diff options
| author |   Mikael Pettersson <mikpe@it.uu.se> | 2010-06-29 15:05:25 -0700 |
|---|---|---|
| committer |   Linus Torvalds <torvalds@linux-foundation.org> | 2010-06-29 15:29:31 -0700 |
| commit | 9c695203a7ddbe49dba5f22f4c941d24f47475df (patch) | |
| tree | 0dcfa624ecb7c5810f7062fe950bf3f0de2e55b2 /include/linux/compiler-gcc4.h | |
| parent | flat: tweak default stack alignment (diff) | |
| download | linux-dev-9c695203a7ddbe49dba5f22f4c941d24f47475df.tar.xz linux-dev-9c695203a7ddbe49dba5f22f4c941d24f47475df.zip | |
compiler-gcc.h: gcc-4.5 needs noclone and noinline on __naked functions
A __naked function is defined in C but with a body completely implemented
by asm(), including any prologue and epilogue. These asm() bodies expect
standard calling conventions for parameter passing. Older GCCs implement
that correctly, but 4.[56] currently do not, see GCC PR44290. In the
Linux kernel this breaks ARM, causing most arch/arm/mm/copypage-*.c
modules to get miscompiled, resulting in kernel crashes during bootup.
Part of the kernel fix is to augment the __naked function attribute to
also imply noinline and noclone. This patch implements that, and has been
verified to fix boot failures with gcc-4.5 compiled 2.6.34 and 2.6.35-rc1
kernels. The patch is a no-op with older GCCs.
Signed-off-by: Mikael Pettersson <mikpe@it.uu.se>
Signed-off-by: Khem Raj <raj.khem@gmail.com>
Cc: Russell King <rmk@arm.linux.org.uk>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'include/linux/compiler-gcc4.h')
| -rw-r--r-- | include/linux/compiler-gcc4.h | 4 |
1 files changed, 4 insertions, 0 deletions
diff --git a/include/linux/compiler-gcc4.h b/include/linux/compiler-gcc4.h index 94dea3ffbfa1..fcfa5b9a4317 100644 --- a/include/linux/compiler-gcc4.h +++ b/include/linux/compiler-gcc4.h @@ -48,6 +48,10 @@ * unreleased. Really, we need to have autoconf for the kernel. */ #define unreachable() __builtin_unreachable() + +/* Mark a function definition as prohibited from being cloned. */ +#define __noclone __attribute__((__noclone__)) + #endif #endif |