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authorAndy Lutomirski <luto@kernel.org>2015-10-05 17:48:18 -0700
committerIngo Molnar <mingo@kernel.org>2015-10-09 09:41:11 +0200
commit460d12453e1afe20416ce9536cfecb31d17a9abd (patch)
treecd6ab9658e1a4afe9641e988803374a129aad727
parent8b13c2552ffc8e54e57598df36707183933e8e8c (diff)
x86/entry: Make irqs_disabled checks in exit code depend on lockdep
These checks are quite slow. Disable them in non-lockdep kernels to reduce the performance hit. Signed-off-by: Andy Lutomirski <luto@kernel.org> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-kernel@vger.kernel.org Link: http://lkml.kernel.org/r/eccff2a154ae6fb50f40228901003a6e9c24f3d0.1444091585.git.luto@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
-rw-r--r--arch/x86/entry/common.c6
1 files changed, 3 insertions, 3 deletions
diff --git a/arch/x86/entry/common.c b/arch/x86/entry/common.c
index 0d1c842ef3ca..03aacd188458 100644
--- a/arch/x86/entry/common.c
+++ b/arch/x86/entry/common.c
@@ -219,7 +219,7 @@ static struct thread_info *pt_regs_to_thread_info(struct pt_regs *regs)
/* Called with IRQs disabled. */
__visible void prepare_exit_to_usermode(struct pt_regs *regs)
{
- if (WARN_ON(!irqs_disabled()))
+ if (IS_ENABLED(CONFIG_PROVE_LOCKING) && WARN_ON(!irqs_disabled()))
local_irq_disable();
lockdep_sys_exit();
@@ -281,8 +281,8 @@ __visible void syscall_return_slowpath(struct pt_regs *regs)
CT_WARN_ON(ct_state() != CONTEXT_KERNEL);
- if (WARN(irqs_disabled(), "syscall %ld left IRQs disabled",
- regs->orig_ax))
+ if (IS_ENABLED(CONFIG_PROVE_LOCKING) &&
+ WARN(irqs_disabled(), "syscall %ld left IRQs disabled", regs->orig_ax))
local_irq_enable();
/*