoof
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kraoof commented Apr 15, 2017

Getting error 404

avagin pushed a commit to avagin/linux that referenced this issue Apr 19, 2017
Patch series "scope GFP_NOFS api", v5.

This patch (of 7):

Commit 21caf2f ("mm: teach mm by current context info to not do I/O
during memory allocation") added the memalloc_noio_(save|restore)
functions to enable people to modify the MM behavior by disabling I/O
during memory allocation.  This was further extended in Fixes:
934f307 ("mm: clear __GFP_FS when PF_MEMALLOC_NOIO is set").
memalloc_noio_* functions prevent allocation paths recursing back into the
filesystem without explicitly changing the flags for every allocation
site.  However, lockdep hasn't been keeping up with the changes and it
entirely misses handling the memalloc_noio adjustments.  Instead, it is
left to the callers of __lockdep_trace_alloc to call the function after
they have shaven the respective GFP flags which can lead to false
positives:

[  644.173373] =================================
[  644.174012] [ INFO: inconsistent lock state ]
[  644.174012] 4.10.0-nbor #134 Not tainted
[  644.174012] ---------------------------------
[  644.174012] inconsistent {IN-RECLAIM_FS-W} -> {RECLAIM_FS-ON-W} usage.
[  644.174012] fsstress/3365 [HC0[0]:SC0[0]:HE1:SE1] takes:
[  644.174012]  (&xfs_nondir_ilock_class){++++?.}, at: [<ffffffff8136f231>] xfs_ilock+0x141/0x230
[  644.174012] {IN-RECLAIM_FS-W} state was registered at:
[  644.174012]   __lock_acquire+0x62a/0x17c0
[  644.174012]   lock_acquire+0xc5/0x220
[  644.174012]   down_write_nested+0x4f/0x90
[  644.174012]   xfs_ilock+0x141/0x230
[  644.174012]   xfs_reclaim_inode+0x12a/0x320
[  644.174012]   xfs_reclaim_inodes_ag+0x2c8/0x4e0
[  644.174012]   xfs_reclaim_inodes_nr+0x33/0x40
[  644.174012]   xfs_fs_free_cached_objects+0x19/0x20
[  644.174012]   super_cache_scan+0x191/0x1a0
[  644.174012]   shrink_slab+0x26f/0x5f0
[  644.174012]   shrink_node+0xf9/0x2f0
[  644.174012]   kswapd+0x356/0x920
[  644.174012]   kthread+0x10c/0x140
[  644.174012]   ret_from_fork+0x31/0x40
[  644.174012] irq event stamp: 173777
[  644.174012] hardirqs last  enabled at (173777): [<ffffffff8105b440>] __local_bh_enable_ip+0x70/0xc0
[  644.174012] hardirqs last disabled at (173775): [<ffffffff8105b407>] __local_bh_enable_ip+0x37/0xc0
[  644.174012] softirqs last  enabled at (173776): [<ffffffff81357e2a>] _xfs_buf_find+0x67a/0xb70
[  644.174012] softirqs last disabled at (173774): [<ffffffff81357d8b>] _xfs_buf_find+0x5db/0xb70
[  644.174012]
[  644.174012] other info that might help us debug this:
[  644.174012]  Possible unsafe locking scenario:
[  644.174012]
[  644.174012]        CPU0
[  644.174012]        ----
[  644.174012]   lock(&xfs_nondir_ilock_class);
[  644.174012]   <Interrupt>
[  644.174012]     lock(&xfs_nondir_ilock_class);
[  644.174012]
[  644.174012]  *** DEADLOCK ***
[  644.174012]
[  644.174012] 4 locks held by fsstress/3365:
[  644.174012]  #0:  (sb_writers#10){++++++}, at: [<ffffffff81208d04>] mnt_want_write+0x24/0x50
[  644.174012]  svenkatr#1:  (&sb->s_type->i_mutex_key#12){++++++}, at: [<ffffffff8120ea2f>] vfs_setxattr+0x6f/0xb0
[  644.174012]  svenkatr#2:  (sb_internal#2){++++++}, at: [<ffffffff8138185c>] xfs_trans_alloc+0xfc/0x140
[  644.174012]  svenkatr#3:  (&xfs_nondir_ilock_class){++++?.}, at: [<ffffffff8136f231>] xfs_ilock+0x141/0x230
[  644.174012]
[  644.174012] stack backtrace:
[  644.174012] CPU: 0 PID: 3365 Comm: fsstress Not tainted 4.10.0-nbor #134
[  644.174012] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Ubuntu-1.8.2-1ubuntu1 04/01/2014
[  644.174012] Call Trace:
[  644.174012]  dump_stack+0x85/0xc9
[  644.174012]  print_usage_bug.part.37+0x284/0x293
[  644.174012]  ? print_shortest_lock_dependencies+0x1b0/0x1b0
[  644.174012]  mark_lock+0x27e/0x660
[  644.174012]  mark_held_locks+0x66/0x90
[  644.174012]  lockdep_trace_alloc+0x6f/0xd0
[  644.174012]  kmem_cache_alloc_node_trace+0x3a/0x2c0
[  644.174012]  ? vm_map_ram+0x2a1/0x510
[  644.174012]  vm_map_ram+0x2a1/0x510
[  644.174012]  ? vm_map_ram+0x46/0x510
[  644.174012]  _xfs_buf_map_pages+0x77/0x140
[  644.174012]  xfs_buf_get_map+0x185/0x2a0
[  644.174012]  xfs_attr_rmtval_set+0x233/0x430
[  644.174012]  xfs_attr_leaf_addname+0x2d2/0x500
[  644.174012]  xfs_attr_set+0x214/0x420
[  644.174012]  xfs_xattr_set+0x59/0xb0
[  644.174012]  __vfs_setxattr+0x76/0xa0
[  644.174012]  __vfs_setxattr_noperm+0x5e/0xf0
[  644.174012]  vfs_setxattr+0xae/0xb0
[  644.174012]  ? __might_fault+0x43/0xa0
[  644.174012]  setxattr+0x15e/0x1a0
[  644.174012]  ? __lock_is_held+0x53/0x90
[  644.174012]  ? rcu_read_lock_sched_held+0x93/0xa0
[  644.174012]  ? rcu_sync_lockdep_assert+0x2f/0x60
[  644.174012]  ? __sb_start_write+0x130/0x1d0
[  644.174012]  ? mnt_want_write+0x24/0x50
[  644.174012]  path_setxattr+0x8f/0xc0
[  644.174012]  SyS_lsetxattr+0x11/0x20
[  644.174012]  entry_SYSCALL_64_fastpath+0x23/0xc6

Let's fix this by making lockdep explicitly do the shaving of respective
GFP flags.

Fixes: 934f307 ("mm: clear __GFP_FS when PF_MEMALLOC_NOIO is set")
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Nikolay Borisov <[email protected]>
Signed-off-by: Michal Hocko <[email protected]>
Acked-by: Peter Zijlstra (Intel) <[email protected]>
Cc: Dave Chinner <[email protected]>
Cc: Theodore Ts'o <[email protected]>
Cc: Chris Mason <[email protected]>
Cc: David Sterba <[email protected]>
Cc: Jan Kara <[email protected]>
Cc: Brian Foster <[email protected]>
Cc: Darrick J. Wong <[email protected]>
Cc: Vlastimil Babka <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
avagin pushed a commit to avagin/linux that referenced this issue Apr 21, 2017
The MMC hosts could be left in an unconsistent or uninitialized state from
the firmware. Instead of assuming, the firmware did the right things, let's
reset the host controllers.

This change fixes a bug when the mmc2/sdio is initialized leading to a hung
task:

[  242.704294] INFO: task kworker/7:1:675 blocked for more than 120 seconds.
[  242.711129]       Not tainted 4.9.0-rc8-00017-gcf0251f svenkatr#3
[  242.716571] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
[  242.724435] kworker/7:1     D    0   675      2 0x00000000
[  242.729973] Workqueue: events_freezable mmc_rescan
[  242.734796] Call trace:
[  242.737269] [<ffff00000808611c>] __switch_to+0xa8/0xb4
[  242.742437] [<ffff000008d07c04>] __schedule+0x1c0/0x67c
[  242.747689] [<ffff000008d08254>] schedule+0x40/0xa0
[  242.752594] [<ffff000008d0b284>] schedule_timeout+0x1c4/0x35c
[  242.758366] [<ffff000008d08e38>] wait_for_common+0xd0/0x15c
[  242.763964] [<ffff000008d09008>] wait_for_completion+0x28/0x34
[  242.769825] [<ffff000008a1a9f4>] mmc_wait_for_req_done+0x40/0x124
[  242.775949] [<ffff000008a1ab98>] mmc_wait_for_req+0xc0/0xf8
[  242.781549] [<ffff000008a1ac3c>] mmc_wait_for_cmd+0x6c/0x84
[  242.787149] [<ffff000008a26610>] mmc_io_rw_direct_host+0x9c/0x114
[  242.793270] [<ffff000008a26aa0>] sdio_reset+0x34/0x7c
[  242.798347] [<ffff000008a1d46c>] mmc_rescan+0x2fc/0x360

[ ... ]

Cc: [email protected]
Signed-off-by: Daniel Lezcano <[email protected]>
Signed-off-by: Wei Xu <[email protected]>
avagin pushed a commit to avagin/linux that referenced this issue Apr 28, 2017
Patch series "scope GFP_NOFS api", v5.

This patch (of 7):

Commit 21caf2f ("mm: teach mm by current context info to not do I/O
during memory allocation") added the memalloc_noio_(save|restore)
functions to enable people to modify the MM behavior by disabling I/O
during memory allocation.  This was further extended in Fixes:
934f307 ("mm: clear __GFP_FS when PF_MEMALLOC_NOIO is set").
memalloc_noio_* functions prevent allocation paths recursing back into the
filesystem without explicitly changing the flags for every allocation
site.  However, lockdep hasn't been keeping up with the changes and it
entirely misses handling the memalloc_noio adjustments.  Instead, it is
left to the callers of __lockdep_trace_alloc to call the function after
they have shaven the respective GFP flags which can lead to false
positives:

[  644.173373] =================================
[  644.174012] [ INFO: inconsistent lock state ]
[  644.174012] 4.10.0-nbor #134 Not tainted
[  644.174012] ---------------------------------
[  644.174012] inconsistent {IN-RECLAIM_FS-W} -> {RECLAIM_FS-ON-W} usage.
[  644.174012] fsstress/3365 [HC0[0]:SC0[0]:HE1:SE1] takes:
[  644.174012]  (&xfs_nondir_ilock_class){++++?.}, at: [<ffffffff8136f231>] xfs_ilock+0x141/0x230
[  644.174012] {IN-RECLAIM_FS-W} state was registered at:
[  644.174012]   __lock_acquire+0x62a/0x17c0
[  644.174012]   lock_acquire+0xc5/0x220
[  644.174012]   down_write_nested+0x4f/0x90
[  644.174012]   xfs_ilock+0x141/0x230
[  644.174012]   xfs_reclaim_inode+0x12a/0x320
[  644.174012]   xfs_reclaim_inodes_ag+0x2c8/0x4e0
[  644.174012]   xfs_reclaim_inodes_nr+0x33/0x40
[  644.174012]   xfs_fs_free_cached_objects+0x19/0x20
[  644.174012]   super_cache_scan+0x191/0x1a0
[  644.174012]   shrink_slab+0x26f/0x5f0
[  644.174012]   shrink_node+0xf9/0x2f0
[  644.174012]   kswapd+0x356/0x920
[  644.174012]   kthread+0x10c/0x140
[  644.174012]   ret_from_fork+0x31/0x40
[  644.174012] irq event stamp: 173777
[  644.174012] hardirqs last  enabled at (173777): [<ffffffff8105b440>] __local_bh_enable_ip+0x70/0xc0
[  644.174012] hardirqs last disabled at (173775): [<ffffffff8105b407>] __local_bh_enable_ip+0x37/0xc0
[  644.174012] softirqs last  enabled at (173776): [<ffffffff81357e2a>] _xfs_buf_find+0x67a/0xb70
[  644.174012] softirqs last disabled at (173774): [<ffffffff81357d8b>] _xfs_buf_find+0x5db/0xb70
[  644.174012]
[  644.174012] other info that might help us debug this:
[  644.174012]  Possible unsafe locking scenario:
[  644.174012]
[  644.174012]        CPU0
[  644.174012]        ----
[  644.174012]   lock(&xfs_nondir_ilock_class);
[  644.174012]   <Interrupt>
[  644.174012]     lock(&xfs_nondir_ilock_class);
[  644.174012]
[  644.174012]  *** DEADLOCK ***
[  644.174012]
[  644.174012] 4 locks held by fsstress/3365:
[  644.174012]  #0:  (sb_writers#10){++++++}, at: [<ffffffff81208d04>] mnt_want_write+0x24/0x50
[  644.174012]  svenkatr#1:  (&sb->s_type->i_mutex_key#12){++++++}, at: [<ffffffff8120ea2f>] vfs_setxattr+0x6f/0xb0
[  644.174012]  svenkatr#2:  (sb_internal#2){++++++}, at: [<ffffffff8138185c>] xfs_trans_alloc+0xfc/0x140
[  644.174012]  svenkatr#3:  (&xfs_nondir_ilock_class){++++?.}, at: [<ffffffff8136f231>] xfs_ilock+0x141/0x230
[  644.174012]
[  644.174012] stack backtrace:
[  644.174012] CPU: 0 PID: 3365 Comm: fsstress Not tainted 4.10.0-nbor #134
[  644.174012] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Ubuntu-1.8.2-1ubuntu1 04/01/2014
[  644.174012] Call Trace:
[  644.174012]  dump_stack+0x85/0xc9
[  644.174012]  print_usage_bug.part.37+0x284/0x293
[  644.174012]  ? print_shortest_lock_dependencies+0x1b0/0x1b0
[  644.174012]  mark_lock+0x27e/0x660
[  644.174012]  mark_held_locks+0x66/0x90
[  644.174012]  lockdep_trace_alloc+0x6f/0xd0
[  644.174012]  kmem_cache_alloc_node_trace+0x3a/0x2c0
[  644.174012]  ? vm_map_ram+0x2a1/0x510
[  644.174012]  vm_map_ram+0x2a1/0x510
[  644.174012]  ? vm_map_ram+0x46/0x510
[  644.174012]  _xfs_buf_map_pages+0x77/0x140
[  644.174012]  xfs_buf_get_map+0x185/0x2a0
[  644.174012]  xfs_attr_rmtval_set+0x233/0x430
[  644.174012]  xfs_attr_leaf_addname+0x2d2/0x500
[  644.174012]  xfs_attr_set+0x214/0x420
[  644.174012]  xfs_xattr_set+0x59/0xb0
[  644.174012]  __vfs_setxattr+0x76/0xa0
[  644.174012]  __vfs_setxattr_noperm+0x5e/0xf0
[  644.174012]  vfs_setxattr+0xae/0xb0
[  644.174012]  ? __might_fault+0x43/0xa0
[  644.174012]  setxattr+0x15e/0x1a0
[  644.174012]  ? __lock_is_held+0x53/0x90
[  644.174012]  ? rcu_read_lock_sched_held+0x93/0xa0
[  644.174012]  ? rcu_sync_lockdep_assert+0x2f/0x60
[  644.174012]  ? __sb_start_write+0x130/0x1d0
[  644.174012]  ? mnt_want_write+0x24/0x50
[  644.174012]  path_setxattr+0x8f/0xc0
[  644.174012]  SyS_lsetxattr+0x11/0x20
[  644.174012]  entry_SYSCALL_64_fastpath+0x23/0xc6

Let's fix this by making lockdep explicitly do the shaving of respective
GFP flags.

Fixes: 934f307 ("mm: clear __GFP_FS when PF_MEMALLOC_NOIO is set")
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Nikolay Borisov <[email protected]>
Signed-off-by: Michal Hocko <[email protected]>
Acked-by: Peter Zijlstra (Intel) <[email protected]>
Cc: Dave Chinner <[email protected]>
Cc: Theodore Ts'o <[email protected]>
Cc: Chris Mason <[email protected]>
Cc: David Sterba <[email protected]>
Cc: Jan Kara <[email protected]>
Cc: Brian Foster <[email protected]>
Cc: Darrick J. Wong <[email protected]>
Cc: Vlastimil Babka <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
avagin pushed a commit to avagin/linux that referenced this issue May 1, 2017
The driver with nvme had this routine stubbed.

Right now XRI_ABORTED_CQE is not handled and the FC NVMET
Transport has a new API for the driver.

Missing code path, new NVME abort API
Update ABORT processing for NVMET

There are 3 new FC NVMET Transport API/ template routines for NVMET:

lpfc_nvmet_xmt_fcp_release
This NVMET template callback routine called to release context
associated with an IO This routine is ALWAYS called last, even
if the IO was aborted or completed in error.

lpfc_nvmet_xmt_fcp_abort
This NVMET template callback routine called to abort an exchange that
has an IO in progress

nvmet_fc_rcv_fcp_req
When the lpfc driver receives an ABTS, this NVME FC transport layer
callback routine is called. For this case there are 2 paths thru the
driver: the driver either has an outstanding exchange / context for the
XRI to be aborted or not.  If not, a BA_RJT is issued otherwise a BA_ACC

NVMET Driver abort paths:

There are 2 paths for aborting an IO. The first one is we receive an IO and
decide not to process it because of lack of resources. An unsolicated ABTS
is immediately sent back to the initiator as a response.
lpfc_nvmet_unsol_fcp_buffer
            lpfc_nvmet_unsol_issue_abort  (XMIT_SEQUENCE_WQE)

The second one is we sent the IO up to the NVMET transport layer to
process, and for some reason the NVME Transport layer decided to abort the
IO before it completes all its phases. For this case there are 2 paths
thru the driver:
the driver either has an outstanding TSEND/TRECEIVE/TRSP WQE or no
outstanding WQEs are present for the exchange / context.
lpfc_nvmet_xmt_fcp_abort
    if (LPFC_NVMET_IO_INP)
        lpfc_nvmet_sol_fcp_issue_abort  (ABORT_WQE)
                lpfc_nvmet_sol_fcp_abort_cmp
    else
        lpfc_nvmet_unsol_fcp_issue_abort
                lpfc_nvmet_unsol_issue_abort  (XMIT_SEQUENCE_WQE)
                        lpfc_nvmet_unsol_fcp_abort_cmp

Context flags:
LPFC_NVMET_IOP - his flag signifies an IO is in progress on the exchange.
LPFC_NVMET_XBUSY  - this flag indicates the IO completed but the firmware
is still busy with the corresponding exchange. The exchange should not be
reused until after a XRI_ABORTED_CQE is received for that exchange.
LPFC_NVMET_ABORT_OP - this flag signifies an ABORT_WQE was issued on the
exchange.
LPFC_NVMET_CTX_RLS  - this flag signifies a context free was requested,
but we are deferring it due to an XBUSY or ABORT in progress.

A ctxlock is added to the context structure that is used whenever these
flags are set/read  within the context of an IO.
The LPFC_NVMET_CTX_RLS flag is only set in the defer_relase routine when
the transport has resolved all IO associated with the buffer. The flag is
cleared when the CTX is associated with a new IO.

An exchange can has both an LPFC_NVMET_XBUSY and a LPFC_NVMET_ABORT_OP
condition active simultaneously. Both conditions must complete before the
exchange is freed.
When the abort callback (lpfc_nvmet_xmt_fcp_abort) is envoked:
If there is an outstanding IO, the driver will issue an ABORT_WQE. This
should result in 3 completions for the exchange:
1) IO cmpl with XB bit set
2) Abort WQE cmpl
3) XRI_ABORTED_CQE cmpl
For this scenerio, after completion svenkatr#1, the NVMET Transport IO rsp
callback is called.  After completion svenkatr#2, no action is taken with respect
to the exchange / context.  After completion svenkatr#3, the exchange context is
free for re-use on another IO.

If there is no outstanding activity on the exchange, the driver will send a
ABTS to the Initiator. Upon completion of this WQE, the exchange / context
is freed for re-use on another IO.

Signed-off-by: Dick Kennedy <[email protected]>
Signed-off-by: James Smart <[email protected]>
Reviewed-by: Johannes Thumshirn <[email protected]>
avagin pushed a commit to avagin/linux that referenced this issue May 1, 2017
…/jkirsher/next-queue

Jeff Kirsher says:

====================
10GbE Intel Wired LAN Driver Updates 2017-04-29

This series contains updates to ixgbe and ixgbevf only, most notable is
the addition of XDP support to our 10GbE drivers.

Paul fixes ixgbe to acquire the PHY semaphore before accessing PHY
registers when issuing a device reset.

John adds XDP support (yeah!) for ixgbe.

Emil fixes an issue by flushing the MACVLAN filters on VF reset to avoid
conflicts with other VFs that may end up using the same MAC address.  Also
fixed a bug where ethtool -S displayed some empty fields for ixgbevf
because it was using ixgbe_stats instead ixgbevf_stats for
IXGBEVF_QUEUE_STATS_LEN.

Tony adds the ability to specify a zero MAC address in order to clear the
VF's MAC address from the RAR table.  Also adds support for a new
1000Base-T device based on x550EM_X MAC type.  Fixed an issue where the
RSS key specified by the user would be over-written with a pre-existing
value, so change the rss_key to a pointer so we can check to see if the
key has a value set before attempting to set it.  Fixed the logic for
mailbox support for getting RETA and RSS values, which are only supported
by 82599 and x540 devices.

v2: fixed up patches svenkatr#2 and svenkatr#3 based on feedback from Jakub and to
    address build issues when page sizes are larger than 4k
====================

Signed-off-by: David S. Miller <[email protected]>
avagin pushed a commit to avagin/linux that referenced this issue May 1, 2017
Yuval Mintz says:

====================
qed: RoCE related pseudo-fixes

This series contains multiple small corrections to the RoCE logic
in qed plus some debug information and inter-module parameter
meant to prevent issues further along.

 - svenkatr#1, svenkatr#6 Share information with protocol driver
   [either new or filling missing bits in existing API].
 - svenkatr#2, svenkatr#3 correct error flows in qed.
 - svenkatr#4 add debug related information.
 - svenkatr#5 fixes a minor issue in the HW configuration.
====================

Signed-off-by: David S. Miller <[email protected]>
avagin pushed a commit to avagin/linux that referenced this issue May 2, 2017
When the instruction right before the branch destination is
a 64 bit load immediate, we currently calculate the wrong
jump offset in the ctx->offset[] array as we only account
one instruction slot for the 64 bit load immediate although
it uses two BPF instructions. Fix it up by setting the offset
into the right slot after we incremented the index.

Before (ldimm64 test 1):

  [...]
  00000020:  52800007  mov w7, #0x0 // #0
  00000024:  d2800060  mov x0, #0x3 // svenkatr#3
  00000028:  d2800041  mov x1, #0x2 // svenkatr#2
  0000002c:  eb01001f  cmp x0, x1
  00000030:  54ffff82  b.cs 0x00000020
  00000034:  d29fffe7  mov x7, #0xffff // #65535
  00000038:  f2bfffe7  movk x7, #0xffff, lsl #16
  0000003c:  f2dfffe7  movk x7, #0xffff, lsl #32
  00000040:  f2ffffe7  movk x7, #0xffff, lsl #48
  00000044:  d29dddc7  mov x7, #0xeeee // #61166
  00000048:  f2bdddc7  movk x7, #0xeeee, lsl #16
  0000004c:  f2ddddc7  movk x7, #0xeeee, lsl #32
  00000050:  f2fdddc7  movk x7, #0xeeee, lsl #48
  [...]

After (ldimm64 test 1):

  [...]
  00000020:  52800007  mov w7, #0x0 // #0
  00000024:  d2800060  mov x0, #0x3 // svenkatr#3
  00000028:  d2800041  mov x1, #0x2 // svenkatr#2
  0000002c:  eb01001f  cmp x0, x1
  00000030:  540000a2  b.cs 0x00000044
  00000034:  d29fffe7  mov x7, #0xffff // #65535
  00000038:  f2bfffe7  movk x7, #0xffff, lsl #16
  0000003c:  f2dfffe7  movk x7, #0xffff, lsl #32
  00000040:  f2ffffe7  movk x7, #0xffff, lsl #48
  00000044:  d29dddc7  mov x7, #0xeeee // #61166
  00000048:  f2bdddc7  movk x7, #0xeeee, lsl #16
  0000004c:  f2ddddc7  movk x7, #0xeeee, lsl #32
  00000050:  f2fdddc7  movk x7, #0xeeee, lsl #48
  [...]

Also, add a couple of test cases to make sure JITs pass
this test. Tested on Cavium ThunderX ARMv8. The added
test cases all pass after the fix.

Fixes: 8eee539 ("arm64: bpf: fix out-of-bounds read in bpf2a64_offset()")
Reported-by: David S. Miller <[email protected]>
Signed-off-by: Daniel Borkmann <[email protected]>
Acked-by: Alexei Starovoitov <[email protected]>
Cc: Xi Wang <[email protected]>
Signed-off-by: David S. Miller <[email protected]>
avagin pushed a commit to avagin/linux that referenced this issue May 4, 2017
Patch series "scope GFP_NOFS api", v5.

This patch (of 7):

Commit 21caf2f ("mm: teach mm by current context info to not do I/O
during memory allocation") added the memalloc_noio_(save|restore)
functions to enable people to modify the MM behavior by disabling I/O
during memory allocation.

This was further extended in commit 934f307 ("mm: clear __GFP_FS
when PF_MEMALLOC_NOIO is set").

memalloc_noio_* functions prevent allocation paths recursing back into
the filesystem without explicitly changing the flags for every
allocation site.

However, lockdep hasn't been keeping up with the changes and it entirely
misses handling the memalloc_noio adjustments.  Instead, it is left to
the callers of __lockdep_trace_alloc to call the function after they
have shaven the respective GFP flags which can lead to false positives:

  =================================
   [ INFO: inconsistent lock state ]
   4.10.0-nbor #134 Not tainted
   ---------------------------------
   inconsistent {IN-RECLAIM_FS-W} -> {RECLAIM_FS-ON-W} usage.
   fsstress/3365 [HC0[0]:SC0[0]:HE1:SE1] takes:
    (&xfs_nondir_ilock_class){++++?.}, at: xfs_ilock+0x141/0x230
   {IN-RECLAIM_FS-W} state was registered at:
     __lock_acquire+0x62a/0x17c0
     lock_acquire+0xc5/0x220
     down_write_nested+0x4f/0x90
     xfs_ilock+0x141/0x230
     xfs_reclaim_inode+0x12a/0x320
     xfs_reclaim_inodes_ag+0x2c8/0x4e0
     xfs_reclaim_inodes_nr+0x33/0x40
     xfs_fs_free_cached_objects+0x19/0x20
     super_cache_scan+0x191/0x1a0
     shrink_slab+0x26f/0x5f0
     shrink_node+0xf9/0x2f0
     kswapd+0x356/0x920
     kthread+0x10c/0x140
     ret_from_fork+0x31/0x40
   irq event stamp: 173777
   hardirqs last  enabled at (173777): __local_bh_enable_ip+0x70/0xc0
   hardirqs last disabled at (173775): __local_bh_enable_ip+0x37/0xc0
   softirqs last  enabled at (173776): _xfs_buf_find+0x67a/0xb70
   softirqs last disabled at (173774): _xfs_buf_find+0x5db/0xb70

   other info that might help us debug this:
    Possible unsafe locking scenario:

          CPU0
          ----
     lock(&xfs_nondir_ilock_class);
     <Interrupt>
       lock(&xfs_nondir_ilock_class);

    *** DEADLOCK ***

   4 locks held by fsstress/3365:
    #0:  (sb_writers#10){++++++}, at: mnt_want_write+0x24/0x50
    svenkatr#1:  (&sb->s_type->i_mutex_key#12){++++++}, at: vfs_setxattr+0x6f/0xb0
    svenkatr#2:  (sb_internal#2){++++++}, at: xfs_trans_alloc+0xfc/0x140
    svenkatr#3:  (&xfs_nondir_ilock_class){++++?.}, at: xfs_ilock+0x141/0x230

   stack backtrace:
   CPU: 0 PID: 3365 Comm: fsstress Not tainted 4.10.0-nbor #134
   Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Ubuntu-1.8.2-1ubuntu1 04/01/2014
   Call Trace:
    kmem_cache_alloc_node_trace+0x3a/0x2c0
    vm_map_ram+0x2a1/0x510
    _xfs_buf_map_pages+0x77/0x140
    xfs_buf_get_map+0x185/0x2a0
    xfs_attr_rmtval_set+0x233/0x430
    xfs_attr_leaf_addname+0x2d2/0x500
    xfs_attr_set+0x214/0x420
    xfs_xattr_set+0x59/0xb0
    __vfs_setxattr+0x76/0xa0
    __vfs_setxattr_noperm+0x5e/0xf0
    vfs_setxattr+0xae/0xb0
    setxattr+0x15e/0x1a0
    path_setxattr+0x8f/0xc0
    SyS_lsetxattr+0x11/0x20
    entry_SYSCALL_64_fastpath+0x23/0xc6

Let's fix this by making lockdep explicitly do the shaving of respective
GFP flags.

Fixes: 934f307 ("mm: clear __GFP_FS when PF_MEMALLOC_NOIO is set")
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Nikolay Borisov <[email protected]>
Signed-off-by: Michal Hocko <[email protected]>
Acked-by: Peter Zijlstra (Intel) <[email protected]>
Cc: Dave Chinner <[email protected]>
Cc: Theodore Ts'o <[email protected]>
Cc: Chris Mason <[email protected]>
Cc: David Sterba <[email protected]>
Cc: Jan Kara <[email protected]>
Cc: Brian Foster <[email protected]>
Cc: Darrick J. Wong <[email protected]>
Cc: Vlastimil Babka <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
avagin pushed a commit to avagin/linux that referenced this issue May 4, 2017
Patch series "scope GFP_NOFS api", v5.

