x86/fault: Document the locking in the fault_signal_pending() path

If fault_signal_pending() returns true, then the core mm has unlocked the mm for us. Add a comment to help future readers of this code. Cc: Dave Hansen <[email protected]> Cc: Peter Zijlstra <[email protected]> Signed-off-by: Andy Lutomirski <[email protected]>
0day-ci · Jan 31, 2021 · ca9fd73 · ca9fd73
1 parent f65d36c
commit ca9fd73
Showing 1 changed file with 4 additions and 1 deletion.
diff --git a/arch/x86/mm/fault.c b/arch/x86/mm/fault.c
@@ -1343,8 +1343,11 @@ void do_user_addr_fault(struct pt_regs *regs,
 	 */
 	fault = handle_mm_fault(vma, address, flags, regs);
 
-	/* Quick path to respond to signals */
 	if (fault_signal_pending(fault, regs)) {
+		/*
+		 * Quick path to respond to signals.  The core mm code
+		 * has unlocked the mm for us if we get here.
+		 */
 		if (!user_mode(regs))
 			no_context(regs, error_code, address, SIGBUS,
 				   BUS_ADRERR);