From: tip-bot for Ingo Molnar <tipbot@zytor.com>
To: linux-tip-commits@vger.kernel.org
Cc: mingo@kernel.org, dave.hansen@linux.intel.com, riel@redhat.com,
yu-cheng.yu@intel.com, akpm@linux-foundation.org,
peterz@infradead.org, luto@kernel.org,
torvalds@linux-foundation.org, fenghua.yu@intel.com,
ebiggers3@gmail.com, luto@amacapital.net, oleg@redhat.com,
tglx@linutronix.de, hpa@zytor.com, bp@alien8.de,
linux-kernel@vger.kernel.org
Subject: [tip:x86/fpu] x86/fpu: Split the state handling in fpu__drop()
Date: Tue, 26 Sep 2017 01:28:10 -0700 [thread overview]
Message-ID: <tip-b6aa85558d7e7b18fc3470d2bc1731d2205dd275@git.kernel.org> (raw)
In-Reply-To: <20170923130016.21448-18-mingo@kernel.org>
Commit-ID: b6aa85558d7e7b18fc3470d2bc1731d2205dd275
Gitweb: http://git.kernel.org/tip/b6aa85558d7e7b18fc3470d2bc1731d2205dd275
Author: Ingo Molnar <mingo@kernel.org>
AuthorDate: Sat, 23 Sep 2017 15:00:00 +0200
Committer: Ingo Molnar <mingo@kernel.org>
CommitDate: Sun, 24 Sep 2017 13:04:34 +0200
x86/fpu: Split the state handling in fpu__drop()
Prepare fpu__drop() to use fpu->fpregs_active.
There are two distinct usecases for fpu__drop() in this context:
exit_thread() when called for 'current' in exit(), and when called
for another task in fork().
This patch does not change behavior, it only adds a couple of
debug checks and structures the code to make the ->fpregs_active
change more obviously correct.
All the complications will be removed later on.
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Eric Biggers <ebiggers3@gmail.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rik van Riel <riel@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Yu-cheng Yu <yu-cheng.yu@intel.com>
Link: http://lkml.kernel.org/r/20170923130016.21448-18-mingo@kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
---
arch/x86/kernel/fpu/core.c | 19 +++++++++++++------
1 file changed, 13 insertions(+), 6 deletions(-)
diff --git a/arch/x86/kernel/fpu/core.c b/arch/x86/kernel/fpu/core.c
index b7dc383..815dfba 100644
--- a/arch/x86/kernel/fpu/core.c
+++ b/arch/x86/kernel/fpu/core.c
@@ -414,12 +414,19 @@ void fpu__drop(struct fpu *fpu)
{
preempt_disable();
- if (fpu->fpregs_active) {
- /* Ignore delayed exceptions from user space */
- asm volatile("1: fwait\n"
- "2:\n"
- _ASM_EXTABLE(1b, 2b));
- fpregs_deactivate(fpu);
+ if (fpu == ¤t->thread.fpu) {
+ WARN_ON_FPU(fpu->fpstate_active != fpu->fpregs_active);
+
+ if (fpu->fpregs_active) {
+ /* Ignore delayed exceptions from user space */
+ asm volatile("1: fwait\n"
+ "2:\n"
+ _ASM_EXTABLE(1b, 2b));
+ if (fpu->fpregs_active)
+ fpregs_deactivate(fpu);
+ }
+ } else {
+ WARN_ON_FPU(fpu->fpregs_active);
}
fpu->fpstate_active = 0;
next prev parent reply other threads:[~2017-09-26 8:34 UTC|newest]
Thread overview: 94+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-09-23 12:59 [PATCH 00/33] x86 FPU fixes and cleanups for v4.14 Ingo Molnar
2017-09-23 12:59 ` [PATCH 01/33] x86/fpu: Rename copyin_to_xsaves()/copyout_from_xsaves() to copy_user_to_xstate()/copy_xstate_to_user() Ingo Molnar
2017-09-26 8:21 ` [tip:x86/fpu] " tip-bot for Ingo Molnar
2017-09-23 12:59 ` [PATCH 02/33] x86/fpu: Split copy_xstate_to_user() into copy_xstate_to_kernel() & copy_xstate_to_user() Ingo Molnar
2017-09-26 8:22 ` [tip:x86/fpu] " tip-bot for Ingo Molnar
2017-09-23 12:59 ` [PATCH 03/33] x86/fpu: Remove 'ubuf' parameter from the copy_xstate_to_kernel() APIs Ingo Molnar
2017-09-26 8:22 ` [tip:x86/fpu] " tip-bot for Ingo Molnar