This patch (of 7):

Commit 21caf2f ("mm: teach mm by current context info to not do I/O
during memory allocation") added the memalloc_noio_(save|restore)
functions to enable people to modify the MM behavior by disabling I/O
during memory allocation.  This was further extended in Fixes:
934f307 ("mm: clear __GFP_FS when PF_MEMALLOC_NOIO is set").
memalloc_noio_* functions prevent allocation paths recursing back into the
filesystem without explicitly changing the flags for every allocation
site.  However, lockdep hasn't been keeping up with the changes and it
entirely misses handling the memalloc_noio adjustments.  Instead, it is
left to the callers of __lockdep_trace_alloc to call the function after
they have shaven the respective GFP flags which can lead to false
positives:

[  644.173373] =================================
[  644.174012] [ INFO: inconsistent lock state ]
[  644.174012] 4.10.0-nbor #134 Not tainted
[  644.174012] ---------------------------------
[  644.174012] inconsistent {IN-RECLAIM_FS-W} -> {RECLAIM_FS-ON-W} usage.
[  644.174012] fsstress/3365 [HC0[0]:SC0[0]:HE1:SE1] takes:
[  644.174012]  (&xfs_nondir_ilock_class){++++?.}, at: [<ffffffff8136f231>] xfs_ilock+0x141/0x230
[  644.174012] {IN-RECLAIM_FS-W} state was registered at:
[  644.174012]   __lock_acquire+0x62a/0x17c0
[  644.174012]   lock_acquire+0xc5/0x220
[  644.174012]   down_write_nested+0x4f/0x90
[  644.174012]   xfs_ilock+0x141/0x230
[  644.174012]   xfs_reclaim_inode+0x12a/0x320
[  644.174012]   xfs_reclaim_inodes_ag+0x2c8/0x4e0
[  644.174012]   xfs_reclaim_inodes_nr+0x33/0x40
[  644.174012]   xfs_fs_free_cached_objects+0x19/0x20
[  644.174012]   super_cache_scan+0x191/0x1a0
[  644.174012]   shrink_slab+0x26f/0x5f0
[  644.174012]   shrink_node+0xf9/0x2f0
[  644.174012]   kswapd+0x356/0x920
[  644.174012]   kthread+0x10c/0x140
[  644.174012]   ret_from_fork+0x31/0x40
[  644.174012] irq event stamp: 173777
[  644.174012] hardirqs last  enabled at (173777): [<ffffffff8105b440>] __local_bh_enable_ip+0x70/0xc0
[  644.174012] hardirqs last disabled at (173775): [<ffffffff8105b407>] __local_bh_enable_ip+0x37/0xc0
[  644.174012] softirqs last  enabled at (173776): [<ffffffff81357e2a>] _xfs_buf_find+0x67a/0xb70
[  644.174012] softirqs last disabled at (173774): [<ffffffff81357d8b>] _xfs_buf_find+0x5db/0xb70
[  644.174012]
[  644.174012] other info that might help us debug this:
[  644.174012]  Possible unsafe locking scenario:
[  644.174012]
[  644.174012]        CPU0
[  644.174012]        ----
[  644.174012]   lock(&xfs_nondir_ilock_class);
[  644.174012]   <Interrupt>
[  644.174012]     lock(&xfs_nondir_ilock_class);
[  644.174012]
[  644.174012]  *** DEADLOCK ***
[  644.174012]
[  644.174012] 4 locks held by fsstress/3365:
[  644.174012]  #0:  (sb_writers#10){++++++}, at: [<ffffffff81208d04>] mnt_want_write+0x24/0x50
[  644.174012]  svenkatr#1:  (&sb->s_type->i_mutex_key#12){++++++}, at: [<ffffffff8120ea2f>] vfs_setxattr+0x6f/0xb0
[  644.174012]  svenkatr#2:  (sb_internal#2){++++++}, at: [<ffffffff8138185c>] xfs_trans_alloc+0xfc/0x140
[  644.174012]  svenkatr#3:  (&xfs_nondir_ilock_class){++++?.}, at: [<ffffffff8136f231>] xfs_ilock+0x141/0x230
[  644.174012]
[  644.174012] stack backtrace:
[  644.174012] CPU: 0 PID: 3365 Comm: fsstress Not tainted 4.10.0-nbor #134
[  644.174012] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Ubuntu-1.8.2-1ubuntu1 04/01/2014
[  644.174012] Call Trace:
[  644.174012]  dump_stack+0x85/0xc9
[  644.174012]  print_usage_bug.part.37+0x284/0x293
[  644.174012]  ? print_shortest_lock_dependencies+0x1b0/0x1b0
[  644.174012]  mark_lock+0x27e/0x660
[  644.174012]  mark_held_locks+0x66/0x90
[  644.174012]  lockdep_trace_alloc+0x6f/0xd0
[  644.174012]  kmem_cache_alloc_node_trace+0x3a/0x2c0
[  644.174012]  ? vm_map_ram+0x2a1/0x510
[  644.174012]  vm_map_ram+0x2a1/0x510
[  644.174012]  ? vm_map_ram+0x46/0x510
[  644.174012]  _xfs_buf_map_pages+0x77/0x140
[  644.174012]  xfs_buf_get_map+0x185/0x2a0
[  644.174012]  xfs_attr_rmtval_set+0x233/0x430
[  644.174012]  xfs_attr_leaf_addname+0x2d2/0x500
[  644.174012]  xfs_attr_set+0x214/0x420
[  644.174012]  xfs_xattr_set+0x59/0xb0
[  644.174012]  __vfs_setxattr+0x76/0xa0
[  644.174012]  __vfs_setxattr_noperm+0x5e/0xf0
[  644.174012]  vfs_setxattr+0xae/0xb0
[  644.174012]  ? __might_fault+0x43/0xa0
[  644.174012]  setxattr+0x15e/0x1a0
[  644.174012]  ? __lock_is_held+0x53/0x90
[  644.174012]  ? rcu_read_lock_sched_held+0x93/0xa0
[  644.174012]  ? rcu_sync_lockdep_assert+0x2f/0x60
[  644.174012]  ? __sb_start_write+0x130/0x1d0
[  644.174012]  ? mnt_want_write+0x24/0x50
[  644.174012]  path_setxattr+0x8f/0xc0
[  644.174012]  SyS_lsetxattr+0x11/0x20
[  644.174012]  entry_SYSCALL_64_fastpath+0x23/0xc6

Let's fix this by making lockdep explicitly do the shaving of respective
GFP flags.

Fixes: 934f307 ("mm: clear __GFP_FS when PF_MEMALLOC_NOIO is set")
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Nikolay Borisov <[email protected]>
Signed-off-by: Michal Hocko <[email protected]>
Acked-by: Peter Zijlstra (Intel) <[email protected]>
Cc: Dave Chinner <[email protected]>
Cc: Theodore Ts'o <[email protected]>
Cc: Chris Mason <[email protected]>
Cc: David Sterba <[email protected]>
Cc: Jan Kara <[email protected]>
Cc: Brian Foster <[email protected]>
Cc: Darrick J. Wong <[email protected]>
Cc: Vlastimil Babka <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
avagin pushed a commit to avagin/linux that referenced this issue May 5, 2017
Updates svenkatr#3 for 4.12 kernel merge window

- The hfi1 15 patch set that landed late
- IPoIB get_link_ksettings which landed late because I asked for a
  respin
- One late rxe change
- One -rc worthy fix that's in early
avagin pushed a commit to avagin/linux that referenced this issue May 8, 2017
Updates svenkatr#3 for 4.12 kernel merge window

- The hfi1 15 patch set that landed late
- IPoIB get_link_ksettings which landed late because I asked for a
  respin
- One late rxe change
- One -rc worthy fix that's in early
avagin pushed a commit to avagin/linux that referenced this issue May 9, 2017
Booting with UBI fastmap and SLUB debugging enabled results in the
following splats.  The problem is that ubi_scan_fastmap() moves the
fastmap blocks from the scan_ai (allocated in scan_fast()) to the ai
allocated in ubi_attach().  This results in two problems:

 - When the scan_ai is freed, aebs which were allocated from its slab
   cache are still in use.

 - When the other ai is being destroyed in destroy_ai(), the
   arguments to kmem_cache_free() call are incorrect since aebs on its
   ->fastmap list were allocated with a slab cache from a differnt ai.

Fix this by making a copy of the aebs in ubi_scan_fastmap() instead of
moving them.

 =============================================================================
 BUG ubi_aeb_slab_cache (Not tainted): Objects remaining in ubi_aeb_slab_cache on __kmem_cache_shutdown()
 -----------------------------------------------------------------------------

 INFO: Slab 0xbfd2da3c objects=17 used=1 fp=0xb33d7748 flags=0x40000080
 CPU: 1 PID: 118 Comm: ubiattach Tainted: G    B           4.9.15 svenkatr#3
 [<80111910>] (unwind_backtrace) from [<8010d498>] (show_stack+0x18/0x1c)
 [<8010d498>] (show_stack) from [<804a3274>] (dump_stack+0xb4/0xe0)
 [<804a3274>] (dump_stack) from [<8026c47c>] (slab_err+0x78/0x88)
 [<8026c47c>] (slab_err) from [<802735bc>] (__kmem_cache_shutdown+0x180/0x3e0)
 [<802735bc>] (__kmem_cache_shutdown) from [<8024e13c>] (shutdown_cache+0x1c/0x60)
 [<8024e13c>] (shutdown_cache) from [<8024ed64>] (kmem_cache_destroy+0x19c/0x20c)
 [<8024ed64>] (kmem_cache_destroy) from [<8057cc14>] (destroy_ai+0x1dc/0x1e8)
 [<8057cc14>] (destroy_ai) from [<8057f04c>] (ubi_attach+0x3f4/0x450)
 [<8057f04c>] (ubi_attach) from [<8056fe70>] (ubi_attach_mtd_dev+0x60c/0xff8)
 [<8056fe70>] (ubi_attach_mtd_dev) from [<80571d78>] (ctrl_cdev_ioctl+0x110/0x2b8)
 [<80571d78>] (ctrl_cdev_ioctl) from [<8029c77c>] (do_vfs_ioctl+0xac/0xa00)
 [<8029c77c>] (do_vfs_ioctl) from [<8029d10c>] (SyS_ioctl+0x3c/0x64)
 [<8029d10c>] (SyS_ioctl) from [<80108860>] (ret_fast_syscall+0x0/0x1c)
 INFO: Object 0xb33d7e88 @offset=3720
 INFO: Allocated in scan_peb+0x608/0x81c age=72 cpu=1 pid=118
 	kmem_cache_alloc+0x3b0/0x43c
 	scan_peb+0x608/0x81c
 	ubi_attach+0x124/0x450
 	ubi_attach_mtd_dev+0x60c/0xff8
 	ctrl_cdev_ioctl+0x110/0x2b8
 	do_vfs_ioctl+0xac/0xa00
 	SyS_ioctl+0x3c/0x64
 	ret_fast_syscall+0x0/0x1c
 kmem_cache_destroy ubi_aeb_slab_cache: Slab cache still has objects
 CPU: 1 PID: 118 Comm: ubiattach Tainted: G    B           4.9.15 svenkatr#3
 [<80111910>] (unwind_backtrace) from [<8010d498>] (show_stack+0x18/0x1c)
 [<8010d498>] (show_stack) from [<804a3274>] (dump_stack+0xb4/0xe0)
 [<804a3274>] (dump_stack) from [<8024ed80>] (kmem_cache_destroy+0x1b8/0x20c)
 [<8024ed80>] (kmem_cache_destroy) from [<8057cc14>] (destroy_ai+0x1dc/0x1e8)
 [<8057cc14>] (destroy_ai) from [<8057f04c>] (ubi_attach+0x3f4/0x450)
 [<8057f04c>] (ubi_attach) from [<8056fe70>] (ubi_attach_mtd_dev+0x60c/0xff8)
 [<8056fe70>] (ubi_attach_mtd_dev) from [<80571d78>] (ctrl_cdev_ioctl+0x110/0x2b8)
 [<80571d78>] (ctrl_cdev_ioctl) from [<8029c77c>] (do_vfs_ioctl+0xac/0xa00)
 [<8029c77c>] (do_vfs_ioctl) from [<8029d10c>] (SyS_ioctl+0x3c/0x64)
 [<8029d10c>] (SyS_ioctl) from [<80108860>] (ret_fast_syscall+0x0/0x1c)
 cache_from_obj: Wrong slab cache. ubi_aeb_slab_cache but object is from ubi_aeb_slab_cache
 ------------[ cut here ]------------
 WARNING: CPU: 1 PID: 118 at mm/slab.h:354 kmem_cache_free+0x39c/0x450
 Modules linked in:
 CPU: 1 PID: 118 Comm: ubiattach Tainted: G    B           4.9.15 svenkatr#3
 [<80111910>] (unwind_backtrace) from [<8010d498>] (show_stack+0x18/0x1c)
 [<8010d498>] (show_stack) from [<804a3274>] (dump_stack+0xb4/0xe0)
 [<804a3274>] (dump_stack) from [<80120e40>] (__warn+0xf4/0x10c)
 [<80120e40>] (__warn) from [<80120f20>] (warn_slowpath_null+0x28/0x30)
 [<80120f20>] (warn_slowpath_null) from [<80271fe0>] (kmem_cache_free+0x39c/0x450)
 [<80271fe0>] (kmem_cache_free) from [<8057cb88>] (destroy_ai+0x150/0x1e8)
 [<8057cb88>] (destroy_ai) from [<8057ef1c>] (ubi_attach+0x2c4/0x450)
 [<8057ef1c>] (ubi_attach) from [<8056fe70>] (ubi_attach_mtd_dev+0x60c/0xff8)
 [<8056fe70>] (ubi_attach_mtd_dev) from [<80571d78>] (ctrl_cdev_ioctl+0x110/0x2b8)
 [<80571d78>] (ctrl_cdev_ioctl) from [<8029c77c>] (do_vfs_ioctl+0xac/0xa00)
 [<8029c77c>] (do_vfs_ioctl) from [<8029d10c>] (SyS_ioctl+0x3c/0x64)
 [<8029d10c>] (SyS_ioctl) from [<80108860>] (ret_fast_syscall+0x0/0x1c)
 ---[ end trace 2bd8396277fd0a0b ]---
 =============================================================================
 BUG ubi_aeb_slab_cache (Tainted: G    B   W      ): page slab pointer corrupt.
 -----------------------------------------------------------------------------

 INFO: Allocated in scan_peb+0x608/0x81c age=104 cpu=1 pid=118
 	kmem_cache_alloc+0x3b0/0x43c
 	scan_peb+0x608/0x81c
 	ubi_attach+0x124/0x450
 	ubi_attach_mtd_dev+0x60c/0xff8
 	ctrl_cdev_ioctl+0x110/0x2b8
 	do_vfs_ioctl+0xac/0xa00
 	SyS_ioctl+0x3c/0x64
 	ret_fast_syscall+0x0/0x1c
 INFO: Slab 0xbfd2da3c objects=17 used=1 fp=0xb33d7748 flags=0x40000081
 INFO: Object 0xb33d7e88 @offset=3720 fp=0xb33d7da0

 Redzone b33d7e80: cc cc cc cc cc cc cc cc                          ........
 Object b33d7e88: 02 00 00 00 01 00 00 00 00 f0 ff 7f ff ff ff ff  ................
 Object b33d7e98: 00 00 00 00 00 00 00 00 bd 16 00 00 00 00 00 00  ................
 Object b33d7ea8: 00 01 00 00 00 02 00 00 00 00 00 00 00 00 00 00  ................
 Redzone b33d7eb8: cc cc cc cc                                      ....
 Padding b33d7f60: 5a 5a 5a 5a 5a 5a 5a 5a                          ZZZZZZZZ
 CPU: 1 PID: 118 Comm: ubiattach Tainted: G    B   W       4.9.15 svenkatr#3
 [<80111910>] (unwind_backtrace) from [<8010d498>] (show_stack+0x18/0x1c)
 [<8010d498>] (show_stack) from [<804a3274>] (dump_stack+0xb4/0xe0)
 [<804a3274>] (dump_stack) from [<80271770>] (free_debug_processing+0x320/0x3c4)
 [<80271770>] (free_debug_processing) from [<80271ad0>] (__slab_free+0x2bc/0x430)
 [<80271ad0>] (__slab_free) from [<80272024>] (kmem_cache_free+0x3e0/0x450)
 [<80272024>] (kmem_cache_free) from [<8057cb88>] (destroy_ai+0x150/0x1e8)
 [<8057cb88>] (destroy_ai) from [<8057ef1c>] (ubi_attach+0x2c4/0x450)
 [<8057ef1c>] (ubi_attach) from [<8056fe70>] (ubi_attach_mtd_dev+0x60c/0xff8)
 [<8056fe70>] (ubi_attach_mtd_dev) from [<80571d78>] (ctrl_cdev_ioctl+0x110/0x2b8)
 [<80571d78>] (ctrl_cdev_ioctl) from [<8029c77c>] (do_vfs_ioctl+0xac/0xa00)
 [<8029c77c>] (do_vfs_ioctl) from [<8029d10c>] (SyS_ioctl+0x3c/0x64)
 [<8029d10c>] (SyS_ioctl) from [<80108860>] (ret_fast_syscall+0x0/0x1c)
 FIX ubi_aeb_slab_cache: Object at 0xb33d7e88 not freed

Signed-off-by: Rabin Vincent <[email protected]>
Signed-off-by: Richard Weinberger <[email protected]>
avagin pushed a commit to avagin/linux that referenced this issue May 9, 2017
Updates svenkatr#3 for 4.12 kernel merge window

- The hfi1 15 patch set that landed late
- IPoIB get_link_ksettings which landed late because I asked for a
  respin
- One late rxe change
- One -rc worthy fix that's in early
avagin pushed a commit to avagin/linux that referenced this issue May 11, 2017
Yuval Mintz says:

====================
qed*: General fixes

This series contain several fixes for qed and qede.

 - svenkatr#1 [and ~svenkatr#5] relate to XDP cleanups
 - svenkatr#2 and svenkatr#5 correct VF behavior
 - svenkatr#3 and svenkatr#4 fix and add missing configurations needed for RoCE & storage
====================

Signed-off-by: David S. Miller <[email protected]>
avagin pushed a commit to avagin/linux that referenced this issue May 11, 2017
This can be triggered by hot-unplug one cpu.

======================================================
 [ INFO: possible circular locking dependency detected ]
 4.11.0+ #17 Not tainted
 -------------------------------------------------------
 step_after_susp/2640 is trying to acquire lock:
  (all_q_mutex){+.+...}, at: [<ffffffffb33f95b8>] blk_mq_queue_reinit_work+0x18/0x110

 but task is already holding lock:
  (cpu_hotplug.lock){+.+.+.}, at: [<ffffffffb306d04f>] cpu_hotplug_begin+0x7f/0xe0

 which lock already depends on the new lock.

 the existing dependency chain (in reverse order) is:

 -> svenkatr#1 (cpu_hotplug.lock){+.+.+.}:
        lock_acquire+0x11c/0x230
        __mutex_lock+0x92/0x990
        mutex_lock_nested+0x1b/0x20
        get_online_cpus+0x64/0x80
        blk_mq_init_allocated_queue+0x3a0/0x4e0
        blk_mq_init_queue+0x3a/0x60
        loop_add+0xe5/0x280
        loop_init+0x124/0x177
        do_one_initcall+0x53/0x1c0
        kernel_init_freeable+0x1e3/0x27f
        kernel_init+0xe/0x100
        ret_from_fork+0x31/0x40

 -> #0 (all_q_mutex){+.+...}:
        __lock_acquire+0x189a/0x18a0
        lock_acquire+0x11c/0x230
        __mutex_lock+0x92/0x990
        mutex_lock_nested+0x1b/0x20
        blk_mq_queue_reinit_work+0x18/0x110
        blk_mq_queue_reinit_dead+0x1c/0x20
        cpuhp_invoke_callback+0x1f2/0x810
        cpuhp_down_callbacks+0x42/0x80
        _cpu_down+0xb2/0xe0
        freeze_secondary_cpus+0xb6/0x390
        suspend_devices_and_enter+0x3b3/0xa40
        pm_suspend+0x129/0x490
        state_store+0x82/0xf0
        kobj_attr_store+0xf/0x20
        sysfs_kf_write+0x45/0x60
        kernfs_fop_write+0x135/0x1c0
        __vfs_write+0x37/0x160
        vfs_write+0xcd/0x1d0
        SyS_write+0x58/0xc0
        do_syscall_64+0x8f/0x710
        return_from_SYSCALL_64+0x0/0x7a

 other info that might help us debug this:

  Possible unsafe locking scenario:

        CPU0                    CPU1
        ----                    ----
   lock(cpu_hotplug.lock);
                                lock(all_q_mutex);
                                lock(cpu_hotplug.lock);
   lock(all_q_mutex);

  *** DEADLOCK ***

 8 locks held by step_after_susp/2640:
  #0:  (sb_writers#6){.+.+.+}, at: [<ffffffffb3244aed>] vfs_write+0x1ad/0x1d0
  svenkatr#1:  (&of->mutex){+.+.+.}, at: [<ffffffffb32d3a51>] kernfs_fop_write+0x101/0x1c0
  svenkatr#2:  (s_active#166){.+.+.+}, at: [<ffffffffb32d3a59>] kernfs_fop_write+0x109/0x1c0
  svenkatr#3:  (pm_mutex){+.+...}, at: [<ffffffffb30d2ecd>] pm_suspend+0x21d/0x490
  svenkatr#4:  (acpi_scan_lock){+.+.+.}, at: [<ffffffffb34dc3d7>] acpi_scan_lock_acquire+0x17/0x20
  svenkatr#5:  (cpu_add_remove_lock){+.+.+.}, at: [<ffffffffb306d6d7>] freeze_secondary_cpus+0x27/0x390
  svenkatr#6:  (cpu_hotplug.dep_map){++++++}, at: [<ffffffffb306cfd5>] cpu_hotplug_begin+0x5/0xe0
  svenkatr#7:  (cpu_hotplug.lock){+.+.+.}, at: [<ffffffffb306d04f>] cpu_hotplug_begin+0x7f/0xe0

 stack backtrace:
 CPU: 3 PID: 2640 Comm: step_after_susp Not tainted 4.11.0+ #17
 Hardware name: Dell Inc. OptiPlex 7040/0JCTF8, BIOS 1.4.9 09/12/2016
 Call Trace:
  dump_stack+0x99/0xce
  print_circular_bug+0x1fa/0x270
  __lock_acquire+0x189a/0x18a0
  lock_acquire+0x11c/0x230
  ? lock_acquire+0x11c/0x230
  ? blk_mq_queue_reinit_work+0x18/0x110
  ? blk_mq_queue_reinit_work+0x18/0x110
  __mutex_lock+0x92/0x990
  ? blk_mq_queue_reinit_work+0x18/0x110
  ? kmem_cache_free+0x2cb/0x330
  ? anon_transport_class_unregister+0x20/0x20
  ? blk_mq_queue_reinit_work+0x110/0x110
  mutex_lock_nested+0x1b/0x20
  ? mutex_lock_nested+0x1b/0x20
  blk_mq_queue_reinit_work+0x18/0x110
  blk_mq_queue_reinit_dead+0x1c/0x20
  cpuhp_invoke_callback+0x1f2/0x810
  ? __flow_cache_shrink+0x160/0x160
  cpuhp_down_callbacks+0x42/0x80
  _cpu_down+0xb2/0xe0
  freeze_secondary_cpus+0xb6/0x390
  suspend_devices_and_enter+0x3b3/0xa40
  ? rcu_read_lock_sched_held+0x79/0x80
  pm_suspend+0x129/0x490
  state_store+0x82/0xf0
  kobj_attr_store+0xf/0x20
  sysfs_kf_write+0x45/0x60
  kernfs_fop_write+0x135/0x1c0
  __vfs_write+0x37/0x160
  ? rcu_read_lock_sched_held+0x79/0x80
  ? rcu_sync_lockdep_assert+0x2f/0x60
  ? __sb_start_write+0xd9/0x1c0
  ? vfs_write+0x1ad/0x1d0
  vfs_write+0xcd/0x1d0
  SyS_write+0x58/0xc0
  ? rcu_read_lock_sched_held+0x79/0x80
  do_syscall_64+0x8f/0x710
  ? trace_hardirqs_on_thunk+0x1a/0x1c
  entry_SYSCALL64_slow_path+0x25/0x25

The cpu hotplug path will hold cpu_hotplug.lock and then reinit all exiting
queues for blk mq w/ all_q_mutex, however, blk_mq_init_allocated_queue() will
contend these two locks in the inversion order. This is due to commit eabe065
(blk/mq: Cure cpu hotplug lock inversion), it fixes a cpu hotplug lock inversion
issue because of hotplug rework, however the hotplug rework is still work-in-progress
and lives in a -tip branch and mainline cannot yet trigger that splat. The commit
breaks the linus's tree in the merge window, so this patch reverts the lock order
and avoids to splat linus's tree.

Cc: Jens Axboe <[email protected]>
Cc: Peter Zijlstra (Intel) <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Signed-off-by: Wanpeng Li <[email protected]>
Signed-off-by: Jens Axboe <[email protected]>
avagin pushed a commit to avagin/linux that referenced this issue May 12, 2017
Shubham was recently asking on netdev why in arm64 JIT we don't multiply
the index for accessing the tail call map by 8. That led me into testing
out arm64 JIT wrt tail calls and it turned out I got a NULL pointer
dereference on the tail call.

The buggy access is at:

  prog = array->ptrs[index];
  if (prog == NULL)
      goto out;

  [...]
  00000060:  d2800e0a  mov x10, #0x70 // #112
  00000064:  f86a682a  ldr x10, [x1,x10]
  00000068:  f862694b  ldr x11, [x10,x2]
  0000006c:  b40000ab  cbz x11, 0x00000080
  [...]

The code triggering the crash is f862694b. x1 at the time contains the
address of the bpf array, x10 offsetof(struct bpf_array, ptrs). Meaning,
above we load the pointer to the program at map slot 0 into x10. x10
can then be NULL if the slot is not occupied, which we later on try to
access with a user given offset in x2 that is the map index.

Fix this by emitting the following instead:

  [...]
  00000060:  d2800e0a  mov x10, #0x70 // #112
  00000064:  8b0a002a  add x10, x1, x10
  00000068:  d37df04b  lsl x11, x2, svenkatr#3
  0000006c:  f86b694b  ldr x11, [x10,x11]
  00000070:  b40000ab  cbz x11, 0x00000084
  [...]

This basically adds the offset to ptrs to the base address of the bpf
array we got and we later on access the map with an index * 8 offset
relative to that. The tail call map itself is basically one large area
with meta data at the head followed by the array of prog pointers.
This makes tail calls working again, tested on Cavium ThunderX ARMv8.

Fixes: ddb5599 ("arm64: bpf: implement bpf_tail_call() helper")
Reported-by: Shubham Bansal <[email protected]>
Signed-off-by: Daniel Borkmann <[email protected]>
Signed-off-by: David S. Miller <[email protected]>
avagin pushed a commit to avagin/linux that referenced this issue May 15, 2017
Implement deduplication feature in zram.  The purpose of this work is
naturally to save amount of memory usage by zram.

Android is one of the biggest users to use zram as swap and it's really
important to save amount of memory usage.  There is a paper that reports
that duplication ratio of Android's memory content is rather high [1].
And, there is a similar work on zswap that also reports that experiments
has shown that around 10-15% of pages stored in zswp are duplicates and
deduplicate them provides some benefits [2].

Also, there is a different kind of workload that uses zram as blockdev and
store build outputs into it to reduce wear-out problem of real blockdev.
In this workload, deduplication hit is very high due to temporary files
and intermediate object files.  Detailed analysis is on the bottom of this
description.

Anyway, if we can detect duplicated content and avoid to store duplicated
content at different memory space, we can save memory.  This patch tries
to do that.

Implementation is almost simple and intuitive but I should note one thing
about implementation detail.

To check duplication, this patch uses checksum of the page and collision
of this checksum could be possible.  There would be many choices to handle
this situation but this patch chooses to allow entry with duplicated
checksum to be added to the hash, but, not to compare all entries with
duplicated checksum when checking duplication.  I guess that checksum
collision is quite rare event and we don't need to pay any attention to
such a case.  Therefore, I decided the most simplest way to implement the
feature.  If there is a different opinion, I can accept and go that way.

Following is the result of this patch.

Test result svenkatr#1 (Swap):
Android Marshmallow, emulator, x86_64, Backporting to kernel v3.18

orig_data_size: 145297408
compr_data_size: 32408125
mem_used_total: 32276480
dup_data_size: 3188134
meta_data_size: 1444272

Last two metrics added to mm_stat are related to this work.  First one,
dup_data_size, is amount of saved memory by avoiding to store duplicated
page.  Later one, meta_data_size, is the amount of data structure to
support deduplication.  If dup > meta, we can judge that the patch
improves memory usage.

In Adnroid, we can save 5% of memory usage by this work.

Test result svenkatr#2 (Blockdev):
build the kernel and store output to ext4 FS on zram

<no-dedup>
Elapsed time: 249 s
mm_stat: 430845952 191014886 196898816 0 196898816 28320 0 0 0

<dedup>
Elapsed time: 250 s
mm_stat: 430505984 190971334 148365312 0 148365312 28404 0 47287038  3945792

There is no performance degradation and save 23% memory.

Test result svenkatr#3 (Blockdev):
copy android build output dir(out/host) to ext4 FS on zram

<no-dedup>
Elapsed time: out/host: 88 s
mm_stat: 8834420736 3658184579 3834208256 0 3834208256 32889 0 0 0

<dedup>
Elapsed time: out/host: 100 s
mm_stat: 8832929792 3657329322 2832015360 0 2832015360 32609 0 952568877 80880336

It shows performance degradation roughly 13% and save 24% memory. Maybe,
it is due to overhead of calculating checksum and comparison.

Test result svenkatr#4 (Blockdev):
copy android build output dir(out/target/common) to ext4 FS on zram

<no-dedup>
Elapsed time: out/host: 203 s
mm_stat: 4041678848 2310355010 2346577920 0 2346582016 500 4 0 0

<dedup>
Elapsed time: out/host: 201 s
mm_stat: 4041666560 2310488276 1338150912 0 1338150912 476 0 989088794 24564336

Memory is saved by 42% and performance is the same. Even if there is overhead
of calculating checksum and comparison, large hit ratio compensate it since
hit leads to less compression attempt.

I checked the detailed reason of savings on kernel build workload and
there are some cases that deduplication happens.

