xiaomi-sm8450/android_kernel_xiaomi_sm8450
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

x86/fpu/xstate: Re-enable XSAVES

Browse Source 
We did not handle XSAVES instructions correctly. There were issues in
converting between standard and compacted format when interfacing with
user-space. These issues have been corrected.

Add a WARN_ONCE() to make it clear that XSAVES supervisor states are not
yet implemented.

Signed-off-by: Yu-cheng Yu <yu-cheng.yu@intel.com>
Signed-off-by: Fenghua Yu <fenghua.yu@intel.com>
Reviewed-by: Dave Hansen <dave.hansen@intel.com>
Cc: H. Peter Anvin <h.peter.anvin@intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ravi V Shankar <ravi.v.shankar@intel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1468253937-40008-5-git-send-email-fenghua.yu@intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
This commit is contained in:
Yu-cheng Yu
2016-07-11 09:18:57 -07:00
committed by Ingo Molnar
parent 35ac2d7ba7
commit b8be15d588
2 changed files with 9 additions and 15 deletions
Download Patch File Download Diff File Expand all files Collapse all files

9
arch/x86/kernel/fpu/xstate.c
View File

@@ -221,6 +221,15 @@ void fpu__init_cpu_xstate(void)
{
if (!boot_cpu_has(X86_FEATURE_XSAVE) || !xfeatures_mask)
return;
/*
* Make it clear that XSAVES supervisor states are not yet
* implemented should anyone expect it to work by changing
* bits in XFEATURE_MASK_* macros and XCR0.
*/
WARN_ONCE((xfeatures_mask & XFEATURE_MASK_SUPERVISOR),
"x86/fpu: XSAVES supervisor states are not yet implemented.\n");
xfeatures_mask &= ~XFEATURE_MASK_SUPERVISOR;
cr4_set_bits(X86_CR4_OSXSAVE);
xsetbv(XCR_XFEATURE_ENABLED_MASK, xfeatures_mask);