Messages in this thread Patch in this message | | | Date | Sat, 18 Oct 2008 10:22:09 +0200 | From | Ingo Molnar <> | Subject | Re: [announce] new tree: "fix all build warnings, on all configs" |
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* Roland Dreier <rdreier@cisco.com> wrote:
> > i certainly have a found a couple of such cases, see tip/warnings/ugly - > > for example see the one below where gcc is not able to see through type > > width. > > Yes, the uninitialized variable warnings are obnoxious too. By the way, > I think this: > > @@ -72,7 +72,7 @@ static __always_inline void *__constant_memcpy(void *to, const void *from, > return to; > case 5: > *(int *)to = *(int *)from; > - *((char *)to + 4) = *((char *)from + 4); > + *((short *)to + 3) = *((short *)from + 3); > return to; > case 6: > *(int *)to = *(int *)from; > > is actually *wrong*, because the cast operator binds tighter than > addition -- so > > + *((short *)to + 3) = *((short *)from + 3); > > actually copies bytes at offset 6 and 7; I think what you intended was: > > + *((short *)(to + 3)) = *((short *)(from + 3));
thx, you are right - fixed it via the patch below.
> which illustrates the risks in fixing warnings.
yeah. Note that this was not a routine case at all, i did the commit in the early stages when i didnt even know how much effort it all would be to keep the whole kernel warning-free, in all configs. It looked odd and ugly and was in tip/warnings/ugly rightfully.
It would be nice if you could find an outright incorrect change in tip/warnings/simple. The ones flagged 'simple' are the ones that have the highest risk of not being reviewed much beyond their initial addition.
Ingo
---------------> From 9d8f9578ca252bf26474ed77fde7ea30e9dee595 Mon Sep 17 00:00:00 2001 From: Ingo Molnar <mingo@elte.hu> Date: Sat, 18 Oct 2008 10:17:36 +0200 Subject: [PATCH] hack, workaround for warning drivers/acpi/tables/tbfadt.c, fix
Fix commit fbf03326a16b29f8d34a5a3883a267bac4d38fc2, pointed out by Roland Dreier.
Signed-off-by: Ingo Molnar <mingo@elte.hu> --- include/asm-x86/string_32.h | 2 +- 1 files changed, 1 insertions(+), 1 deletions(-)
diff --git a/include/asm-x86/string_32.h b/include/asm-x86/string_32.h index 419ab10..be82619 100644 --- a/include/asm-x86/string_32.h +++ b/include/asm-x86/string_32.h @@ -72,7 +72,7 @@ static __always_inline void *__constant_memcpy(void *to, const void *from, return to; case 5: *(int *)to = *(int *)from; - *((short *)to + 3) = *((short *)from + 3); + *((char *)(to + 3)) = *((char *)(from + 3)); return to; case 6: *(int *)to = *(int *)from;
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