Messages in this thread | | | From | Andy Lutomirski <> | Date | Wed, 25 Mar 2015 11:03:11 -0700 | Subject | Re: [PATCH 3/4] x86/asm/entry/64: use smaller insns |
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On Wed, Mar 25, 2015 at 10:18 AM, Denys Vlasenko <dvlasenk@redhat.com> wrote: > The $AUDIT_ARCH_X86_64 parameter to syscall_trace_enter_phase1/2 > is a 32-bit constant, loading it with 32-bit MOV produces 5-byte insn > instead of 10-byte one.
Acked-by: Andy Lutomirski <luto@kernel.org>
> > 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/kernel/entry_64.S | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) > > diff --git a/arch/x86/kernel/entry_64.S b/arch/x86/kernel/entry_64.S > index 11b7339..23aa43e 100644 > --- a/arch/x86/kernel/entry_64.S > +++ b/arch/x86/kernel/entry_64.S > @@ -306,7 +306,7 @@ system_call_fastpath: > /* Do syscall entry tracing */ > tracesys: > movq %rsp, %rdi > - movq $AUDIT_ARCH_X86_64, %rsi > + movl $AUDIT_ARCH_X86_64, %esi > call syscall_trace_enter_phase1 > test %rax, %rax > jnz tracesys_phase2 /* if needed, run the slow path */ > @@ -317,7 +317,7 @@ tracesys: > tracesys_phase2: > SAVE_EXTRA_REGS > movq %rsp, %rdi > - movq $AUDIT_ARCH_X86_64, %rsi > + movl $AUDIT_ARCH_X86_64, %esi > movq %rax,%rdx > call syscall_trace_enter_phase2 > > -- > 1.8.1.4 >
-- Andy Lutomirski AMA Capital Management, LLC
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