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Commit 10c11f30 authored by Brian Gerst's avatar Brian Gerst Committed by H. Peter Anvin
Browse files

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: default avatarBrian Gerst <brgerst@gmail.com>
Acked-by: default avatarPekka 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: default avatarH. Peter Anvin <hpa@linux.intel.com>
parent a4d4fbc7

arch/x86/kernel/i387.c

+8 −10
Original line number Diff line number Diff line
@@ -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;

	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));

	env->fcs = task_pt_regs(tsk)->cs;

	if (tsk == current) {

		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);