@@ -559,23 +559,6 @@ static inline void switch_fpu_finish(struct fpu *new_fpu, int cpu)
}
}
-/*
- * Needs to be preemption-safe.
- *
- * NOTE! user_fpu_begin() must be used only immediately before restoring
- * the save state. It does not do any saving/restoring on its own. In
- * lazy FPU mode, it is just an optimization to avoid a #NM exception,
- * the task can lose the FPU right after preempt_enable().
- */
-static inline void user_fpu_begin(void)
-{
- struct fpu *fpu = ¤t->thread.fpu;
-
- preempt_disable();
- fpregs_activate(fpu);
- preempt_enable();
-}
-
/*
* MXCSR and XCR definitions:
*/
@@ -328,10 +328,8 @@ void fpu__clear(struct fpu *fpu)
* Make sure fpstate is cleared and initialized.
*/
fpu__initialize(fpu);
- if (static_cpu_has(X86_FEATURE_FPU)) {
- user_fpu_begin();
+ if (static_cpu_has(X86_FEATURE_FPU))
copy_init_fpstate_to_fpregs();
- }
}
/*
@@ -328,7 +328,6 @@ static int __fpu__restore_sig(void __user *buf, void __user *buf_fx, int size)
* For 64-bit frames and 32-bit fsave frames, restore the user
* state to the registers directly (with exceptions handled).
*/
- user_fpu_begin();
if (copy_user_to_fpregs_zeroing(buf_fx, xfeatures, fx_only)) {
fpu__clear(fpu);
return -1;
user_fpu_begin() sets fpu_fpregs_owner_ctx to task's fpu struct. This is always the case since there is no lazy FPU anymore. fpu_fpregs_owner_ctx is used during context switch to decide if it needs to load the saved registers or if the currently loaded registers are valid. This field is always updated on context switch so setting it manually has no benefit. Before the removal of the ->initialized member, fpu_fpregs_owner_ctx wouldn't be updated for kernel threads. But kernel threads don't use the fpu struct so again, user_fpu_begin() would not make a difference in user context (and would be wrong in kernel context). Remove user_fpu_begin(), it does not change fpu_fpregs_owner_ctx's content. Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> --- arch/x86/include/asm/fpu/internal.h | 17 ----------------- arch/x86/kernel/fpu/core.c | 4 +--- arch/x86/kernel/fpu/signal.c | 1 - 3 files changed, 1 insertion(+), 21 deletions(-)