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From: tip-bot for Ingo Molnar <tipbot@zytor.com>
To: linux-tip-commits@vger.kernel.org
Cc: peterz@infradead.org, luto@amacapital.net, ebiggers3@gmail.com,
	torvalds@linux-foundation.org, fenghua.yu@intel.com,
	mingo@kernel.org, hpa@zytor.com, linux-kernel@vger.kernel.org,
	oleg@redhat.com, akpm@linux-foundation.org, riel@redhat.com,
	dave.hansen@linux.intel.com, bp@alien8.de, tglx@linutronix.de,
	yu-cheng.yu@intel.com, luto@kernel.org
Subject: [tip:x86/fpu] x86/fpu: Change fpu->fpregs_active users to fpu->fpstate_active
Date: Tue, 26 Sep 2017 01:28:35 -0700	[thread overview]
Message-ID: <tip-f1c8cd0176078c7bcafdc89cac447cab672a0b5e@git.kernel.org> (raw)
In-Reply-To: <20170923130016.21448-19-mingo@kernel.org>

Commit-ID:  f1c8cd0176078c7bcafdc89cac447cab672a0b5e
Gitweb:     http://git.kernel.org/tip/f1c8cd0176078c7bcafdc89cac447cab672a0b5e
Author:     Ingo Molnar <mingo@kernel.org>
AuthorDate: Sat, 23 Sep 2017 15:00:01 +0200
Committer:  Ingo Molnar <mingo@kernel.org>
CommitDate: Sun, 24 Sep 2017 13:04:34 +0200

x86/fpu: Change fpu->fpregs_active users to fpu->fpstate_active

We want to simplify the FPU state machine by eliminating fpu->fpregs_active,
and we can do that because the two state flags (::fpregs_active and
::fpstate_active) are set essentially together.

The old lazy FPU switching code used to make a distinction - but there's
no lazy switching code anymore, we always switch in an 'eager' fashion.

Do this by first changing all substantial uses of fpu->fpregs_active
to fpu->fpstate_active and adding a few debug checks to double check
our assumption is correct.

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/20170923130016.21448-19-mingo@kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
---
 arch/x86/include/asm/fpu/internal.h |  4 +++-
 arch/x86/kernel/fpu/core.c          | 16 ++++++++++------
 arch/x86/kernel/fpu/signal.c        |  4 +++-
 arch/x86/mm/pkeys.c                 |  3 +--
 4 files changed, 17 insertions(+), 10 deletions(-)

diff --git a/arch/x86/include/asm/fpu/internal.h b/arch/x86/include/asm/fpu/internal.h
index b223c57..7fa676f 100644
--- a/arch/x86/include/asm/fpu/internal.h
+++ b/arch/x86/include/asm/fpu/internal.h
@@ -556,7 +556,9 @@ static inline void fpregs_activate(struct fpu *fpu)
 static inline void
 switch_fpu_prepare(struct fpu *old_fpu, int cpu)
 {
-	if (old_fpu->fpregs_active) {
+	WARN_ON_FPU(old_fpu->fpregs_active != old_fpu->fpstate_active);
+
+	if (old_fpu->fpstate_active) {
 		if (!copy_fpregs_to_fpstate(old_fpu))
 			old_fpu->last_cpu = -1;
 		else
diff --git a/arch/x86/kernel/fpu/core.c b/arch/x86/kernel/fpu/core.c
index 815dfba..eab2446 100644
--- a/arch/x86/kernel/fpu/core.c
+++ b/arch/x86/kernel/fpu/core.c
@@ -100,7 +100,7 @@ void __kernel_fpu_begin(void)
 
 	kernel_fpu_disable();
 
-	if (fpu->fpregs_active) {
+	if (fpu->fpstate_active) {
 		/*
 		 * Ignore return value -- we don't care if reg state
 		 * is clobbered.
@@ -116,7 +116,7 @@ void __kernel_fpu_end(void)
 {
 	struct fpu *fpu = &current->thread.fpu;
 
