[PATCH 052/208] x86/fpu: Open code PF_USED_MATH usages

Ingo Molnar
2015-05-05T16:53:36Z

PF_USED_MATH is used directly, but also in a handful of helper inlines.

To ease the elimination of PF_USED_MATH, convert all inline helpers
to open-coded PF_USED_MATH usage.

Reviewed-by: Borislav Petkov <bp@alien8.de>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
---
arch/x86/ia32/ia32_signal.c | 2 +-
arch/x86/include/asm/fpu-internal.h | 5 +++--
arch/x86/kernel/fpu/core.c | 14 ++++++++------
arch/x86/kernel/fpu/xsave.c | 10 +++++-----
arch/x86/kernel/signal.c | 6 +++---
arch/x86/kvm/x86.c | 2 +-
arch/x86/math-emu/fpu_entry.c | 2 +-
7 files changed, 22 insertions(+), 19 deletions(-)

diff --git a/arch/x86/ia32/ia32_signal.c b/arch/x86/ia32/ia32_signal.c
index 4bafd5b05aca..bffb2c49ceb6 100644
--- a/arch/x86/ia32/ia32_signal.c
+++ b/arch/x86/ia32/ia32_signal.c
@@ -321,7 +321,7 @@ static void __user *get_sigframe(struct ksignal *ksig, struct pt_regs *regs,
ksig->ka.sa.sa_restorer)
sp = (unsigned long) ksig->ka.sa.sa_restorer;

- if (used_math()) {
+ if (current->flags & PF_USED_MATH) {
unsigned long fx_aligned, math_size;

sp = alloc_mathframe(sp, 1, &fx_aligned, &math_size);
diff --git a/arch/x86/include/asm/fpu-internal.h b/arch/x86/include/asm/fpu-internal.h
index 44516ad6c890..2cac49e3b4bd 100644
--- a/arch/x86/include/asm/fpu-internal.h
+++ b/arch/x86/include/asm/fpu-internal.h
@@ -375,7 +375,8 @@ static inline void drop_fpu(struct task_struct *tsk)
__thread_fpu_end(fpu);
}

- clear_stopped_child_used_math(tsk);
+ tsk->flags &= ~PF_USED_MATH;
+
preempt_enable();
}

@@ -423,7 +424,7 @@ static inline fpu_switch_t switch_fpu_prepare(struct task_struct *old, struct ta
* If the task has used the math, pre-load the FPU on xsave processors
* or if the past 5 consecutive context-switches used math.
*/
- fpu.preload = tsk_used_math(new) &&
+ fpu.preload = (new->flags & PF_USED_MATH) &&
(use_eager_fpu() || new->thread.fpu.counter > 5);

if (old_fpu->has_fpu) {
diff --git a/arch/x86/kernel/fpu/core.c b/arch/x86/kernel/fpu/core.c
index 275bdb768895..b8e3dbbcdc16 100644
--- a/arch/x86/kernel/fpu/core.c
+++ b/arch/x86/kernel/fpu/core.c
@@ -242,7 +242,7 @@ int fpu__copy(struct task_struct *dst, struct task_struct *src)

task_disable_lazy_fpu_restore(dst);

- if (tsk_used_math(src)) {
+ if (src->flags & PF_USED_MATH) {
int err = fpstate_alloc(&dst->thread.fpu);

if (err)
@@ -331,7 +331,7 @@ void fpu__restore(void)
struct task_struct *tsk = current;
struct fpu *fpu = &tsk->thread.fpu;

- if (!tsk_used_math(tsk)) {
+ if (!(tsk->flags & PF_USED_MATH)) {
local_irq_enable();
/*
* does a slab alloc which can sleep
@@ -361,11 +361,13 @@ EXPORT_SYMBOL_GPL(fpu__restore);

void fpu__flush_thread(struct task_struct *tsk)
{
+ WARN_ON(tsk != current);
+
if (!use_eager_fpu()) {
/* FPU state will be reallocated lazily at the first use. */
drop_fpu(tsk);
fpstate_free(&tsk->thread.fpu);
- } else if (!used_math()) {
+ } else if (!(tsk->flags & PF_USED_MATH)) {
/* kthread execs. TODO: cleanup this horror. */
if (WARN_ON(fpstate_alloc_init(tsk)))
force_sig(SIGKILL, tsk);
@@ -381,12 +383,12 @@ void fpu__flush_thread(struct task_struct *tsk)
*/
int fpregs_active(struct task_struct *target, const struct user_regset *regset)
{
- return tsk_used_math(target) ? regset->n : 0;
+ return (target->flags & PF_USED_MATH) ? regset->n : 0;
}

int xfpregs_active(struct task_struct *target, const struct user_regset *regset)
{
- return (cpu_has_fxsr && tsk_used_math(target)) ? regset->n : 0;
+ return (cpu_has_fxsr && (target->flags & PF_USED_MATH)) ? regset->n : 0;
}

int xfpregs_get(struct task_struct *target, const struct user_regset *regset,
@@ -717,7 +719,7 @@ int dump_fpu(struct pt_regs *regs, struct user_i387_struct *fpu)
struct task_struct *tsk = current;
int fpvalid;

