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    Subject[PATCH 04/22] x86/fpu: Always init the `state' in fpu__clear()
    Date
    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(-)

    diff --git a/arch/x86/include/asm/fpu/internal.h b/arch/x86/include/asm/fpu/internal.h
    index 67675d023d4f8..9f0b3ff8c9b7b 100644
    --- 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);
    diff --git a/arch/x86/kernel/fpu/core.c b/arch/x86/kernel/fpu/core.c
    index 1940319268aef..e43296854e379 100644
    --- 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, struct fpu *src_fpu)
    * 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 != &current->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();
    }
    diff --git a/arch/x86/math-emu/fpu_entry.c b/arch/x86/math-emu/fpu_entry.c
    index 9e2ba7e667f61..a873da6b46d6b 100644
    --- 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 *info)
    unsigned long code_base = 0;
    unsigned long code_limit = 0; /* Initialized to stop compiler warnings */
    struct desc_struct code_descriptor;
    - struct fpu *fpu = &current->thread.fpu;
    -
    - fpu__initialize(fpu);

    #ifdef RE_ENTRANT_CHECKING
    if (emulating) {
    --
    2.20.1
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