* Re: [tip:x86/urgent] x86/fpu/xstate: Fix xcomp_bv in XSAVES header
2017-02-14 21:26 ` [tip:x86/urgent] x86/fpu/xstate: Fix xcomp_bv in XSAVES header Yu-cheng Yu
@ 2017-02-14 22:53 ` Greg Kroah-Hartman
2017-02-16 17:51 ` Greg Kroah-Hartman
1 sibling, 0 replies; 4+ messages in thread
From: Greg Kroah-Hartman @ 2017-02-14 22:53 UTC (permalink / raw)
To: Yu-cheng Yu
Cc: dave.hansen, linux-kernel, ravi.v.shankar, torvalds, haokexin,
tglx, Joakim.Tjernlund, mingo, peterz, hpa, fenghua.yu, luto, bp,
stable
On Tue, Feb 14, 2017 at 01:26:41PM -0800, Yu-cheng Yu wrote:
> On Tue, Jan 24, 2017 at 12:46:17AM -0800, tip-bot for Yu-cheng Yu wrote:
> > Commit-ID: dffba9a31c7769be3231c420d4b364c92ba3f1ac
> > Gitweb: http://git.kernel.org/tip/dffba9a31c7769be3231c420d4b364c92ba3f1ac
> > Author: Yu-cheng Yu <yu-cheng.yu@intel.com>
> > AuthorDate: Mon, 23 Jan 2017 14:54:44 -0800
> > Committer: Ingo Molnar <mingo@kernel.org>
> > CommitDate: Tue, 24 Jan 2017 09:04:48 +0100
> >
> > x86/fpu/xstate: Fix xcomp_bv in XSAVES header
> >
> > The compacted-format XSAVES area is determined at boot time and
> > never changed after. The field xsave.header.xcomp_bv indicates
> > which components are in the fixed XSAVES format.
> >
> > In fpstate_init() we did not set xcomp_bv to reflect the XSAVES
> > format since at the time there is no valid data.
> >
> > However, after we do copy_init_fpstate_to_fpregs() in fpu__clear(),
> > as in commit:
> >
> > b22cbe404a9c x86/fpu: Fix invalid FPU ptrace state after execve()
> >
> > and when __fpu_restore_sig() does fpu__restore() for a COMPAT-mode
> > app, a #GP occurs. This can be easily triggered by doing valgrind on
> > a COMPAT-mode "Hello World," as reported by Joakim Tjernlund and
> > others:
> >
> > https://bugzilla.kernel.org/show_bug.cgi?id=190061
> >
> > Fix it by setting xcomp_bv correctly.
> >
>
> Please consider pulling this into the stable tree because my previous
> patch in commit:
>
> b22cbe404a9c x86/fpu: Fix invalid FPU ptrace state after execve()
>
> exposes the same issue in the stable tree.
Ah, thanks, I'll do that for the next round of stable releases after the
ones that happen tomorrow.
greg k-h
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [tip:x86/urgent] x86/fpu/xstate: Fix xcomp_bv in XSAVES header
2017-02-14 21:26 ` [tip:x86/urgent] x86/fpu/xstate: Fix xcomp_bv in XSAVES header Yu-cheng Yu
2017-02-14 22:53 ` Greg Kroah-Hartman
@ 2017-02-16 17:51 ` Greg Kroah-Hartman
2017-02-16 17:51 ` Yu-cheng Yu
1 sibling, 1 reply; 4+ messages in thread
From: Greg Kroah-Hartman @ 2017-02-16 17:51 UTC (permalink / raw)
To: Yu-cheng Yu
Cc: dave.hansen, linux-kernel, ravi.v.shankar, torvalds, haokexin,
tglx, Joakim.Tjernlund, mingo, peterz, hpa, fenghua.yu, luto, bp,
stable
On Tue, Feb 14, 2017 at 01:26:41PM -0800, Yu-cheng Yu wrote:
> On Tue, Jan 24, 2017 at 12:46:17AM -0800, tip-bot for Yu-cheng Yu wrote:
> > Commit-ID: dffba9a31c7769be3231c420d4b364c92ba3f1ac
> > Gitweb: http://git.kernel.org/tip/dffba9a31c7769be3231c420d4b364c92ba3f1ac
> > Author: Yu-cheng Yu <yu-cheng.yu@intel.com>
> > AuthorDate: Mon, 23 Jan 2017 14:54:44 -0800
> > Committer: Ingo Molnar <mingo@kernel.org>
> > CommitDate: Tue, 24 Jan 2017 09:04:48 +0100
> >
> > x86/fpu/xstate: Fix xcomp_bv in XSAVES header
> >
> > The compacted-format XSAVES area is determined at boot time and
> > never changed after. The field xsave.header.xcomp_bv indicates
> > which components are in the fixed XSAVES format.
> >
> > In fpstate_init() we did not set xcomp_bv to reflect the XSAVES
> > format since at the time there is no valid data.
> >
> > However, after we do copy_init_fpstate_to_fpregs() in fpu__clear(),
> > as in commit:
> >
> > b22cbe404a9c x86/fpu: Fix invalid FPU ptrace state after execve()
> >
> > and when __fpu_restore_sig() does fpu__restore() for a COMPAT-mode
> > app, a #GP occurs. This can be easily triggered by doing valgrind on
> > a COMPAT-mode "Hello World," as reported by Joakim Tjernlund and
> > others:
> >
> > https://bugzilla.kernel.org/show_bug.cgi?id=190061
> >
> > Fix it by setting xcomp_bv correctly.
> >
>
> Please consider pulling this into the stable tree because my previous
> patch in commit:
>
> b22cbe404a9c x86/fpu: Fix invalid FPU ptrace state after execve()
>
> exposes the same issue in the stable tree.
I just tried to apply this, and it does not apply at all. Can you
please provide a backported version that you have verified will work, so
that I can apply it?
thanks,
greg k-h
^ permalink raw reply [flat|nested] 4+ messages in thread