1) *.cmd
Build command is usually similar in one directory so content of these file
are very similar. In my system, more than 789 lines in fs/ext4/.namei.o.cmd
and fs/ext4/.inode.o.cmd are the same in 944 and 938 lines of the file,
respectively.

2) intermediate object files
built-in.o and temporary object file have the similar contents. More than
50% of fs/ext4/ext4.o is the same with fs/ext4/built-in.o.

3) vmlinux
.tmp_vmlinux1 and .tmp_vmlinux2 and arch/x86/boo/compressed/vmlinux.bin
have the similar contents.

Android test has similar case that some of object files(.class
and .so) are similar with another ones.
(./host/linux-x86/lib/libartd.so and
./host/linux-x86-lib/libartd-comiler.so)

Anyway, benefit seems to be largely dependent on the workload so
following patch will make this feature optional. However, this feature
can help some usecases so is deserved to be merged.

[1]: MemScope: Analyzing Memory Duplication on Android Systems,
dl.acm.org/citation.cfm?id=2797023
[2]: zswap: Optimize compressed pool memory utilization,
lkml.kernel.org/r/1341407574.7551.1471584870761.JavaMail.weblogic@epwas3p2

Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Joonsoo Kim <[email protected]>
Reviewed-by: Sergey Senozhatsky <[email protected]>
Acked-by: Minchan Kim <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
avagin pushed a commit to avagin/linux that referenced this issue May 18, 2017
[ Upstream commit ddc665a ]

When the instruction right before the branch destination is
a 64 bit load immediate, we currently calculate the wrong
jump offset in the ctx->offset[] array as we only account
one instruction slot for the 64 bit load immediate although
it uses two BPF instructions. Fix it up by setting the offset
into the right slot after we incremented the index.

Before (ldimm64 test 1):

  [...]
  00000020:  52800007  mov w7, #0x0 // #0
  00000024:  d2800060  mov x0, #0x3 // svenkatr#3
  00000028:  d2800041  mov x1, #0x2 // svenkatr#2
  0000002c:  eb01001f  cmp x0, x1
  00000030:  54ffff82  b.cs 0x00000020
  00000034:  d29fffe7  mov x7, #0xffff // #65535
  00000038:  f2bfffe7  movk x7, #0xffff, lsl #16
  0000003c:  f2dfffe7  movk x7, #0xffff, lsl #32
  00000040:  f2ffffe7  movk x7, #0xffff, lsl #48
  00000044:  d29dddc7  mov x7, #0xeeee // #61166
  00000048:  f2bdddc7  movk x7, #0xeeee, lsl #16
  0000004c:  f2ddddc7  movk x7, #0xeeee, lsl #32
  00000050:  f2fdddc7  movk x7, #0xeeee, lsl #48
  [...]

After (ldimm64 test 1):

  [...]
  00000020:  52800007  mov w7, #0x0 // #0
  00000024:  d2800060  mov x0, #0x3 // svenkatr#3
  00000028:  d2800041  mov x1, #0x2 // svenkatr#2
  0000002c:  eb01001f  cmp x0, x1
  00000030:  540000a2  b.cs 0x00000044
  00000034:  d29fffe7  mov x7, #0xffff // #65535
  00000038:  f2bfffe7  movk x7, #0xffff, lsl #16
  0000003c:  f2dfffe7  movk x7, #0xffff, lsl #32
  00000040:  f2ffffe7  movk x7, #0xffff, lsl #48
  00000044:  d29dddc7  mov x7, #0xeeee // #61166
  00000048:  f2bdddc7  movk x7, #0xeeee, lsl #16
  0000004c:  f2ddddc7  movk x7, #0xeeee, lsl #32
  00000050:  f2fdddc7  movk x7, #0xeeee, lsl #48
  [...]

Also, add a couple of test cases to make sure JITs pass
this test. Tested on Cavium ThunderX ARMv8. The added
test cases all pass after the fix.

Fixes: 8eee539 ("arm64: bpf: fix out-of-bounds read in bpf2a64_offset()")
Reported-by: David S. Miller <[email protected]>
Signed-off-by: Daniel Borkmann <[email protected]>
Acked-by: Alexei Starovoitov <[email protected]>
Cc: Xi Wang <[email protected]>
Signed-off-by: David S. Miller <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
avagin pushed a commit to avagin/linux that referenced this issue May 19, 2017
Implement deduplication feature in zram.  The purpose of this work is
naturally to save amount of memory usage by zram.

Android is one of the biggest users to use zram as swap and it's really
important to save amount of memory usage.  There is a paper that reports
that duplication ratio of Android's memory content is rather high [1].
And, there is a similar work on zswap that also reports that experiments
has shown that around 10-15% of pages stored in zswp are duplicates and
deduplicate them provides some benefits [2].

Also, there is a different kind of workload that uses zram as blockdev and
store build outputs into it to reduce wear-out problem of real blockdev.
In this workload, deduplication hit is very high due to temporary files
and intermediate object files.  Detailed analysis is on the bottom of this
description.

Anyway, if we can detect duplicated content and avoid to store duplicated
content at different memory space, we can save memory.  This patch tries
to do that.

Implementation is almost simple and intuitive but I should note one thing
about implementation detail.

To check duplication, this patch uses checksum of the page and collision
of this checksum could be possible.  There would be many choices to handle
this situation but this patch chooses to allow entry with duplicated
checksum to be added to the hash, but, not to compare all entries with
duplicated checksum when checking duplication.  I guess that checksum
collision is quite rare event and we don't need to pay any attention to
such a case.  Therefore, I decided the most simplest way to implement the
feature.  If there is a different opinion, I can accept and go that way.

Following is the result of this patch.

Test result svenkatr#1 (Swap):
Android Marshmallow, emulator, x86_64, Backporting to kernel v3.18

orig_data_size: 145297408
compr_data_size: 32408125
mem_used_total: 32276480
dup_data_size: 3188134
meta_data_size: 1444272

Last two metrics added to mm_stat are related to this work.  First one,
dup_data_size, is amount of saved memory by avoiding to store duplicated
page.  Later one, meta_data_size, is the amount of data structure to
support deduplication.  If dup > meta, we can judge that the patch
improves memory usage.

In Adnroid, we can save 5% of memory usage by this work.

Test result svenkatr#2 (Blockdev):
build the kernel and store output to ext4 FS on zram

<no-dedup>
Elapsed time: 249 s
mm_stat: 430845952 191014886 196898816 0 196898816 28320 0 0 0

<dedup>
Elapsed time: 250 s
mm_stat: 430505984 190971334 148365312 0 148365312 28404 0 47287038  3945792

There is no performance degradation and save 23% memory.

Test result svenkatr#3 (Blockdev):
copy android build output dir(out/host) to ext4 FS on zram

<no-dedup>
Elapsed time: out/host: 88 s
mm_stat: 8834420736 3658184579 3834208256 0 3834208256 32889 0 0 0

<dedup>
Elapsed time: out/host: 100 s
mm_stat: 8832929792 3657329322 2832015360 0 2832015360 32609 0 952568877 80880336

It shows performance degradation roughly 13% and save 24% memory. Maybe,
it is due to overhead of calculating checksum and comparison.

Test result svenkatr#4 (Blockdev):
copy android build output dir(out/target/common) to ext4 FS on zram

<no-dedup>
Elapsed time: out/host: 203 s
mm_stat: 4041678848 2310355010 2346577920 0 2346582016 500 4 0 0

<dedup>
Elapsed time: out/host: 201 s
mm_stat: 4041666560 2310488276 1338150912 0 1338150912 476 0 989088794 24564336

Memory is saved by 42% and performance is the same. Even if there is overhead
of calculating checksum and comparison, large hit ratio compensate it since
hit leads to less compression attempt.

I checked the detailed reason of savings on kernel build workload and
there are some cases that deduplication happens.

1) *.cmd
Build command is usually similar in one directory so content of these file
are very similar. In my system, more than 789 lines in fs/ext4/.namei.o.cmd
and fs/ext4/.inode.o.cmd are the same in 944 and 938 lines of the file,
respectively.

2) intermediate object files
built-in.o and temporary object file have the similar contents. More than
50% of fs/ext4/ext4.o is the same with fs/ext4/built-in.o.

3) vmlinux
.tmp_vmlinux1 and .tmp_vmlinux2 and arch/x86/boo/compressed/vmlinux.bin
have the similar contents.

Android test has similar case that some of object files(.class
and .so) are similar with another ones.
(./host/linux-x86/lib/libartd.so and
./host/linux-x86-lib/libartd-comiler.so)

Anyway, benefit seems to be largely dependent on the workload so
following patch will make this feature optional. However, this feature
can help some usecases so is deserved to be merged.

[1]: MemScope: Analyzing Memory Duplication on Android Systems,
dl.acm.org/citation.cfm?id=2797023
[2]: zswap: Optimize compressed pool memory utilization,
lkml.kernel.org/r/1341407574.7551.1471584870761.JavaMail.weblogic@epwas3p2

Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Joonsoo Kim <[email protected]>
Reviewed-by: Sergey Senozhatsky <[email protected]>
Acked-by: Minchan Kim <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
avagin pushed a commit to avagin/linux that referenced this issue May 23, 2017
Yuval Mintz says:

====================
qed/qede updates

This series contains some general minor fixes and enhancements:

 - svenkatr#1, svenkatr#2 and svenkatr#9 correct small missing ethtool functionality.
 - svenkatr#3, svenkatr#6  and svenkatr#8 correct minor issues in driver, but those are either
   print-related or unexposed in existing code.
 - svenkatr#4 adds proper support to TLB mode bonding.
 - #10 is meant to improve performance on varying cache-line sizes.
====================

Signed-off-by: David S. Miller <[email protected]>
avagin pushed a commit to avagin/linux that referenced this issue May 28, 2017
…_range()

With function tracing starting in early bootup and having its trampoline
pages being read only, a bug triggered with the following:

kernel BUG at arch/x86/mm/pageattr.c:189!
invalid opcode: 0000 [svenkatr#1] SMP
Modules linked in:
CPU: 0 PID: 0 Comm: swapper Not tainted 4.12.0-rc2-test+ svenkatr#3
Hardware name: MSI MS-7823/CSM-H87M-G43 (MS-7823), BIOS V1.6 02/22/2014
task: ffffffffb4222500 task.stack: ffffffffb4200000
RIP: 0010:change_page_attr_set_clr+0x269/0x302
RSP: 0000:ffffffffb4203c88 EFLAGS: 00010046
RAX: 0000000000000046 RBX: 0000000000000000 RCX: 00000001b6000000
RDX: ffffffffb4203d40 RSI: 0000000000000000 RDI: ffffffffb4240d60
RBP: ffffffffb4203d18 R08: 00000001b6000000 R09: 0000000000000001
R10: ffffffffb4203aa8 R11: 0000000000000003 R12: ffffffffc029b000
R13: ffffffffb4203d40 R14: 0000000000000001 R15: 0000000000000000
FS:  0000000000000000(0000) GS:ffff9a639ea00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffff9a636b384000 CR3: 00000001ea21d000 CR4: 00000000000406b0
Call Trace:
 change_page_attr_clear+0x1f/0x21
 set_memory_ro+0x1e/0x20
 arch_ftrace_update_trampoline+0x207/0x21c
 ? ftrace_caller+0x64/0x64
 ? 0xffffffffc029b000
 ftrace_startup+0xf4/0x198
 register_ftrace_function+0x26/0x3c
 function_trace_init+0x5e/0x73
 tracer_init+0x1e/0x23
 tracing_set_tracer+0x127/0x15a
 register_tracer+0x19b/0x1bc
 init_function_trace+0x90/0x92
 early_trace_init+0x236/0x2b3
 start_kernel+0x200/0x3f5
 x86_64_start_reservations+0x29/0x2b
 x86_64_start_kernel+0x17c/0x18f
 secondary_startup_64+0x9f/0x9f
 ? secondary_startup_64+0x9f/0x9f

Interrupts should not be enabled at this early in the boot process. It is
also fine to leave interrupts enabled during this time as there's only one
CPU running, and on_each_cpu() means to only run on the current CPU.

If early_boot_irqs_disabled is set, it is safe to run cpu_flush_range() with
interrupts disabled. Don't trigger a BUG_ON() in that case.

Link: http://lkml.kernel.org/r/[email protected]
Suggested-by: Thomas Gleixner <[email protected]>
Signed-off-by: Steven Rostedt (VMware) <[email protected]>
avagin pushed a commit to avagin/linux that referenced this issue May 28, 2017
Babu Moger says:

====================
Enable queued rwlock and queued spinlock for SPARC

This series of patches enables queued rwlock and queued spinlock support
for SPARC. These features were introduced some time ago in upstream.
Here are some of the earlier discussions.
https://lwn.net/Articles/572765/
https://lwn.net/Articles/582200/
https://lwn.net/Articles/561775/
https://lwn.net/Articles/590243/

Tests: Ran AIM7 benchmark to verify the performance on various workloads.
https://github.com/davidlohr/areaim. Same benchmark was used when this
feature was introduced and enabled on x86. Here are the test results.

Kernel				4.11.0-rc6     4.11.0-rc6 + 	Change
				baseline	queued locks
			      (Avg No.of jobs) (Avg No.of jobs)
Workload
High systime 10-100 user	 17290.48	 17295.18	+0.02
High systime 200-1000 users	109814.95	110248.87	+0.39
High systime 1200-2000 users	107912.40	127923.16	+18.54

Disk IO 10-100 users		168910.16	158834.17	-5.96
Disk IO 200-1000 users		242781.74	281285.80	+15.85
Disk IO 1200-2000 users		228518.23	218421.23	-4.41

Disk IO 10-100 users		183933.77	207928.67	+13.04
Disk IO 200-1000 users		491981.56	500162.33	+1.66
Disk IO 1200-2000 users		463395.66	467312.70	+0.84

fserver 10-100 users		254177.53	270283.08	+6.33
fserver IO 200-1000 users	269017.35	324812.2	+20.74
fserver IO 1200-2000 users	229538.87	284713.77	+24.03

Disk I/O results are little bit in negative territory. But majority of the
performance changes are in positive and it is significant in some cases.

Changes:
v3 -> v4:
 1. Took care of Geert Uytterhoeven's comment about patch svenkatr#3(def_bool y)
 2. Working on separate patch sets to define CPU_BIG_ENDIAN for all the
    default big endian architectures based on feedback from Geert and Arnd.

v2 -> v3:
 1. Rebased the patches on top of 4.12-rc2.
 2. Re-ordered the patch svenkatr#1 and patch svenkatr#2. That is the same order I have seen
    the issues. So, it should be addressed in the same order. Patch svenkatr#1 removes
    the check __LINUX_SPINLOCK_TYPES_H. Patch svenkatr#2 addreses the compile error
    with qrwlock.c. This addresses the comments from Dave Miller on v2.

v1 -> v2:
Addressed the comments from David Miller.
1. Added CPU_BIG_ENDIAN for all SPARC
2. Removed #ifndef __LINUX_SPINLOCK_TYPES_H guard from spinlock_types.h
3. Removed check for CONFIG_QUEUED_RWLOCKS in SPARC64 as it is the
   default definition for SPARC64 now. Cleaned-up the previous arch_read_xxx
   and arch_write_xxx definitions as it is defined now in qrwlock.h.
4. Removed check for CONFIG_QUEUED_SPINLOCKS in SPARC64 as it is the default
   definition now for SPARC64 now. Cleaned-up the previous arch_spin_xxx
   definitions as it is defined in qspinlock.h.

v1: Initial version
====================

Signed-off-by: David S. Miller <[email protected]>
avagin pushed a commit to avagin/linux that referenced this issue May 28, 2017
Implement deduplication feature in zram.  The purpose of this work is
naturally to save amount of memory usage by zram.

Android is one of the biggest users to use zram as swap and it's really
important to save amount of memory usage.  There is a paper that reports
that duplication ratio of Android's memory content is rather high [1].
And, there is a similar work on zswap that also reports that experiments
has shown that around 10-15% of pages stored in zswp are duplicates and
deduplicate them provides some benefits [2].

Also, there is a different kind of workload that uses zram as blockdev and
store build outputs into it to reduce wear-out problem of real blockdev.
In this workload, deduplication hit is very high due to temporary files
and intermediate object files.  Detailed analysis is on the bottom of this
description.

Anyway, if we can detect duplicated content and avoid to store duplicated
content at different memory space, we can save memory.  This patch tries
to do that.

Implementation is almost simple and intuitive but I should note one thing
about implementation detail.

To check duplication, this patch uses checksum of the page and collision
of this checksum could be possible.  There would be many choices to handle
this situation but this patch chooses to allow entry with duplicated
checksum to be added to the hash, but, not to compare all entries with
duplicated checksum when checking duplication.  I guess that checksum
collision is quite rare event and we don't need to pay any attention to
such a case.  Therefore, I decided the most simplest way to implement the
feature.  If there is a different opinion, I can accept and go that way.

Following is the result of this patch.

Test result svenkatr#1 (Swap):
Android Marshmallow, emulator, x86_64, Backporting to kernel v3.18

orig_data_size: 145297408
compr_data_size: 32408125
mem_used_total: 32276480
dup_data_size: 3188134
meta_data_size: 1444272

Last two metrics added to mm_stat are related to this work.  First one,
dup_data_size, is amount of saved memory by avoiding to store duplicated
page.  Later one, meta_data_size, is the amount of data structure to
support deduplication.  If dup > meta, we can judge that the patch
improves memory usage.

In Adnroid, we can save 5% of memory usage by this work.

Test result svenkatr#2 (Blockdev):
build the kernel and store output to ext4 FS on zram

<no-dedup>
Elapsed time: 249 s
mm_stat: 430845952 191014886 196898816 0 196898816 28320 0 0 0

<dedup>
Elapsed time: 250 s
mm_stat: 430505984 190971334 148365312 0 148365312 28404 0 47287038  3945792

There is no performance degradation and save 23% memory.

Test result svenkatr#3 (Blockdev):
copy android build output dir(out/host) to ext4 FS on zram

<no-dedup>
Elapsed time: out/host: 88 s
mm_stat: 8834420736 3658184579 3834208256 0 3834208256 32889 0 0 0

<dedup>
Elapsed time: out/host: 100 s
mm_stat: 8832929792 3657329322 2832015360 0 2832015360 32609 0 952568877 80880336

It shows performance degradation roughly 13% and save 24% memory. Maybe,
it is due to overhead of calculating checksum and comparison.

Test result svenkatr#4 (Blockdev):
copy android build output dir(out/target/common) to ext4 FS on zram

<no-dedup>
Elapsed time: out/host: 203 s
mm_stat: 4041678848 2310355010 2346577920 0 2346582016 500 4 0 0

<dedup>
Elapsed time: out/host: 201 s
mm_stat: 4041666560 2310488276 1338150912 0 1338150912 476 0 989088794 24564336

Memory is saved by 42% and performance is the same. Even if there is overhead
of calculating checksum and comparison, large hit ratio compensate it since
hit leads to less compression attempt.

I checked the detailed reason of savings on kernel build workload and
there are some cases that deduplication happens.

1) *.cmd
Build command is usually similar in one directory so content of these file
are very similar. In my system, more than 789 lines in fs/ext4/.namei.o.cmd
and fs/ext4/.inode.o.cmd are the same in 944 and 938 lines of the file,
respectively.

2) intermediate object files
built-in.o and temporary object file have the similar contents. More than
50% of fs/ext4/ext4.o is the same with fs/ext4/built-in.o.

3) vmlinux
.tmp_vmlinux1 and .tmp_vmlinux2 and arch/x86/boo/compressed/vmlinux.bin
have the similar contents.

Android test has similar case that some of object files(.class
and .so) are similar with another ones.
(./host/linux-x86/lib/libartd.so and
./host/linux-x86-lib/libartd-comiler.so)

Anyway, benefit seems to be largely dependent on the workload so
following patch will make this feature optional. However, this feature
can help some usecases so is deserved to be merged.

[1]: MemScope: Analyzing Memory Duplication on Android Systems,
dl.acm.org/citation.cfm?id=2797023
[2]: zswap: Optimize compressed pool memory utilization,
lkml.kernel.org/r/1341407574.7551.1471584870761.JavaMail.weblogic@epwas3p2

Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Joonsoo Kim <[email protected]>
Reviewed-by: Sergey Senozhatsky <[email protected]>
Acked-by: Minchan Kim <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
avagin pushed a commit to avagin/linux that referenced this issue Jun 1, 2017
Implement deduplication feature in zram.  The purpose of this work is
naturally to save amount of memory usage by zram.

Android is one of the biggest users to use zram as swap and it's really
important to save amount of memory usage.  There is a paper that reports
that duplication ratio of Android's memory content is rather high [1].
And, there is a similar work on zswap that also reports that experiments
has shown that around 10-15% of pages stored in zswp are duplicates and
deduplicate them provides some benefits [2].

Also, there is a different kind of workload that uses zram as blockdev and
store build outputs into it to reduce wear-out problem of real blockdev.
In this workload, deduplication hit is very high due to temporary files
and intermediate object files.  Detailed analysis is on the bottom of this
description.

Anyway, if we can detect duplicated content and avoid to store duplicated
content at different memory space, we can save memory.  This patch tries
to do that.

Implementation is almost simple and intuitive but I should note one thing
about implementation detail.

To check duplication, this patch uses checksum of the page and collision
of this checksum could be possible.  There would be many choices to handle
this situation but this patch chooses to allow entry with duplicated
checksum to be added to the hash, but, not to compare all entries with
duplicated checksum when checking duplication.  I guess that checksum
collision is quite rare event and we don't need to pay any attention to
such a case.  Therefore, I decided the most simplest way to implement the
feature.  If there is a different opinion, I can accept and go that way.

Following is the result of this patch.

Test result svenkatr#1 (Swap):
Android Marshmallow, emulator, x86_64, Backporting to kernel v3.18

orig_data_size: 145297408
compr_data_size: 32408125
mem_used_total: 32276480
dup_data_size: 3188134
meta_data_size: 1444272

Last two metrics added to mm_stat are related to this work.  First one,
dup_data_size, is amount of saved memory by avoiding to store duplicated
page.  Later one, meta_data_size, is the amount of data structure to
support deduplication.  If dup > meta, we can judge that the patch
improves memory usage.

In Adnroid, we can save 5% of memory usage by this work.

Test result svenkatr#2 (Blockdev):
build the kernel and store output to ext4 FS on zram

<no-dedup>
Elapsed time: 249 s
mm_stat: 430845952 191014886 196898816 0 196898816 28320 0 0 0

<dedup>
Elapsed time: 250 s
mm_stat: 430505984 190971334 148365312 0 148365312 28404 0 47287038  3945792

There is no performance degradation and save 23% memory.

Test result svenkatr#3 (Blockdev):
copy android build output dir(out/host) to ext4 FS on zram

<no-dedup>
Elapsed time: out/host: 88 s
mm_stat: 8834420736 3658184579 3834208256 0 3834208256 32889 0 0 0

<dedup>
Elapsed time: out/host: 100 s
mm_stat: 8832929792 3657329322 2832015360 0 2832015360 32609 0 952568877 80880336

It shows performance degradation roughly 13% and save 24% memory. Maybe,
it is due to overhead of calculating checksum and comparison.

Test result svenkatr#4 (Blockdev):
copy android build output dir(out/target/common) to ext4 FS on zram

<no-dedup>
Elapsed time: out/host: 203 s
mm_stat: 4041678848 2310355010 2346577920 0 2346582016 500 4 0 0

<dedup>
Elapsed time: out/host: 201 s
mm_stat: 4041666560 2310488276 1338150912 0 1338150912 476 0 989088794 24564336

Memory is saved by 42% and performance is the same. Even if there is overhead
of calculating checksum and comparison, large hit ratio compensate it since
hit leads to less compression attempt.

I checked the detailed reason of savings on kernel build workload and
there are some cases that deduplication happens.

1) *.cmd
Build command is usually similar in one directory so content of these file
are very similar. In my system, more than 789 lines in fs/ext4/.namei.o.cmd
and fs/ext4/.inode.o.cmd are the same in 944 and 938 lines of the file,
respectively.

2) intermediate object files
built-in.o and temporary object file have the similar contents. More than
50% of fs/ext4/ext4.o is the same with fs/ext4/built-in.o.

3) vmlinux
.tmp_vmlinux1 and .tmp_vmlinux2 and arch/x86/boo/compressed/vmlinux.bin
have the similar contents.

Android test has similar case that some of object files(.class
and .so) are similar with another ones.
(./host/linux-x86/lib/libartd.so and
./host/linux-x86-lib/libartd-comiler.so)

Anyway, benefit seems to be largely dependent on the workload so
following patch will make this feature optional. However, this feature
can help some usecases so is deserved to be merged.

[1]: MemScope: Analyzing Memory Duplication on Android Systems,
dl.acm.org/citation.cfm?id=2797023
[2]: zswap: Optimize compressed pool memory utilization,
lkml.kernel.org/r/1341407574.7551.1471584870761.JavaMail.weblogic@epwas3p2

Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Joonsoo Kim <[email protected]>
Reviewed-by: Sergey Senozhatsky <[email protected]>
Acked-by: Minchan Kim <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
avagin pushed a commit to avagin/linux that referenced this issue Jun 5, 2017
Yuval Mintz says:

====================
qed: Enhance storage APIs

This series is intended to add additional information and features
to the API between qed and its storage protocol drivers [qedi, qedf].

Patch svenkatr#2 adds some information stored on device such as wwpn & wwnn
to allow qedf utilize it; svenkatr#1 fixes an issue with the reading of those
values [which were unused until now].

Patch svenkatr#3 would allow the protocol drivers access to images on persistent
storage which is a prerequirement for adding boot from SAN support.

Patch svenkatr#4 adds infrastrucutre to a future feature for qedi.
====================

Signed-off-by: David S. Miller <[email protected]>
avagin pushed a commit to avagin/linux that referenced this issue Jun 5, 2017
Implement deduplication feature in zram.  The purpose of this work is
naturally to save amount of memory usage by zram.

Android is one of the biggest users to use zram as swap and it's really
important to save amount of memory usage.  There is a paper that reports
that duplication ratio of Android's memory content is rather high [1].
And, there is a similar work on zswap that also reports that experiments
has shown that around 10-15% of pages stored in zswp are duplicates and
deduplicate them provides some benefits [2].

Also, there is a different kind of workload that uses zram as blockdev and
store build outputs into it to reduce wear-out problem of real blockdev.
In this workload, deduplication hit is very high due to temporary files
and intermediate object files.  Detailed analysis is on the bottom of this
description.

Anyway, if we can detect duplicated content and avoid to store duplicated
content at different memory space, we can save memory.  This patch tries
to do that.

Implementation is almost simple and intuitive but I should note one thing
about implementation detail.

To check duplication, this patch uses checksum of the page and collision
of this checksum could be possible.  There would be many choices to handle
this situation but this patch chooses to allow entry with duplicated
checksum to be added to the hash, but, not to compare all entries with
duplicated checksum when checking duplication.  I guess that checksum
collision is quite rare event and we don't need to pay any attention to
such a case.  Therefore, I decided the most simplest way to implement the
feature.  If there is a different opinion, I can accept and go that way.

Following is the result of this patch.

Test result svenkatr#1 (Swap):
Android Marshmallow, emulator, x86_64, Backporting to kernel v3.18

orig_data_size: 145297408
compr_data_size: 32408125
mem_used_total: 32276480
dup_data_size: 3188134
meta_data_size: 1444272

Last two metrics added to mm_stat are related to this work.  First one,
dup_data_size, is amount of saved memory by avoiding to store duplicated
page.  Later one, meta_data_size, is the amount of data structure to
support deduplication.  If dup > meta, we can judge that the patch
improves memory usage.

In Adnroid, we can save 5% of memory usage by this work.

Test result svenkatr#2 (Blockdev):
build the kernel and store output to ext4 FS on zram

<no-dedup>
Elapsed time: 249 s
mm_stat: 430845952 191014886 196898816 0 196898816 28320 0 0 0

<dedup>
Elapsed time: 250 s
mm_stat: 430505984 190971334 148365312 0 148365312 28404 0 47287038  3945792

There is no performance degradation and save 23% memory.

Test result svenkatr#3 (Blockdev):
copy android build output dir(out/host) to ext4 FS on zram

<no-dedup>
Elapsed time: out/host: 88 s
mm_stat: 8834420736 3658184579 3834208256 0 3834208256 32889 0 0 0

<dedup>
Elapsed time: out/host: 100 s
mm_stat: 8832929792 3657329322 2832015360 0 2832015360 32609 0 952568877 80880336

It shows performance degradation roughly 13% and save 24% memory. Maybe,
it is due to overhead of calculating checksum and comparison.

Test result svenkatr#4 (Blockdev):
copy android build output dir(out/target/common) to ext4 FS on zram

<no-dedup>
Elapsed time: out/host: 203 s
mm_stat: 4041678848 2310355010 2346577920 0 2346582016 500 4 0 0

<dedup>
Elapsed time: out/host: 201 s
mm_stat: 4041666560 2310488276 1338150912 0 1338150912 476 0 989088794 24564336

Memory is saved by 42% and performance is the same. Even if there is overhead
of calculating checksum and comparison, large hit ratio compensate it since
hit leads to less compression attempt.

I checked the detailed reason of savings on kernel build workload and
there are some cases that deduplication happens.

1) *.cmd
Build command is usually similar in one directory so content of these file
are very similar. In my system, more than 789 lines in fs/ext4/.namei.o.cmd
and fs/ext4/.inode.o.cmd are the same in 944 and 938 lines of the file,
respectively.

2) intermediate object files
built-in.o and temporary object file have the similar contents. More than
50% of fs/ext4/ext4.o is the same with fs/ext4/built-in.o.

3) vmlinux
.tmp_vmlinux1 and .tmp_vmlinux2 and arch/x86/boo/compressed/vmlinux.bin
have the similar contents.

Android test has similar case that some of object files(.class
and .so) are similar with another ones.
(./host/linux-x86/lib/libartd.so and
./host/linux-x86-lib/libartd-comiler.so)

Anyway, benefit seems to be largely dependent on the workload so
following patch will make this feature optional. However, this feature
can help some usecases so is deserved to be merged.

