[PATCH 3/3] x86: 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 CC: Linus Torvalds CC: Steven Rostedt CC: Ingo Molnar CC: Borislav Petkov CC: "H. Peter Anvin" CC: Andy Lutomirski CC: Oleg Nesterov CC: Frederic Weisbecker CC: Alexei Starovoitov CC: Will Drewry CC: Kees Cook CC: x...@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 -- 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/
Re: [PATCH 3/3] x86: do not save callee-preserved registers around lockdep_sys_exit_thunk
On Sun, Mar 01, 2015 at 08:16:18AM -0800, Andy Lutomirski wrote: > On Fri, Feb 27, 2015 at 4:29 PM, Denys Vlasenko 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. It was, I'm forever unsure on when what register are saved by which macros/functions. Thanks! -- 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/
Re: [PATCH 3/3] x86: do not save callee-preserved registers around lockdep_sys_exit_thunk
On Fri, Feb 27, 2015 at 4:29 PM, Denys Vlasenko 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 > CC: Linus Torvalds > CC: Steven Rostedt > CC: Ingo Molnar > CC: Borislav Petkov > CC: "H. Peter Anvin" > CC: Andy Lutomirski > CC: Oleg Nesterov > CC: Frederic Weisbecker > CC: Alexei Starovoitov > CC: Will Drewry > CC: Kees Cook > CC: x...@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 -- 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/
[PATCH 3/3] x86: 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_exix. Thus, callee-preserved won't be mangled, there is no need to save them. Patch was run-tested. Signed-off-by: Denys Vlasenko CC: Linus Torvalds CC: Steven Rostedt CC: Ingo Molnar CC: Borislav Petkov CC: "H. Peter Anvin" CC: Andy Lutomirski CC: Oleg Nesterov CC: Frederic Weisbecker CC: Alexei Starovoitov CC: Will Drewry CC: Kees Cook CC: x...@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 -- 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/
