From fd51f666fa591294bd7462447512666e61c56ea0 Mon Sep 17 00:00:00 2001 From: "H. J. Lu" Date: Sun, 1 May 2005 08:58:48 -0700 Subject: [PATCH] i386/x86_64 segment register access update The new i386/x86_64 assemblers no longer accept instructions for moving between a segment register and a 32bit memory location, i.e., movl (%eax),%ds movl %ds,(%eax) To generate instructions for moving between a segment register and a 16bit memory location without the 16bit operand size prefix, 0x66, mov (%eax),%ds mov %ds,(%eax) should be used. It will work with both new and old assemblers. The assembler starting from 2.16.90.0.1 will also support movw (%eax),%ds movw %ds,(%eax) without the 0x66 prefix. I am enclosing patches for 2.4 and 2.6 kernels here. The resulting kernel binaries should be unchanged as before, with old and new assemblers, if gcc never generates memory access for unsigned gsindex; asm volatile("movl %%gs,%0" : "=g" (gsindex)); If gcc does generate memory access for the code above, the upper bits in gsindex are undefined and the new assembler doesn't allow it. Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- arch/i386/kernel/vm86.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'arch/i386/kernel/vm86.c') diff --git a/arch/i386/kernel/vm86.c b/arch/i386/kernel/vm86.c index 2f3d52d..d16cd37 100644 --- a/arch/i386/kernel/vm86.c +++ b/arch/i386/kernel/vm86.c @@ -294,8 +294,8 @@ static void do_sys_vm86(struct kernel_vm86_struct *info, struct task_struct *tsk */ info->regs32->eax = 0; tsk->thread.saved_esp0 = tsk->thread.esp0; - asm volatile("movl %%fs,%0":"=m" (tsk->thread.saved_fs)); - asm volatile("movl %%gs,%0":"=m" (tsk->thread.saved_gs)); + asm volatile("mov %%fs,%0":"=m" (tsk->thread.saved_fs)); + asm volatile("mov %%gs,%0":"=m" (tsk->thread.saved_gs)); tss = &per_cpu(init_tss, get_cpu()); tsk->thread.esp0 = (unsigned long) &info->VM86_TSS_ESP0; -- cgit v1.1