On 9/20/22 05:23, David Hildenbrand wrote: > checkpatch does not point out that VM_BUG_ON() and friends should be > avoided, however, Linus notes: > > VM_BUG_ON() has the exact same semantics as BUG_ON. It is literally > no different, the only difference is "we can make the code smaller > because these are less important". [1] > > So let's warn on VM_BUG_ON() and other BUG variants as well. While at it, > make it clearer that the kernel really shouldn't be crashed. > > As there are some subsystem BUG macros that actually don't end up crashing > the kernel -- for example, KVM_BUG_ON() -- exclude these manually. > > [1] https://lore.kernel.org/r/CAHk-=wg40EAZofO16Eviaj7mfqDhZ2gVEbvfsMf6gYzspRjYvw@xxxxxxxxxxxxxx > > Signed-off-by: David Hildenbrand <david@xxxxxxxxxx> > --- > scripts/checkpatch.pl | 6 +++--- > 1 file changed, 3 insertions(+), 3 deletions(-) > > diff --git a/scripts/checkpatch.pl b/scripts/checkpatch.pl > index 79e759aac543..21f3a79aa46f 100755 > --- a/scripts/checkpatch.pl > +++ b/scripts/checkpatch.pl > @@ -4695,12 +4695,12 @@ sub process { > } > } > > -# avoid BUG() or BUG_ON() > - if ($line =~ /\b(?:BUG|BUG_ON)\b/) { > +# do not use BUG() or variants > + if ($line =~ /\b(?!AA_|BUILD_|DCCP_|IDA_|KVM_|RWLOCK_|snd_|SPIN_)(?:[a-zA-Z_]*_)?BUG(?:_ON)?(?:_[A-Z_]+)?\s*\(/) { Should this be a separate patch? Adding a bunch of exceptions to the BUG() rules is a separate and distinct thing from adding VM_BUG_ON() and other *BUG*() variants to the mix. > my $msg_level = \&WARN; > $msg_level = \&CHK if ($file); > &{$msg_level}("AVOID_BUG", > - "Avoid crashing the kernel - try using WARN_ON & recovery code rather than BUG() or BUG_ON()\n" . $herecurr); > + "Do not crash the kernel unless it is unavoidable - use WARN_ON_ONCE & recovery code (if reasonable) rather than BUG() or variants.\n" . $herecurr); Here's a requested tweak, to clean up the output and fix punctuation: "Avoid crashing the kernel--use WARN_ON_ONCE() plus recovery code (if feasible) instead of BUG() or variants.\n" . $herecurr); thanks, -- John Hubbard NVIDIA