2017-09-23 12:59 ` [PATCH 04/33] x86/fpu: Remove 'kbuf' parameter from the copy_xstate_to_user() APIs Ingo Molnar
2017-09-26 8:23 ` [tip:x86/fpu] " tip-bot for Ingo Molnar
2017-09-23 12:59 ` [PATCH 05/33] x86/fpu: Clean up parameter order in the copy_xstate_to_*() APIs Ingo Molnar
2017-09-26 8:23 ` [tip:x86/fpu] " tip-bot for Ingo Molnar
2017-09-23 12:59 ` [PATCH 06/33] x86/fpu: Clean up the parameter definitions of copy_xstate_to_*() Ingo Molnar
2017-09-26 8:23 ` [tip:x86/fpu] " tip-bot for Ingo Molnar
2017-09-23 12:59 ` [PATCH 07/33] x86/fpu: Remove the 'start_pos' parameter from the __copy_xstate_to_*() functions Ingo Molnar
2017-09-26 8:24 ` [tip:x86/fpu] " tip-bot for Ingo Molnar
2017-09-23 12:59 ` [PATCH 08/33] x86/fpu: Clarify parameter names in the copy_xstate_to_*() methods Ingo Molnar
2017-09-25 19:56 ` Thomas Gleixner
2017-09-25 20:01 ` Thomas Gleixner
2017-09-26 8:24 ` [tip:x86/fpu] " tip-bot for Ingo Molnar
2017-09-23 12:59 ` [PATCH 09/33] x86/fpu: Change 'size_total' parameter to unsigned and standardize the size checks in copy_xstate_to_*() Ingo Molnar
2017-09-26 8:25 ` [tip:x86/fpu] " tip-bot for Ingo Molnar
2017-09-23 12:59 ` [PATCH 10/33] x86/fpu: Simplify __copy_xstate_to_kernel() return values Ingo Molnar
2017-09-26 8:25 ` [tip:x86/fpu] " tip-bot for Ingo Molnar
2017-09-23 12:59 ` [PATCH 11/33] x86/fpu: Split copy_user_to_xstate() into copy_kernel_to_xstate() & copy_user_to_xstate() Ingo Molnar
2017-09-26 8:25 ` [tip:x86/fpu] " tip-bot for Ingo Molnar
2017-09-23 12:59 ` [PATCH 12/33] x86/fpu: Remove 'ubuf' parameter from the copy_kernel_to_xstate() API Ingo Molnar
2017-09-26 8:26 ` [tip:x86/fpu] " tip-bot for Ingo Molnar
2017-09-23 12:59 ` [PATCH 13/33] x86/fpu: Remove 'kbuf' parameter from the copy_user_to_xstate() API Ingo Molnar
2017-09-26 8:26 ` [tip:x86/fpu] " tip-bot for Ingo Molnar
2017-09-23 12:59 ` [PATCH 14/33] x86/fpu: Flip the parameter order in copy_*_to_xstate() Ingo Molnar
2017-09-26 8:27 ` [tip:x86/fpu] " tip-bot for Ingo Molnar
2017-09-23 12:59 ` [PATCH 15/33] x86/fpu: Simplify fpu->fpregs_active use Ingo Molnar
2017-09-26 8:27 ` [tip:x86/fpu] " tip-bot for Ingo Molnar
2017-09-23 12:59 ` [PATCH 16/33] x86/fpu: Make the fpu state change in fpu__clear() scheduler-atomic Ingo Molnar
2017-09-26 8:27 ` [tip:x86/fpu] " tip-bot for Ingo Molnar
2017-09-23 13:00 ` [PATCH 17/33] x86/fpu: Split the state handling in fpu__drop() Ingo Molnar
2017-09-26 8:28 ` tip-bot for Ingo Molnar [this message]
2017-09-23 13:00 ` [PATCH 18/33] x86/fpu: Change fpu->fpregs_active users to fpu->fpstate_active Ingo Molnar
2017-09-26 8:28 ` [tip:x86/fpu] " tip-bot for Ingo Molnar
2017-09-23 13:00 ` [PATCH 19/33] x86/fpu: Decouple fpregs_activate()/fpregs_deactivate() from fpu->fpregs_active Ingo Molnar
2017-09-26 8:28 ` [tip:x86/fpu] " tip-bot for Ingo Molnar
2017-09-23 13:00 ` [PATCH 20/33] x86/fpu: Remove struct fpu::fpregs_active Ingo Molnar
2017-09-26 8:29 ` [tip:x86/fpu] " tip-bot for Ingo Molnar
2017-09-23 13:00 ` [PATCH 21/33] x86/fpu: Add FPU state copying quirk to handle XRSTOR failure on Intel Skylake CPUs Ingo Molnar
2017-09-26 8:29 ` [tip:x86/fpu] " tip-bot for Rik van Riel
2017-09-23 13:00 ` [PATCH 22/33] x86/fpu: Fix boolreturn.cocci warnings Ingo Molnar
2017-09-26 8:30 ` [tip:x86/fpu] " tip-bot for kbuild test robot
2017-09-23 13:00 ` [PATCH 23/33] x86/fpu: Turn WARN_ON() in context switch into WARN_ON_FPU() Ingo Molnar
2017-09-26 8:30 ` [tip:x86/fpu] " tip-bot for Andi Kleen
2017-09-23 13:00 ` [PATCH 24/33] x86/fpu: Don't let userspace set bogus xcomp_bv Ingo Molnar
