From 2fb29fc7c690d3d318471c42a62a05153d433cc1 Mon Sep 17 00:00:00 2001 From: Ingo Molnar Date: Mon, 27 Apr 2015 06:55:54 +0200 Subject: [PATCH] x86/fpu: Simplify fpu__unlazy_stopped() error handling Now that FPU contexts are always allocated, fpu__unlazy_stopped() cannot fail. Remove its error return and propagate the changes to the callers. Reviewed-by: Borislav Petkov Cc: Andy Lutomirski Cc: Dave Hansen Cc: Fenghua Yu Cc: H. Peter Anvin Cc: Linus Torvalds Cc: Oleg Nesterov Cc: Peter Zijlstra Cc: Thomas Gleixner Signed-off-by: Ingo Molnar --- arch/x86/kernel/fpu/core.c | 48 +++++++++++--------------------------- 1 file changed, 13 insertions(+), 35 deletions(-) diff --git a/arch/x86/kernel/fpu/core.c b/arch/x86/kernel/fpu/core.c index 45f014e2e204..97b4f9e76f60 100644 --- a/arch/x86/kernel/fpu/core.c +++ b/arch/x86/kernel/fpu/core.c @@ -296,24 +296,18 @@ EXPORT_SYMBOL_GPL(fpstate_init_curr); * the read-only case, it's not strictly necessary for * read-only access to the context. */ -static int fpu__unlazy_stopped(struct fpu *child_fpu) +static void fpu__unlazy_stopped(struct fpu *child_fpu) { - int ret; - - if (WARN_ON_ONCE(child_fpu == ¤t->thread.fpu)) - return -EINVAL; + WARN_ON_ONCE(child_fpu == ¤t->thread.fpu); if (child_fpu->fpstate_active) { child_fpu->last_cpu = -1; - return 0; + } else { + fpstate_init(child_fpu); + + /* Safe to do for stopped child tasks: */ + child_fpu->fpstate_active = 1; } - - fpstate_init(child_fpu); - - /* Safe to do for stopped child tasks: */ - child_fpu->fpstate_active = 1; - - return 0; } /* @@ -389,15 +383,11 @@ int xfpregs_get(struct task_struct *target, const struct user_regset *regset, void *kbuf, void __user *ubuf) { struct fpu *fpu = &target->thread.fpu; - int ret; if (!cpu_has_fxsr) return -ENODEV; - ret = fpu__unlazy_stopped(fpu); - if (ret) - return ret; - + fpu__unlazy_stopped(fpu); sanitize_i387_state(target); return user_regset_copyout(&pos, &count, &kbuf, &ubuf, @@ -414,10 +404,7 @@ int xfpregs_set(struct task_struct *target, const struct user_regset *regset, if (!cpu_has_fxsr) return -ENODEV; - ret = fpu__unlazy_stopped(fpu); - if (ret) - return ret; - + fpu__unlazy_stopped(fpu); sanitize_i387_state(target); ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, @@ -449,9 +436,7 @@ int xstateregs_get(struct task_struct *target, const struct user_regset *regset, if (!cpu_has_xsave) return -ENODEV; - ret = fpu__unlazy_stopped(fpu); - if (ret) - return ret; + fpu__unlazy_stopped(fpu); xsave = &fpu->state.xsave; @@ -480,9 +465,7 @@ int xstateregs_set(struct task_struct *target, const struct user_regset *regset, if (!cpu_has_xsave) return -ENODEV; - ret = fpu__unlazy_stopped(fpu); - if (ret) - return ret; + fpu__unlazy_stopped(fpu); xsave = &fpu->state.xsave; @@ -643,11 +626,8 @@ int fpregs_get(struct task_struct *target, const struct user_regset *regset, { struct fpu *fpu = &target->thread.fpu; struct user_i387_ia32_struct env; - int ret; - ret = fpu__unlazy_stopped(fpu); - if (ret) - return ret; + fpu__unlazy_stopped(fpu); if (!static_cpu_has(X86_FEATURE_FPU)) return fpregs_soft_get(target, regset, pos, count, kbuf, ubuf); @@ -677,9 +657,7 @@ int fpregs_set(struct task_struct *target, const struct user_regset *regset, struct user_i387_ia32_struct env; int ret; - ret = fpu__unlazy_stopped(fpu); - if (ret) - return ret; + fpu__unlazy_stopped(fpu); sanitize_i387_state(target);