Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]
Groups > linux.kernel > #1565317
| From | Dave Hansen <dave.hansen@linux.intel.com> |
|---|---|
| Newsgroups | linux.kernel |
| Subject | Re: [tip:x86/urgent] x86/fpu: Set the xcomp_bv when we fake up a XSAVES area |
| Date | 2017-01-23 22:30 +0100 |
| Message-ID | <t2Ulz-3fA-9@gated-at.bofh.it> (permalink) |
| References | (3 earlier) <t2Q8i-qo-31@gated-at.bofh.it> <t2QBl-Qy-29@gated-at.bofh.it> <t2U2f-36U-69@gated-at.bofh.it> <t2UbU-3bl-39@gated-at.bofh.it> <t2Ulz-3fA-5@gated-at.bofh.it> |
| Organization | linux.* mail to news gateway |
On 01/23/2017 01:16 PM, Yu-cheng Yu wrote:
> On Mon, Jan 23, 2017 at 01:10:20PM -0800, Dave Hansen wrote:
>> The code is:
>>
>>> void fpstate_init(union fpregs_state *state)
>>> {
>>> if (!static_cpu_has(X86_FEATURE_FPU)) {
>>> fpstate_init_soft(&state->soft);
>>> return;
>>> }
>>>
>>> memset(state, 0, fpu_kernel_xstate_size);
>>>
>>> /*
>>> * XRSTORS requires that this bit is set in xcomp_bv, or
>>> * it will #GP. Make sure it is replaced after the memset().
>>> */
>>> if (static_cpu_has(X86_FEATURE_XSAVES))
>>> state->xsave.header.xcomp_bv = XCOMP_BV_COMPACTED_FORMAT;
>>
>> That seems to set it unconditionally. What am I missing?
>
> The fix I am proposing is...
>
> state->xsave.header.xcomp_bv = XCOMP_BV_COMPACTED_FORMAT |
> xfeatures_mask;
Ahh, that makes sense. That does indeed look like a bug in fpstate_init().
Back to linux.kernel | Previous | Next — Previous in thread | Next in thread | Find similar | Unroll thread
[PATCH] x86/fpu: set the xcomp_bv when we fake up a XSAVES area Kevin Hao <haokexin@gmail.com> - 2017-01-22 10:00 +0100
[tip:x86/urgent] x86/fpu: Set the xcomp_bv when we fake up a XSAVES area tip-bot for Kevin Hao <tipbot@zytor.com> - 2017-01-23 09:30 +0100
Re: [tip:x86/urgent] x86/fpu: Set the xcomp_bv when we fake up a XSAVES area Dave Hansen <dave.hansen@linux.intel.com> - 2017-01-23 16:40 +0100
Re: [tip:x86/urgent] x86/fpu: Set the xcomp_bv when we fake up a XSAVES area Yu-cheng Yu <yu-cheng.yu@intel.com> - 2017-01-23 18:00 +0100
Re: [tip:x86/urgent] x86/fpu: Set the xcomp_bv when we fake up a XSAVES area Dave Hansen <dave.hansen@linux.intel.com> - 2017-01-23 18:30 +0100
Re: [tip:x86/urgent] x86/fpu: Set the xcomp_bv when we fake up a XSAVES area Yu-cheng Yu <yu-cheng.yu@intel.com> - 2017-01-23 22:10 +0100
Re: [tip:x86/urgent] x86/fpu: Set the xcomp_bv when we fake up a XSAVES area Dave Hansen <dave.hansen@linux.intel.com> - 2017-01-23 22:20 +0100
Re: [tip:x86/urgent] x86/fpu: Set the xcomp_bv when we fake up a XSAVES area Yu-cheng Yu <yu-cheng.yu@intel.com> - 2017-01-23 22:30 +0100
Re: [tip:x86/urgent] x86/fpu: Set the xcomp_bv when we fake up a XSAVES area Dave Hansen <dave.hansen@linux.intel.com> - 2017-01-23 22:30 +0100
Re: [tip:x86/urgent] x86/fpu: Set the xcomp_bv when we fake up a XSAVES area Kevin Hao <haokexin@gmail.com> - 2017-01-24 01:20 +0100
Re: [tip:x86/urgent] x86/fpu: Set the xcomp_bv when we fake up a XSAVES area Dave Hansen <dave.hansen@linux.intel.com> - 2017-01-24 02:00 +0100
Re: [tip:x86/urgent] x86/fpu: Set the xcomp_bv when we fake up a XSAVES area Kevin Hao <haokexin@gmail.com> - 2017-01-24 03:00 +0100
Re: [tip:x86/urgent] x86/fpu: Set the xcomp_bv when we fake up a XSAVES area Dave Hansen <dave.hansen@linux.intel.com> - 2017-01-24 03:10 +0100
Re: [tip:x86/urgent] x86/fpu: Set the xcomp_bv when we fake up a XSAVES area Kevin Hao <haokexin@gmail.com> - 2017-01-24 03:20 +0100
Re: [tip:x86/urgent] x86/fpu: Set the xcomp_bv when we fake up a XSAVES area Dave Hansen <dave.hansen@linux.intel.com> - 2017-01-24 03:40 +0100
Re: [tip:x86/urgent] x86/fpu: Set the xcomp_bv when we fake up a XSAVES area Kevin Hao <haokexin@gmail.com> - 2017-01-24 06:20 +0100
Re: [tip:x86/urgent] x86/fpu: Set the xcomp_bv when we fake up a XSAVES area Ingo Molnar <mingo@kernel.org> - 2017-01-24 09:10 +0100
[tip:x86/urgent] x86/fpu: Set the xcomp_bv when we fake up a XSAVES area tip-bot for Kevin Hao <tipbot@zytor.com> - 2017-01-23 10:50 +0100
csiph-web