2017-09-26 8:30 ` [tip:x86/fpu] " tip-bot for Eric Biggers
2017-09-23 13:00 ` [PATCH 25/33] x86/fpu: Tighten validation of user-supplied xstate_header Ingo Molnar
2017-09-23 13:00 ` [PATCH 26/33] x86/fpu: Reinitialize FPU registers if restoring FPU state fails Ingo Molnar
2017-09-26 8:31 ` [tip:x86/fpu] " tip-bot for Eric Biggers
2017-09-23 13:00 ` [PATCH 27/33] x86/fpu: Simplify fpu__activate_fpstate_read() Ingo Molnar
2017-09-26 8:31 ` [tip:x86/fpu] x86/fpu: Fix fpu__activate_fpstate_read() and update comments tip-bot for Ingo Molnar
2017-09-23 13:00 ` [PATCH 28/33] x86/fpu: Remove fpu__current_fpstate_write_begin/end() Ingo Molnar
2017-09-26 8:32 ` [tip:x86/fpu] " tip-bot for Ingo Molnar
2017-09-23 13:00 ` [PATCH 29/33] x86/fpu: Rename fpu::fpstate_active to fpu::initialized Ingo Molnar
2017-09-26 8:32 ` [tip:x86/fpu] " tip-bot for Ingo Molnar
2017-09-23 13:00 ` [PATCH 30/33] x86/fpu: Fix stale comments about lazy FPU logic Ingo Molnar
2017-09-26 8:32 ` [tip:x86/fpu] " tip-bot for Ingo Molnar
2017-09-23 13:00 ` [PATCH 31/33] x86/fpu: Simplify and speed up fpu__copy() Ingo Molnar
2017-09-26 8:33 ` [tip:x86/fpu] " tip-bot for Ingo Molnar
2017-09-23 13:00 ` [PATCH 32/33] x86/fpu: Rename fpu__activate_curr() to fpu__initialize() Ingo Molnar
2017-09-26 8:33 ` [tip:x86/fpu] " tip-bot for Ingo Molnar
2017-09-23 13:00 ` [PATCH 33/33] x86/fpu: Rename fpu__activate_fpstate_read/write() to fpu__read/write() Ingo Molnar
2017-09-23 13:02 ` [PATCH 00/33] x86 FPU fixes and cleanups for v4.14 Ingo Molnar
2017-09-23 15:03 ` Juergen Gross
2017-09-23 23:27 ` Ingo Molnar
-- strict thread matches above, loose matches on Subject: below --
2017-09-22 17:41 [PATCH v4 0/3] x86/fpu: prevent leaking FPU registers via invalid FPU state Eric Biggers
2017-09-22 17:41 ` [PATCH v4 1/3] x86/fpu: don't let userspace set bogus xcomp_bv Eric Biggers
2017-09-22 17:41 ` [PATCH v4 2/3] x86/fpu: tighten validation of user-supplied xstate_header Eric Biggers
2017-09-22 17:41 ` [PATCH v4 3/3] x86/fpu: reinitialize FPU registers if restoring FPU state fails Eric Biggers
2017-09-23 9:09 ` [PATCH v4 0/3] x86/fpu: prevent leaking FPU registers via invalid FPU state Ingo Molnar
2017-03-29 6:26 [PATCH] x86/fpu: Turn WARN_ON in context switch into WARN_ON_FPU Andi Kleen
2017-04-24 21:00 ` [tip:perf/core] x86/fpu: Turn WARN_ON() in context switch into WARN_ON_FPU() tip-bot for Andi Kleen
2017-03-06 0:45 [tip:WIP.x86/fpu 31/31] arch/x86/kernel/fpu/xstate.c:931:9-10: WARNING: return of 0/1 in function 'xfeatures_mxcsr_quirk' with return type bool kbuild test robot
2017-03-06 0:45 ` [PATCH] x86/fpu: fix boolreturn.cocci warnings kbuild test robot
2017-03-07 7:23 ` Ingo Molnar
2017-03-07 8:33 ` Thomas Gleixner
2017-03-07 9:01 ` Ingo Molnar
2017-03-07 12:01 ` Joe Perches
2017-04-24 20:54 ` [tip:perf/core] x86/fpu: Fix " tip-bot for kbuild test robot
2017-02-09 23:43 [PATCH v2] x86/fpu: copy MXCSR & MXCSR_FLAGS with SSE/YMM state Rik van Riel
2017-02-10 0:02 ` Borislav Petkov
2017-02-10 0:51 ` Rik van Riel
2017-02-10 8:00 ` Ingo Molnar
2017-02-10 13:54 ` [PATCH v3] " Rik van Riel
2017-02-11 10:02 ` Ingo Molnar
2017-04-24 20:54 ` [tip:perf/core] x86/fpu: Add FPU state copying quirk to handle XRSTOR failure on Intel Skylake CPUs tip-bot for Rik van Riel
2017-02-10 0:45 ` [PATCH v2] x86/fpu: copy MXCSR & MXCSR_FLAGS with SSE/YMM state Yu-cheng Yu
2017-02-10 1:00 ` Rik van Riel
2017-02-10 17:18 ` Yu-cheng Yu
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