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From: Denys Vlasenko <dvlasenk@redhat.com>
To: Ingo Molnar <mingo@kernel.org>
Cc: Denys Vlasenko <dvlasenk@redhat.com>,
	Linus Torvalds <torvalds@linux-foundation.org>,
	Steven Rostedt <rostedt@goodmis.org>,
	Borislav Petkov <bp@alien8.de>, "H. Peter Anvin" <hpa@zytor.com>,
	Andy Lutomirski <luto@amacapital.net>,
	Oleg Nesterov <oleg@redhat.com>,
	Frederic Weisbecker <fweisbec@gmail.com>,
	Alexei Starovoitov <ast@plumgrid.com>,
	Will Drewry <wad@chromium.org>, Kees Cook <keescook@chromium.org>,
	x86@kernel.org, linux-kernel@vger.kernel.org
Subject: [PATCH 3/4] x86/asm/entry/64: use smaller insns
Date: Wed, 25 Mar 2015 18:18:15 +0100	[thread overview]
Message-ID: <1427303896-24023-3-git-send-email-dvlasenk@redhat.com> (raw)
In-Reply-To: <1427303896-24023-1-git-send-email-dvlasenk@redhat.com>

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.

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


  parent reply	other threads:[~2015-03-25 17:19 UTC|newest]

Thread overview: 24+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2015-03-25 17:18 [PATCH 1/4] x86/asm/entry/64: better label name, fix comments Denys Vlasenko
2015-03-25 17:18 ` [PATCH 2/4] x86/asm/entry/64: do not TRACE_IRQS fast SYSRET64 path Denys Vlasenko
2015-03-25 17:29   ` Ingo Molnar
2015-03-25 17:41     ` Denys Vlasenko
2015-03-25 18:04       ` Ingo Molnar
2015-03-25 18:19         ` Denys Vlasenko
2015-03-25 17:18 ` Denys Vlasenko [this message]
2015-03-25 18:03   ` [PATCH 3/4] x86/asm/entry/64: use smaller insns Andy Lutomirski
2015-03-25 23:51   ` Linus Torvalds
2015-03-25 23:56     ` H. Peter Anvin
2015-03-26  0:05       ` Linus Torvalds
2015-03-26  0:12         ` H. Peter Anvin
2015-03-26  9:27         ` Borislav Petkov
2015-03-26  9:37           ` Ingo Molnar
2015-03-26  9:51             ` Borislav Petkov
2015-03-26 10:07             ` Denys Vlasenko
2015-03-26 10:25               ` Ingo Molnar
2015-03-26 10:53                 ` Denys Vlasenko
2015-03-26 10:25               ` Borislav Petkov
2015-03-26  9:30     ` Ingo Molnar
2015-03-27 11:47   ` [tip:x86/asm] x86/asm/entry/64: Use smaller instructions tip-bot for Denys Vlasenko
2015-03-25 17:18 ` [PATCH 4/4] x86/asm/entry/64: fix typo in comment Denys Vlasenko
2015-03-27 11:46 ` [tip:x86/asm] x86/asm/entry/64: Use better label name, fix comments tip-bot for Denys Vlasenko
2015-03-27 12:15   ` Borislav Petkov

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