-	if (fpu->fpregs_active)
+	if (fpu->fpstate_active)
 		copy_kernel_to_fpregs(&fpu->state);
 
 	kernel_fpu_enable();
@@ -147,8 +147,10 @@ void fpu__save(struct fpu *fpu)
 	WARN_ON_FPU(fpu != &current->thread.fpu);
 
 	preempt_disable();
+	WARN_ON_FPU(fpu->fpstate_active != fpu->fpregs_active);
+
 	trace_x86_fpu_before_save(fpu);
-	if (fpu->fpregs_active) {
+	if (fpu->fpstate_active) {
 		if (!copy_fpregs_to_fpstate(fpu)) {
 			copy_kernel_to_fpregs(&fpu->state);
 		}
@@ -262,11 +264,12 @@ EXPORT_SYMBOL_GPL(fpu__activate_curr);
  */
 void fpu__activate_fpstate_read(struct fpu *fpu)
 {
+	WARN_ON_FPU(fpu->fpstate_active != fpu->fpregs_active);
 	/*
 	 * If fpregs are active (in the current CPU), then
 	 * copy them to the fpstate:
 	 */
-	if (fpu->fpregs_active) {
+	if (fpu->fpstate_active) {
 		fpu__save(fpu);
 	} else {
 		if (!fpu->fpstate_active) {
@@ -362,12 +365,13 @@ void fpu__current_fpstate_write_end(void)
 {
 	struct fpu *fpu = &current->thread.fpu;
 
+	WARN_ON_FPU(fpu->fpstate_active != fpu->fpregs_active);
 	/*
 	 * 'fpu' now has an updated copy of the state, but the
 	 * registers may still be out of date.  Update them with
 	 * an XRSTOR if they are active.
 	 */
-	if (fpu->fpregs_active)
+	if (fpu->fpstate_active)
 		copy_kernel_to_fpregs(&fpu->state);
 
 	/*
@@ -417,7 +421,7 @@ void fpu__drop(struct fpu *fpu)
 	if (fpu == &current->thread.fpu) {
 		WARN_ON_FPU(fpu->fpstate_active != fpu->fpregs_active);
 
-		if (fpu->fpregs_active) {
+		if (fpu->fpstate_active) {
 			/* Ignore delayed exceptions from user space */
 			asm volatile("1: fwait\n"
 				     "2:\n"
diff --git a/arch/x86/kernel/fpu/signal.c b/arch/x86/kernel/fpu/signal.c
index 6840256..a88083b 100644
--- a/arch/x86/kernel/fpu/signal.c
+++ b/arch/x86/kernel/fpu/signal.c
@@ -171,7 +171,9 @@ 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;
 
-	if (fpu->fpregs_active || using_compacted_format()) {
+	WARN_ON_FPU(fpu->fpstate_active != fpu->fpregs_active);
+
+	if (fpu->fpstate_active || using_compacted_format()) {
 		/* Save the live register state to the user directly. */
 		if (copy_fpregs_to_sigframe(buf_fx))
 			return -1;
diff --git a/arch/x86/mm/pkeys.c b/arch/x86/mm/pkeys.c
index e2c2347..4d24269 100644
--- a/arch/x86/mm/pkeys.c
+++ b/arch/x86/mm/pkeys.c
@@ -18,7 +18,6 @@
 
 #include <asm/cpufeature.h>             /* boot_cpu_has, ...            */
 #include <asm/mmu_context.h>            /* vma_pkey()                   */
-#include <asm/fpu/internal.h>           /* fpregs_active()              */
 
 int __execute_only_pkey(struct mm_struct *mm)
 {
@@ -45,7 +44,7 @@ int __execute_only_pkey(struct mm_struct *mm)
 	 */
 	preempt_disable();
 	if (!need_to_set_mm_pkey &&
-	    current->thread.fpu.fpregs_active &&
+	    current->thread.fpu.fpstate_active &&
 	    !__pkru_allows_read(read_pkru(), execute_only_pkey)) {
 		preempt_enable();
 		return execute_only_pkey;

  reply	other threads:[~2017-09-26  8:35 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:x86/fpu] " tip-bot for Ingo Molnar
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-bot for Ingo Molnar [this message]
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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