[PATCH] checkpatch: Warn on BUG and BUG_ON uses

From: Joe Perches
Date: Mon Jun 08 2015 - 01:44:29 EST


Spake Linus:

> Hell no.
>
> Stop with the random BUG_ON() additions.
>
> I have said this before, and apparently I need to sat this again, and
> probably I will have to say it in the future.
>
> We don't add BUG_ON's for random reasons.
>
> The *ONLY* acceptable reason for a BUG_ON() is if the machine is dead
> anyway because of some major internal corruption.
>
> We have too many BUG_ON's. We've had people add BUG_ON's because "this
> cannot happen", and then it turns out they were wrong, and they just
> killed the machine.
>
> Dammit, there's no reason to add a BUG_ON() here in the first place,
> and the reason of "but but it's an unused error return": is f*cking
> retarded.
>
> Stop this idiocy. We don't write crap code just to satisfy some random
> coding standard or shut up a compiler error.
>
> At most, it could be a "WARN_ON_ONCE()". Maybe even just silently
> ignore the error. But BUG_ON()? Hell no.
>
> NO NO NO.
>
> Quite frankly, if you want to add error handling, then dammit, add it
> right. And no, BUG_ON() is _never_ proper error handling.
>
> BUG_ON() is for things like "uhhuh, somebody is trying to free a page
> that is already free". That is some serious internal corruption.
>
> BUG_ON() is _not_ for "I'm not doing any error handling, so I'll
> sprinkle random lines of BUG_ON() like fairy dust to make the compiler
> happen".
>
> Really. I'm getting very tired indeed of people adding BUG_ON's like
> that. Stop it.

Signed-off-by: Joe Perches <joe@xxxxxxxxxxx>
---
scripts/checkpatch.pl | 11 +++++------
1 file changed, 5 insertions(+), 6 deletions(-)

diff --git a/scripts/checkpatch.pl b/scripts/checkpatch.pl
index 69c4716..f3daa4e 100755
--- a/scripts/checkpatch.pl
+++ b/scripts/checkpatch.pl
@@ -3423,12 +3423,11 @@ sub process {
}
}

-# # no BUG() or BUG_ON()
-# if ($line =~ /\b(BUG|BUG_ON)\b/) {
-# print "Try to use WARN_ON & Recovery code rather than BUG() or BUG_ON()\n";
-# print "$herecurr";
-# $clean = 0;
-# }
+# avoid BUG() or BUG_ON()
+ if ($line =~ /\b(BUG|BUG_ON)\b/) {
+ WARN("BUG",
+ "Avoid using $1 unless there is a serious corruption - try to use WARN_ON & recovery code instead\n" . $herecurr);
+ }

if ($line =~ /\bLINUX_VERSION_CODE\b/) {
WARN("LINUX_VERSION_CODE",


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