[1]: MemScope: Analyzing Memory Duplication on Android Systems,
dl.acm.org/citation.cfm?id=2797023
[2]: zswap: Optimize compressed pool memory utilization,
lkml.kernel.org/r/1341407574.7551.1471584870761.JavaMail.weblogic@epwas3p2

Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Joonsoo Kim <[email protected]>
Reviewed-by: Sergey Senozhatsky <[email protected]>
Acked-by: Minchan Kim <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
avagin pushed a commit to avagin/linux that referenced this issue Jun 5, 2017
Yuval Mintz says:

qed*: Support VF XDP attachment

====================
Each driver queue [Rx, Tx, XDP-forwarding] requires an allocated HW/FW
connection + configured queue-zone.

VF handling by the PF has several limitations that prevented adding the
capability to perform XDP at driver-level:

 - The VF assumes there's 1-to-1 correspondance between the VF queue and
   the used connection, meaning q<x> is always going to use cid<x>,
   whereas for its own queues the PF is acquiring a new cid per each new
   queue.

 - There's a 1-to-1 correspondate between the VF-queues and the HW queue
   zones. While this is necessary for Rx-queues [as the queue-zone
   contains the producer], transmission queues can share the underlaying
   queue-zone [only shared configuration is coalescing].
   But all VF<->PF communication mechanisms assume there's a single
   identifier that identify a queue [as queue-zone == queue], while
   sharing queue-zones requires passing additional information.

 - VFs currently don't try mapping a doorbell bar - there's a small
   doorbell window in the regview allowing VFs to doorbell up to 16
   connections; but this window isn's wide enough for the added XDP
   forwarding queues.

This series is going to add the necessary infrastrucutre to finally let
our VFs support XDP assuming both the PF and VF drivers are sufficiently
new [Legacy support would be retained both for older VFs and older PFs,
but both will be needed for this new support to work].
Basically, the various database driver maintains for its queue-cids
would be revised, and queue-cids would be identified using the
(queue-zone, unique index) pair. The TLV mechanism would then be
extended to allow VFs to communicate that unique-index as well as the
already provided queue-zone. Finally, the VFs would try to map their
doorbell bar and inform their PF that they're using it.

Almost all the changes are in qed, with exception of svenkatr#3 [which does some
cleanup in qede as well] and #11 that actually enables the feature.
====================

Signed-off-by: David S. Miller <[email protected]>
avagin pushed a commit to avagin/linux that referenced this issue Jun 6, 2017
Implement deduplication feature in zram.  The purpose of this work is
naturally to save amount of memory usage by zram.

Android is one of the biggest users to use zram as swap and it's really
important to save amount of memory usage.  There is a paper that reports
that duplication ratio of Android's memory content is rather high [1].
And, there is a similar work on zswap that also reports that experiments
has shown that around 10-15% of pages stored in zswp are duplicates and
deduplicate them provides some benefits [2].

Also, there is a different kind of workload that uses zram as blockdev and
store build outputs into it to reduce wear-out problem of real blockdev.
In this workload, deduplication hit is very high due to temporary files
and intermediate object files.  Detailed analysis is on the bottom of this
description.

Anyway, if we can detect duplicated content and avoid to store duplicated
content at different memory space, we can save memory.  This patch tries
to do that.

Implementation is almost simple and intuitive but I should note one thing
about implementation detail.

To check duplication, this patch uses checksum of the page and collision
of this checksum could be possible.  There would be many choices to handle
this situation but this patch chooses to allow entry with duplicated
checksum to be added to the hash, but, not to compare all entries with
duplicated checksum when checking duplication.  I guess that checksum
collision is quite rare event and we don't need to pay any attention to
such a case.  Therefore, I decided the most simplest way to implement the
feature.  If there is a different opinion, I can accept and go that way.

Following is the result of this patch.

Test result svenkatr#1 (Swap):
Android Marshmallow, emulator, x86_64, Backporting to kernel v3.18

orig_data_size: 145297408
compr_data_size: 32408125
mem_used_total: 32276480
dup_data_size: 3188134
meta_data_size: 1444272

Last two metrics added to mm_stat are related to this work.  First one,
dup_data_size, is amount of saved memory by avoiding to store duplicated
page.  Later one, meta_data_size, is the amount of data structure to
support deduplication.  If dup > meta, we can judge that the patch
improves memory usage.

In Adnroid, we can save 5% of memory usage by this work.

Test result svenkatr#2 (Blockdev):
build the kernel and store output to ext4 FS on zram

<no-dedup>
Elapsed time: 249 s
mm_stat: 430845952 191014886 196898816 0 196898816 28320 0 0 0

<dedup>
Elapsed time: 250 s
mm_stat: 430505984 190971334 148365312 0 148365312 28404 0 47287038  3945792

There is no performance degradation and save 23% memory.

Test result svenkatr#3 (Blockdev):
copy android build output dir(out/host) to ext4 FS on zram

<no-dedup>
Elapsed time: out/host: 88 s
mm_stat: 8834420736 3658184579 3834208256 0 3834208256 32889 0 0 0

<dedup>
Elapsed time: out/host: 100 s
mm_stat: 8832929792 3657329322 2832015360 0 2832015360 32609 0 952568877 80880336

It shows performance degradation roughly 13% and save 24% memory. Maybe,
it is due to overhead of calculating checksum and comparison.

Test result svenkatr#4 (Blockdev):
copy android build output dir(out/target/common) to ext4 FS on zram

<no-dedup>
Elapsed time: out/host: 203 s
mm_stat: 4041678848 2310355010 2346577920 0 2346582016 500 4 0 0

<dedup>
Elapsed time: out/host: 201 s
mm_stat: 4041666560 2310488276 1338150912 0 1338150912 476 0 989088794 24564336

Memory is saved by 42% and performance is the same. Even if there is overhead
of calculating checksum and comparison, large hit ratio compensate it since
hit leads to less compression attempt.

I checked the detailed reason of savings on kernel build workload and
there are some cases that deduplication happens.

1) *.cmd
Build command is usually similar in one directory so content of these file
are very similar. In my system, more than 789 lines in fs/ext4/.namei.o.cmd
and fs/ext4/.inode.o.cmd are the same in 944 and 938 lines of the file,
respectively.

2) intermediate object files
built-in.o and temporary object file have the similar contents. More than
50% of fs/ext4/ext4.o is the same with fs/ext4/built-in.o.

3) vmlinux
.tmp_vmlinux1 and .tmp_vmlinux2 and arch/x86/boo/compressed/vmlinux.bin
have the similar contents.

Android test has similar case that some of object files(.class
and .so) are similar with another ones.
(./host/linux-x86/lib/libartd.so and
./host/linux-x86-lib/libartd-comiler.so)

Anyway, benefit seems to be largely dependent on the workload so
following patch will make this feature optional. However, this feature
can help some usecases so is deserved to be merged.

[1]: MemScope: Analyzing Memory Duplication on Android Systems,
dl.acm.org/citation.cfm?id=2797023
[2]: zswap: Optimize compressed pool memory utilization,
lkml.kernel.org/r/1341407574.7551.1471584870761.JavaMail.weblogic@epwas3p2

Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Joonsoo Kim <[email protected]>
Reviewed-by: Sergey Senozhatsky <[email protected]>
Acked-by: Minchan Kim <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
avagin pushed a commit to avagin/linux that referenced this issue Jun 13, 2017
ACPICA commit eaa455accf165fee2df26410e271aab162264f6c

UBSAN reports an index out of range use in dsutils.c.
  acpi_db_display_argument_object(
  	walk_state->operands[walk_state->num_operands - 1],
  	                     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  	walk_state);

This call was simply wrong, generated redundant debugger messages, and
resulted in a -1 index into the operand stack. Linux kernel bug #120351
(link svenkatr#1) and #194845 (link svenkatr#2).

Originally fixed by Navin P.S. (link svenkatr#1, comment 8), refined by Lv Zheng
(link svenkatr#3).

Link: https://bugzilla.kernel.org/show_bug.cgi?id=120351 [svenkatr#1]
Link: https://bugzilla.kernel.org/show_bug.cgi?id=194845 [svenkatr#2]
Link: acpica/acpica#245          [svenkatr#3]
Link: acpica/acpica@eaa455ac
Reported-by: Wilfried Klaebe <[email protected]>
Reported-by: Ronald Warsow <[email protected]>
Original-by: Navin P.S. <[email protected]>
Signed-off-by: Lv Zheng <[email protected]>
Signed-off-by: Bob Moore <[email protected]>
Signed-off-by: Rafael J. Wysocki <[email protected]>
afaerber pushed a commit to afaerber/linux that referenced this issue Jun 20, 2017
A vendor with a system having more than 128 CPUs occasionally encounters
the following crash during shutdown. This is not an easily reproduceable
event, but the vendor was able to provide the following analysis of the
crash, which exhibits the same footprint each time.

crash> bt
PID: 0      TASK: ffff88017c70ce70  CPU: 5   COMMAND: "swapper/5"
 #0 [ffff88085c143ac8] machine_kexec at ffffffff81059c8b
 svenkatr#1 [ffff88085c143b28] __crash_kexec at ffffffff811052e2
 svenkatr#2 [ffff88085c143bf8] crash_kexec at ffffffff811053d0
 svenkatr#3 [ffff88085c143c10] oops_end at ffffffff8168ef88
 svenkatr#4 [ffff88085c143c38] no_context at ffffffff8167ebb3
 svenkatr#5 [ffff88085c143c88] __bad_area_nosemaphore at ffffffff8167ec49
 svenkatr#6 [ffff88085c143cd0] bad_area_nosemaphore at ffffffff8167edb3
 svenkatr#7 [ffff88085c143ce0] __do_page_fault at ffffffff81691d1e
 svenkatr#8 [ffff88085c143d40] do_page_fault at ffffffff81691ec5
 svenkatr#9 [ffff88085c143d70] page_fault at ffffffff8168e188
    [exception RIP: unknown or invalid address]
    RIP: ffffffffa053c800  RSP: ffff88085c143e28  RFLAGS: 00010206
    RAX: ffff88017c72bfd8  RBX: ffff88017a8dc000  RCX: ffff8810588b5ac8
    RDX: ffff8810588b5a00  RSI: ffffffffa053c800  RDI: ffff8810588b5a00
    RBP: ffff88085c143e58   R8: ffff88017c70d408   R9: ffff88017a8dc000
    R10: 0000000000000002  R11: ffff88085c143da0  R12: ffff8810588b5ac8
    R13: 0000000000000100  R14: ffffffffa053c800  R15: ffff8810588b5a00
    ORIG_RAX: ffffffffffffffff  CS: 0010  SS: 0018
    <IRQ stack>
    [exception RIP: cpuidle_enter_state+82]
    RIP: ffffffff81514192  RSP: ffff88017c72be50  RFLAGS: 00000202
    RAX: 0000001e4c3c6f16  RBX: 000000000000f8a0  RCX: 0000000000000018
    RDX: 0000000225c17d03  RSI: ffff88017c72bfd8  RDI: 0000001e4c3c6f16
    RBP: ffff88017c72be78   R8: 000000000000237e   R9: 0000000000000018
    R10: 0000000000002494  R11: 0000000000000001  R12: ffff88017c72be20
    R13: ffff88085c14f8e0  R14: 0000000000000082  R15: 0000001e4c3bb400
    ORIG_RAX: ffffffffffffff10  CS: 0010  SS: 0018

This is the corresponding stack trace

It has crashed because the area pointed with RIP extracted from timer
element is already removed during a shutdown process.

The function is smi_timeout().

And we think ffff8810588b5a00 in RDX is a parameter struct smi_info

crash> rd ffff8810588b5a00 20
ffff8810588b5a00:  ffff8810588b6000 0000000000000000   .`.X............
ffff8810588b5a10:  ffff880853264400 ffffffffa05417e0   .D&S......T.....
ffff8810588b5a20:  24a024a000000000 0000000000000000   .....$.$........
ffff8810588b5a30:  0000000000000000 0000000000000000   ................
ffff8810588b5a30:  0000000000000000 0000000000000000   ................
ffff8810588b5a40:  ffffffffa053a040 ffffffffa053a060   @.S.....`.S.....
ffff8810588b5a50:  0000000000000000 0000000100000001   ................
ffff8810588b5a60:  0000000000000000 0000000000000e00   ................
ffff8810588b5a70:  ffffffffa053a580 ffffffffa053a6e0   ..S.......S.....
ffff8810588b5a80:  ffffffffa053a4a0 ffffffffa053a250   ..S.....P.S.....
ffff8810588b5a90:  0000000500000002 0000000000000000   ................

Unfortunately the top of this area is already detroyed by someone.
But because of two reasonns we think this is struct smi_info
 1) The address included in between  ffff8810588b5a70 and ffff8810588b5a80:
  are inside of ipmi_si_intf.c  see crash> module ffff88085779d2c0

 2) We've found the area which point this.
  It is offset 0x68 of  ffff880859df4000

crash> rd  ffff880859df4000 100
ffff880859df4000:  0000000000000000 0000000000000001   ................
ffff880859df4010:  ffffffffa0535290 dead000000000200   .RS.............
ffff880859df4020:  ffff880859df4020 ffff880859df4020    @.Y.... @.Y....
ffff880859df4030:  0000000000000002 0000000000100010   ................
ffff880859df4040:  ffff880859df4040 ffff880859df4040   @@.Y....@@.Y....
ffff880859df4050:  0000000000000000 0000000000000000   ................
ffff880859df4060:  0000000000000000 ffff8810588b5a00   .........Z.X....
ffff880859df4070:  0000000000000001 ffff880859df4078   [email protected]....

 If we regards it as struct ipmi_smi in shutdown process
 it looks consistent.

The remedy for this apparent race is affixed below.

Signed-off-by: Tony Camuso <[email protected]>
Cc: [email protected] # 3.19

This was first introduced in 7ea0ed2 ipmi: Make the
message handler easier to use for SMI interfaces
where some code was moved outside of the rcu_read_lock()
and the lock was not added.

Signed-off-by: Corey Minyard <[email protected]>
ideak pushed a commit to ideak/linux that referenced this issue Apr 19, 2024
At current x1e80100 interface table, interface svenkatr#3 is wrongly
connected to DP controller #0 and interface svenkatr#4 wrongly connected
to DP controller svenkatr#2. Fix this problem by connect Interface svenkatr#3 to
DP controller #0 and interface svenkatr#4 connect to DP controller svenkatr#1.
Also add interface svenkatr#6, svenkatr#7 and svenkatr#8 connections to DP controller to
complete x1e80100 interface table.

Changs in V3:
-- add v2 changes log

Changs in V2:
-- add x1e80100 to subject
-- add Fixes

Fixes: e3b1f36 ("drm/msm/dpu: Add X1E80100 support")
Signed-off-by: Kuogee Hsieh <[email protected]>
Reviewed-by: Abhinav Kumar <[email protected]>
Reviewed-by: Abel Vesa <[email protected]>
Patchwork: https://patchwork.freedesktop.org/patch/585549/
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Abhinav Kumar <[email protected]>
ideak pushed a commit to ideak/linux that referenced this issue Apr 19, 2024
…git/netfilter/nf

Pablo Neira Ayuso says:

====================
Netfilter fixes for net

The following patchset contains Netfilter fixes for net:

Patch svenkatr#1 unlike early commit path stage which triggers a call to abort,
         an explicit release of the batch is required on abort, otherwise
         mutex is released and commit_list remains in place.

Patch svenkatr#2 release mutex after nft_gc_seq_end() in commit path, otherwise
         async GC worker could collect expired objects.

Patch svenkatr#3 flush pending destroy work in module removal path, otherwise UaF
         is possible.

Patch svenkatr#4 and svenkatr#6 restrict the table dormant flag with basechain updates
	 to fix state inconsistency in the hook registration.

Patch svenkatr#5 adds missing RCU read side lock to flowtable type to avoid races
	 with module removal.

* tag 'nf-24-04-04' of git://git.kernel.org/pub/scm/linux/kernel/git/netfilter/nf:
  netfilter: nf_tables: discard table flag update with pending basechain deletion
  netfilter: nf_tables: Fix potential data-race in __nft_flowtable_type_get()
  netfilter: nf_tables: reject new basechain after table flag update
  netfilter: nf_tables: flush pending destroy work before exit_net release
  netfilter: nf_tables: release mutex after nft_gc_seq_end from abort path
  netfilter: nf_tables: release batch on table validation from abort path
====================

Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Jakub Kicinski <[email protected]>
blitz pushed a commit to blitz/linux that referenced this issue May 8, 2024
The driver creates /sys/kernel/debug/dri/0/mob_ttm even when the
corresponding ttm_resource_manager is not allocated.
This leads to a crash when trying to read from this file.

Add a check to create mob_ttm, system_mob_ttm, and gmr_ttm debug file
only when the corresponding ttm_resource_manager is allocated.

crash> bt
PID: 3133409  TASK: ffff8fe4834a5000  CPU: 3    COMMAND: "grep"
 #0 [ffffb954506b3b20] machine_kexec at ffffffffb2a6bec3
 svenkatr#1 [ffffb954506b3b78] __crash_kexec at ffffffffb2bb598a
 svenkatr#2 [ffffb954506b3c38] crash_kexec at ffffffffb2bb68c1
 svenkatr#3 [ffffb954506b3c50] oops_end at ffffffffb2a2a9b1
 svenkatr#4 [ffffb954506b3c70] no_context at ffffffffb2a7e913
 svenkatr#5 [ffffb954506b3cc8] __bad_area_nosemaphore at ffffffffb2a7ec8c
 svenkatr#6 [ffffb954506b3d10] do_page_fault at ffffffffb2a7f887
 svenkatr#7 [ffffb954506b3d40] page_fault at ffffffffb360116e
    [exception RIP: ttm_resource_manager_debug+0x11]
    RIP: ffffffffc04afd11  RSP: ffffb954506b3df0  RFLAGS: 00010246
    RAX: ffff8fe41a6d1200  RBX: 0000000000000000  RCX: 0000000000000940
    RDX: 0000000000000000  RSI: ffffffffc04b4338  RDI: 0000000000000000
    RBP: ffffb954506b3e08   R8: ffff8fee3ffad000   R9: 0000000000000000
    R10: ffff8fe41a76a000  R11: 0000000000000001  R12: 00000000ffffffff
    R13: 0000000000000001  R14: ffff8fe5bb6f3900  R15: ffff8fe41a6d1200
    ORIG_RAX: ffffffffffffffff  CS: 0010  SS: 0018
 svenkatr#8 [ffffb954506b3e00] ttm_resource_manager_show at ffffffffc04afde7 [ttm]
 svenkatr#9 [ffffb954506b3e30] seq_read at ffffffffb2d8f9f3
    RIP: 00007f4c4eda8985  RSP: 00007ffdbba9e9f8  RFLAGS: 00000246
    RAX: ffffffffffffffda  RBX: 000000000037e000  RCX: 00007f4c4eda8985
    RDX: 000000000037e000  RSI: 00007f4c41573000  RDI: 0000000000000003
    RBP: 000000000037e000   R8: 0000000000000000   R9: 000000000037fe30
    R10: 0000000000000000  R11: 0000000000000246  R12: 00007f4c41573000
    R13: 0000000000000003  R14: 00007f4c41572010  R15: 0000000000000003
    ORIG_RAX: 0000000000000000  CS: 0033  SS: 002b

Signed-off-by: Jocelyn Falempe <[email protected]>
Fixes: af4a25b ("drm/vmwgfx: Add debugfs entries for various ttm resource managers")
Cc: <[email protected]>
Reviewed-by: Zack Rusin <[email protected]>
Link: https://patchwork.freedesktop.org/patch/msgid/[email protected]
blitz pushed a commit to blitz/linux that referenced this issue May 8, 2024
…git/netfilter/nf

Pablo Neira Ayuso says:

====================
Netfilter fixes for net

The following patchset contains Netfilter fixes for net:

Patch svenkatr#1 reject destroy chain command to delete device hooks in netdev
         family, hence, only delchain commands are allowed.

Patch svenkatr#2 reject table flag update interference with netdev basechain
	 hook updates, this can leave hooks in inconsistent
	 registration/unregistration state.

Patch svenkatr#3 do not unregister netdev basechain hooks if table is dormant.
	 Otherwise, splat with double unregistration is possible.

Patch svenkatr#4 fixes Kconfig to allow to restore IP_NF_ARPTABLES,
	 from Kuniyuki Iwashima.

There are a more fixes still in progress on my side that need more work.

* tag 'nf-24-03-28' of git://git.kernel.org/pub/scm/linux/kernel/git/netfilter/nf:
  netfilter: arptables: Select NETFILTER_FAMILY_ARP when building arp_tables.c
  netfilter: nf_tables: skip netdev hook unregistration if table is dormant
  netfilter: nf_tables: reject table flag and netdev basechain updates
  netfilter: nf_tables: reject destroy command to remove basechain hooks
====================

Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Paolo Abeni <[email protected]>
blitz pushed a commit to blitz/linux that referenced this issue May 8, 2024
Drop support for virtualizing adaptive PEBS, as KVM's implementation is
architecturally broken without an obvious/easy path forward, and because
exposing adaptive PEBS can leak host LBRs to the guest, i.e. can leak
host kernel addresses to the guest.

Bug svenkatr#1 is that KVM doesn't account for the upper 32 bits of
IA32_FIXED_CTR_CTRL when (re)programming fixed counters, e.g
fixed_ctrl_field() drops the upper bits, reprogram_fixed_counters()
stores local variables as u8s and truncates the upper bits too, etc.

Bug svenkatr#2 is that, because KVM _always_ sets precise_ip to a non-zero value
for PEBS events, perf will _always_ generate an adaptive record, even if
the guest requested a basic record.  Note, KVM will also enable adaptive
PEBS in individual *counter*, even if adaptive PEBS isn't exposed to the
guest, but this is benign as MSR_PEBS_DATA_CFG is guaranteed to be zero,
i.e. the guest will only ever see Basic records.

Bug svenkatr#3 is in perf.  intel_pmu_disable_fixed() doesn't clear the upper
bits either, i.e. leaves ICL_FIXED_0_ADAPTIVE set, and
intel_pmu_enable_fixed() effectively doesn't clear ICL_FIXED_0_ADAPTIVE
either.  I.e. perf _always_ enables ADAPTIVE counters, regardless of what
KVM requests.

Bug svenkatr#4 is that adaptive PEBS *might* effectively bypass event filters set
by the host, as "Updated Memory Access Info Group" records information
that might be disallowed by userspace via KVM_SET_PMU_EVENT_FILTER.

Bug svenkatr#5 is that KVM doesn't ensure LBR MSRs hold guest values (or at least
zeros) when entering a vCPU with adaptive PEBS, which allows the guest
to read host LBRs, i.e. host RIPs/addresses, by enabling "LBR Entries"
records.

Disable adaptive PEBS support as an immediate fix due to the severity of
the LBR leak in particular, and because fixing all of the bugs will be
non-trivial, e.g. not suitable for backporting to stable kernels.

Note!  This will break live migration, but trying to make KVM play nice
with live migration would be quite complicated, wouldn't be guaranteed to
work (i.e. KVM might still kill/confuse the guest), and it's not clear
that there are any publicly available VMMs that support adaptive PEBS,
let alone live migrate VMs that support adaptive PEBS, e.g. QEMU doesn't
support PEBS in any capacity.

Link: https://lore.kernel.org/all/[email protected]
Link: https://lore.kernel.org/all/[email protected]
Fixes: c59a1f1 ("KVM: x86/pmu: Add IA32_PEBS_ENABLE MSR emulation for extended PEBS")
Cc: [email protected]
Cc: Like Xu <[email protected]>
Cc: Mingwei Zhang <[email protected]>
Cc: Zhenyu Wang <[email protected]>
Cc: Zhang Xiong <[email protected]>
Cc: Lv Zhiyuan <[email protected]>
Cc: Dapeng Mi <[email protected]>
Cc: Jim Mattson <[email protected]>
Acked-by: Like Xu <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Sean Christopherson <[email protected]>
blitz pushed a commit to blitz/linux that referenced this issue May 8, 2024
…git/netfilter/nf

netfilter pull request 24-04-11

Pablo Neira Ayuso says:

====================
Netfilter fixes for net

The following patchset contains Netfilter fixes for net:

Patches svenkatr#1 and svenkatr#2 add missing rcu read side lock when iterating over
expression and object type list which could race with module removal.

Patch svenkatr#3 prevents promisc packet from visiting the bridge/input hook
	 to amend a recent fix to address conntrack confirmation race
	 in br_netfilter and nf_conntrack_bridge.

Patch svenkatr#4 adds and uses iterate decorator type to fetch the current
	 pipapo set backend datastructure view when netlink dumps the
	 set elements.

Patch svenkatr#5 fixes removal of duplicate elements in the pipapo set backend.

Patch svenkatr#6 flowtable validates pppoe header before accessing it.

Patch svenkatr#7 fixes flowtable datapath for pppoe packets, otherwise lookup
         fails and pppoe packets follow classic path.
====================

Signed-off-by: David S. Miller <[email protected]>
blitz pushed a commit to blitz/linux that referenced this issue May 8, 2024
When I did hard offline test with hugetlb pages, below deadlock occurs:

======================================================
WARNING: possible circular locking dependency detected
6.8.0-11409-gf6cef5f8c37f svenkatr#1 Not tainted
------------------------------------------------------
bash/46904 is trying to acquire lock:
ffffffffabe68910 (cpu_hotplug_lock){++++}-{0:0}, at: static_key_slow_dec+0x16/0x60

but task is already holding lock:
ffffffffabf92ea8 (pcp_batch_high_lock){+.+.}-{3:3}, at: zone_pcp_disable+0x16/0x40

which lock already depends on the new lock.

the existing dependency chain (in reverse order) is:

-> svenkatr#1 (pcp_batch_high_lock){+.+.}-{3:3}:
       __mutex_lock+0x6c/0x770
       page_alloc_cpu_online+0x3c/0x70
       cpuhp_invoke_callback+0x397/0x5f0
       __cpuhp_invoke_callback_range+0x71/0xe0
       _cpu_up+0xeb/0x210
       cpu_up+0x91/0xe0
       cpuhp_bringup_mask+0x49/0xb0
       bringup_nonboot_cpus+0xb7/0xe0
       smp_init+0x25/0xa0
       kernel_init_freeable+0x15f/0x3e0
       kernel_init+0x15/0x1b0
       ret_from_fork+0x2f/0x50
       ret_from_fork_asm+0x1a/0x30

-> #0 (cpu_hotplug_lock){++++}-{0:0}:
       __lock_acquire+0x1298/0x1cd0
       lock_acquire+0xc0/0x2b0
       cpus_read_lock+0x2a/0xc0
       static_key_slow_dec+0x16/0x60
       __hugetlb_vmemmap_restore_folio+0x1b9/0x200
       dissolve_free_huge_page+0x211/0x260
       __page_handle_poison+0x45/0xc0
       memory_failure+0x65e/0xc70
       hard_offline_page_store+0x55/0xa0
       kernfs_fop_write_iter+0x12c/0x1d0
       vfs_write+0x387/0x550
       ksys_write+0x64/0xe0
       do_syscall_64+0xca/0x1e0
       entry_SYSCALL_64_after_hwframe+0x6d/0x75

other info that might help us debug this:

 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock(pcp_batch_high_lock);
                               lock(cpu_hotplug_lock);
                               lock(pcp_batch_high_lock);
  rlock(cpu_hotplug_lock);

 *** DEADLOCK ***

5 locks held by bash/46904:
 #0: ffff98f6c3bb23f0 (sb_writers#5){.+.+}-{0:0}, at: ksys_write+0x64/0xe0
 svenkatr#1: ffff98f6c328e488 (&of->mutex){+.+.}-{3:3}, at: kernfs_fop_write_iter+0xf8/0x1d0
 svenkatr#2: ffff98ef83b31890 (kn->active#113){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x100/0x1d0
 svenkatr#3: ffffffffabf9db48 (mf_mutex){+.+.}-{3:3}, at: memory_failure+0x44/0xc70
 svenkatr#4: ffffffffabf92ea8 (pcp_batch_high_lock){+.+.}-{3:3}, at: zone_pcp_disable+0x16/0x40

stack backtrace:
CPU: 10 PID: 46904 Comm: bash Kdump: loaded Not tainted 6.8.0-11409-gf6cef5f8c37f svenkatr#1
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.14.0-0-g155821a1990b-prebuilt.qemu.org 04/01/2014
Call Trace:
 <TASK>
 dump_stack_lvl+0x68/0xa0
 check_noncircular+0x129/0x140
 __lock_acquire+0x1298/0x1cd0
 lock_acquire+0xc0/0x2b0
 cpus_read_lock+0x2a/0xc0
 static_key_slow_dec+0x16/0x60
 __hugetlb_vmemmap_restore_folio+0x1b9/0x200
 dissolve_free_huge_page+0x211/0x260
 __page_handle_poison+0x45/0xc0
 memory_failure+0x65e/0xc70
 hard_offline_page_store+0x55/0xa0
 kernfs_fop_write_iter+0x12c/0x1d0
 vfs_write+0x387/0x550
 ksys_write+0x64/0xe0
 do_syscall_64+0xca/0x1e0
 entry_SYSCALL_64_after_hwframe+0x6d/0x75
RIP: 0033:0x7fc862314887
Code: 10 00 f7 d8 64 89 02 48 c7 c0 ff ff ff ff eb b7 0f 1f 00 f3 0f 1e fa 64 8b 04 25 18 00 00 00 85 c0 75 10 b8 01 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 51 c3 48 83 ec 28 48 89 54 24 18 48 89 74 24
RSP: 002b:00007fff19311268 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 000000000000000c RCX: 00007fc862314887
RDX: 000000000000000c RSI: 000056405645fe10 RDI: 0000000000000001
RBP: 000056405645fe10 R08: 00007fc8623d1460 R09: 000000007fffffff
R10: 0000000000000000 R11: 0000000000000246 R12: 000000000000000c
R13: 00007fc86241b780 R14: 00007fc862417600 R15: 00007fc862416a00

In short, below scene breaks the lock dependency chain:

 memory_failure
  __page_handle_poison
   zone_pcp_disable -- lock(pcp_batch_high_lock)
   dissolve_free_huge_page
    __hugetlb_vmemmap_restore_folio
     static_key_slow_dec
      cpus_read_lock -- rlock(cpu_hotplug_lock)

Fix this by calling drain_all_pages() instead.

