| From | Paul Gortmaker <> | Subject | [34-longterm 112/196] i8k: Tell gcc that *regs gets clobbered | Date | Mon, 12 Mar 2012 20:20:25 -0400 |
| |
From: Jim Bos <jim876@xs4all.nl>
------------------- This is a commit scheduled for the next v2.6.34 longterm release. If you see a problem with using this for longterm, please comment. -------------------
commit 6b4e81db2552bad04100e7d5ddeed7e848f53b48 upstream.
More recent GCC caused the i8k driver to stop working, on Slackware compiler was upgraded from gcc-4.4.4 to gcc-4.5.1 after which it didn't work anymore, meaning the driver didn't load or gave total nonsensical output.
As it turned out the asm(..) statement forgot to mention it modifies the *regs variable.
Credits to Andi Kleen and Andreas Schwab for providing the fix.
Signed-off-by: Jim Bos <jim876@xs4all.nl> Cc: Andi Kleen <andi@firstfloor.org> Cc: Andreas Schwab <schwab@linux-m68k.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com> --- drivers/char/i8k.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-)
diff --git a/drivers/char/i8k.c b/drivers/char/i8k.c index fc8cf7a..828fd24 100644 --- a/drivers/char/i8k.c +++ b/drivers/char/i8k.c @@ -141,7 +141,7 @@ static int i8k_smm(struct smm_regs *regs) "lahf\n\t" "shrl $8,%%eax\n\t" "andl $1,%%eax\n" - :"=a"(rc) + :"=a"(rc), "+m" (*regs) : "a"(regs) : "%ebx", "%ecx", "%edx", "%esi", "%edi", "memory"); #else @@ -166,7 +166,8 @@ static int i8k_smm(struct smm_regs *regs) "movl %%edx,0(%%eax)\n\t" "lahf\n\t" "shrl $8,%%eax\n\t" - "andl $1,%%eax\n":"=a"(rc) + "andl $1,%%eax\n" + :"=a"(rc), "+m" (*regs) : "a"(regs) : "%ebx", "%ecx", "%edx", "%esi", "%edi", "memory"); #endif -- 1.7.9.3
|