i8k: Avoid lahf in 64-bit code

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 <[email protected]> Reported-by: Jeff Rickman <[email protected]> Tested-by: Jeff Rickman <[email protected]> Tested-by: Harry G McGavran Jr <[email protected]> Cc: [email protected] Cc: Massimo Dal Zotto <[email protected]> Signed-off-by: Jean Delvare <[email protected]>
quicksilveramalgum · May 25, 2011 · bc1f419 · bc1f419
1 parent 4a7df24
commit bc1f419
Showing 1 changed file with 2 additions and 2 deletions.
diff --git a/drivers/char/i8k.c b/drivers/char/i8k.c
@@ -139,8 +139,8 @@ 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)