- fpvalid = !!used_math();
+ fpvalid = !!(tsk->flags & PF_USED_MATH);
if (fpvalid)
fpvalid = !fpregs_get(tsk, NULL,
0, sizeof(struct user_i387_ia32_struct),
diff --git a/arch/x86/kernel/fpu/xsave.c b/arch/x86/kernel/fpu/xsave.c
index 61696c5005eb..8cd127049c9b 100644
--- a/arch/x86/kernel/fpu/xsave.c
+++ b/arch/x86/kernel/fpu/xsave.c
@@ -349,7 +349,7 @@ int __restore_xstate_sig(void __user *buf, void __user *buf_fx, int size)
if (!access_ok(VERIFY_READ, buf, size))
return -EACCES;

- if (!used_math() && fpstate_alloc_init(tsk))
+ if (!(tsk->flags & PF_USED_MATH) && fpstate_alloc_init(tsk))
return -1;

if (!static_cpu_has(X86_FEATURE_FPU))
@@ -384,12 +384,12 @@ int __restore_xstate_sig(void __user *buf, void __user *buf_fx, int size)
int err = 0;

/*
- * Drop the current fpu which clears used_math(). This ensures
+ * Drop the current fpu which clears PF_USED_MATH. This ensures
* that any context-switch during the copy of the new state,
* avoids the intermediate state from getting restored/saved.
* Thus avoiding the new restored state from getting corrupted.
* We will be ready to restore/save the state only after
- * set_used_math() is again set.
+ * PF_USED_MATH is again set.
*/
drop_fpu(tsk);

@@ -401,7 +401,7 @@ int __restore_xstate_sig(void __user *buf, void __user *buf_fx, int size)
sanitize_restored_xstate(tsk, &env, xstate_bv, fx_only);
}

- set_used_math();
+ tsk->flags |= PF_USED_MATH;
if (use_eager_fpu()) {
preempt_disable();
fpu__restore();
@@ -685,7 +685,7 @@ void xsave_init(void)
*/
void __init_refok eager_fpu_init(void)
{
- WARN_ON(used_math());
+ WARN_ON(current->flags & PF_USED_MATH);
current_thread_info()->status = 0;

if (eagerfpu == ENABLE)
diff --git a/arch/x86/kernel/signal.c b/arch/x86/kernel/signal.c
index 35f867aa597e..8e2529ebb8c6 100644
--- a/arch/x86/kernel/signal.c
+++ b/arch/x86/kernel/signal.c
@@ -217,7 +217,7 @@ get_sigframe(struct k_sigaction *ka, struct pt_regs *regs, size_t frame_size,
}
}

- if (used_math()) {
+ if (current->flags & PF_USED_MATH) {
sp = alloc_mathframe(sp, config_enabled(CONFIG_X86_32),
&buf_fx, &math_size);
*fpstate = (void __user *)sp;
@@ -233,7 +233,7 @@ get_sigframe(struct k_sigaction *ka, struct pt_regs *regs, size_t frame_size,
return (void __user *)-1L;

/* save i387 and extended state */
- if (used_math() &&
+ if ((current->flags & PF_USED_MATH) &&
save_xstate_sig(*fpstate, (void __user *)buf_fx, math_size) < 0)
return (void __user *)-1L;

@@ -664,7 +664,7 @@ handle_signal(struct ksignal *ksig, struct pt_regs *regs)
/*
* Ensure the signal handler starts with the new fpu state.
*/
- if (used_math())
+ if (current->flags & PF_USED_MATH)
fpu_reset_state(current);
}
signal_setup_done(failed, ksig, stepping);
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index be276e0fe0ff..0635a1fd43ba 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -6600,7 +6600,7 @@ int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu, struct kvm_run *kvm_run)
int r;
sigset_t sigsaved;

- if (!tsk_used_math(current) && fpstate_alloc_init(current))
+ if (!(current->flags & PF_USED_MATH) && fpstate_alloc_init(current))
return -ENOMEM;

if (vcpu->sigset_active)
diff --git a/arch/x86/math-emu/fpu_entry.c b/arch/x86/math-emu/fpu_entry.c
index c9ff09a02385..bf628804d67c 100644
--- a/arch/x86/math-emu/fpu_entry.c
+++ b/arch/x86/math-emu/fpu_entry.c
@@ -148,7 +148,7 @@ void math_emulate(struct math_emu_info *info)
unsigned long code_limit = 0; /* Initialized to stop compiler warnings */
struct desc_struct code_descriptor;

- if (!used_math()) {
+ if (!(current->flags & PF_USED_MATH)) {
if (fpstate_alloc_init(current)) {
do_group_exit(SIGKILL);
return;
--
2.1.0