Messages in this thread Patch in this message | | | From | Hans Rosenfeld <> | Subject | [PATCH 1/1] x86, xsave: fix non-lazy allocation of the xsave area | Date | Fri, 15 Apr 2011 18:47:22 +0200 |
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A single static xsave area just for init is not enough, since there are more user processes that are directly executed by kernel threads. Add a call to a new arch-specific function to flush_old_exec(), which will in turn call fpu_alloc() to allocate a xsave area if necessary.
Signed-off-by: Hans Rosenfeld <hans.rosenfeld@amd.com> --- arch/x86/include/asm/i387.h | 6 ------ arch/x86/kernel/process.c | 7 +++++++ fs/exec.c | 9 +++++++++ 3 files changed, 16 insertions(+), 6 deletions(-)
diff --git a/arch/x86/include/asm/i387.h b/arch/x86/include/asm/i387.h index 989c0ac..0448f45 100644 --- a/arch/x86/include/asm/i387.h +++ b/arch/x86/include/asm/i387.h @@ -329,15 +329,9 @@ static inline void fpu_copy(struct fpu *dst, struct fpu *src) } extern void fpu_finit(struct fpu *fpu); -static union thread_xstate __init_xstate, *init_xstate = &__init_xstate; static inline void fpu_clear(struct fpu *fpu) { - if (!fpu_allocated(fpu)) { - BUG_ON(init_xstate == NULL); - fpu->state = init_xstate; - init_xstate = NULL; - } memset(fpu->state, 0, xstate_size); fpu_finit(fpu); set_used_math(); diff --git a/arch/x86/kernel/process.c b/arch/x86/kernel/process.c index 0382f98..3edfbf2 100644 --- a/arch/x86/kernel/process.c +++ b/arch/x86/kernel/process.c @@ -26,6 +26,13 @@ struct kmem_cache *task_xstate_cachep; EXPORT_SYMBOL_GPL(task_xstate_cachep); +int arch_prealloc_fpu(struct task_struct *tsk) +{ + if (!fpu_allocated(&tsk->thread.fpu)) + return fpu_alloc(&tsk->thread.fpu); + return 0; +} + int arch_dup_task_struct(struct task_struct *dst, struct task_struct *src) { int ret; diff --git a/fs/exec.c b/fs/exec.c index 5e62d26..c5b5c1e 100644 --- a/fs/exec.c +++ b/fs/exec.c @@ -1022,10 +1022,19 @@ void set_task_comm(struct task_struct *tsk, char *buf) perf_event_comm(tsk); } +int __attribute__((weak)) arch_prealloc_fpu(struct task_struct *tsk) +{ + return 0; +} + int flush_old_exec(struct linux_binprm * bprm) { int retval; + retval = arch_prealloc_fpu(current); + if (retval) + goto out; + /* * Make sure we have a private signal table and that * we are unassociated from the previous thread group. -- 1.5.6.5
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