This issue won't occur until commit a6b4085 ("mm: hugetlb: replace
hugetlb_free_vmemmap_enabled with a static_key").  As it introduced
rlock(cpu_hotplug_lock) in dissolve_free_huge_page() code path while
lock(pcp_batch_high_lock) is already in the __page_handle_poison().

[[email protected]: extend comment per Oscar]
[[email protected]: reflow block comment]
Link: https://lkml.kernel.org/r/[email protected]
Fixes: a6b4085 ("mm: hugetlb: replace hugetlb_free_vmemmap_enabled with a static_key")
Signed-off-by: Miaohe Lin <[email protected]>
Acked-by: Oscar Salvador <[email protected]>
Reviewed-by: Jane Chu <[email protected]>
Cc: Naoya Horiguchi <[email protected]>
Cc: <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
blitz pushed a commit to blitz/linux that referenced this issue May 8, 2024
vhost_worker will call tun call backs to receive packets. If too many
illegal packets arrives, tun_do_read will keep dumping packet contents.
When console is enabled, it will costs much more cpu time to dump
packet and soft lockup will be detected.

net_ratelimit mechanism can be used to limit the dumping rate.

PID: 33036    TASK: ffff949da6f20000  CPU: 23   COMMAND: "vhost-32980"
 #0 [fffffe00003fce50] crash_nmi_callback at ffffffff89249253
 svenkatr#1 [fffffe00003fce58] nmi_handle at ffffffff89225fa3
 svenkatr#2 [fffffe00003fceb0] default_do_nmi at ffffffff8922642e
 svenkatr#3 [fffffe00003fced0] do_nmi at ffffffff8922660d
 svenkatr#4 [fffffe00003fcef0] end_repeat_nmi at ffffffff89c01663
    [exception RIP: io_serial_in+20]
    RIP: ffffffff89792594  RSP: ffffa655314979e8  RFLAGS: 00000002
    RAX: ffffffff89792500  RBX: ffffffff8af428a0  RCX: 0000000000000000
    RDX: 00000000000003fd  RSI: 0000000000000005  RDI: ffffffff8af428a0
    RBP: 0000000000002710   R8: 0000000000000004   R9: 000000000000000f
    R10: 0000000000000000  R11: ffffffff8acbf64f  R12: 0000000000000020
    R13: ffffffff8acbf698  R14: 0000000000000058  R15: 0000000000000000
    ORIG_RAX: ffffffffffffffff  CS: 0010  SS: 0018
 svenkatr#5 [ffffa655314979e8] io_serial_in at ffffffff89792594
 svenkatr#6 [ffffa655314979e8] wait_for_xmitr at ffffffff89793470
 svenkatr#7 [ffffa65531497a08] serial8250_console_putchar at ffffffff897934f6
 svenkatr#8 [ffffa65531497a20] uart_console_write at ffffffff8978b605
 svenkatr#9 [ffffa65531497a48] serial8250_console_write at ffffffff89796558
 #10 [ffffa65531497ac8] console_unlock at ffffffff89316124
 #11 [ffffa65531497b10] vprintk_emit at ffffffff89317c07
 #12 [ffffa65531497b68] printk at ffffffff89318306
 #13 [ffffa65531497bc8] print_hex_dump at ffffffff89650765
 #14 [ffffa65531497ca8] tun_do_read at ffffffffc0b06c27 [tun]
 #15 [ffffa65531497d38] tun_recvmsg at ffffffffc0b06e34 [tun]
 #16 [ffffa65531497d68] handle_rx at ffffffffc0c5d682 [vhost_net]
 #17 [ffffa65531497ed0] vhost_worker at ffffffffc0c644dc [vhost]
 #18 [ffffa65531497f10] kthread at ffffffff892d2e72
 #19 [ffffa65531497f50] ret_from_fork at ffffffff89c0022f

Fixes: ef3db4a ("tun: avoid BUG, dump packet on GSO errors")
Signed-off-by: Lei Chen <[email protected]>
Reviewed-by: Willem de Bruijn <[email protected]>
Acked-by: Jason Wang <[email protected]>
Reviewed-by: Eric Dumazet <[email protected]>
Acked-by: Michael S. Tsirkin <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Jakub Kicinski <[email protected]>
blitz pushed a commit to blitz/linux that referenced this issue May 8, 2024
…git/netfilter/nf

Pablo Neira Ayuso says:

====================
Netfilter fixes for net

The following patchset contains Netfilter fixes for net:

Patch svenkatr#1 amends a missing spot where the set iterator type is unset.
	 This is fixing a issue in the previous pull request.

Patch svenkatr#2 fixes the delete set command abort path by restoring state
         of the elements. Reverse logic for the activate (abort) case
	 otherwise element state is not restored, this requires to move
	 the check for active/inactive elements to the set iterator
	 callback. From the deactivate path, toggle the next generation
	 bit and from the activate (abort) path, clear the next generation
	 bitmask.

Patch svenkatr#3 skips elements already restored by delete set command from the
	 abort path in case there is a previous delete element command in
	 the batch. Check for the next generation bit just like it is done
	 via set iteration to restore maps.

netfilter pull request 24-04-18

* tag 'nf-24-04-18' of git://git.kernel.org/pub/scm/linux/kernel/git/netfilter/nf:
  netfilter: nf_tables: fix memleak in map from abort path
  netfilter: nf_tables: restore set elements when delete set fails
  netfilter: nf_tables: missing iterator type in lookup walk
====================

Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Paolo Abeni <[email protected]>
blitz pushed a commit to blitz/linux that referenced this issue May 8, 2024
Petr Machata says:

====================
mlxsw: Fixes

This patchset fixes the following issues:

- During driver de-initialization the driver unregisters the EMAD
  response trap by setting its action to DISCARD. However the manual
  only permits TRAP and FORWARD, and future firmware versions will
  enforce this.

  In patch svenkatr#1, suppress the error message by aligning the driver to the
  manual and use a FORWARD (NOP) action when unregistering the trap.

- The driver queries the Management Capabilities Mask (MCAM) register
  during initialization to understand if certain features are supported.

  However, not all firmware versions support this register, leading to
  the driver failing to load.

  Patches svenkatr#2 and svenkatr#3 fix this issue by treating an error in the register
  query as an indication that the feature is not supported.

v2:
- Patch svenkatr#2:
    - Make mlxsw_env_max_module_eeprom_len_query() void
====================

Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Jakub Kicinski <[email protected]>
blitz pushed a commit to blitz/linux that referenced this issue May 8, 2024
9f74a3d ("ice: Fix VF Reset paths when interface in a failed over
aggregate"), the ice driver has acquired the LAG mutex in ice_reset_vf().
The commit placed this lock acquisition just prior to the acquisition of
the VF configuration lock.

If ice_reset_vf() acquires the configuration lock via the ICE_VF_RESET_LOCK
flag, this could deadlock with ice_vc_cfg_qs_msg() because it always
acquires the locks in the order of the VF configuration lock and then the
LAG mutex.

Lockdep reports this violation almost immediately on creating and then
removing 2 VF:

======================================================
WARNING: possible circular locking dependency detected
6.8.0-rc6 #54 Tainted: G        W  O
------------------------------------------------------
kworker/60:3/6771 is trying to acquire lock:
ff40d43e099380a0 (&vf->cfg_lock){+.+.}-{3:3}, at: ice_reset_vf+0x22f/0x4d0 [ice]

but task is already holding lock:
ff40d43ea1961210 (&pf->lag_mutex){+.+.}-{3:3}, at: ice_reset_vf+0xb7/0x4d0 [ice]

which lock already depends on the new lock.

the existing dependency chain (in reverse order) is:

-> svenkatr#1 (&pf->lag_mutex){+.+.}-{3:3}:
       __lock_acquire+0x4f8/0xb40
       lock_acquire+0xd4/0x2d0
       __mutex_lock+0x9b/0xbf0
       ice_vc_cfg_qs_msg+0x45/0x690 [ice]
       ice_vc_process_vf_msg+0x4f5/0x870 [ice]
       __ice_clean_ctrlq+0x2b5/0x600 [ice]
       ice_service_task+0x2c9/0x480 [ice]
       process_one_work+0x1e9/0x4d0
       worker_thread+0x1e1/0x3d0
       kthread+0x104/0x140
       ret_from_fork+0x31/0x50
       ret_from_fork_asm+0x1b/0x30

-> #0 (&vf->cfg_lock){+.+.}-{3:3}:
       check_prev_add+0xe2/0xc50
       validate_chain+0x558/0x800
       __lock_acquire+0x4f8/0xb40
       lock_acquire+0xd4/0x2d0
       __mutex_lock+0x9b/0xbf0
       ice_reset_vf+0x22f/0x4d0 [ice]
       ice_process_vflr_event+0x98/0xd0 [ice]
       ice_service_task+0x1cc/0x480 [ice]
       process_one_work+0x1e9/0x4d0
       worker_thread+0x1e1/0x3d0
       kthread+0x104/0x140
       ret_from_fork+0x31/0x50
       ret_from_fork_asm+0x1b/0x30

other info that might help us debug this:
 Possible unsafe locking scenario:
       CPU0                    CPU1
       ----                    ----
  lock(&pf->lag_mutex);
                               lock(&vf->cfg_lock);
                               lock(&pf->lag_mutex);
  lock(&vf->cfg_lock);

 *** DEADLOCK ***
4 locks held by kworker/60:3/6771:
 #0: ff40d43e05428b38 ((wq_completion)ice){+.+.}-{0:0}, at: process_one_work+0x176/0x4d0
 svenkatr#1: ff50d06e05197e58 ((work_completion)(&pf->serv_task)){+.+.}-{0:0}, at: process_one_work+0x176/0x4d0
 svenkatr#2: ff40d43ea1960e50 (&pf->vfs.table_lock){+.+.}-{3:3}, at: ice_process_vflr_event+0x48/0xd0 [ice]
 svenkatr#3: ff40d43ea1961210 (&pf->lag_mutex){+.+.}-{3:3}, at: ice_reset_vf+0xb7/0x4d0 [ice]

stack backtrace:
CPU: 60 PID: 6771 Comm: kworker/60:3 Tainted: G        W  O       6.8.0-rc6 #54
Hardware name:
Workqueue: ice ice_service_task [ice]
Call Trace:
 <TASK>
 dump_stack_lvl+0x4a/0x80
 check_noncircular+0x12d/0x150
 check_prev_add+0xe2/0xc50
 ? save_trace+0x59/0x230
 ? add_chain_cache+0x109/0x450
 validate_chain+0x558/0x800
 __lock_acquire+0x4f8/0xb40
 ? lockdep_hardirqs_on+0x7d/0x100
 lock_acquire+0xd4/0x2d0
 ? ice_reset_vf+0x22f/0x4d0 [ice]
 ? lock_is_held_type+0xc7/0x120
 __mutex_lock+0x9b/0xbf0
 ? ice_reset_vf+0x22f/0x4d0 [ice]
 ? ice_reset_vf+0x22f/0x4d0 [ice]
 ? rcu_is_watching+0x11/0x50
 ? ice_reset_vf+0x22f/0x4d0 [ice]
 ice_reset_vf+0x22f/0x4d0 [ice]
 ? process_one_work+0x176/0x4d0
 ice_process_vflr_event+0x98/0xd0 [ice]
 ice_service_task+0x1cc/0x480 [ice]
 process_one_work+0x1e9/0x4d0
 worker_thread+0x1e1/0x3d0
 ? __pfx_worker_thread+0x10/0x10
 kthread+0x104/0x140
 ? __pfx_kthread+0x10/0x10
 ret_from_fork+0x31/0x50
 ? __pfx_kthread+0x10/0x10
 ret_from_fork_asm+0x1b/0x30
 </TASK>

To avoid deadlock, we must acquire the LAG mutex only after acquiring the
VF configuration lock. Fix the ice_reset_vf() to acquire the LAG mutex only
after we either acquire or check that the VF configuration lock is held.

Fixes: 9f74a3d ("ice: Fix VF Reset paths when interface in a failed over aggregate")
Signed-off-by: Jacob Keller <[email protected]>
Reviewed-by: Dave Ertman <[email protected]>
Reviewed-by: Mateusz Polchlopek <[email protected]>
Tested-by: Przemek Kitszel <[email protected]>
Tested-by: Rafal Romanowski <[email protected]>
Signed-off-by: Tony Nguyen <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Jakub Kicinski <[email protected]>
blitz pushed a commit to blitz/linux that referenced this issue May 8, 2024
…io()

When I did memory failure tests recently, below warning occurs:

DEBUG_LOCKS_WARN_ON(1)
WARNING: CPU: 8 PID: 1011 at kernel/locking/lockdep.c:232 __lock_acquire+0xccb/0x1ca0
Modules linked in: mce_inject hwpoison_inject
CPU: 8 PID: 1011 Comm: bash Kdump: loaded Not tainted 6.9.0-rc3-next-20240410-00012-gdb69f219f4be svenkatr#3
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.14.0-0-g155821a1990b-prebuilt.qemu.org 04/01/2014
RIP: 0010:__lock_acquire+0xccb/0x1ca0
RSP: 0018:ffffa7a1c7fe3bd0 EFLAGS: 00000082
RAX: 0000000000000000 RBX: eb851eb853975fcf RCX: ffffa1ce5fc1c9c8
RDX: 00000000ffffffd8 RSI: 0000000000000027 RDI: ffffa1ce5fc1c9c0
RBP: ffffa1c6865d3280 R08: ffffffffb0f570a8 R09: 0000000000009ffb
R10: 0000000000000286 R11: ffffffffb0f2ad50 R12: ffffa1c6865d3d10
R13: ffffa1c6865d3c70 R14: 0000000000000000 R15: 0000000000000004
FS:  00007ff9f32aa740(0000) GS:ffffa1ce5fc00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007ff9f3134ba0 CR3: 00000008484e4000 CR4: 00000000000006f0
Call Trace:
 <TASK>
 lock_acquire+0xbe/0x2d0
 _raw_spin_lock_irqsave+0x3a/0x60
 hugepage_subpool_put_pages.part.0+0xe/0xc0
 free_huge_folio+0x253/0x3f0
 dissolve_free_huge_page+0x147/0x210
 __page_handle_poison+0x9/0x70
 memory_failure+0x4e6/0x8c0
 hard_offline_page_store+0x55/0xa0
 kernfs_fop_write_iter+0x12c/0x1d0
 vfs_write+0x380/0x540
 ksys_write+0x64/0xe0
 do_syscall_64+0xbc/0x1d0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7ff9f3114887
RSP: 002b:00007ffecbacb458 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 000000000000000c RCX: 00007ff9f3114887
RDX: 000000000000000c RSI: 0000564494164e10 RDI: 0000000000000001
RBP: 0000564494164e10 R08: 00007ff9f31d1460 R09: 000000007fffffff
R10: 0000000000000000 R11: 0000000000000246 R12: 000000000000000c
R13: 00007ff9f321b780 R14: 00007ff9f3217600 R15: 00007ff9f3216a00
 </TASK>
Kernel panic - not syncing: kernel: panic_on_warn set ...
CPU: 8 PID: 1011 Comm: bash Kdump: loaded Not tainted 6.9.0-rc3-next-20240410-00012-gdb69f219f4be svenkatr#3
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.14.0-0-g155821a1990b-prebuilt.qemu.org 04/01/2014
Call Trace:
 <TASK>
 panic+0x326/0x350
 check_panic_on_warn+0x4f/0x50
 __warn+0x98/0x190
 report_bug+0x18e/0x1a0
 handle_bug+0x3d/0x70
 exc_invalid_op+0x18/0x70
 asm_exc_invalid_op+0x1a/0x20
RIP: 0010:__lock_acquire+0xccb/0x1ca0
RSP: 0018:ffffa7a1c7fe3bd0 EFLAGS: 00000082
RAX: 0000000000000000 RBX: eb851eb853975fcf RCX: ffffa1ce5fc1c9c8
RDX: 00000000ffffffd8 RSI: 0000000000000027 RDI: ffffa1ce5fc1c9c0
RBP: ffffa1c6865d3280 R08: ffffffffb0f570a8 R09: 0000000000009ffb
R10: 0000000000000286 R11: ffffffffb0f2ad50 R12: ffffa1c6865d3d10
R13: ffffa1c6865d3c70 R14: 0000000000000000 R15: 0000000000000004
 lock_acquire+0xbe/0x2d0
 _raw_spin_lock_irqsave+0x3a/0x60
 hugepage_subpool_put_pages.part.0+0xe/0xc0
 free_huge_folio+0x253/0x3f0
 dissolve_free_huge_page+0x147/0x210
 __page_handle_poison+0x9/0x70
 memory_failure+0x4e6/0x8c0
 hard_offline_page_store+0x55/0xa0
 kernfs_fop_write_iter+0x12c/0x1d0
 vfs_write+0x380/0x540
 ksys_write+0x64/0xe0
 do_syscall_64+0xbc/0x1d0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7ff9f3114887
RSP: 002b:00007ffecbacb458 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 000000000000000c RCX: 00007ff9f3114887
RDX: 000000000000000c RSI: 0000564494164e10 RDI: 0000000000000001
RBP: 0000564494164e10 R08: 00007ff9f31d1460 R09: 000000007fffffff
R10: 0000000000000000 R11: 0000000000000246 R12: 000000000000000c
R13: 00007ff9f321b780 R14: 00007ff9f3217600 R15: 00007ff9f3216a00
 </TASK>

After git bisecting and digging into the code, I believe the root cause is
that _deferred_list field of folio is unioned with _hugetlb_subpool field.
In __update_and_free_hugetlb_folio(), folio->_deferred_list is
initialized leading to corrupted folio->_hugetlb_subpool when folio is
hugetlb.  Later free_huge_folio() will use _hugetlb_subpool and above
warning happens.

But it is assumed hugetlb flag must have been cleared when calling
folio_put() in update_and_free_hugetlb_folio().  This assumption is broken
due to below race:

CPU1					CPU2
dissolve_free_huge_page			update_and_free_pages_bulk
 update_and_free_hugetlb_folio		 hugetlb_vmemmap_restore_folios
					  folio_clear_hugetlb_vmemmap_optimized
  clear_flag = folio_test_hugetlb_vmemmap_optimized
  if (clear_flag) <-- False, it's already cleared.
   __folio_clear_hugetlb(folio) <-- Hugetlb is not cleared.
  folio_put
   free_huge_folio <-- free_the_page is expected.
					 list_for_each_entry()
					  __folio_clear_hugetlb <-- Too late.

Fix this issue by checking whether folio is hugetlb directly instead of
checking clear_flag to close the race window.

Link: https://lkml.kernel.org/r/[email protected]
Fixes: 32c8771 ("hugetlb: do not clear hugetlb dtor until allocating vmemmap")
Signed-off-by: Miaohe Lin <[email protected]>
Reviewed-by: Oscar Salvador <[email protected]>
Cc: <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
mhiramat pushed a commit to mhiramat/linux that referenced this issue Jun 11, 2024
Andrii Nakryiko says:

====================
Fix BPF multi-uprobe PID filtering logic

It turns out that current implementation of multi-uprobe PID filtering logic
is broken. It filters by thread, while the promise is filtering by process.
Patch svenkatr#1 fixes the logic trivially. The rest is testing and mitigations that
are necessary for libbpf to not break users of USDT programs.

v1->v2:
  - fix selftest in last patch (CI);
  - use semicolon in patch svenkatr#3 (Jiri).
====================

Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Alexei Starovoitov <[email protected]>
mhiramat pushed a commit to mhiramat/linux that referenced this issue Jun 11, 2024
…git/netfilter/nf

Pablo Neira Ayuso says:

====================
Netfilter fixes for net

The following patchset contains Netfilter fixes for net:

Patch svenkatr#1 syzbot reports that nf_reinject() could be called without
         rcu_read_lock() when flushing pending packets at nfnetlink
         queue removal, from Eric Dumazet.

Patch svenkatr#2 flushes ipset list:set when canceling garbage collection to
         reference to other lists to fix a race, from Jozsef Kadlecsik.

Patch svenkatr#3 restores q-in-q matching with nft_payload by reverting
         f6ae9f1 ("netfilter: nft_payload: add C-VLAN support").

Patch svenkatr#4 fixes vlan mangling in skbuff when vlan offload is present
         in skbuff, without this patch nft_payload corrupts packets
         in this case.

Patch svenkatr#5 fixes possible nul-deref in tproxy no IP address is found in
         netdevice, reported by syzbot and patch from Florian Westphal.

Patch svenkatr#6 removes a superfluous restriction which prevents loose fib
         lookups from input and forward hooks, from Eric Garver.

My assessment is that patches svenkatr#1, svenkatr#2 and svenkatr#5 address possible kernel
crash, anything else in this batch fixes broken features.

netfilter pull request 24-05-29

* tag 'nf-24-05-29' of git://git.kernel.org/pub/scm/linux/kernel/git/netfilter/nf:
  netfilter: nft_fib: allow from forward/input without iif selector
  netfilter: tproxy: bail out if IP has been disabled on the device
  netfilter: nft_payload: skbuff vlan metadata mangle support
  netfilter: nft_payload: restore vlan q-in-q match support
  netfilter: ipset: Add list flush to cancel_gc
  netfilter: nfnetlink_queue: acquire rcu_read_lock() in instance_destroy_rcu()
====================

Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Paolo Abeni <[email protected]>
mhiramat pushed a commit to mhiramat/linux that referenced this issue Jun 11, 2024
With commit c4cb231 ("iommu/amd: Add support for enable/disable IOPF")
we are hitting below issue. This happens because in IOPF enablement path
it holds spin lock with irq disable and then tries to take mutex lock.

dmesg:
-----
[    0.938739] =============================
[    0.938740] [ BUG: Invalid wait context ]
[    0.938742] 6.10.0-rc1+ svenkatr#1 Not tainted
[    0.938745] -----------------------------
[    0.938746] swapper/0/1 is trying to lock:
[    0.938748] ffffffff8c9f01d8 (&port_lock_key){....}-{3:3}, at: serial8250_console_write+0x78/0x4a0
[    0.938767] other info that might help us debug this:
[    0.938768] context-{5:5}
[    0.938769] 7 locks held by swapper/0/1:
[    0.938772]  #0: ffff888101a91310 (&group->mutex){+.+.}-{4:4}, at: bus_iommu_probe+0x70/0x160
[    0.938790]  svenkatr#1: ffff888101d1f1b8 (&domain->lock){....}-{3:3}, at: amd_iommu_attach_device+0xa5/0x700
[    0.938799]  svenkatr#2: ffff888101cc3d18 (&dev_data->lock){....}-{3:3}, at: amd_iommu_attach_device+0xc5/0x700
[    0.938806]  svenkatr#3: ffff888100052830 (&iommu->lock){....}-{2:2}, at: amd_iommu_iopf_add_device+0x3f/0xa0
[    0.938813]  svenkatr#4: ffffffff8945a340 (console_lock){+.+.}-{0:0}, at: _printk+0x48/0x50
[    0.938822]  svenkatr#5: ffffffff8945a390 (console_srcu){....}-{0:0}, at: console_flush_all+0x58/0x4e0
[    0.938867]  svenkatr#6: ffffffff82459f80 (console_owner){....}-{0:0}, at: console_flush_all+0x1f0/0x4e0
[    0.938872] stack backtrace:
[    0.938874] CPU: 2 PID: 1 Comm: swapper/0 Not tainted 6.10.0-rc1+ svenkatr#1
[    0.938877] Hardware name: HP HP EliteBook 745 G3/807E, BIOS N73 Ver. 01.39 04/16/2019

Fix above issue by re-arranging code in attach device path:
  - move device PASID/IOPF enablement outside lock in AMD IOMMU driver.
    This is safe as core layer holds group->mutex lock before calling
    iommu_ops->attach_dev.

Reported-by: Borislav Petkov <[email protected]>
Reported-by: Mikhail Gavrilov <[email protected]>
Reported-by: Chris Bainbridge <[email protected]>
Fixes: c4cb231 ("iommu/amd: Add support for enable/disable IOPF")
Tested-by: Borislav Petkov <[email protected]>
Tested-by: Chris Bainbridge <[email protected]>
Tested-by: Mikhail Gavrilov <[email protected]>
Signed-off-by: Vasant Hegde <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Joerg Roedel <[email protected]>
mhiramat pushed a commit to mhiramat/linux that referenced this issue Jun 11, 2024
…PLES event"

This reverts commit 7d1405c.

This causes segfaults in some cases, as reported by Milian:

  ```
  sudo /usr/bin/perf record -z --call-graph dwarf -e cycles -e
  raw_syscalls:sys_enter ls
  ...
  [ perf record: Woken up 3 times to write data ]
  malloc(): invalid next size (unsorted)
  Aborted
  ```

  Backtrace with GDB + debuginfod:

  ```
  malloc(): invalid next size (unsorted)

  Thread 1 "perf" received signal SIGABRT, Aborted.
  __pthread_kill_implementation (threadid=<optimized out>, signo=signo@entry=6,
  no_tid=no_tid@entry=0) at pthread_kill.c:44
  Downloading source file /usr/src/debug/glibc/glibc/nptl/pthread_kill.c
  44            return INTERNAL_SYSCALL_ERROR_P (ret) ? INTERNAL_SYSCALL_ERRNO
  (ret) : 0;
  (gdb) bt
  #0  __pthread_kill_implementation (threadid=<optimized out>,
  signo=signo@entry=6, no_tid=no_tid@entry=0) at pthread_kill.c:44
  svenkatr#1  0x00007ffff6ea8eb3 in __pthread_kill_internal (threadid=<optimized out>,
  signo=6) at pthread_kill.c:78
  svenkatr#2  0x00007ffff6e50a30 in __GI_raise (sig=sig@entry=6) at ../sysdeps/posix/
  raise.c:26
  svenkatr#3  0x00007ffff6e384c3 in __GI_abort () at abort.c:79
  svenkatr#4  0x00007ffff6e39354 in __libc_message_impl (fmt=fmt@entry=0x7ffff6fc22ea
  "%s\n") at ../sysdeps/posix/libc_fatal.c:132
  svenkatr#5  0x00007ffff6eb3085 in malloc_printerr (str=str@entry=0x7ffff6fc5850
  "malloc(): invalid next size (unsorted)") at malloc.c:5772
  svenkatr#6  0x00007ffff6eb657c in _int_malloc (av=av@entry=0x7ffff6ff6ac0
  <main_arena>, bytes=bytes@entry=368) at malloc.c:4081
  svenkatr#7  0x00007ffff6eb877e in __libc_calloc (n=<optimized out>,
  elem_size=<optimized out>) at malloc.c:3754
  svenkatr#8  0x000055555569bdb6 in perf_session.do_write_header ()
  svenkatr#9  0x00005555555a373a in __cmd_record.constprop.0 ()
  #10 0x00005555555a6846 in cmd_record ()
  #11 0x000055555564db7f in run_builtin ()
  #12 0x000055555558ed77 in main ()
  ```

