diff options
Diffstat (limited to 'arch')
| -rw-r--r-- | arch/x86/kernel/fpu/core.c | 31 |
1 files changed, 16 insertions, 15 deletions
diff --git a/arch/x86/kernel/fpu/core.c b/arch/x86/kernel/fpu/core.c index 74cc32265918..a407bf5cb92f 100644 --- a/arch/x86/kernel/fpu/core.c +++ b/arch/x86/kernel/fpu/core.c @@ -276,29 +276,30 @@ void fpu__activate_curr(struct fpu *fpu) EXPORT_SYMBOL_GPL(fpu__activate_curr); /* - * This function is called before we modify a stopped child's - * FPU state context. + * This function must be called before we modify a stopped child's + * fpstate. * * If the child has not used the FPU before then initialize its - * FPU context. + * fpstate. * * If the child has used the FPU before then unlazy it. * - * [ After this function call, after the context is modified and - * the child task is woken up, the child task will restore - * the modified FPU state from the modified context. If we + * [ After this function call, after registers in the fpstate are + * modified and the child task has woken up, the child task will + * restore the modified FPU state from the modified context. If we * didn't clear its lazy status here then the lazy in-registers - * state pending on its former CPU could be restored, losing + * state pending on its former CPU could be restored, corrupting * the modifications. ] * * This function is also called before we read a stopped child's - * FPU state - to make sure it's modified. + * FPU state - to make sure it's initialized if the child has + * no active FPU state. * * TODO: A future optimization would be to skip the unlazying in * the read-only case, it's not strictly necessary for * read-only access to the context. */ -static void fpu__unlazy_stopped(struct fpu *child_fpu) +static void fpu__activate_stopped(struct fpu *child_fpu) { WARN_ON_ONCE(child_fpu == ¤t->thread.fpu); @@ -388,7 +389,7 @@ int xfpregs_get(struct task_struct *target, const struct user_regset *regset, if (!cpu_has_fxsr) return -ENODEV; - fpu__unlazy_stopped(fpu); + fpu__activate_stopped(fpu); sanitize_i387_state(target); return user_regset_copyout(&pos, &count, &kbuf, &ubuf, @@ -405,7 +406,7 @@ int xfpregs_set(struct task_struct *target, const struct user_regset *regset, if (!cpu_has_fxsr) return -ENODEV; - fpu__unlazy_stopped(fpu); + fpu__activate_stopped(fpu); sanitize_i387_state(target); ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, @@ -437,7 +438,7 @@ int xstateregs_get(struct task_struct *target, const struct user_regset *regset, if (!cpu_has_xsave) return -ENODEV; - fpu__unlazy_stopped(fpu); + fpu__activate_stopped(fpu); xsave = &fpu->state.xsave; @@ -466,7 +467,7 @@ int xstateregs_set(struct task_struct *target, const struct user_regset *regset, if (!cpu_has_xsave) return -ENODEV; - fpu__unlazy_stopped(fpu); + fpu__activate_stopped(fpu); xsave = &fpu->state.xsave; @@ -628,7 +629,7 @@ int fpregs_get(struct task_struct *target, const struct user_regset *regset, struct fpu *fpu = &target->thread.fpu; struct user_i387_ia32_struct env; - fpu__unlazy_stopped(fpu); + fpu__activate_stopped(fpu); if (!static_cpu_has(X86_FEATURE_FPU)) return fpregs_soft_get(target, regset, pos, count, kbuf, ubuf); @@ -658,7 +659,7 @@ int fpregs_set(struct task_struct *target, const struct user_regset *regset, struct user_i387_ia32_struct env; int ret; - fpu__unlazy_stopped(fpu); + fpu__activate_stopped(fpu); sanitize_i387_state(target); |