Commit-ID: 08a744c6bfded3d5fa66f94263f81773226113d1 Gitweb: http://git.kernel.org/tip/08a744c6bfded3d5fa66f94263f81773226113d1 Author: Oleg Nesterov <o...@redhat.com> AuthorDate: Fri, 6 Feb 2015 15:02:00 -0500 Committer: Borislav Petkov <b...@suse.de> CommitDate: Thu, 19 Feb 2015 11:15:03 +0100
x86/fpu: Change math_error() to use unlazy_fpu(), kill (now) unused save_init_fpu() math_error() calls save_init_fpu() after conditional_sti(), this means that the caller can be preempted. If !use_eager_fpu() we can hit the WARN_ON_ONCE(!__thread_has_fpu(tsk)) and/or save the wrong FPU state. Change math_error() to use unlazy_fpu() and kill save_init_fpu(). Signed-off-by: Oleg Nesterov <o...@redhat.com> Signed-off-by: Rik van Riel <r...@redhat.com> Cc: Linus Torvalds <torva...@linux-foundation.org> Link: http://lkml.kernel.org/r/1423252925-14451-4-git-send-email-r...@redhat.com Signed-off-by: Borislav Petkov <b...@suse.de> --- arch/x86/include/asm/fpu-internal.h | 18 ------------------ arch/x86/kernel/traps.c | 2 +- 2 files changed, 1 insertion(+), 19 deletions(-) diff --git a/arch/x86/include/asm/fpu-internal.h b/arch/x86/include/asm/fpu-internal.h index e97622f..02f2e08 100644 --- a/arch/x86/include/asm/fpu-internal.h +++ b/arch/x86/include/asm/fpu-internal.h @@ -518,24 +518,6 @@ static inline void __save_fpu(struct task_struct *tsk) } /* - * These disable preemption on their own and are safe - */ -static inline void save_init_fpu(struct task_struct *tsk) -{ - WARN_ON_ONCE(!__thread_has_fpu(tsk)); - - if (use_eager_fpu()) { - __save_fpu(tsk); - return; - } - - preempt_disable(); - __save_init_fpu(tsk); - __thread_fpu_end(tsk); - preempt_enable(); -} - -/* * i387 state interaction */ static inline unsigned short get_fpu_cwd(struct task_struct *tsk) diff --git a/arch/x86/kernel/traps.c b/arch/x86/kernel/traps.c index 88900e2..9d889f7 100644 --- a/arch/x86/kernel/traps.c +++ b/arch/x86/kernel/traps.c @@ -663,7 +663,7 @@ static void math_error(struct pt_regs *regs, int error_code, int trapnr) /* * Save the info for the exception handler and clear the error. */ - save_init_fpu(task); + unlazy_fpu(task); task->thread.trap_nr = trapnr; task->thread.error_code = error_code; info.si_signo = SIGFPE; -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
