Commit 91c9afaf97ee554d2cd3042a5ad01ad21c99e8c4

Authored by Andy Lutomirski
Committed by Linus Torvalds
1 parent c17893c740

checkpatch.pl: new instances of ENOSYS are errors

ENOSYS means that a nonexistent system call was called.  We have a
bad habit of using it for things like invalid operations on
otherwise valid syscalls.  We should avoid this in new code.

Pervasive incorrect usage of ENOSYS came up at the kernel summit ABI
review discussion.  Let's see if checkpatch can help.

I'll submit a separate patch for include/uapi/asm-generic/errno.h.

Signed-off-by: Andy Lutomirski <luto@amacapital.net>
Cc: Pavel Machek <pavel@ucw.cz>
Cc: Michael Kerrisk <mtk.manpages@gmail.com>
Cc: Joe Perches <joe@perches.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Showing 1 changed file with 8 additions and 0 deletions Side-by-side Diff

scripts/checkpatch.pl
... ... @@ -3396,6 +3396,14 @@
3396 3396 "Prefer dev_$level(... to dev_printk(KERN_$orig, ...\n" . $herecurr);
3397 3397 }
3398 3398  
  3399 +# ENOSYS means "bad syscall nr" and nothing else. This will have a small
  3400 +# number of false positives, but assembly files are not checked, so at
  3401 +# least the arch entry code will not trigger this warning.
  3402 + if ($line =~ /\bENOSYS\b/) {
  3403 + WARN("ENOSYS",
  3404 + "ENOSYS means 'invalid syscall nr' and nothing else\n" . $herecurr);
  3405 + }
  3406 +
3399 3407 # function brace can't be on same line, except for #defines of do while,
3400 3408 # or if closed on same line
3401 3409 if (($line=~/$Type\s*$Ident\(.*\).*\s*{/) and