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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>
This commit is contained in:
Brian Gerst 2010-09-03 21:17:13 -04:00 committed by H. Peter Anvin
parent a4d4fbc773
commit 10c11f3049
1 changed files with 8 additions and 10 deletions
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18
arch/x86/kernel/i387.c
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@ -389,19 +389,17 @@ convert_from_fxsr(struct user_i387_ia32_struct *env, struct task_struct *tsk)
#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);