Messages in this thread | | | From | Andy Lutomirski <> | Date | Sun, 1 Mar 2015 08:16:18 -0800 | Subject | Re: [PATCH 3/3] x86: do not save callee-preserved registers around lockdep_sys_exit_thunk |
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On Fri, Feb 27, 2015 at 4:29 PM, Denys Vlasenko <dvlasenk@redhat.com> wrote: > Internally, lockdep_sys_exit_thunk saves callee-clobbered registers, > and calls a C function, lockdep_sys_exix. Thus, callee-preserved > won't be mangled, there is no need to save them. > > Patch was run-tested.
Peterz, I think this was your code.
--Andy
> > Signed-off-by: Denys Vlasenko <dvlasenk@redhat.com> > CC: Linus Torvalds <torvalds@linux-foundation.org> > CC: Steven Rostedt <rostedt@goodmis.org> > CC: Ingo Molnar <mingo@kernel.org> > CC: Borislav Petkov <bp@alien8.de> > CC: "H. Peter Anvin" <hpa@zytor.com> > CC: Andy Lutomirski <luto@amacapital.net> > CC: Oleg Nesterov <oleg@redhat.com> > CC: Frederic Weisbecker <fweisbec@gmail.com> > CC: Alexei Starovoitov <ast@plumgrid.com> > CC: Will Drewry <wad@chromium.org> > CC: Kees Cook <keescook@chromium.org> > CC: x86@kernel.org > CC: linux-kernel@vger.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 > -- > 1.8.1.4 >
-- Andy Lutomirski AMA Capital Management, LLC
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