x86: add %gs accessors for x86_32
Impact: cleanup
On x86_32, %gs is handled lazily. It's not saved and restored on
kernel entry/exit but only when necessary which usually is during task
switch but there are few other places. Currently, it's done by
calling savesegment() and loadsegment() explicitly. Define
get_user_gs(), set_user_gs() and task_user_gs() and use them instead.
While at it, clean up register access macros in signal.c.
This cleans up code a bit and will help future changes.
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
diff --git a/arch/x86/kernel/vm86_32.c b/arch/x86/kernel/vm86_32.c
index 4eeb5cf..55ea30d 100644
--- a/arch/x86/kernel/vm86_32.c
+++ b/arch/x86/kernel/vm86_32.c
@@ -158,7 +158,7 @@
ret = KVM86->regs32;
ret->fs = current->thread.saved_fs;
- loadsegment(gs, current->thread.saved_gs);
+ set_user_gs(ret, current->thread.saved_gs);
return ret;
}
@@ -323,7 +323,7 @@
info->regs32->ax = 0;
tsk->thread.saved_sp0 = tsk->thread.sp0;
tsk->thread.saved_fs = info->regs32->fs;
- savesegment(gs, tsk->thread.saved_gs);
+ tsk->thread.saved_gs = get_user_gs(info->regs32);
tss = &per_cpu(init_tss, get_cpu());
tsk->thread.sp0 = (unsigned long) &info->VM86_TSS_ESP0;
