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From: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Date: Wed, 17 Oct 2018 15:27:34 +0200
Subject: [PATCH 04/27] x86/fpu: Always init the `state' in fpu__clear()
Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/5.0/older/patches-5.0.7-rt5.tar.xz
fpu__clear() only initializes the `state' if the FPU is present. This
initialisation is also required for the FPU-less system and takes place
in math_emulate(). Since fpu__initialize() only performs the
initialization if ->initialized is zero it does not matter that it is
invoked each time an opcode is emulated. It makes the removal of
->initialized easier if the struct is also initialized in the FPU-less
case at the same time.
Move fpu__initialize() before the FPU check so it is also performed in
the FPU-less case.
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Reviewed-by: Borislav Petkov <bp@suse.de>
---
arch/x86/include/asm/fpu/internal.h | 1 -
arch/x86/kernel/fpu/core.c | 5 ++---
arch/x86/math-emu/fpu_entry.c | 3 ---
3 files changed, 2 insertions(+), 7 deletions(-)
--- a/arch/x86/include/asm/fpu/internal.h
+++ b/arch/x86/include/asm/fpu/internal.h
@@ -24,7 +24,6 @@
/*
* High level FPU state handling functions:
*/
-extern void fpu__initialize(struct fpu *fpu);
extern void fpu__prepare_read(struct fpu *fpu);
extern void fpu__prepare_write(struct fpu *fpu);
extern void fpu__save(struct fpu *fpu);
--- a/arch/x86/kernel/fpu/core.c
+++ b/arch/x86/kernel/fpu/core.c
@@ -223,7 +223,7 @@ int fpu__copy(struct fpu *dst_fpu, struc
* Activate the current task's in-memory FPU context,
* if it has not been used before:
*/
-void fpu__initialize(struct fpu *fpu)
+static void fpu__initialize(struct fpu *fpu)
{
WARN_ON_FPU(fpu != ¤t->thread.fpu);
@@ -236,7 +236,6 @@ void fpu__initialize(struct fpu *fpu)
fpu->initialized = 1;
}
}
-EXPORT_SYMBOL_GPL(fpu__initialize);
/*
* This function must be called before we read a task's fpstate.
@@ -365,8 +364,8 @@ void fpu__clear(struct fpu *fpu)
/*
* Make sure fpstate is cleared and initialized.
*/
+ fpu__initialize(fpu);
if (static_cpu_has(X86_FEATURE_FPU)) {
- fpu__initialize(fpu);
user_fpu_begin();
copy_init_fpstate_to_fpregs();
}
--- a/arch/x86/math-emu/fpu_entry.c
+++ b/arch/x86/math-emu/fpu_entry.c
@@ -113,9 +113,6 @@ void math_emulate(struct math_emu_info *
unsigned long code_base = 0;
unsigned long code_limit = 0; /* Initialized to stop compiler warnings */
struct desc_struct code_descriptor;
- struct fpu *fpu = ¤t->thread.fpu;
-
- fpu__initialize(fpu);
#ifdef RE_ENTRANT_CHECKING
if (emulating) {
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