  Valgrind memcheck:
  ```
  ==45136== Invalid write of size 8
  ==45136==    at 0x2B38A5: perf_event__synthesize_id_sample (in /usr/bin/perf)
  ==45136==    by 0x157069: __cmd_record.constprop.0 (in /usr/bin/perf)
  ==45136==    by 0x15A845: cmd_record (in /usr/bin/perf)
  ==45136==    by 0x201B7E: run_builtin (in /usr/bin/perf)
  ==45136==    by 0x142D76: main (in /usr/bin/perf)
  ==45136==  Address 0x6a866a8 is 0 bytes after a block of size 40 alloc'd
  ==45136==    at 0x4849BF3: calloc (vg_replace_malloc.c:1675)
  ==45136==    by 0x3574AB: zalloc (in /usr/bin/perf)
  ==45136==    by 0x1570E0: __cmd_record.constprop.0 (in /usr/bin/perf)
  ==45136==    by 0x15A845: cmd_record (in /usr/bin/perf)
  ==45136==    by 0x201B7E: run_builtin (in /usr/bin/perf)
  ==45136==    by 0x142D76: main (in /usr/bin/perf)
  ==45136==
  ==45136== Syscall param write(buf) points to unaddressable byte(s)
  ==45136==    at 0x575953D: __libc_write (write.c:26)
  ==45136==    by 0x575953D: write (write.c:24)
  ==45136==    by 0x35761F: ion (in /usr/bin/perf)
  ==45136==    by 0x357778: writen (in /usr/bin/perf)
  ==45136==    by 0x1548F7: record__write (in /usr/bin/perf)
  ==45136==    by 0x15708A: __cmd_record.constprop.0 (in /usr/bin/perf)
  ==45136==    by 0x15A845: cmd_record (in /usr/bin/perf)
  ==45136==    by 0x201B7E: run_builtin (in /usr/bin/perf)
  ==45136==    by 0x142D76: main (in /usr/bin/perf)
  ==45136==  Address 0x6a866a8 is 0 bytes after a block of size 40 alloc'd
  ==45136==    at 0x4849BF3: calloc (vg_replace_malloc.c:1675)
  ==45136==    by 0x3574AB: zalloc (in /usr/bin/perf)
  ==45136==    by 0x1570E0: __cmd_record.constprop.0 (in /usr/bin/perf)
  ==45136==    by 0x15A845: cmd_record (in /usr/bin/perf)
  ==45136==    by 0x201B7E: run_builtin (in /usr/bin/perf)
  ==45136==    by 0x142D76: main (in /usr/bin/perf)
  ==45136==
 -----

Closes: https://lore.kernel.org/linux-perf-users/23879991.0LEYPuXRzz@milian-workstation/
Reported-by: Milian Wolff <[email protected]>
Tested-by: Milian Wolff <[email protected]>
Cc: Adrian Hunter <[email protected]>
Cc: Ian Rogers <[email protected]>
Cc: Jiri Olsa <[email protected]>
Cc: Kan Liang <[email protected]>
Cc: Namhyung Kim <[email protected]>
Cc: [email protected] # 6.8+
Link: https://lore.kernel.org/lkml/Zl9ksOlHJHnKM70p@x1
Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
mhiramat pushed a commit to mhiramat/linux that referenced this issue Jun 11, 2024
We have been seeing crashes on duplicate keys in
btrfs_set_item_key_safe():

  BTRFS critical (device vdb): slot 4 key (450 108 8192) new key (450 108 8192)
  ------------[ cut here ]------------
  kernel BUG at fs/btrfs/ctree.c:2620!
  invalid opcode: 0000 [svenkatr#1] PREEMPT SMP PTI
  CPU: 0 PID: 3139 Comm: xfs_io Kdump: loaded Not tainted 6.9.0 svenkatr#6
  Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.3-2.fc40 04/01/2014
  RIP: 0010:btrfs_set_item_key_safe+0x11f/0x290 [btrfs]

With the following stack trace:

  #0  btrfs_set_item_key_safe (fs/btrfs/ctree.c:2620:4)
  svenkatr#1  btrfs_drop_extents (fs/btrfs/file.c:411:4)
  svenkatr#2  log_one_extent (fs/btrfs/tree-log.c:4732:9)
  svenkatr#3  btrfs_log_changed_extents (fs/btrfs/tree-log.c:4955:9)
  svenkatr#4  btrfs_log_inode (fs/btrfs/tree-log.c:6626:9)
  svenkatr#5  btrfs_log_inode_parent (fs/btrfs/tree-log.c:7070:8)
  svenkatr#6  btrfs_log_dentry_safe (fs/btrfs/tree-log.c:7171:8)
  svenkatr#7  btrfs_sync_file (fs/btrfs/file.c:1933:8)
  svenkatr#8  vfs_fsync_range (fs/sync.c:188:9)
  svenkatr#9  vfs_fsync (fs/sync.c:202:9)
  #10 do_fsync (fs/sync.c:212:9)
  #11 __do_sys_fdatasync (fs/sync.c:225:9)
  #12 __se_sys_fdatasync (fs/sync.c:223:1)
  #13 __x64_sys_fdatasync (fs/sync.c:223:1)
  #14 do_syscall_x64 (arch/x86/entry/common.c:52:14)
  #15 do_syscall_64 (arch/x86/entry/common.c:83:7)
  #16 entry_SYSCALL_64+0xaf/0x14c (arch/x86/entry/entry_64.S:121)

So we're logging a changed extent from fsync, which is splitting an
extent in the log tree. But this split part already exists in the tree,
triggering the BUG().

This is the state of the log tree at the time of the crash, dumped with
drgn (https://github.com/osandov/drgn/blob/main/contrib/btrfs_tree.py)
to get more details than btrfs_print_leaf() gives us:

  >>> print_extent_buffer(prog.crashed_thread().stack_trace()[0]["eb"])
  leaf 33439744 level 0 items 72 generation 9 owner 18446744073709551610
  leaf 33439744 flags 0x100000000000000
  fs uuid e5bd3946-400c-4223-8923-190ef1f18677
  chunk uuid d58cb17e-6d02-494a-829a-18b7d8a399da
          item 0 key (450 INODE_ITEM 0) itemoff 16123 itemsize 160
                  generation 7 transid 9 size 8192 nbytes 8473563889606862198
                  block group 0 mode 100600 links 1 uid 0 gid 0 rdev 0
                  sequence 204 flags 0x10(PREALLOC)
                  atime 1716417703.220000000 (2024-05-22 15:41:43)
                  ctime 1716417704.983333333 (2024-05-22 15:41:44)
                  mtime 1716417704.983333333 (2024-05-22 15:41:44)
                  otime 17592186044416.000000000 (559444-03-08 01:40:16)
          item 1 key (450 INODE_REF 256) itemoff 16110 itemsize 13
                  index 195 namelen 3 name: 193
          item 2 key (450 XATTR_ITEM 1640047104) itemoff 16073 itemsize 37
                  location key (0 UNKNOWN.0 0) type XATTR
                  transid 7 data_len 1 name_len 6
                  name: user.a
                  data a
          item 3 key (450 EXTENT_DATA 0) itemoff 16020 itemsize 53
                  generation 9 type 1 (regular)
                  extent data disk byte 303144960 nr 12288
                  extent data offset 0 nr 4096 ram 12288
                  extent compression 0 (none)
          item 4 key (450 EXTENT_DATA 4096) itemoff 15967 itemsize 53
                  generation 9 type 2 (prealloc)
                  prealloc data disk byte 303144960 nr 12288
                  prealloc data offset 4096 nr 8192
          item 5 key (450 EXTENT_DATA 8192) itemoff 15914 itemsize 53
                  generation 9 type 2 (prealloc)
                  prealloc data disk byte 303144960 nr 12288
                  prealloc data offset 8192 nr 4096
  ...

So the real problem happened earlier: notice that items 4 (4k-12k) and 5
(8k-12k) overlap. Both are prealloc extents. Item 4 straddles i_size and
item 5 starts at i_size.

Here is the state of the filesystem tree at the time of the crash:

  >>> root = prog.crashed_thread().stack_trace()[2]["inode"].root
  >>> ret, nodes, slots = btrfs_search_slot(root, BtrfsKey(450, 0, 0))
  >>> print_extent_buffer(nodes[0])
  leaf 30425088 level 0 items 184 generation 9 owner 5
  leaf 30425088 flags 0x100000000000000
  fs uuid e5bd3946-400c-4223-8923-190ef1f18677
  chunk uuid d58cb17e-6d02-494a-829a-18b7d8a399da
  	...
          item 179 key (450 INODE_ITEM 0) itemoff 4907 itemsize 160
                  generation 7 transid 7 size 4096 nbytes 12288
                  block group 0 mode 100600 links 1 uid 0 gid 0 rdev 0
                  sequence 6 flags 0x10(PREALLOC)
                  atime 1716417703.220000000 (2024-05-22 15:41:43)
                  ctime 1716417703.220000000 (2024-05-22 15:41:43)
                  mtime 1716417703.220000000 (2024-05-22 15:41:43)
                  otime 1716417703.220000000 (2024-05-22 15:41:43)
          item 180 key (450 INODE_REF 256) itemoff 4894 itemsize 13
                  index 195 namelen 3 name: 193
          item 181 key (450 XATTR_ITEM 1640047104) itemoff 4857 itemsize 37
                  location key (0 UNKNOWN.0 0) type XATTR
                  transid 7 data_len 1 name_len 6
                  name: user.a
                  data a
          item 182 key (450 EXTENT_DATA 0) itemoff 4804 itemsize 53
                  generation 9 type 1 (regular)
                  extent data disk byte 303144960 nr 12288
                  extent data offset 0 nr 8192 ram 12288
                  extent compression 0 (none)
          item 183 key (450 EXTENT_DATA 8192) itemoff 4751 itemsize 53
                  generation 9 type 2 (prealloc)
                  prealloc data disk byte 303144960 nr 12288
                  prealloc data offset 8192 nr 4096

Item 5 in the log tree corresponds to item 183 in the filesystem tree,
but nothing matches item 4. Furthermore, item 183 is the last item in
the leaf.

btrfs_log_prealloc_extents() is responsible for logging prealloc extents
beyond i_size. It first truncates any previously logged prealloc extents
that start beyond i_size. Then, it walks the filesystem tree and copies
the prealloc extent items to the log tree.

If it hits the end of a leaf, then it calls btrfs_next_leaf(), which
unlocks the tree and does another search. However, while the filesystem
tree is unlocked, an ordered extent completion may modify the tree. In
particular, it may insert an extent item that overlaps with an extent
item that was already copied to the log tree.

This may manifest in several ways depending on the exact scenario,
including an EEXIST error that is silently translated to a full sync,
overlapping items in the log tree, or this crash. This particular crash
is triggered by the following sequence of events:

- Initially, the file has i_size=4k, a regular extent from 0-4k, and a
  prealloc extent beyond i_size from 4k-12k. The prealloc extent item is
  the last item in its B-tree leaf.
- The file is fsync'd, which copies its inode item and both extent items
  to the log tree.
- An xattr is set on the file, which sets the
  BTRFS_INODE_COPY_EVERYTHING flag.
- The range 4k-8k in the file is written using direct I/O. i_size is
  extended to 8k, but the ordered extent is still in flight.
- The file is fsync'd. Since BTRFS_INODE_COPY_EVERYTHING is set, this
  calls copy_inode_items_to_log(), which calls
  btrfs_log_prealloc_extents().
- btrfs_log_prealloc_extents() finds the 4k-12k prealloc extent in the
  filesystem tree. Since it starts before i_size, it skips it. Since it
  is the last item in its B-tree leaf, it calls btrfs_next_leaf().
- btrfs_next_leaf() unlocks the path.
- The ordered extent completion runs, which converts the 4k-8k part of
  the prealloc extent to written and inserts the remaining prealloc part
  from 8k-12k.
- btrfs_next_leaf() does a search and finds the new prealloc extent
  8k-12k.
- btrfs_log_prealloc_extents() copies the 8k-12k prealloc extent into
  the log tree. Note that it overlaps with the 4k-12k prealloc extent
  that was copied to the log tree by the first fsync.
- fsync calls btrfs_log_changed_extents(), which tries to log the 4k-8k
  extent that was written.
- This tries to drop the range 4k-8k in the log tree, which requires
  adjusting the start of the 4k-12k prealloc extent in the log tree to
  8k.
- btrfs_set_item_key_safe() sees that there is already an extent
  starting at 8k in the log tree and calls BUG().

Fix this by detecting when we're about to insert an overlapping file
extent item in the log tree and truncating the part that would overlap.

CC: [email protected] # 6.1+
Reviewed-by: Filipe Manana <[email protected]>
Signed-off-by: Omar Sandoval <[email protected]>
Signed-off-by: David Sterba <[email protected]>
mhiramat pushed a commit to mhiramat/linux that referenced this issue Jul 5, 2024
Add a set of tests to validate that stack traces captured from or in the
presence of active uprobes and uretprobes are valid and complete.

For this we use BPF program that are installed either on entry or exit
of user function, plus deep-nested USDT. One of target funtions
(target_1) is recursive to generate two different entries in the stack
trace for the same uprobe/uretprobe, testing potential edge conditions.

If there is no fixes, we get something like this for one of the scenarios:

 caller: 0x758fff - 0x7595ab
 target_1: 0x758fd5 - 0x758fff
 target_2: 0x758fca - 0x758fd5
 target_3: 0x758fbf - 0x758fca
 target_4: 0x758fb3 - 0x758fbf
 ENTRY #0: 0x758fb3 (in target_4)
 ENTRY svenkatr#1: 0x758fd3 (in target_2)
 ENTRY svenkatr#2: 0x758ffd (in target_1)
 ENTRY svenkatr#3: 0x7fffffffe000
 ENTRY svenkatr#4: 0x7fffffffe000
 ENTRY svenkatr#5: 0x6f8f39
 ENTRY svenkatr#6: 0x6fa6f0
 ENTRY svenkatr#7: 0x7f403f229590

Entry svenkatr#3 and svenkatr#4 (0x7fffffffe000) are uretprobe trampoline addresses
which obscure actual target_1 and another target_1 invocations. Also
note that between entry #0 and entry svenkatr#1 we are missing an entry for
target_3.

With fixes, we get desired full stack traces:

 caller: 0x758fff - 0x7595ab
 target_1: 0x758fd5 - 0x758fff
 target_2: 0x758fca - 0x758fd5
 target_3: 0x758fbf - 0x758fca
 target_4: 0x758fb3 - 0x758fbf
 ENTRY #0: 0x758fb7 (in target_4)
 ENTRY svenkatr#1: 0x758fc8 (in target_3)
 ENTRY svenkatr#2: 0x758fd3 (in target_2)
 ENTRY svenkatr#3: 0x758ffd (in target_1)
 ENTRY svenkatr#4: 0x758ff3 (in target_1)
 ENTRY svenkatr#5: 0x75922c (in caller)
 ENTRY svenkatr#6: 0x6f8f39
 ENTRY svenkatr#7: 0x6fa6f0
 ENTRY svenkatr#8: 0x7f986adc4cd0

Now there is a logical and complete sequence of function calls.

Link: https://lore.kernel.org/all/[email protected]/

Signed-off-by: Andrii Nakryiko <[email protected]>
Acked-by: Jiri Olsa <[email protected]>
Signed-off-by: Masami Hiramatsu (Google) <[email protected]>
ideak pushed a commit to ideak/linux that referenced this issue Jul 26, 2024
…play

During inode logging (and log replay too), we are holding a transaction
handle and we often need to call btrfs_iget(), which will read an inode
from its subvolume btree if it's not loaded in memory and that results in
allocating an inode with GFP_KERNEL semantics at the btrfs_alloc_inode()
callback - and this may recurse into the filesystem in case we are under
memory pressure and attempt to commit the current transaction, resulting
in a deadlock since the logging (or log replay) task is holding a
transaction handle open.

Syzbot reported this with the following stack traces:

  WARNING: possible circular locking dependency detected
  6.10.0-rc2-syzkaller-00361-g061d1af7b030 #0 Not tainted
  ------------------------------------------------------
  syz-executor.1/9919 is trying to acquire lock:
  ffffffff8dd3aac0 (fs_reclaim){+.+.}-{0:0}, at: might_alloc include/linux/sched/mm.h:334 [inline]
  ffffffff8dd3aac0 (fs_reclaim){+.+.}-{0:0}, at: slab_pre_alloc_hook mm/slub.c:3891 [inline]
  ffffffff8dd3aac0 (fs_reclaim){+.+.}-{0:0}, at: slab_alloc_node mm/slub.c:3981 [inline]
  ffffffff8dd3aac0 (fs_reclaim){+.+.}-{0:0}, at: kmem_cache_alloc_lru_noprof+0x58/0x2f0 mm/slub.c:4020

  but task is already holding lock:
  ffff88804b569358 (&ei->log_mutex){+.+.}-{3:3}, at: btrfs_log_inode+0x39c/0x4660 fs/btrfs/tree-log.c:6481

  which lock already depends on the new lock.

  the existing dependency chain (in reverse order) is:

  -> svenkatr#3 (&ei->log_mutex){+.+.}-{3:3}:
         __mutex_lock_common kernel/locking/mutex.c:608 [inline]
         __mutex_lock+0x175/0x9c0 kernel/locking/mutex.c:752
         btrfs_log_inode+0x39c/0x4660 fs/btrfs/tree-log.c:6481
         btrfs_log_inode_parent+0x8cb/0x2a90 fs/btrfs/tree-log.c:7079
         btrfs_log_dentry_safe+0x59/0x80 fs/btrfs/tree-log.c:7180
         btrfs_sync_file+0x9c1/0xe10 fs/btrfs/file.c:1959
         vfs_fsync_range+0x141/0x230 fs/sync.c:188
         generic_write_sync include/linux/fs.h:2794 [inline]
         btrfs_do_write_iter+0x584/0x10c0 fs/btrfs/file.c:1705
         new_sync_write fs/read_write.c:497 [inline]
         vfs_write+0x6b6/0x1140 fs/read_write.c:590
         ksys_write+0x12f/0x260 fs/read_write.c:643
         do_syscall_32_irqs_on arch/x86/entry/common.c:165 [inline]
         __do_fast_syscall_32+0x73/0x120 arch/x86/entry/common.c:386
         do_fast_syscall_32+0x32/0x80 arch/x86/entry/common.c:411
         entry_SYSENTER_compat_after_hwframe+0x84/0x8e

  -> svenkatr#2 (btrfs_trans_num_extwriters){++++}-{0:0}:
         join_transaction+0x164/0xf40 fs/btrfs/transaction.c:315
         start_transaction+0x427/0x1a70 fs/btrfs/transaction.c:700
         btrfs_commit_super+0xa1/0x110 fs/btrfs/disk-io.c:4170
         close_ctree+0xcb0/0xf90 fs/btrfs/disk-io.c:4324
         generic_shutdown_super+0x159/0x3d0 fs/super.c:642
         kill_anon_super+0x3a/0x60 fs/super.c:1226
         btrfs_kill_super+0x3b/0x50 fs/btrfs/super.c:2096
         deactivate_locked_super+0xbe/0x1a0 fs/super.c:473
         deactivate_super+0xde/0x100 fs/super.c:506
         cleanup_mnt+0x222/0x450 fs/namespace.c:1267
         task_work_run+0x14e/0x250 kernel/task_work.c:180
         resume_user_mode_work include/linux/resume_user_mode.h:50 [inline]
         exit_to_user_mode_loop kernel/entry/common.c:114 [inline]
         exit_to_user_mode_prepare include/linux/entry-common.h:328 [inline]
         __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline]
         syscall_exit_to_user_mode+0x278/0x2a0 kernel/entry/common.c:218
         __do_fast_syscall_32+0x80/0x120 arch/x86/entry/common.c:389
         do_fast_syscall_32+0x32/0x80 arch/x86/entry/common.c:411
         entry_SYSENTER_compat_after_hwframe+0x84/0x8e

  -> svenkatr#1 (btrfs_trans_num_writers){++++}-{0:0}:
         __lock_release kernel/locking/lockdep.c:5468 [inline]
         lock_release+0x33e/0x6c0 kernel/locking/lockdep.c:5774
         percpu_up_read include/linux/percpu-rwsem.h:99 [inline]
         __sb_end_write include/linux/fs.h:1650 [inline]
         sb_end_intwrite include/linux/fs.h:1767 [inline]
         __btrfs_end_transaction+0x5ca/0x920 fs/btrfs/transaction.c:1071
         btrfs_commit_inode_delayed_inode+0x228/0x330 fs/btrfs/delayed-inode.c:1301
         btrfs_evict_inode+0x960/0xe80 fs/btrfs/inode.c:5291
         evict+0x2ed/0x6c0 fs/inode.c:667
         iput_final fs/inode.c:1741 [inline]
         iput.part.0+0x5a8/0x7f0 fs/inode.c:1767
         iput+0x5c/0x80 fs/inode.c:1757
         dentry_unlink_inode+0x295/0x480 fs/dcache.c:400
         __dentry_kill+0x1d0/0x600 fs/dcache.c:603
         dput.part.0+0x4b1/0x9b0 fs/dcache.c:845
         dput+0x1f/0x30 fs/dcache.c:835
         ovl_stack_put+0x60/0x90 fs/overlayfs/util.c:132
         ovl_destroy_inode+0xc6/0x190 fs/overlayfs/super.c:182
         destroy_inode+0xc4/0x1b0 fs/inode.c:311
         iput_final fs/inode.c:1741 [inline]
         iput.part.0+0x5a8/0x7f0 fs/inode.c:1767
         iput+0x5c/0x80 fs/inode.c:1757
         dentry_unlink_inode+0x295/0x480 fs/dcache.c:400
         __dentry_kill+0x1d0/0x600 fs/dcache.c:603
         shrink_kill fs/dcache.c:1048 [inline]
         shrink_dentry_list+0x140/0x5d0 fs/dcache.c:1075
         prune_dcache_sb+0xeb/0x150 fs/dcache.c:1156
         super_cache_scan+0x32a/0x550 fs/super.c:221
         do_shrink_slab+0x44f/0x11c0 mm/shrinker.c:435
         shrink_slab_memcg mm/shrinker.c:548 [inline]
         shrink_slab+0xa87/0x1310 mm/shrinker.c:626
         shrink_one+0x493/0x7c0 mm/vmscan.c:4790
         shrink_many mm/vmscan.c:4851 [inline]
         lru_gen_shrink_node+0x89f/0x1750 mm/vmscan.c:4951
         shrink_node mm/vmscan.c:5910 [inline]
         kswapd_shrink_node mm/vmscan.c:6720 [inline]
         balance_pgdat+0x1105/0x1970 mm/vmscan.c:6911
         kswapd+0x5ea/0xbf0 mm/vmscan.c:7180
         kthread+0x2c1/0x3a0 kernel/kthread.c:389
         ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147
         ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244

  -> #0 (fs_reclaim){+.+.}-{0:0}:
         check_prev_add kernel/locking/lockdep.c:3134 [inline]
         check_prevs_add kernel/locking/lockdep.c:3253 [inline]
         validate_chain kernel/locking/lockdep.c:3869 [inline]
         __lock_acquire+0x2478/0x3b30 kernel/locking/lockdep.c:5137
         lock_acquire kernel/locking/lockdep.c:5754 [inline]
         lock_acquire+0x1b1/0x560 kernel/locking/lockdep.c:5719
         __fs_reclaim_acquire mm/page_alloc.c:3801 [inline]
         fs_reclaim_acquire+0x102/0x160 mm/page_alloc.c:3815
         might_alloc include/linux/sched/mm.h:334 [inline]
         slab_pre_alloc_hook mm/slub.c:3891 [inline]
         slab_alloc_node mm/slub.c:3981 [inline]
         kmem_cache_alloc_lru_noprof+0x58/0x2f0 mm/slub.c:4020
         btrfs_alloc_inode+0x118/0xb20 fs/btrfs/inode.c:8411
         alloc_inode+0x5d/0x230 fs/inode.c:261
         iget5_locked fs/inode.c:1235 [inline]
         iget5_locked+0x1c9/0x2c0 fs/inode.c:1228
         btrfs_iget_locked fs/btrfs/inode.c:5590 [inline]
         btrfs_iget_path fs/btrfs/inode.c:5607 [inline]
         btrfs_iget+0xfb/0x230 fs/btrfs/inode.c:5636
         add_conflicting_inode fs/btrfs/tree-log.c:5657 [inline]
         copy_inode_items_to_log+0x1039/0x1e30 fs/btrfs/tree-log.c:5928
         btrfs_log_inode+0xa48/0x4660 fs/btrfs/tree-log.c:6592
         log_new_delayed_dentries fs/btrfs/tree-log.c:6363 [inline]
         btrfs_log_inode+0x27dd/0x4660 fs/btrfs/tree-log.c:6718
         btrfs_log_all_parents fs/btrfs/tree-log.c:6833 [inline]
         btrfs_log_inode_parent+0x22ba/0x2a90 fs/btrfs/tree-log.c:7141
         btrfs_log_dentry_safe+0x59/0x80 fs/btrfs/tree-log.c:7180
         btrfs_sync_file+0x9c1/0xe10 fs/btrfs/file.c:1959
         vfs_fsync_range+0x141/0x230 fs/sync.c:188
         generic_write_sync include/linux/fs.h:2794 [inline]
         btrfs_do_write_iter+0x584/0x10c0 fs/btrfs/file.c:1705
         do_iter_readv_writev+0x504/0x780 fs/read_write.c:741
         vfs_writev+0x36f/0xde0 fs/read_write.c:971
         do_pwritev+0x1b2/0x260 fs/read_write.c:1072
         __do_compat_sys_pwritev2 fs/read_write.c:1218 [inline]
         __se_compat_sys_pwritev2 fs/read_write.c:1210 [inline]
         __ia32_compat_sys_pwritev2+0x121/0x1b0 fs/read_write.c:1210
         do_syscall_32_irqs_on arch/x86/entry/common.c:165 [inline]
         __do_fast_syscall_32+0x73/0x120 arch/x86/entry/common.c:386
         do_fast_syscall_32+0x32/0x80 arch/x86/entry/common.c:411
         entry_SYSENTER_compat_after_hwframe+0x84/0x8e

  other info that might help us debug this:

  Chain exists of:
    fs_reclaim --> btrfs_trans_num_extwriters --> &ei->log_mutex

   Possible unsafe locking scenario:

         CPU0                    CPU1
         ----                    ----
    lock(&ei->log_mutex);
                                 lock(btrfs_trans_num_extwriters);
                                 lock(&ei->log_mutex);
    lock(fs_reclaim);

   *** DEADLOCK ***

  7 locks held by syz-executor.1/9919:
   #0: ffff88802be20420 (sb_writers#23){.+.+}-{0:0}, at: do_pwritev+0x1b2/0x260 fs/read_write.c:1072
   svenkatr#1: ffff888065c0f8f0 (&sb->s_type->i_mutex_key#33){++++}-{3:3}, at: inode_lock include/linux/fs.h:791 [inline]
   svenkatr#1: ffff888065c0f8f0 (&sb->s_type->i_mutex_key#33){++++}-{3:3}, at: btrfs_inode_lock+0xc8/0x110 fs/btrfs/inode.c:385
   svenkatr#2: ffff888065c0f778 (&ei->i_mmap_lock){++++}-{3:3}, at: btrfs_inode_lock+0xee/0x110 fs/btrfs/inode.c:388
   svenkatr#3: ffff88802be20610 (sb_internal#4){.+.+}-{0:0}, at: btrfs_sync_file+0x95b/0xe10 fs/btrfs/file.c:1952
   svenkatr#4: ffff8880546323f0 (btrfs_trans_num_writers){++++}-{0:0}, at: join_transaction+0x430/0xf40 fs/btrfs/transaction.c:290
   svenkatr#5: ffff888054632418 (btrfs_trans_num_extwriters){++++}-{0:0}, at: join_transaction+0x430/0xf40 fs/btrfs/transaction.c:290
   svenkatr#6: ffff88804b569358 (&ei->log_mutex){+.+.}-{3:3}, at: btrfs_log_inode+0x39c/0x4660 fs/btrfs/tree-log.c:6481

  stack backtrace:
  CPU: 2 PID: 9919 Comm: syz-executor.1 Not tainted 6.10.0-rc2-syzkaller-00361-g061d1af7b030 #0
  Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014
  Call Trace:
   <TASK>
   __dump_stack lib/dump_stack.c:88 [inline]
   dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:114
   check_noncircular+0x31a/0x400 kernel/locking/lockdep.c:2187
   check_prev_add kernel/locking/lockdep.c:3134 [inline]
   check_prevs_add kernel/locking/lockdep.c:3253 [inline]
   validate_chain kernel/locking/lockdep.c:3869 [inline]
   __lock_acquire+0x2478/0x3b30 kernel/locking/lockdep.c:5137
   lock_acquire kernel/locking/lockdep.c:5754 [inline]
   lock_acquire+0x1b1/0x560 kernel/locking/lockdep.c:5719
   __fs_reclaim_acquire mm/page_alloc.c:3801 [inline]
   fs_reclaim_acquire+0x102/0x160 mm/page_alloc.c:3815
   might_alloc include/linux/sched/mm.h:334 [inline]
   slab_pre_alloc_hook mm/slub.c:3891 [inline]
   slab_alloc_node mm/slub.c:3981 [inline]
   kmem_cache_alloc_lru_noprof+0x58/0x2f0 mm/slub.c:4020
   btrfs_alloc_inode+0x118/0xb20 fs/btrfs/inode.c:8411
   alloc_inode+0x5d/0x230 fs/inode.c:261
   iget5_locked fs/inode.c:1235 [inline]
   iget5_locked+0x1c9/0x2c0 fs/inode.c:1228
   btrfs_iget_locked fs/btrfs/inode.c:5590 [inline]
   btrfs_iget_path fs/btrfs/inode.c:5607 [inline]
   btrfs_iget+0xfb/0x230 fs/btrfs/inode.c:5636
   add_conflicting_inode fs/btrfs/tree-log.c:5657 [inline]
   copy_inode_items_to_log+0x1039/0x1e30 fs/btrfs/tree-log.c:5928
