lkml.org 
[lkml]   [2018]   [Sep]   [12]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[RFC PATCH 08/10] x86/fpu: prepare copy_fpstate_to_sigframe for TIF_LOAD_FPU
Date
From: Rik van Riel <riel@surriel.com>

If TIF_LOAD_FPU is set, then the registers are saved (not loaded). In that case
we skip the saving part.

Signed-off-by: Rik van Riel <riel@surriel.com>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
---
arch/x86/kernel/fpu/signal.c | 16 ++++++++++------
1 file changed, 10 insertions(+), 6 deletions(-)

diff --git a/arch/x86/kernel/fpu/signal.c b/arch/x86/kernel/fpu/signal.c
index ff6e7a67522d8..906efd9572ffa 100644
--- a/arch/x86/kernel/fpu/signal.c
+++ b/arch/x86/kernel/fpu/signal.c
@@ -155,13 +155,17 @@ int copy_fpstate_to_sigframe(void __user *buf, void __user *buf_fx, int size)
sizeof(struct user_i387_ia32_struct), NULL,
(struct _fpstate_32 __user *) buf) ? -1 : 1;

- /* Update the thread's fxstate to save the fsave header. */
- if (ia32_fxstate)
- copy_fxregs_to_kernel(fpu);
- else {
- copy_fpregs_to_fpstate(fpu);
- fpregs_deactivate(fpu);
+ __fpregs_changes_begin();
+ if (!test_thread_flag(TIF_LOAD_FPU)) {
+ /* Update the thread's fxstate to save the fsave header. */
+ if (ia32_fxstate)
+ copy_fxregs_to_kernel(fpu);
+ else {
+ copy_fpregs_to_fpstate(fpu);
+ fpregs_deactivate(fpu);
+ }
}
+ __fpregs_changes_end();

if (using_compacted_format()) {
copy_xstate_to_user(buf_fx, xsave, 0, size);
--
2.19.0
\
 
 \ /
  Last update: 2018-09-12 15:37    [W:0.146 / U:0.528 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site