modpost: Add .irqentry.text to OTHER_SECTIONS

commit 7912405 upstream.

The compiler can fully inline the actual handler function of an interrupt
entry into the .irqentry.text entry point. If such a function contains an
access which has an exception table entry, modpost complains about a
section mismatch:

  WARNING: vmlinux.o(__ex_table+0x447c): Section mismatch in reference ...

  The relocation at __ex_table+0x447c references section ".irqentry.text"
  which is not in the list of authorized sections.

Add .irqentry.text to OTHER_SECTIONS to cure the issue.

Reported-by: Sergey Senozhatsky <[email protected]>
Signed-off-by: Thomas Gleixner <[email protected]>
Cc: [email protected] # needed for linux-5.4-y
Link: https://lore.kernel.org/all/[email protected]/
Signed-off-by: Masahiro Yamada <[email protected]>
[ bump the size of good_tosec[] to prevent overflow - gregkh ]
Signed-off-by: Greg Kroah-Hartman <[email protected]>

scripts/mod/modpost.c

@@ -829,7 +829,7 @@ static void check_section(const char *modname, struct elf_info *elf,
 		".ltext", ".ltext.*"
 #define OTHER_TEXT_SECTIONS ".ref.text", ".head.text", ".spinlock.text", \
 		".fixup", ".entry.text", ".exception.text", \
-		".coldtext", ".softirqentry.text"
+		".coldtext", ".softirqentry.text", ".irqentry.text"
 
 #define INIT_SECTIONS      ".init.*"
 #define MEM_INIT_SECTIONS  ".meminit.*"
@@ -889,7 +889,7 @@ enum mismatch {
 struct sectioncheck {
 	const char *fromsec[20];
 	const char *bad_tosec[20];
-	const char *good_tosec[20];
+	const char *good_tosec[21];
 	enum mismatch mismatch;
 	void (*handler)(const char *modname, struct elf_info *elf,
 			const struct sectioncheck* const mismatch,