x86-64, fpu: Fix %cs value in convert_from_fxsr()
While %ds still contains the userspace selector, %cs is KERNEL_CS at
this point. Always get %cs from pt_regs even for the current task.
Signed-off-by: Brian Gerst <brgerst@gmail.com>
Acked-by: Pekka Enberg <penberg@kernel.org>
Cc: Suresh Siddha <suresh.b.siddha@intel.com>
LKML-Reference: <1283563039-3466-7-git-send-email-brgerst@gmail.com>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
diff --git a/arch/x86/kernel/i387.c b/arch/x86/kernel/i387.c
index 8216651..f3775f5 100644
--- a/arch/x86/kernel/i387.c
+++ b/arch/x86/kernel/i387.c
@@ -389,19 +389,17 @@
#ifdef CONFIG_X86_64
env->fip = fxsave->rip;
env->foo = fxsave->rdp;
+ /*
+ * should be actually ds/cs at fpu exception time, but
+ * that information is not available in 64bit mode.
+ */
+ env->fcs = task_pt_regs(tsk)->cs;
if (tsk == current) {
- /*
- * should be actually ds/cs at fpu exception time, but
- * that information is not available in 64bit mode.
- */
- asm("mov %%ds, %[fos]" : [fos] "=r" (env->fos));
- asm("mov %%cs, %[fcs]" : [fcs] "=r" (env->fcs));
+ savesegment(ds, env->fos);
} else {
- struct pt_regs *regs = task_pt_regs(tsk);
-
- env->fos = 0xffff0000 | tsk->thread.ds;
- env->fcs = regs->cs;
+ env->fos = tsk->thread.ds;
}
+ env->fos |= 0xffff0000;
#else
env->fip = fxsave->fip;
env->fcs = (u16) fxsave->fcs | ((u32) fxsave->fop << 16);