Commit-ID: 2fb29fc7c690d3d318471c42a62a05153d433cc1
Gitweb: http://git.kernel.org/tip/2fb29fc7c690d3d318471c42a62a05153d433cc1
Author: Ingo Molnar <mingo@xxxxxxxxxx>
AuthorDate: Mon, 27 Apr 2015 06:55:54 +0200
Committer: Ingo Molnar <mingo@xxxxxxxxxx>
CommitDate: Tue, 19 May 2015 15:47:51 +0200
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 <bp@xxxxxxxxx>
Cc: Andy Lutomirski <luto@xxxxxxxxxxxxxx>
Cc: Dave Hansen <dave.hansen@xxxxxxxxxxxxxxx>
Cc: Fenghua Yu <fenghua.yu@xxxxxxxxx>
Cc: H. Peter Anvin <hpa@xxxxxxxxx>
Cc: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Cc: Oleg Nesterov <oleg@xxxxxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx>
---
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 45f014e..97b4f9e 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;
- }
-
- fpstate_init(child_fpu);
-
- /* Safe to do for stopped child tasks: */
- child_fpu->fpstate_active = 1;
+ } else {
+ fpstate_init(child_fpu);
- return 0;
+ /* Safe to do for stopped child tasks: */
+ child_fpu->fpstate_active = 1;
+ }
}
/*
@@ -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);
--
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