Commit-ID: 739390035c5fba2132fa424309786ff7bdd2cc1e
Gitweb: http://git.kernel.org/tip/739390035c5fba2132fa424309786ff7bdd2cc1e
Author: Suresh Siddha <suresh.b.siddha@xxxxxxxxx>
AuthorDate: Fri, 24 Aug 2012 14:12:57 -0700
Committer: H. Peter Anvin <hpa@xxxxxxxxxxxxxxx>
CommitDate: Fri, 24 Aug 2012 14:26:47 -0700
x86, fpu: drop_fpu() before restoring new state from sigframe
No need to save the state with unlazy_fpu(), that is about to get overwritten
by the state from the signal frame. Instead use drop_fpu() and continue
to restore the new state.
Also fold the stop_fpu_preload() into drop_fpu().
Signed-off-by: Suresh Siddha <suresh.b.siddha@xxxxxxxxx>
Link: http://lkml.kernel.org/r/1345842782-24175-2-git-send-email-suresh.b.siddha@xxxxxxxxx
Signed-off-by: H. Peter Anvin <hpa@xxxxxxxxxxxxxxx>
---
arch/x86/include/asm/fpu-internal.h | 7 +------
arch/x86/kernel/xsave.c | 8 +++-----
2 files changed, 4 insertions(+), 11 deletions(-)
diff --git a/arch/x86/include/asm/fpu-internal.h b/arch/x86/include/asm/fpu-internal.h
index ba83a08..fe95ad0 100644
--- a/arch/x86/include/asm/fpu-internal.h
+++ b/arch/x86/include/asm/fpu-internal.h
@@ -448,17 +448,12 @@ static inline void save_init_fpu(struct task_struct *tsk)
preempt_enable();
}
-static inline void stop_fpu_preload(struct task_struct *tsk)
-{
- tsk->fpu_counter = 0;
-}
-
static inline void drop_fpu(struct task_struct *tsk)
{
/*
* Forget coprocessor state..
*/
- stop_fpu_preload(tsk);
+ tsk->fpu_counter = 0;
preempt_disable();
__drop_fpu(tsk);
preempt_enable();
diff --git a/arch/x86/kernel/xsave.c b/arch/x86/kernel/xsave.c
index a23d100..6cfc7d9 100644
--- a/arch/x86/kernel/xsave.c
+++ b/arch/x86/kernel/xsave.c
@@ -381,16 +381,14 @@ int __restore_xstate_sig(void __user *buf, void __user *buf_fx, int size)
struct xsave_struct *xsave = &tsk->thread.fpu.state->xsave;
struct user_i387_ia32_struct env;
- stop_fpu_preload(tsk);
- unlazy_fpu(tsk);
+ drop_fpu(tsk);
if (__copy_from_user(xsave, buf_fx, state_size) ||
- __copy_from_user(&env, buf, sizeof(env))) {
- drop_fpu(tsk);
+ __copy_from_user(&env, buf, sizeof(env)))
return -1;
- }
sanitize_restored_xstate(tsk, &env, xstate_bv, fx_only);
+ set_used_math();
} else {
/*
* For 64-bit frames and 32-bit fsave frames, restore the user
--
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