[PATCH] checkpatch: extend BUG warning

From: Joe Perches
Date: Wed Oct 05 2016 - 13:01:08 EST


Include the prefixed and postfixed BUG/BUG_ON variants like VM_BUG_ON
that can kill the kernel. Exclude the BUILD and lower case variants.

$ grep -rP --include=*.[ch] -oh "\w+_BUG_ON\w*" * | \
sort | uniq -c | sort -rn
  1838 BUILD_BUG_ON
  632 snd_BUG_ON
  263 VM_BUG_ON_PAGE
  260 VM_BUG_ON
  97 GEM_BUG_ON
  57 SNIC_BUG_ON
  49 EFX_BUG_ON_PARANOID
  45 BUILD_BUG_ON_ZERO
  45 BUILD_BUG_ON_MSG
  30 B43legacy_BUG_ON
  24 VM_BUG_ON_VMA
  21 BUILD_BUG_ON_NOT_POWER_OF_2
  16 PCPU_SETUP_BUG_ON
  15 GLOCK_BUG_ON
  12 LOGFS_BUG_ON
  11 RWLOCK_BUG_ON
  10 VIRTUAL_BUG_ON
  9 SPIN_BUG_ON
  9 BUILD_BUG_ON_INVALID
  8 UNWINDER_BUG_ON
  8 DEBUG_SPINLOCK_BUG_ON
  7 VM_BUG_ON_MM
  7 LIST_BL_BUG_ON
  6 BUILD_BUG_ON_NULL
  5 MAYBE_BUILD_BUG_ON
  4 VM_BUG_ON_PGFLAGS
  4 SSB_BUG_ON
  4 HAVE_ARCH_BUG_ON
  4 BIO_BUG_ON
  3 DCCP_BUG_ON
  3 __BUILD_BUG_ON_NOT_POWER_OF_2
  2 __BUG_ON_cond
  2 __BUG_ON
  1 CONFIG_BUG_ON_DATA_CORRUPTION

Suggested-by: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Joe Perches <joe@xxxxxxxxxxx>
---
 scripts/checkpatch.pl | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/scripts/checkpatch.pl b/scripts/checkpatch.pl
index 3373c65fef1c..be796704e218 100755
--- a/scripts/checkpatch.pl
+++ b/scripts/checkpatch.pl
@@ -3725,8 +3725,9 @@ sub process {
}
}

-# avoid BUG() or BUG_ON()
- if ($line =~ /\b(?:BUG|BUG_ON)\b/) {
+# avoid BUG() or BUG_ON() like mechanisms (exclude BUILD_BUG)
+ if ($line =~ /\b((?:[A-Z_]+_)?BUG(?:_ON(?:_[A-Z_]+)?))\s*\(/ &&
+     $1 !~ /BUILD/) {
my $msg_type = \&WARN;
$msg_type = \&CHK if ($file);
&{$msg_type}("AVOID_BUG",