From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753251AbbCDW4W (ORCPT ); Wed, 4 Mar 2015 17:56:22 -0500 Received: from terminus.zytor.com ([198.137.202.10]:42009 "EHLO terminus.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751062AbbCDW4S (ORCPT ); Wed, 4 Mar 2015 17:56:18 -0500 Date: Wed, 4 Mar 2015 14:55:49 -0800 From: tip-bot for Denys Vlasenko Message-ID: Cc: hpa@zytor.com, luto@amacapital.net, ast@plumgrid.com, tglx@linutronix.de, torvalds@linux-foundation.org, fweisbec@gmail.com, bp@alien8.de, wad@chromium.org, dvlasenk@redhat.com, mingo@kernel.org, linux-kernel@vger.kernel.org, keescook@chromium.org, oleg@redhat.com Reply-To: linux-kernel@vger.kernel.org, oleg@redhat.com, keescook@chromium.org, wad@chromium.org, mingo@kernel.org, dvlasenk@redhat.com, bp@alien8.de, tglx@linutronix.de, torvalds@linux-foundation.org, fweisbec@gmail.com, ast@plumgrid.com, hpa@zytor.com, luto@amacapital.net In-Reply-To: <4da092094cd78734384ac31e0d4ec1d8f69145a2.1424989793.git.luto@amacapital.net> References: <4da092094cd78734384ac31e0d4ec1d8f69145a2.1424989793.git.luto@amacapital.net> To: linux-tip-commits@vger.kernel.org Subject: [tip:x86/asm] x86/asm/entry/64/compat: Fold the IA32_ARG_FIXUP macro into its callers Git-Commit-ID: 14f6e9532dda399a7b789f744dc045f8865a9e42 X-Mailer: tip-git-log-daemon Robot-ID: Robot-Unsubscribe: Contact to get blacklisted from these emails MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Content-Type: text/plain; charset=UTF-8 Content-Disposition: inline Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Commit-ID: 14f6e9532dda399a7b789f744dc045f8865a9e42 Gitweb: http://git.kernel.org/tip/14f6e9532dda399a7b789f744dc045f8865a9e42 Author: Denys Vlasenko AuthorDate: Thu, 26 Feb 2015 14:40:35 -0800 Committer: Ingo Molnar CommitDate: Wed, 4 Mar 2015 22:50:52 +0100 x86/asm/entry/64/compat: Fold the IA32_ARG_FIXUP macro into its callers Use of a small macro - one with conditional expansion - does more harm than good. It obfuscates code, with minimal code reuse. For example, because of obfuscation it's not obvious that in 'ia32_sysenter_target', we can optimize loading of r9 - currently it is loaded with a detour through ebp. This patch folds the IA32_ARG_FIXUP macro into its callers. No code changes. Signed-off-by: Denys Vlasenko Signed-off-by: Andy Lutomirski Cc: Alexei Starovoitov Cc: Borislav Petkov Cc: Frederic Weisbecker Cc: H. Peter Anvin Cc: Kees Cook Cc: Linus Torvalds Cc: Oleg Nesterov Cc: Will Drewry Link: http://lkml.kernel.org/r/4da092094cd78734384ac31e0d4ec1d8f69145a2.1424989793.git.luto@amacapital.net Signed-off-by: Ingo Molnar --- arch/x86/ia32/ia32entry.S | 32 ++++++++++++++++++-------------- 1 file changed, 18 insertions(+), 14 deletions(-) diff --git a/arch/x86/ia32/ia32entry.S b/arch/x86/ia32/ia32entry.S index b567056..6dcd372 100644 --- a/arch/x86/ia32/ia32entry.S +++ b/arch/x86/ia32/ia32entry.S @@ -30,17 +30,6 @@ .section .entry.text, "ax" - .macro IA32_ARG_FIXUP noebp=0 - movl %edi,%r8d - .if \noebp - .else - movl %ebp,%r9d - .endif - xchg %ecx,%esi - movl %ebx,%edi - movl %edx,%edx /* zero extension */ - .endm - /* clobbers %rax */ .macro CLEAR_RREGS _r9=rax xorl %eax,%eax @@ -178,7 +167,12 @@ sysenter_flags_fixed: cmpq $(IA32_NR_syscalls-1),%rax ja ia32_badsys sysenter_do_call: - IA32_ARG_FIXUP + /* 32bit syscall -> 64bit C ABI argument conversion */ + movl %edi,%r8d /* arg5 */ + movl %ebp,%r9d /* arg6 */ + xchg %ecx,%esi /* rsi:arg2, rcx:arg4 */ + movl %ebx,%edi /* arg1 */ + movl %edx,%edx /* arg3 (zero extension) */ sysenter_dispatch: call *ia32_sys_call_table(,%rax,8) movq %rax,RAX(%rsp) @@ -360,7 +354,12 @@ ENTRY(ia32_cstar_target) cmpq $IA32_NR_syscalls-1,%rax ja ia32_badsys cstar_do_call: - IA32_ARG_FIXUP 1 + /* 32bit syscall -> 64bit C ABI argument conversion */ + movl %edi,%r8d /* arg5 */ + /* r9 already loaded */ /* arg6 */ + xchg %ecx,%esi /* rsi:arg2, rcx:arg4 */ + movl %ebx,%edi /* arg1 */ + movl %edx,%edx /* arg3 (zero extension) */ cstar_dispatch: call *ia32_sys_call_table(,%rax,8) movq %rax,RAX(%rsp) @@ -477,7 +476,12 @@ ENTRY(ia32_syscall) cmpq $(IA32_NR_syscalls-1),%rax ja ia32_badsys ia32_do_call: - IA32_ARG_FIXUP + /* 32bit syscall -> 64bit C ABI argument conversion */ + movl %edi,%r8d /* arg5 */ + movl %ebp,%r9d /* arg6 */ + xchg %ecx,%esi /* rsi:arg2, rcx:arg4 */ + movl %ebx,%edi /* arg1 */ + movl %edx,%edx /* arg3 (zero extension) */ call *ia32_sys_call_table(,%rax,8) # xxx: rip relative ia32_sysret: movq %rax,RAX(%rsp)