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    Subject[PATCH 05/22] x86/fpu: Remove fpu->initialized usage in copy_fpstate_to_sigframe()
    Date
    Since ->initialized is always true for user tasks and kernel threads
    don't get this far, we always save the registers directly to userspace.

    Remove check for ->initialized because it is always true and remove the
    false condition.

    Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
    ---
    arch/x86/kernel/fpu/signal.c | 30 ++++++------------------------
    1 file changed, 6 insertions(+), 24 deletions(-)

    diff --git a/arch/x86/kernel/fpu/signal.c b/arch/x86/kernel/fpu/signal.c
    index c0cdcb9b7de5a..c136a4327659d 100644
    --- a/arch/x86/kernel/fpu/signal.c
    +++ b/arch/x86/kernel/fpu/signal.c
    @@ -157,7 +157,6 @@ static inline int copy_fpregs_to_sigframe(struct xregs_state __user *buf)
    int copy_fpstate_to_sigframe(void __user *buf, void __user *buf_fx, int size)
    {
    struct fpu *fpu = &current->thread.fpu;
    - struct xregs_state *xsave = &fpu->state.xsave;
    struct task_struct *tsk = current;
    int ia32_fxstate = (buf != buf_fx);

    @@ -172,29 +171,12 @@ 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->initialized || using_compacted_format()) {
    - /* Save the live register state to the user directly. */
    - if (copy_fpregs_to_sigframe(buf_fx))
    - return -1;
    - /* Update the thread's fxstate to save the fsave header. */
    - if (ia32_fxstate)
    - copy_fxregs_to_kernel(fpu);
    - } else {
    - /*
    - * It is a *bug* if kernel uses compacted-format for xsave
    - * area and we copy it out directly to a signal frame. It
    - * should have been handled above by saving the registers
    - * directly.
    - */
    - if (boot_cpu_has(X86_FEATURE_XSAVES)) {
    - WARN_ONCE(1, "x86/fpu: saving compacted-format xsave area to a signal frame!\n");
    - return -1;
    - }
    -
    - fpstate_sanitize_xstate(fpu);
    - if (__copy_to_user(buf_fx, xsave, fpu_user_xstate_size))
    - return -1;
    - }
    + /* Save the live register state to the user directly. */
    + if (copy_fpregs_to_sigframe(buf_fx))
    + return -1;
    + /* Update the thread's fxstate to save the fsave header. */
    + if (ia32_fxstate)
    + copy_fxregs_to_kernel(fpu);

    /* Save the fsave header for the 32-bit frames. */
    if ((ia32_fxstate || !use_fxsr()) && save_fsave_header(tsk, buf))
    --
    2.20.1
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