| From | Andi Kleen <> | Subject | [PATCH] [25/99] i8k: Avoid lahf in 64-bit code | Date | Wed, 27 Jul 2011 14:48:23 -0700 (PDT) |
| |
2.6.35-longterm review patch. If anyone has any objections, please let me know.
------------------ From: Luca Tettamanti <kronos.it@gmail.com>
commit bc1f419c76a2d6450413ce4349f4e4a07be011d5 upstream.
i8k uses lahf to read the flag register in 64-bit code; early x86-64 CPUs, however, lack this instruction and we get an invalid opcode exception at runtime. Use pushf to load the flag register into the stack instead.
Signed-off-by: Luca Tettamanti <kronos.it@gmail.com> Reported-by: Jeff Rickman <jrickman@myamigos.us> Tested-by: Jeff Rickman <jrickman@myamigos.us> Tested-by: Harry G McGavran Jr <w5pny@arrl.net> Cc: Massimo Dal Zotto <dz@debian.org> Signed-off-by: Jean Delvare <khali@linux-fr.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de> Signed-off-by: Andi Kleen <ak@linux.intel.com>
--- drivers/char/i8k.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)
Index: linux-2.6.35.y/drivers/char/i8k.c =================================================================== --- linux-2.6.35.y.orig/drivers/char/i8k.c +++ linux-2.6.35.y/drivers/char/i8k.c @@ -138,8 +138,8 @@ static int i8k_smm(struct smm_regs *regs "movl %%edi,20(%%rax)\n\t" "popq %%rdx\n\t" "movl %%edx,0(%%rax)\n\t" - "lahf\n\t" - "shrl $8,%%eax\n\t" + "pushfq\n\t" + "popq %%rax\n\t" "andl $1,%%eax\n" :"=a"(rc) : "a"(regs)
|