   btrfs_log_inode+0xa48/0x4660 fs/btrfs/tree-log.c:6592
   log_new_delayed_dentries fs/btrfs/tree-log.c:6363 [inline]
   btrfs_log_inode+0x27dd/0x4660 fs/btrfs/tree-log.c:6718
   btrfs_log_all_parents fs/btrfs/tree-log.c:6833 [inline]
   btrfs_log_inode_parent+0x22ba/0x2a90 fs/btrfs/tree-log.c:7141
   btrfs_log_dentry_safe+0x59/0x80 fs/btrfs/tree-log.c:7180
   btrfs_sync_file+0x9c1/0xe10 fs/btrfs/file.c:1959
   vfs_fsync_range+0x141/0x230 fs/sync.c:188
   generic_write_sync include/linux/fs.h:2794 [inline]
   btrfs_do_write_iter+0x584/0x10c0 fs/btrfs/file.c:1705
   do_iter_readv_writev+0x504/0x780 fs/read_write.c:741
   vfs_writev+0x36f/0xde0 fs/read_write.c:971
   do_pwritev+0x1b2/0x260 fs/read_write.c:1072
   __do_compat_sys_pwritev2 fs/read_write.c:1218 [inline]
   __se_compat_sys_pwritev2 fs/read_write.c:1210 [inline]
   __ia32_compat_sys_pwritev2+0x121/0x1b0 fs/read_write.c:1210
   do_syscall_32_irqs_on arch/x86/entry/common.c:165 [inline]
   __do_fast_syscall_32+0x73/0x120 arch/x86/entry/common.c:386
   do_fast_syscall_32+0x32/0x80 arch/x86/entry/common.c:411
   entry_SYSENTER_compat_after_hwframe+0x84/0x8e
  RIP: 0023:0xf7334579
  Code: b8 01 10 06 03 (...)
  RSP: 002b:00000000f5f265ac EFLAGS: 00000292 ORIG_RAX: 000000000000017b
  RAX: ffffffffffffffda RBX: 0000000000000004 RCX: 00000000200002c0
  RDX: 0000000000000001 RSI: 0000000000000000 RDI: 0000000000000000
  RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
  R10: 0000000000000000 R11: 0000000000000292 R12: 0000000000000000
  R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000

Fix this by ensuring we are under a NOFS scope whenever we call
btrfs_iget() during inode logging and log replay.

Reported-by: [email protected]
Link: https://lore.kernel.org/linux-btrfs/[email protected]/
Fixes: 712e36c ("btrfs: use GFP_KERNEL in btrfs_alloc_inode")
Reviewed-by: Johannes Thumshirn <[email protected]>
Reviewed-by: Josef Bacik <[email protected]>
Reviewed-by: Qu Wenruo <[email protected]>
Signed-off-by: Filipe Manana <[email protected]>
Reviewed-by: David Sterba <[email protected]>
Signed-off-by: David Sterba <[email protected]>
ideak pushed a commit to ideak/linux that referenced this issue Jul 26, 2024
The code in ocfs2_dio_end_io_write() estimates number of necessary
transaction credits using ocfs2_calc_extend_credits().  This however does
not take into account that the IO could be arbitrarily large and can
contain arbitrary number of extents.

Extent tree manipulations do often extend the current transaction but not
in all of the cases.  For example if we have only single block extents in
the tree, ocfs2_mark_extent_written() will end up calling
ocfs2_replace_extent_rec() all the time and we will never extend the
current transaction and eventually exhaust all the transaction credits if
the IO contains many single block extents.  Once that happens a
WARN_ON(jbd2_handle_buffer_credits(handle) <= 0) is triggered in
jbd2_journal_dirty_metadata() and subsequently OCFS2 aborts in response to
this error.  This was actually triggered by one of our customers on a
heavily fragmented OCFS2 filesystem.

To fix the issue make sure the transaction always has enough credits for
one extent insert before each call of ocfs2_mark_extent_written().

Heming Zhao said:

------
PANIC: "Kernel panic - not syncing: OCFS2: (device dm-1): panic forced after error"

PID: xxx  TASK: xxxx  CPU: 5  COMMAND: "SubmitThread-CA"
  #0 machine_kexec at ffffffff8c069932
  svenkatr#1 __crash_kexec at ffffffff8c1338fa
  svenkatr#2 panic at ffffffff8c1d69b9
  svenkatr#3 ocfs2_handle_error at ffffffffc0c86c0c [ocfs2]
  svenkatr#4 __ocfs2_abort at ffffffffc0c88387 [ocfs2]
  svenkatr#5 ocfs2_journal_dirty at ffffffffc0c51e98 [ocfs2]
  svenkatr#6 ocfs2_split_extent at ffffffffc0c27ea3 [ocfs2]
  svenkatr#7 ocfs2_change_extent_flag at ffffffffc0c28053 [ocfs2]
  svenkatr#8 ocfs2_mark_extent_written at ffffffffc0c28347 [ocfs2]
  svenkatr#9 ocfs2_dio_end_io_write at ffffffffc0c2bef9 [ocfs2]
#10 ocfs2_dio_end_io at ffffffffc0c2c0f5 [ocfs2]
#11 dio_complete at ffffffff8c2b9fa7
#12 do_blockdev_direct_IO at ffffffff8c2bc09f
#13 ocfs2_direct_IO at ffffffffc0c2b653 [ocfs2]
#14 generic_file_direct_write at ffffffff8c1dcf14
#15 __generic_file_write_iter at ffffffff8c1dd07b
#16 ocfs2_file_write_iter at ffffffffc0c49f1f [ocfs2]
#17 aio_write at ffffffff8c2cc72e
#18 kmem_cache_alloc at ffffffff8c248dde
#19 do_io_submit at ffffffff8c2ccada
#20 do_syscall_64 at ffffffff8c004984
#21 entry_SYSCALL_64_after_hwframe at ffffffff8c8000ba

Link: https://lkml.kernel.org/r/[email protected]
Link: https://lkml.kernel.org/r/[email protected]
Fixes: c15471f ("ocfs2: fix sparse file & data ordering issue in direct io")
Signed-off-by: Jan Kara <[email protected]>
Reviewed-by: Joseph Qi <[email protected]>
Reviewed-by: Heming Zhao <[email protected]>
Cc: Mark Fasheh <[email protected]>
Cc: Joel Becker <[email protected]>
Cc: Junxiao Bi <[email protected]>
Cc: Changwei Ge <[email protected]>
Cc: Gang He <[email protected]>
Cc: Jun Piao <[email protected]>
Cc: <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
ideak pushed a commit to ideak/linux that referenced this issue Jul 26, 2024
Bos can be put with multiple unrelated dma-resv locks held. But
imported bos attempt to grab the bo dma-resv during dma-buf detach
that typically happens during cleanup. That leads to lockde splats
similar to the below and a potential ABBA deadlock.

Fix this by always taking the delayed workqueue cleanup path for
imported bos.

Requesting stable fixes from when the Xe driver was introduced,
since its usage of drm_exec and wide vm dma_resvs appear to be
the first reliable trigger of this.

[22982.116427] ============================================
[22982.116428] WARNING: possible recursive locking detected
[22982.116429] 6.10.0-rc2+ #10 Tainted: G     U  W
[22982.116430] --------------------------------------------
[22982.116430] glxgears:sh0/5785 is trying to acquire lock:
[22982.116431] ffff8c2bafa539a8 (reservation_ww_class_mutex){+.+.}-{3:3}, at: dma_buf_detach+0x3b/0xf0
[22982.116438]
               but task is already holding lock:
[22982.116438] ffff8c2d9aba6da8 (reservation_ww_class_mutex){+.+.}-{3:3}, at: drm_exec_lock_obj+0x49/0x2b0 [drm_exec]
[22982.116442]
               other info that might help us debug this:
[22982.116442]  Possible unsafe locking scenario:

[22982.116443]        CPU0
[22982.116444]        ----
[22982.116444]   lock(reservation_ww_class_mutex);
[22982.116445]   lock(reservation_ww_class_mutex);
[22982.116447]
                *** DEADLOCK ***

[22982.116447]  May be due to missing lock nesting notation

[22982.116448] 5 locks held by glxgears:sh0/5785:
[22982.116449]  #0: ffff8c2d9aba58c8 (&xef->vm.lock){+.+.}-{3:3}, at: xe_file_close+0xde/0x1c0 [xe]
[22982.116507]  svenkatr#1: ffff8c2e28cc8480 (&vm->lock){++++}-{3:3}, at: xe_vm_close_and_put+0x161/0x9b0 [xe]
[22982.116578]  svenkatr#2: ffff8c2e31982970 (&val->lock){.+.+}-{3:3}, at: xe_validation_ctx_init+0x6d/0x70 [xe]
[22982.116647]  svenkatr#3: ffffacdc469478a8 (reservation_ww_class_acquire){+.+.}-{0:0}, at: xe_vma_destroy_unlocked+0x7f/0xe0 [xe]
[22982.116716]  svenkatr#4: ffff8c2d9aba6da8 (reservation_ww_class_mutex){+.+.}-{3:3}, at: drm_exec_lock_obj+0x49/0x2b0 [drm_exec]
[22982.116719]
               stack backtrace:
[22982.116720] CPU: 8 PID: 5785 Comm: glxgears:sh0 Tainted: G     U  W          6.10.0-rc2+ #10
[22982.116721] Hardware name: ASUS System Product Name/PRIME B560M-A AC, BIOS 2001 02/01/2023
[22982.116723] Call Trace:
[22982.116724]  <TASK>
[22982.116725]  dump_stack_lvl+0x77/0xb0
[22982.116727]  __lock_acquire+0x1232/0x2160
[22982.116730]  lock_acquire+0xcb/0x2d0
[22982.116732]  ? dma_buf_detach+0x3b/0xf0
[22982.116734]  ? __lock_acquire+0x417/0x2160
[22982.116736]  __ww_mutex_lock.constprop.0+0xd0/0x13b0
[22982.116738]  ? dma_buf_detach+0x3b/0xf0
[22982.116741]  ? dma_buf_detach+0x3b/0xf0
[22982.116743]  ? ww_mutex_lock+0x2b/0x90
[22982.116745]  ww_mutex_lock+0x2b/0x90
[22982.116747]  dma_buf_detach+0x3b/0xf0
[22982.116749]  drm_prime_gem_destroy+0x2f/0x40 [drm]
[22982.116775]  xe_ttm_bo_destroy+0x32/0x220 [xe]
[22982.116818]  ? __mutex_unlock_slowpath+0x3a/0x290
[22982.116821]  drm_exec_unlock_all+0xa1/0xd0 [drm_exec]
[22982.116823]  drm_exec_fini+0x12/0xb0 [drm_exec]
[22982.116824]  xe_validation_ctx_fini+0x15/0x40 [xe]
[22982.116892]  xe_vma_destroy_unlocked+0xb1/0xe0 [xe]
[22982.116959]  xe_vm_close_and_put+0x41a/0x9b0 [xe]
[22982.117025]  ? xa_find+0xe3/0x1e0
[22982.117028]  xe_file_close+0x10a/0x1c0 [xe]
[22982.117074]  drm_file_free+0x22a/0x280 [drm]
[22982.117099]  drm_release_noglobal+0x22/0x70 [drm]
[22982.117119]  __fput+0xf1/0x2d0
[22982.117122]  task_work_run+0x59/0x90
[22982.117125]  do_exit+0x330/0xb40
[22982.117127]  do_group_exit+0x36/0xa0
[22982.117129]  get_signal+0xbd2/0xbe0
[22982.117131]  arch_do_signal_or_restart+0x3e/0x240
[22982.117134]  syscall_exit_to_user_mode+0x1e7/0x290
[22982.117137]  do_syscall_64+0xa1/0x180
[22982.117139]  ? lock_acquire+0xcb/0x2d0
[22982.117140]  ? __set_task_comm+0x28/0x1e0
[22982.117141]  ? find_held_lock+0x2b/0x80
[22982.117144]  ? __set_task_comm+0xe1/0x1e0
[22982.117145]  ? lock_release+0xca/0x290
[22982.117147]  ? __do_sys_prctl+0x245/0xab0
[22982.117149]  ? lockdep_hardirqs_on_prepare+0xde/0x190
[22982.117150]  ? syscall_exit_to_user_mode+0xb0/0x290
[22982.117152]  ? do_syscall_64+0xa1/0x180
[22982.117154]  ? __lock_acquire+0x417/0x2160
[22982.117155]  ? reacquire_held_locks+0xd1/0x1f0
[22982.117156]  ? do_user_addr_fault+0x30c/0x790
[22982.117158]  ? lock_acquire+0xcb/0x2d0
[22982.117160]  ? find_held_lock+0x2b/0x80
[22982.117162]  ? do_user_addr_fault+0x357/0x790
[22982.117163]  ? lock_release+0xca/0x290
[22982.117164]  ? do_user_addr_fault+0x361/0x790
[22982.117166]  ? trace_hardirqs_off+0x4b/0xc0
[22982.117168]  ? clear_bhb_loop+0x45/0xa0
[22982.117170]  ? clear_bhb_loop+0x45/0xa0
[22982.117172]  ? clear_bhb_loop+0x45/0xa0
[22982.117174]  entry_SYSCALL_64_after_hwframe+0x76/0x7e
[22982.117176] RIP: 0033:0x7f943d267169
[22982.117192] Code: Unable to access opcode bytes at 0x7f943d26713f.
[22982.117193] RSP: 002b:00007f9430bffc80 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca
[22982.117195] RAX: fffffffffffffe00 RBX: 0000000000000000 RCX: 00007f943d267169
[22982.117196] RDX: 0000000000000000 RSI: 0000000000000189 RDI: 00005622f89579d0
[22982.117197] RBP: 00007f9430bffcb0 R08: 0000000000000000 R09: 00000000ffffffff
[22982.117198] R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
[22982.117199] R13: 0000000000000000 R14: 0000000000000000 R15: 00005622f89579d0
[22982.117202]  </TASK>

Fixes: dd08ebf ("drm/xe: Introduce a new DRM driver for Intel GPUs")
Cc: Christian König <[email protected]>
Cc: Daniel Vetter <[email protected]>
Cc: [email protected]
Cc: [email protected]
Cc: <[email protected]> # v6.8+
Signed-off-by: Thomas Hellström <[email protected]>
Reviewed-by: Matthew Brost <[email protected]>
Reviewed-by: Daniel Vetter <[email protected]>
Reviewed-by: Christian König <[email protected]>
Link: https://patchwork.freedesktop.org/patch/msgid/[email protected]
ideak pushed a commit to ideak/linux that referenced this issue Aug 15, 2024
When l2tp tunnels use a socket provided by userspace, we can hit
lockdep splats like the below when data is transmitted through another
(unrelated) userspace socket which then gets routed over l2tp.

This issue was previously discussed here:
https://lore.kernel.org/netdev/[email protected]/

The solution is to have lockdep treat socket locks of l2tp tunnel
sockets separately than those of standard INET sockets. To do so, use
a different lockdep subclass where lock nesting is possible.

  ============================================
  WARNING: possible recursive locking detected
  6.10.0+ #34 Not tainted
  --------------------------------------------
  iperf3/771 is trying to acquire lock:
  ffff8881027601d8 (slock-AF_INET/1){+.-.}-{2:2}, at: l2tp_xmit_skb+0x243/0x9d0

  but task is already holding lock:
  ffff888102650d98 (slock-AF_INET/1){+.-.}-{2:2}, at: tcp_v4_rcv+0x1848/0x1e10

  other info that might help us debug this:
   Possible unsafe locking scenario:

         CPU0
         ----
    lock(slock-AF_INET/1);
    lock(slock-AF_INET/1);

   *** DEADLOCK ***

   May be due to missing lock nesting notation

  10 locks held by iperf3/771:
   #0: ffff888102650258 (sk_lock-AF_INET){+.+.}-{0:0}, at: tcp_sendmsg+0x1a/0x40
   svenkatr#1: ffffffff822ac220 (rcu_read_lock){....}-{1:2}, at: __ip_queue_xmit+0x4b/0xbc0
   svenkatr#2: ffffffff822ac220 (rcu_read_lock){....}-{1:2}, at: ip_finish_output2+0x17a/0x1130
   svenkatr#3: ffffffff822ac220 (rcu_read_lock){....}-{1:2}, at: process_backlog+0x28b/0x9f0
   svenkatr#4: ffffffff822ac220 (rcu_read_lock){....}-{1:2}, at: ip_local_deliver_finish+0xf9/0x260
   svenkatr#5: ffff888102650d98 (slock-AF_INET/1){+.-.}-{2:2}, at: tcp_v4_rcv+0x1848/0x1e10
   svenkatr#6: ffffffff822ac220 (rcu_read_lock){....}-{1:2}, at: __ip_queue_xmit+0x4b/0xbc0
   svenkatr#7: ffffffff822ac220 (rcu_read_lock){....}-{1:2}, at: ip_finish_output2+0x17a/0x1130
   svenkatr#8: ffffffff822ac1e0 (rcu_read_lock_bh){....}-{1:2}, at: __dev_queue_xmit+0xcc/0x1450
   svenkatr#9: ffff888101f33258 (dev->qdisc_tx_busylock ?: &qdisc_tx_busylock#2){+...}-{2:2}, at: __dev_queue_xmit+0x513/0x1450

  stack backtrace:
  CPU: 2 UID: 0 PID: 771 Comm: iperf3 Not tainted 6.10.0+ #34
  Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.15.0-1 04/01/2014
  Call Trace:
   <IRQ>
   dump_stack_lvl+0x69/0xa0
   dump_stack+0xc/0x20
   __lock_acquire+0x135d/0x2600
   ? srso_alias_return_thunk+0x5/0xfbef5
   lock_acquire+0xc4/0x2a0
   ? l2tp_xmit_skb+0x243/0x9d0
   ? __skb_checksum+0xa3/0x540
   _raw_spin_lock_nested+0x35/0x50
   ? l2tp_xmit_skb+0x243/0x9d0
   l2tp_xmit_skb+0x243/0x9d0
   l2tp_eth_dev_xmit+0x3c/0xc0
   dev_hard_start_xmit+0x11e/0x420
   sch_direct_xmit+0xc3/0x640
   __dev_queue_xmit+0x61c/0x1450
   ? ip_finish_output2+0xf4c/0x1130
   ip_finish_output2+0x6b6/0x1130
   ? srso_alias_return_thunk+0x5/0xfbef5
   ? __ip_finish_output+0x217/0x380
   ? srso_alias_return_thunk+0x5/0xfbef5
   __ip_finish_output+0x217/0x380
   ip_output+0x99/0x120
   __ip_queue_xmit+0xae4/0xbc0
   ? srso_alias_return_thunk+0x5/0xfbef5
   ? srso_alias_return_thunk+0x5/0xfbef5
   ? tcp_options_write.constprop.0+0xcb/0x3e0
   ip_queue_xmit+0x34/0x40
   __tcp_transmit_skb+0x1625/0x1890
   __tcp_send_ack+0x1b8/0x340
   tcp_send_ack+0x23/0x30
   __tcp_ack_snd_check+0xa8/0x530
   ? srso_alias_return_thunk+0x5/0xfbef5
   tcp_rcv_established+0x412/0xd70
   tcp_v4_do_rcv+0x299/0x420
   tcp_v4_rcv+0x1991/0x1e10
   ip_protocol_deliver_rcu+0x50/0x220
   ip_local_deliver_finish+0x158/0x260
   ip_local_deliver+0xc8/0xe0
   ip_rcv+0xe5/0x1d0
   ? __pfx_ip_rcv+0x10/0x10
   __netif_receive_skb_one_core+0xce/0xe0
   ? process_backlog+0x28b/0x9f0
   __netif_receive_skb+0x34/0xd0
   ? process_backlog+0x28b/0x9f0
   process_backlog+0x2cb/0x9f0
   __napi_poll.constprop.0+0x61/0x280
   net_rx_action+0x332/0x670
   ? srso_alias_return_thunk+0x5/0xfbef5
   ? find_held_lock+0x2b/0x80
   ? srso_alias_return_thunk+0x5/0xfbef5
   ? srso_alias_return_thunk+0x5/0xfbef5
   handle_softirqs+0xda/0x480
   ? __dev_queue_xmit+0xa2c/0x1450
   do_softirq+0xa1/0xd0
   </IRQ>
   <TASK>
   __local_bh_enable_ip+0xc8/0xe0
   ? __dev_queue_xmit+0xa2c/0x1450
   __dev_queue_xmit+0xa48/0x1450
   ? ip_finish_output2+0xf4c/0x1130
   ip_finish_output2+0x6b6/0x1130
   ? srso_alias_return_thunk+0x5/0xfbef5
   ? __ip_finish_output+0x217/0x380
   ? srso_alias_return_thunk+0x5/0xfbef5
   __ip_finish_output+0x217/0x380
   ip_output+0x99/0x120
   __ip_queue_xmit+0xae4/0xbc0
   ? srso_alias_return_thunk+0x5/0xfbef5
   ? srso_alias_return_thunk+0x5/0xfbef5
   ? tcp_options_write.constprop.0+0xcb/0x3e0
   ip_queue_xmit+0x34/0x40
   __tcp_transmit_skb+0x1625/0x1890
   tcp_write_xmit+0x766/0x2fb0
   ? __entry_text_end+0x102ba9/0x102bad
   ? srso_alias_return_thunk+0x5/0xfbef5
   ? __might_fault+0x74/0xc0
   ? srso_alias_return_thunk+0x5/0xfbef5
   __tcp_push_pending_frames+0x56/0x190
   tcp_push+0x117/0x310
   tcp_sendmsg_locked+0x14c1/0x1740
   tcp_sendmsg+0x28/0x40
   inet_sendmsg+0x5d/0x90
   sock_write_iter+0x242/0x2b0
   vfs_write+0x68d/0x800
   ? __pfx_sock_write_iter+0x10/0x10
   ksys_write+0xc8/0xf0
   __x64_sys_write+0x3d/0x50
   x64_sys_call+0xfaf/0x1f50
   do_syscall_64+0x6d/0x140
   entry_SYSCALL_64_after_hwframe+0x76/0x7e
  RIP: 0033:0x7f4d143af992
  Code: c3 8b 07 85 c0 75 24 49 89 fb 48 89 f0 48 89 d7 48 89 ce 4c 89 c2 4d 89 ca 4c 8b 44 24 08 4c 8b 4c 24 10 4c 89 5c 24 08 0f 05 <c3> e9 01 cc ff ff 41 54 b8 02 00 00 0
  RSP: 002b:00007ffd65032058 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
  RAX: ffffffffffffffda RBX: 0000000000000001 RCX: 00007f4d143af992
  RDX: 0000000000000025 RSI: 00007f4d143f3bcc RDI: 0000000000000005
  RBP: 00007f4d143f2b28 R08: 0000000000000000 R09: 0000000000000000
  R10: 0000000000000000 R11: 0000000000000246 R12: 00007f4d143f3bcc
  R13: 0000000000000005 R14: 0000000000000000 R15: 00007ffd650323f0
   </TASK>

Fixes: 0b2c597 ("l2tp: close all race conditions in l2tp_tunnel_register()")
Suggested-by: Eric Dumazet <[email protected]>
Reported-by: [email protected]
Closes: https://syzkaller.appspot.com/bug?extid=6acef9e0a4d1f46c83d4
CC: [email protected]
CC: [email protected]
Signed-off-by: James Chapman <[email protected]>
Signed-off-by: Tom Parkin <[email protected]>
Link: https://patch.msgid.link/[email protected]
Signed-off-by: Jakub Kicinski <[email protected]>
ideak pushed a commit to ideak/linux that referenced this issue Aug 27, 2024
Lockdep reported a warning in Linux version 6.6:

[  414.344659] ================================
[  414.345155] WARNING: inconsistent lock state
[  414.345658] 6.6.0-07439-gba2303cacfda svenkatr#6 Not tainted
[  414.346221] --------------------------------
[  414.346712] inconsistent {IN-SOFTIRQ-W} -> {SOFTIRQ-ON-W} usage.
[  414.347545] kworker/u10:3/1152 [HC0[0]:SC0[0]:HE0:SE1] takes:
[  414.349245] ffff88810edd1098 (&sbq->ws[i].wait){+.?.}-{2:2}, at: blk_mq_dispatch_rq_list+0x131c/0x1ee0
[  414.351204] {IN-SOFTIRQ-W} state was registered at:
[  414.351751]   lock_acquire+0x18d/0x460
[  414.352218]   _raw_spin_lock_irqsave+0x39/0x60
[  414.352769]   __wake_up_common_lock+0x22/0x60
[  414.353289]   sbitmap_queue_wake_up+0x375/0x4f0
[  414.353829]   sbitmap_queue_clear+0xdd/0x270
[  414.354338]   blk_mq_put_tag+0xdf/0x170
[  414.354807]   __blk_mq_free_request+0x381/0x4d0
[  414.355335]   blk_mq_free_request+0x28b/0x3e0
[  414.355847]   __blk_mq_end_request+0x242/0xc30
[  414.356367]   scsi_end_request+0x2c1/0x830
[  414.345155] WARNING: inconsistent lock state
[  414.345658] 6.6.0-07439-gba2303cacfda svenkatr#6 Not tainted
[  414.346221] --------------------------------
[  414.346712] inconsistent {IN-SOFTIRQ-W} -> {SOFTIRQ-ON-W} usage.
[  414.347545] kworker/u10:3/1152 [HC0[0]:SC0[0]:HE0:SE1] takes:
[  414.349245] ffff88810edd1098 (&sbq->ws[i].wait){+.?.}-{2:2}, at: blk_mq_dispatch_rq_list+0x131c/0x1ee0
[  414.351204] {IN-SOFTIRQ-W} state was registered at:
[  414.351751]   lock_acquire+0x18d/0x460
[  414.352218]   _raw_spin_lock_irqsave+0x39/0x60
[  414.352769]   __wake_up_common_lock+0x22/0x60
[  414.353289]   sbitmap_queue_wake_up+0x375/0x4f0
[  414.353829]   sbitmap_queue_clear+0xdd/0x270
[  414.354338]   blk_mq_put_tag+0xdf/0x170
[  414.354807]   __blk_mq_free_request+0x381/0x4d0
[  414.355335]   blk_mq_free_request+0x28b/0x3e0
[  414.355847]   __blk_mq_end_request+0x242/0xc30
[  414.356367]   scsi_end_request+0x2c1/0x830
[  414.356863]   scsi_io_completion+0x177/0x1610
[  414.357379]   scsi_complete+0x12f/0x260
[  414.357856]   blk_complete_reqs+0xba/0xf0
[  414.358338]   __do_softirq+0x1b0/0x7a2
[  414.358796]   irq_exit_rcu+0x14b/0x1a0
[  414.359262]   sysvec_call_function_single+0xaf/0xc0
[  414.359828]   asm_sysvec_call_function_single+0x1a/0x20
[  414.360426]   default_idle+0x1e/0x30
[  414.360873]   default_idle_call+0x9b/0x1f0
[  414.361390]   do_idle+0x2d2/0x3e0
[  414.361819]   cpu_startup_entry+0x55/0x60
[  414.362314]   start_secondary+0x235/0x2b0
[  414.362809]   secondary_startup_64_no_verify+0x18f/0x19b
[  414.363413] irq event stamp: 428794
[  414.363825] hardirqs last  enabled at (428793): [<ffffffff816bfd1c>] ktime_get+0x1dc/0x200
[  414.364694] hardirqs last disabled at (428794): [<ffffffff85470177>] _raw_spin_lock_irq+0x47/0x50
[  414.365629] softirqs last  enabled at (428444): [<ffffffff85474780>] __do_softirq+0x540/0x7a2
[  414.366522] softirqs last disabled at (428419): [<ffffffff813f65ab>] irq_exit_rcu+0x14b/0x1a0
[  414.367425]
               other info that might help us debug this:
[  414.368194]  Possible unsafe locking scenario:
[  414.368900]        CPU0
[  414.369225]        ----
[  414.369548]   lock(&sbq->ws[i].wait);
[  414.370000]   <Interrupt>
[  414.370342]     lock(&sbq->ws[i].wait);
[  414.370802]
                *** DEADLOCK ***
[  414.371569] 5 locks held by kworker/u10:3/1152:
[  414.372088]  #0: ffff88810130e938 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0x357/0x13f0
[  414.373180]  svenkatr#1: ffff88810201fdb8 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x3a3/0x13f0
[  414.374384]  svenkatr#2: ffffffff86ffbdc0 (rcu_read_lock){....}-{1:2}, at: blk_mq_run_hw_queue+0x637/0xa00
[  414.375342]  svenkatr#3: ffff88810edd1098 (&sbq->ws[i].wait){+.?.}-{2:2}, at: blk_mq_dispatch_rq_list+0x131c/0x1ee0
[  414.376377]  svenkatr#4: ffff888106205a08 (&hctx->dispatch_wait_lock){+.-.}-{2:2}, at: blk_mq_dispatch_rq_list+0x1337/0x1ee0
[  414.378607]
               stack backtrace:
[  414.379177] CPU: 0 PID: 1152 Comm: kworker/u10:3 Not tainted 6.6.0-07439-gba2303cacfda svenkatr#6
[  414.380032] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.14.0-0-g155821a1990b-prebuilt.qemu.org 04/01/2014
[  414.381177] Workqueue: writeback wb_workfn (flush-253:0)
[  414.381805] Call Trace:
[  414.382136]  <TASK>
[  414.382429]  dump_stack_lvl+0x91/0xf0
[  414.382884]  mark_lock_irq+0xb3b/0x1260
[  414.383367]  ? __pfx_mark_lock_irq+0x10/0x10
[  414.383889]  ? stack_trace_save+0x8e/0xc0
[  414.384373]  ? __pfx_stack_trace_save+0x10/0x10
[  414.384903]  ? graph_lock+0xcf/0x410
[  414.385350]  ? save_trace+0x3d/0xc70
[  414.385808]  mark_lock.part.20+0x56d/0xa90
[  414.386317]  mark_held_locks+0xb0/0x110
[  414.386791]  ? __pfx_do_raw_spin_lock+0x10/0x10
[  414.387320]  lockdep_hardirqs_on_prepare+0x297/0x3f0
[  414.387901]  ? _raw_spin_unlock_irq+0x28/0x50
[  414.388422]  trace_hardirqs_on+0x58/0x100
[  414.388917]  _raw_spin_unlock_irq+0x28/0x50
[  414.389422]  __blk_mq_tag_busy+0x1d6/0x2a0
[  414.389920]  __blk_mq_get_driver_tag+0x761/0x9f0
[  414.390899]  blk_mq_dispatch_rq_list+0x1780/0x1ee0
[  414.391473]  ? __pfx_blk_mq_dispatch_rq_list+0x10/0x10
[  414.392070]  ? sbitmap_get+0x2b8/0x450
[  414.392533]  ? __blk_mq_get_driver_tag+0x210/0x9f0
[  414.393095]  __blk_mq_sched_dispatch_requests+0xd99/0x1690
[  414.393730]  ? elv_attempt_insert_merge+0x1b1/0x420
[  414.394302]  ? __pfx___blk_mq_sched_dispatch_requests+0x10/0x10
[  414.394970]  ? lock_acquire+0x18d/0x460
[  414.395456]  ? blk_mq_run_hw_queue+0x637/0xa00
[  414.395986]  ? __pfx_lock_acquire+0x10/0x10
[  414.396499]  blk_mq_sched_dispatch_requests+0x109/0x190
[  414.397100]  blk_mq_run_hw_queue+0x66e/0xa00
[  414.397616]  blk_mq_flush_plug_list.part.17+0x614/0x2030
[  414.398244]  ? __pfx_blk_mq_flush_plug_list.part.17+0x10/0x10
[  414.398897]  ? writeback_sb_inodes+0x241/0xcc0
[  414.399429]  blk_mq_flush_plug_list+0x65/0x80
[  414.399957]  __blk_flush_plug+0x2f1/0x530
[  414.400458]  ? __pfx___blk_flush_plug+0x10/0x10
[  414.400999]  blk_finish_plug+0x59/0xa0
[  414.401467]  wb_writeback+0x7cc/0x920
[  414.401935]  ? __pfx_wb_writeback+0x10/0x10
[  414.402442]  ? mark_held_locks+0xb0/0x110
[  414.402931]  ? __pfx_do_raw_spin_lock+0x10/0x10
[  414.403462]  ? lockdep_hardirqs_on_prepare+0x297/0x3f0
[  414.404062]  wb_workfn+0x2b3/0xcf0
[  414.404500]  ? __pfx_wb_workfn+0x10/0x10
[  414.404989]  process_scheduled_works+0x432/0x13f0
[  414.405546]  ? __pfx_process_scheduled_works+0x10/0x10
[  414.406139]  ? do_raw_spin_lock+0x101/0x2a0
[  414.406641]  ? assign_work+0x19b/0x240
[  414.407106]  ? lock_is_held_type+0x9d/0x110
[  414.407604]  worker_thread+0x6f2/0x1160
[  414.408075]  ? __kthread_parkme+0x62/0x210
[  414.408572]  ? lockdep_hardirqs_on_prepare+0x297/0x3f0
[  414.409168]  ? __kthread_parkme+0x13c/0x210
[  414.409678]  ? __pfx_worker_thread+0x10/0x10
[  414.410191]  kthread+0x33c/0x440
[  414.410602]  ? __pfx_kthread+0x10/0x10
[  414.411068]  ret_from_fork+0x4d/0x80
[  414.411526]  ? __pfx_kthread+0x10/0x10
[  414.411993]  ret_from_fork_asm+0x1b/0x30
