| From | Paul Gortmaker <> | Subject | [34-longterm 035/179] i8k: Avoid lahf in 64-bit code | Date | Mon, 14 May 2012 22:12:11 -0400 |
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From: Luca Tettamanti <kronos.it@gmail.com>
------------------- This is a commit scheduled for the next v2.6.34 longterm release. http://git.kernel.org/?p=linux/kernel/git/paulg/longterm-queue-2.6.34.git If you see a problem with using this for longterm, please comment. -------------------
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: Paul Gortmaker <paul.gortmaker@windriver.com> --- drivers/char/i8k.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/drivers/char/i8k.c b/drivers/char/i8k.c index 4365717..1e116ac 100644 --- a/drivers/char/i8k.c +++ b/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) -- 1.7.9.6
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