Commit bc1f419c authored May 25, 2011 by Luca Tettamanti Committed by Jean Delvare May 25, 2011

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 <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: stable@kernel.org
Cc: Massimo Dal Zotto <dz@debian.org>
Signed-off-by: Jean Delvare <khali@linux-fr.org>

parent 4a7df24d

drivers/char/i8k.c

+2 −2

Original line number	Diff line number	Diff line
		@@ -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)