[  414.412489]  </TASK>

When interrupt is turned on while a lock holding by spin_lock_irq it
throws a warning because of potential deadlock.

blk_mq_prep_dispatch_rq
 blk_mq_get_driver_tag
  __blk_mq_get_driver_tag
   __blk_mq_alloc_driver_tag
    blk_mq_tag_busy -> tag is already busy
    // failed to get driver tag
 blk_mq_mark_tag_wait
  spin_lock_irq(&wq->lock) -> lock A (&sbq->ws[i].wait)
  __add_wait_queue(wq, wait) -> wait queue active
  blk_mq_get_driver_tag
  __blk_mq_tag_busy
-> 1) tag must be idle, which means there can't be inflight IO
   spin_lock_irq(&tags->lock) -> lock B (hctx->tags)
   spin_unlock_irq(&tags->lock) -> unlock B, turn on interrupt accidentally
-> 2) context must be preempt by IO interrupt to trigger deadlock.

As shown above, the deadlock is not possible in theory, but the warning
still need to be fixed.

Fix it by using spin_lock_irqsave to get lockB instead of spin_lock_irq.

Fixes: 4f1731d ("blk-mq: fix potential io hang by wrong 'wake_batch'")
Signed-off-by: Li Lingfeng <[email protected]>
Reviewed-by: Ming Lei <[email protected]>
Reviewed-by: Yu Kuai <[email protected]>
Reviewed-by: Bart Van Assche <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Jens Axboe <[email protected]>
ideak pushed a commit to ideak/linux that referenced this issue Aug 27, 2024
We inadvertently create a dependency on mmap_sem with a whole chain.

This breaks any user who wants to take a lock and call rcu_barrier(),
while also taking that lock inside mmap_sem:

<4> [604.892532] ======================================================
<4> [604.892534] WARNING: possible circular locking dependency detected
<4> [604.892536] 5.6.0-rc7-CI-Patchwork_17096+ svenkatr#1 Tainted: G     U
<4> [604.892537] ------------------------------------------------------
<4> [604.892538] kms_frontbuffer/2595 is trying to acquire lock:
<4> [604.892540] ffffffff8264a558 (rcu_state.barrier_mutex){+.+.}, at: rcu_barrier+0x23/0x190
<4> [604.892547]
but task is already holding lock:
<4> [604.892547] ffff888484716050 (reservation_ww_class_mutex){+.+.}, at: i915_gem_object_pin_to_display_plane+0x89/0x270 [i915]
<4> [604.892592]
which lock already depends on the new lock.
<4> [604.892593]
the existing dependency chain (in reverse order) is:
<4> [604.892594]
-> svenkatr#6 (reservation_ww_class_mutex){+.+.}:
<4> [604.892597]        __ww_mutex_lock.constprop.15+0xc3/0x1090
<4> [604.892598]        ww_mutex_lock+0x39/0x70
<4> [604.892600]        dma_resv_lockdep+0x10e/0x1f5
<4> [604.892602]        do_one_initcall+0x58/0x300
<4> [604.892604]        kernel_init_freeable+0x17b/0x1dc
<4> [604.892605]        kernel_init+0x5/0x100
<4> [604.892606]        ret_from_fork+0x24/0x50
<4> [604.892607]
-> svenkatr#5 (reservation_ww_class_acquire){+.+.}:
<4> [604.892609]        dma_resv_lockdep+0xec/0x1f5
<4> [604.892610]        do_one_initcall+0x58/0x300
<4> [604.892610]        kernel_init_freeable+0x17b/0x1dc
<4> [604.892611]        kernel_init+0x5/0x100
<4> [604.892612]        ret_from_fork+0x24/0x50
<4> [604.892613]
-> svenkatr#4 (&mm->mmap_sem#2){++++}:
<4> [604.892615]        __might_fault+0x63/0x90
<4> [604.892617]        _copy_to_user+0x1e/0x80
<4> [604.892619]        perf_read+0x200/0x2b0
<4> [604.892621]        vfs_read+0x96/0x160
<4> [604.892622]        ksys_read+0x9f/0xe0
<4> [604.892623]        do_syscall_64+0x4f/0x220
<4> [604.892624]        entry_SYSCALL_64_after_hwframe+0x49/0xbe
<4> [604.892625]
-> svenkatr#3 (&cpuctx_mutex){+.+.}:
<4> [604.892626]        __mutex_lock+0x9a/0x9c0
<4> [604.892627]        perf_event_init_cpu+0xa4/0x140
<4> [604.892629]        perf_event_init+0x19d/0x1cd
<4> [604.892630]        start_kernel+0x362/0x4e4
<4> [604.892631]        secondary_startup_64+0xa4/0xb0
<4> [604.892631]
-> svenkatr#2 (pmus_lock){+.+.}:
<4> [604.892633]        __mutex_lock+0x9a/0x9c0
<4> [604.892633]        perf_event_init_cpu+0x6b/0x140
<4> [604.892635]        cpuhp_invoke_callback+0x9b/0x9d0
<4> [604.892636]        _cpu_up+0xa2/0x140
<4> [604.892637]        do_cpu_up+0x61/0xa0
<4> [604.892639]        smp_init+0x57/0x96
<4> [604.892639]        kernel_init_freeable+0x87/0x1dc
<4> [604.892640]        kernel_init+0x5/0x100
<4> [604.892642]        ret_from_fork+0x24/0x50
<4> [604.892642]
-> svenkatr#1 (cpu_hotplug_lock.rw_sem){++++}:
<4> [604.892643]        cpus_read_lock+0x34/0xd0
<4> [604.892644]        rcu_barrier+0xaa/0x190
<4> [604.892645]        kernel_init+0x21/0x100
<4> [604.892647]        ret_from_fork+0x24/0x50
<4> [604.892647]
-> #0 (rcu_state.barrier_mutex){+.+.}:
<4> [604.892649]        __lock_acquire+0x1328/0x15d0
<4> [604.892650]        lock_acquire+0xa7/0x1c0
<4> [604.892651]        __mutex_lock+0x9a/0x9c0
<4> [604.892652]        rcu_barrier+0x23/0x190
<4> [604.892680]        i915_gem_object_unbind+0x29d/0x3f0 [i915]
<4> [604.892707]        i915_gem_object_pin_to_display_plane+0x141/0x270 [i915]
<4> [604.892737]        intel_pin_and_fence_fb_obj+0xec/0x1f0 [i915]
<4> [604.892767]        intel_plane_pin_fb+0x3f/0xd0 [i915]
<4> [604.892797]        intel_prepare_plane_fb+0x13b/0x5c0 [i915]
<4> [604.892798]        drm_atomic_helper_prepare_planes+0x85/0x110
<4> [604.892827]        intel_atomic_commit+0xda/0x390 [i915]
<4> [604.892828]        drm_atomic_helper_set_config+0x57/0xa0
<4> [604.892830]        drm_mode_setcrtc+0x1c4/0x720
<4> [604.892830]        drm_ioctl_kernel+0xb0/0xf0
<4> [604.892831]        drm_ioctl+0x2e1/0x390
<4> [604.892833]        ksys_ioctl+0x7b/0x90
<4> [604.892835]        __x64_sys_ioctl+0x11/0x20
<4> [604.892835]        do_syscall_64+0x4f/0x220
<4> [604.892836]        entry_SYSCALL_64_after_hwframe+0x49/0xbe
<4> [604.892837]

Changes since v1:
- Use (*values)[n++] in perf_read_one().
Changes since v2:
- Centrally allocate values.

References: https://gitlab.freedesktop.org/drm/intel/-/issues/8042
Signed-off-by: Maarten Lankhorst <[email protected]>
Link: https://patchwork.freedesktop.org/patch/msgid/[email protected]
Signed-off-by: Rodrigo Vivi <[email protected]>
ideak pushed a commit to ideak/linux that referenced this issue Aug 27, 2024
…git/netfilter/nf

Pablo Neira Ayuso says:

====================
Netfilter fixes for net

The following patchset contains Netfilter fixes for net:

Patch svenkatr#1 disable BH when collecting stats via hardware offload to ensure
         concurrent updates from packet path do not result in losing stats.
         From Sebastian Andrzej Siewior.

Patch svenkatr#2 uses write seqcount to reset counters serialize against reader.
         Also from Sebastian Andrzej Siewior.

Patch svenkatr#3 ensures vlan header is in place before accessing its fields,
         according to KMSAN splat triggered by syzbot.

* tag 'nf-24-08-22' of git://git.kernel.org/pub/scm/linux/kernel/git/netfilter/nf:
  netfilter: flowtable: validate vlan header
  netfilter: nft_counter: Synchronize nft_counter_reset() against reader.
  netfilter: nft_counter: Disable BH in nft_counter_offload_stats().
====================

Link: https://patch.msgid.link/[email protected]
Signed-off-by: Jakub Kicinski <[email protected]>
mhiramat pushed a commit to mhiramat/linux that referenced this issue Oct 28, 2024
On the node of an NFS client, some files saved in the mountpoint of the
NFS server were copied to another location of the same NFS server.
Accidentally, the nfs42_complete_copies() got a NULL-pointer dereference
crash with the following syslog:

[232064.838881] NFSv4: state recovery failed for open file nfs/pvc-12b5200d-cd0f-46a3-b9f0-af8f4fe0ef64.qcow2, error = -116
[232064.839360] NFSv4: state recovery failed for open file nfs/pvc-12b5200d-cd0f-46a3-b9f0-af8f4fe0ef64.qcow2, error = -116
[232066.588183] Unable to handle kernel NULL pointer dereference at virtual address 0000000000000058
[232066.588586] Mem abort info:
[232066.588701]   ESR = 0x0000000096000007
[232066.588862]   EC = 0x25: DABT (current EL), IL = 32 bits
[232066.589084]   SET = 0, FnV = 0
[232066.589216]   EA = 0, S1PTW = 0
[232066.589340]   FSC = 0x07: level 3 translation fault
[232066.589559] Data abort info:
[232066.589683]   ISV = 0, ISS = 0x00000007
[232066.589842]   CM = 0, WnR = 0
[232066.589967] user pgtable: 64k pages, 48-bit VAs, pgdp=00002000956ff400
[232066.590231] [0000000000000058] pgd=08001100ae100003, p4d=08001100ae100003, pud=08001100ae100003, pmd=08001100b3c00003, pte=0000000000000000
[232066.590757] Internal error: Oops: 96000007 [svenkatr#1] SMP
[232066.590958] Modules linked in: rpcsec_gss_krb5 auth_rpcgss nfsv4 dns_resolver nfs lockd grace fscache netfs ocfs2_dlmfs ocfs2_stack_o2cb ocfs2_dlm vhost_net vhost vhost_iotlb tap tun ipt_rpfilter xt_multiport ip_set_hash_ip ip_set_hash_net xfrm_interface xfrm6_tunnel tunnel4 tunnel6 esp4 ah4 wireguard libcurve25519_generic veth xt_addrtype xt_set nf_conntrack_netlink ip_set_hash_ipportnet ip_set_hash_ipportip ip_set_bitmap_port ip_set_hash_ipport dummy ip_set ip_vs_sh ip_vs_wrr ip_vs_rr ip_vs iptable_filter sch_ingress nfnetlink_cttimeout vport_gre ip_gre ip_tunnel gre vport_geneve geneve vport_vxlan vxlan ip6_udp_tunnel udp_tunnel openvswitch nf_conncount dm_round_robin dm_service_time dm_multipath xt_nat xt_MASQUERADE nft_chain_nat nf_nat xt_mark xt_conntrack xt_comment nft_compat nft_counter nf_tables nfnetlink ocfs2 ocfs2_nodemanager ocfs2_stackglue iscsi_tcp libiscsi_tcp libiscsi scsi_transport_iscsi ipmi_ssif nbd overlay 8021q garp mrp bonding tls rfkill sunrpc ext4 mbcache jbd2
[232066.591052]  vfat fat cas_cache cas_disk ses enclosure scsi_transport_sas sg acpi_ipmi ipmi_si ipmi_devintf ipmi_msghandler ip_tables vfio_pci vfio_pci_core vfio_virqfd vfio_iommu_type1 vfio dm_mirror dm_region_hash dm_log dm_mod nf_conntrack nf_defrag_ipv6 nf_defrag_ipv4 br_netfilter bridge stp llc fuse xfs libcrc32c ast drm_vram_helper qla2xxx drm_kms_helper syscopyarea crct10dif_ce sysfillrect ghash_ce sysimgblt sha2_ce fb_sys_fops cec sha256_arm64 sha1_ce drm_ttm_helper ttm nvme_fc igb sbsa_gwdt nvme_fabrics drm nvme_core i2c_algo_bit i40e scsi_transport_fc megaraid_sas aes_neon_bs
[232066.596953] CPU: 6 PID: 4124696 Comm: 10.253.166.125- Kdump: loaded Not tainted 5.15.131-9.cl9_ocfs2.aarch64 svenkatr#1
[232066.597356] Hardware name: Great Wall .\x93\x8e...RF6260 V5/GWMSSE2GL1T, BIOS T656FBE_V3.0.18 2024-01-06
[232066.597721] pstate: 20400009 (nzCv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--)
[232066.598034] pc : nfs4_reclaim_open_state+0x220/0x800 [nfsv4]
[232066.598327] lr : nfs4_reclaim_open_state+0x12c/0x800 [nfsv4]
[232066.598595] sp : ffff8000f568fc70
[232066.598731] x29: ffff8000f568fc70 x28: 0000000000001000 x27: ffff21003db33000
[232066.599030] x26: ffff800005521ae0 x25: ffff0100f98fa3f0 x24: 0000000000000001
[232066.599319] x23: ffff800009920008 x22: ffff21003db33040 x21: ffff21003db33050
[232066.599628] x20: ffff410172fe9e40 x19: ffff410172fe9e00 x18: 0000000000000000
[232066.599914] x17: 0000000000000000 x16: 0000000000000004 x15: 0000000000000000
[232066.600195] x14: 0000000000000000 x13: ffff800008e685a8 x12: 00000000eac0c6e6
[232066.600498] x11: 0000000000000000 x10: 0000000000000008 x9 : ffff8000054e5828
[232066.600784] x8 : 00000000ffffffbf x7 : 0000000000000001 x6 : 000000000a9eb14a
[232066.601062] x5 : 0000000000000000 x4 : ffff70ff8a14a800 x3 : 0000000000000058
[232066.601348] x2 : 0000000000000001 x1 : 54dce46366daa6c6 x0 : 0000000000000000
[232066.601636] Call trace:
[232066.601749]  nfs4_reclaim_open_state+0x220/0x800 [nfsv4]
[232066.601998]  nfs4_do_reclaim+0x1b8/0x28c [nfsv4]
[232066.602218]  nfs4_state_manager+0x928/0x10f0 [nfsv4]
[232066.602455]  nfs4_run_state_manager+0x78/0x1b0 [nfsv4]
[232066.602690]  kthread+0x110/0x114
[232066.602830]  ret_from_fork+0x10/0x20
[232066.602985] Code: 1400000d f9403f20 f9402e61 91016003 (f9402c00)
[232066.603284] SMP: stopping secondary CPUs
[232066.606936] Starting crashdump kernel...
[232066.607146] Bye!

Analysing the vmcore, we know that nfs4_copy_state listed by destination
nfs_server->ss_copies was added by the field copies in handle_async_copy(),
and we found a waiting copy process with the stack as:
PID: 3511963  TASK: ffff710028b47e00  CPU: 0   COMMAND: "cp"
 #0 [ffff8001116ef740] __switch_to at ffff8000081b92f4
 svenkatr#1 [ffff8001116ef760] __schedule at ffff800008dd0650
 svenkatr#2 [ffff8001116ef7c0] schedule at ffff800008dd0a00
 svenkatr#3 [ffff8001116ef7e0] schedule_timeout at ffff800008dd6aa0
 svenkatr#4 [ffff8001116ef860] __wait_for_common at ffff800008dd166c
 svenkatr#5 [ffff8001116ef8e0] wait_for_completion_interruptible at ffff800008dd1898
 svenkatr#6 [ffff8001116ef8f0] handle_async_copy at ffff8000055142f4 [nfsv4]
 svenkatr#7 [ffff8001116ef970] _nfs42_proc_copy at ffff8000055147c8 [nfsv4]
 svenkatr#8 [ffff8001116efa80] nfs42_proc_copy at ffff800005514cf0 [nfsv4]
 svenkatr#9 [ffff8001116efc50] __nfs4_copy_file_range.constprop.0 at ffff8000054ed694 [nfsv4]

The NULL-pointer dereference was due to nfs42_complete_copies() listed
the nfs_server->ss_copies by the field ss_copies of nfs4_copy_state.
So the nfs4_copy_state address ffff0100f98fa3f0 was offset by 0x10 and
the data accessed through this pointer was also incorrect. Generally,
the ordered list nfs4_state_owner->so_states indicate open(O_RDWR) or
open(O_WRITE) states are reclaimed firstly by nfs4_reclaim_open_state().
When destination state reclaim is failed with NFS_STATE_RECOVERY_FAILED
and copies are not deleted in nfs_server->ss_copies, the source state
may be passed to the nfs42_complete_copies() process earlier, resulting
in this crash scene finally. To solve this issue, we add a list_head
nfs_server->ss_src_copies for a server-to-server copy specially.

Fixes: 0e65a32 ("NFS: handle source server reboot")
Signed-off-by: Yanjun Zhang <[email protected]>
Reviewed-by: Trond Myklebust <[email protected]>
Signed-off-by: Anna Schumaker <[email protected]>
mhiramat pushed a commit to mhiramat/linux that referenced this issue Oct 28, 2024
Syzkaller reported a lockdep splat:

  ============================================
  WARNING: possible recursive locking detected
  6.11.0-rc6-syzkaller-00019-g67784a74e258 #0 Not tainted
  --------------------------------------------
  syz-executor364/5113 is trying to acquire lock:
  ffff8880449f1958 (k-slock-AF_INET){+.-.}-{2:2}, at: spin_lock include/linux/spinlock.h:351 [inline]
  ffff8880449f1958 (k-slock-AF_INET){+.-.}-{2:2}, at: sk_clone_lock+0x2cd/0xf40 net/core/sock.c:2328

  but task is already holding lock:
  ffff88803fe3cb58 (k-slock-AF_INET){+.-.}-{2:2}, at: spin_lock include/linux/spinlock.h:351 [inline]
  ffff88803fe3cb58 (k-slock-AF_INET){+.-.}-{2:2}, at: sk_clone_lock+0x2cd/0xf40 net/core/sock.c:2328

  other info that might help us debug this:
   Possible unsafe locking scenario:

         CPU0
         ----
    lock(k-slock-AF_INET);
    lock(k-slock-AF_INET);

   *** DEADLOCK ***

   May be due to missing lock nesting notation

  7 locks held by syz-executor364/5113:
   #0: ffff8880449f0e18 (sk_lock-AF_INET){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1607 [inline]
   #0: ffff8880449f0e18 (sk_lock-AF_INET){+.+.}-{0:0}, at: mptcp_sendmsg+0x153/0x1b10 net/mptcp/protocol.c:1806
   svenkatr#1: ffff88803fe39ad8 (k-sk_lock-AF_INET){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1607 [inline]
   svenkatr#1: ffff88803fe39ad8 (k-sk_lock-AF_INET){+.+.}-{0:0}, at: mptcp_sendmsg_fastopen+0x11f/0x530 net/mptcp/protocol.c:1727
   svenkatr#2: ffffffff8e938320 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:326 [inline]
   svenkatr#2: ffffffff8e938320 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline]
   svenkatr#2: ffffffff8e938320 (rcu_read_lock){....}-{1:2}, at: __ip_queue_xmit+0x5f/0x1b80 net/ipv4/ip_output.c:470
   svenkatr#3: ffffffff8e938320 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:326 [inline]
   svenkatr#3: ffffffff8e938320 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline]
   svenkatr#3: ffffffff8e938320 (rcu_read_lock){....}-{1:2}, at: ip_finish_output2+0x45f/0x1390 net/ipv4/ip_output.c:228
   svenkatr#4: ffffffff8e938320 (rcu_read_lock){....}-{1:2}, at: local_lock_acquire include/linux/local_lock_internal.h:29 [inline]
   svenkatr#4: ffffffff8e938320 (rcu_read_lock){....}-{1:2}, at: process_backlog+0x33b/0x15b0 net/core/dev.c:6104
   svenkatr#5: ffffffff8e938320 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:326 [inline]
   svenkatr#5: ffffffff8e938320 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline]
   svenkatr#5: ffffffff8e938320 (rcu_read_lock){....}-{1:2}, at: ip_local_deliver_finish+0x230/0x5f0 net/ipv4/ip_input.c:232
   svenkatr#6: ffff88803fe3cb58 (k-slock-AF_INET){+.-.}-{2:2}, at: spin_lock include/linux/spinlock.h:351 [inline]
   svenkatr#6: ffff88803fe3cb58 (k-slock-AF_INET){+.-.}-{2:2}, at: sk_clone_lock+0x2cd/0xf40 net/core/sock.c:2328

  stack backtrace:
  CPU: 0 UID: 0 PID: 5113 Comm: syz-executor364 Not tainted 6.11.0-rc6-syzkaller-00019-g67784a74e258 #0
  Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014
  Call Trace:
   <IRQ>
   __dump_stack lib/dump_stack.c:93 [inline]
   dump_stack_lvl+0x241/0x360 lib/dump_stack.c:119
   check_deadlock kernel/locking/lockdep.c:3061 [inline]
   validate_chain+0x15d3/0x5900 kernel/locking/lockdep.c:3855
   __lock_acquire+0x137a/0x2040 kernel/locking/lockdep.c:5142
   lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5759
   __raw_spin_lock include/linux/spinlock_api_smp.h:133 [inline]
   _raw_spin_lock+0x2e/0x40 kernel/locking/spinlock.c:154
   spin_lock include/linux/spinlock.h:351 [inline]
   sk_clone_lock+0x2cd/0xf40 net/core/sock.c:2328
   mptcp_sk_clone_init+0x32/0x13c0 net/mptcp/protocol.c:3279
   subflow_syn_recv_sock+0x931/0x1920 net/mptcp/subflow.c:874
   tcp_check_req+0xfe4/0x1a20 net/ipv4/tcp_minisocks.c:853
   tcp_v4_rcv+0x1c3e/0x37f0 net/ipv4/tcp_ipv4.c:2267
   ip_protocol_deliver_rcu+0x22e/0x440 net/ipv4/ip_input.c:205
   ip_local_deliver_finish+0x341/0x5f0 net/ipv4/ip_input.c:233
   NF_HOOK+0x3a4/0x450 include/linux/netfilter.h:314
   NF_HOOK+0x3a4/0x450 include/linux/netfilter.h:314
   __netif_receive_skb_one_core net/core/dev.c:5661 [inline]
   __netif_receive_skb+0x2bf/0x650 net/core/dev.c:5775
   process_backlog+0x662/0x15b0 net/core/dev.c:6108
   __napi_poll+0xcb/0x490 net/core/dev.c:6772
   napi_poll net/core/dev.c:6841 [inline]
   net_rx_action+0x89b/0x1240 net/core/dev.c:6963
   handle_softirqs+0x2c4/0x970 kernel/softirq.c:554
   do_softirq+0x11b/0x1e0 kernel/softirq.c:455
   </IRQ>
   <TASK>
   __local_bh_enable_ip+0x1bb/0x200 kernel/softirq.c:382
   local_bh_enable include/linux/bottom_half.h:33 [inline]
   rcu_read_unlock_bh include/linux/rcupdate.h:908 [inline]
   __dev_queue_xmit+0x1763/0x3e90 net/core/dev.c:4450
   dev_queue_xmit include/linux/netdevice.h:3105 [inline]
   neigh_hh_output include/net/neighbour.h:526 [inline]
   neigh_output include/net/neighbour.h:540 [inline]
   ip_finish_output2+0xd41/0x1390 net/ipv4/ip_output.c:235
   ip_local_out net/ipv4/ip_output.c:129 [inline]
   __ip_queue_xmit+0x118c/0x1b80 net/ipv4/ip_output.c:535
   __tcp_transmit_skb+0x2544/0x3b30 net/ipv4/tcp_output.c:1466
   tcp_rcv_synsent_state_process net/ipv4/tcp_input.c:6542 [inline]
   tcp_rcv_state_process+0x2c32/0x4570 net/ipv4/tcp_input.c:6729
   tcp_v4_do_rcv+0x77d/0xc70 net/ipv4/tcp_ipv4.c:1934
   sk_backlog_rcv include/net/sock.h:1111 [inline]
   __release_sock+0x214/0x350 net/core/sock.c:3004
   release_sock+0x61/0x1f0 net/core/sock.c:3558
   mptcp_sendmsg_fastopen+0x1ad/0x530 net/mptcp/protocol.c:1733
   mptcp_sendmsg+0x1884/0x1b10 net/mptcp/protocol.c:1812
   sock_sendmsg_nosec net/socket.c:730 [inline]
   __sock_sendmsg+0x1a6/0x270 net/socket.c:745
   ____sys_sendmsg+0x525/0x7d0 net/socket.c:2597
   ___sys_sendmsg net/socket.c:2651 [inline]
   __sys_sendmmsg+0x3b2/0x740 net/socket.c:2737
   __do_sys_sendmmsg net/socket.c:2766 [inline]
   __se_sys_sendmmsg net/socket.c:2763 [inline]
   __x64_sys_sendmmsg+0xa0/0xb0 net/socket.c:2763
   do_syscall_x64 arch/x86/entry/common.c:52 [inline]
   do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
   entry_SYSCALL_64_after_hwframe+0x77/0x7f
  RIP: 0033:0x7f04fb13a6b9
  Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 01 1a 00 00 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 b8 ff ff ff f7 d8 64 89 01 48
  RSP: 002b:00007ffd651f42d8 EFLAGS: 00000246 ORIG_RAX: 0000000000000133
  RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 00007f04fb13a6b9
  RDX: 0000000000000001 RSI: 0000000020000d00 RDI: 0000000000000004
  RBP: 00007ffd651f4310 R08: 0000000000000001 R09: 0000000000000001
  R10: 0000000020000080 R11: 0000000000000246 R12: 00000000000f4240
  R13: 00007f04fb187449 R14: 00007ffd651f42f4 R15: 00007ffd651f4300
   </TASK>

As noted by Cong Wang, the splat is false positive, but the code
path leading to the report is an unexpected one: a client is
attempting an MPC handshake towards the in-kernel listener created
by the in-kernel PM for a port based signal endpoint.

Such connection will be never accepted; many of them can make the
listener queue full and preventing the creation of MPJ subflow via
such listener - its intended role.

Explicitly detect this scenario at initial-syn time and drop the
incoming MPC request.

Fixes: 1729cf1 ("mptcp: create the listening socket for new port")
Cc: [email protected]
Reported-by: [email protected]
Closes: https://syzkaller.appspot.com/bug?extid=f4aacdfef2c6a6529c3e
Cc: Cong Wang <[email protected]>
Signed-off-by: Paolo Abeni <[email protected]>
Reviewed-by: Matthieu Baerts (NGI0) <[email protected]>
Reviewed-by: Mat Martineau <[email protected]>
Signed-off-by: Matthieu Baerts (NGI0) <[email protected]>
Link: https://patch.msgid.link/[email protected]
Signed-off-by: Jakub Kicinski <[email protected]>
mhiramat pushed a commit to mhiramat/linux that referenced this issue Oct 28, 2024
…/kernel/git/kvmarm/kvmarm into HEAD

KVM/arm64 fixes for 6.12, take svenkatr#3

- Stop wasting space in the HYP idmap, as we are dangerously close
  to the 4kB limit, and this has already exploded in -next

- Fix another race in vgic_init()

- Fix a UBSAN error when faking the cache topology with MTE
  enabled
mhiramat pushed a commit to mhiramat/linux that referenced this issue Nov 25, 2024
Hou Tao says:

====================
The patch set fixes several issues in bits iterator. Patch svenkatr#1 fixes the
kmemleak problem of bits iterator. Patch svenkatr#2~svenkatr#3 fix the overflow problem
of nr_bits. Patch svenkatr#4 fixes the potential stack corruption when bits
iterator is used on 32-bit host. Patch svenkatr#5 adds more test cases for bits
iterator.

Please see the individual patches for more details. And comments are
always welcome.
---
v4:
 * patch svenkatr#1: add ack from Yafang
 * patch svenkatr#3: revert code-churn like changes:
   (1) compute nr_bytes and nr_bits before the check of nr_words.
   (2) use nr_bits == 64 to check for single u64, preventing build
       warning on 32-bit hosts.
 * patch svenkatr#4: use "BITS_PER_LONG == 32" instead of "!defined(CONFIG_64BIT)"

v3: https://lore.kernel.org/bpf/[email protected]/T/#t
  * split the bits-iterator related patches from "Misc fixes for bpf"
    patch set
  * patch svenkatr#1: use "!nr_bits || bits >= nr_bits" to stop the iteration
  * patch svenkatr#2: add a new helper for the overflow problem
  * patch svenkatr#3: decrease the limitation from 512 to 511 and check whether
    nr_bytes is too large for bpf memory allocator explicitly
  * patch svenkatr#5: add two more test cases for bit iterator

v2: http://lore.kernel.org/bpf/[email protected]
====================

Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Alexei Starovoitov <[email protected]>
mhiramat pushed a commit to mhiramat/linux that referenced this issue Nov 25, 2024
Petr Machata says:

====================
mlxsw: Fixes

In this patchset:

- Tx header should be pushed for each packet which is transmitted via
  Spectrum ASICs. Patch svenkatr#1 adds a missing call to skb_cow_head() to make
  sure that there is both enough room to push the Tx header and that the
  SKB header is not cloned and can be modified.

- Commit b5b60bb ("mlxsw: pci: Use page pool for Rx buffers
  allocation") converted mlxsw to use page pool for Rx buffers allocation.
  Sync for CPU and for device should be done for Rx pages. In patches svenkatr#2
  and svenkatr#3, add the missing calls to sync pages for, respectively, CPU and
  the device.

- Patch svenkatr#4 then fixes a bug to IPv6 GRE forwarding offload. Patch svenkatr#5 adds
  a generic forwarding test that fails with mlxsw ports prior to the fix.
====================

Link: https://patch.msgid.link/[email protected]
Signed-off-by: Jakub Kicinski <[email protected]>
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