Messages in this thread Patch in this message | | | Date | Fri, 27 Mar 2015 04:47:50 -0700 | From | tip-bot for Denys Vlasenko <> | Subject | [tip:x86/asm] x86/irq/tracing: Do not save callee-preserved registers around lockdep_sys_exit_thunk |
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Commit-ID: aa6d9a128b861fe7e9dc37bcc37179837674b739 Gitweb: http://git.kernel.org/tip/aa6d9a128b861fe7e9dc37bcc37179837674b739 Author: Denys Vlasenko <dvlasenk@redhat.com> AuthorDate: Wed, 25 Mar 2015 21:14:28 +0100 Committer: Ingo Molnar <mingo@kernel.org> CommitDate: Fri, 27 Mar 2015 10:01:49 +0100
x86/irq/tracing: Do not save callee-preserved registers around lockdep_sys_exit_thunk
Internally, lockdep_sys_exit_thunk saves callee-clobbered registers, and calls a C function, lockdep_sys_exit. Thus, callee-preserved registers won't be mangled, there is no need to save them.
Patch was run-tested.
Signed-off-by: Denys Vlasenko <dvlasenk@redhat.com> Cc: Alexei Starovoitov <ast@plumgrid.com> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Borislav Petkov <bp@alien8.de> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Kees Cook <keescook@chromium.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Will Drewry <wad@chromium.org> Link: http://lkml.kernel.org/r/1427314468-12763-4-git-send-email-dvlasenk@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org> --- arch/x86/include/asm/irqflags.h | 2 -- 1 file changed, 2 deletions(-)
diff --git a/arch/x86/include/asm/irqflags.h b/arch/x86/include/asm/irqflags.h index 19355f3..9a63eae 100644 --- a/arch/x86/include/asm/irqflags.h +++ b/arch/x86/include/asm/irqflags.h @@ -179,9 +179,7 @@ static inline int arch_irqs_disabled(void) # define LOCKDEP_SYS_EXIT_IRQ \ TRACE_IRQS_ON; \ sti; \ - SAVE_EXTRA_REGS; \ call lockdep_sys_exit_thunk; \ - RESTORE_EXTRA_REGS; \ cli; \ TRACE_IRQS_OFF; # else
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