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| author | Linus Torvalds <torvalds@woody.linux-foundation.org> | 2007-08-01 08:12:07 +0400 |
|---|---|---|
| committer | Linus Torvalds <torvalds@woody.linux-foundation.org> | 2007-08-01 08:12:07 +0400 |
| commit | 8d4fbcfbe0a4bfc73e7f0297c59ae514e1f1436f (patch) | |
| tree | f4fe8e2028620b8aeb298c78ee5dc9d6df07e708 | |
| parent | 2f63251ed0a803ddbe7bf2577b69d467aa872f68 (diff) | |
| download | linux-8d4fbcfbe0a4bfc73e7f0297c59ae514e1f1436f.tar.xz | |
Fix WARN_ON() on bitfield ops
Alexey Dobriyan noticed that the new WARN_ON() semantics that were
introduced by commit 684f978347deb42d180373ac4c427f82ef963171 (to also
return the value to be warned on) didn't compile when given a bitfield,
because the typeof doesn't work for bitfields.
So instead of the typeof trick, use an "int" variable together with a
"!!(x)" expression, as suggested by Al Viro.
To make matters more interesting, Paul Mackerras points out that that is
sub-optimal on Power, but the old asm-coded comparison seems to be buggy
anyway on 32-bit Power if the conditional was 64-bit, so I think there
are more problems there.
Regardless, the new WARN_ON() semantics may have been a bad idea. But
this at least avoids the more serious complications.
Cc: Alexey Dobriyan <adobriyan@sw.ru>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Al Viro <viro@ftp.linux.org.uk>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
| -rw-r--r-- | include/asm-generic/bug.h | 6 | ||||
| -rw-r--r-- | include/asm-powerpc/bug.h | 2 |
2 files changed, 4 insertions, 4 deletions
diff --git a/include/asm-generic/bug.h b/include/asm-generic/bug.h index 344e3091af24..d56fedbb457a 100644 --- a/include/asm-generic/bug.h +++ b/include/asm-generic/bug.h @@ -33,7 +33,7 @@ struct bug_entry { #ifndef HAVE_ARCH_WARN_ON #define WARN_ON(condition) ({ \ - typeof(condition) __ret_warn_on = (condition); \ + int __ret_warn_on = !!(condition); \ if (unlikely(__ret_warn_on)) { \ printk("WARNING: at %s:%d %s()\n", __FILE__, \ __LINE__, __FUNCTION__); \ @@ -54,7 +54,7 @@ struct bug_entry { #ifndef HAVE_ARCH_WARN_ON #define WARN_ON(condition) ({ \ - typeof(condition) __ret_warn_on = (condition); \ + int __ret_warn_on = !!(condition); \ unlikely(__ret_warn_on); \ }) #endif @@ -62,7 +62,7 @@ struct bug_entry { #define WARN_ON_ONCE(condition) ({ \ static int __warned; \ - typeof(condition) __ret_warn_once = (condition); \ + int __ret_warn_once = !!(condition); \ \ if (unlikely(__ret_warn_once)) \ if (WARN_ON(!__warned)) \ diff --git a/include/asm-powerpc/bug.h b/include/asm-powerpc/bug.h index a248b8bd4d7c..e55d1f66b86f 100644 --- a/include/asm-powerpc/bug.h +++ b/include/asm-powerpc/bug.h @@ -93,7 +93,7 @@ } while (0) #define WARN_ON(x) ({ \ - typeof(x) __ret_warn_on = (x); \ + int __ret_warn_on = !!(x); \ if (__builtin_constant_p(__ret_warn_on)) { \ if (__ret_warn_on) \ __WARN(); \ |