| From bc1f419c76a2d6450413ce4349f4e4a07be011d5 Mon Sep 17 00:00:00 2001 |
| From: Luca Tettamanti <kronos.it@gmail.com> |
| Date: Wed, 25 May 2011 20:43:31 +0200 |
| Subject: i8k: Avoid lahf in 64-bit code |
| |
| 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> |
| |
| --- |
| drivers/char/i8k.c | 4 ++-- |
| 1 file changed, 2 insertions(+), 2 deletions(-) |
| |
| --- 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) |
