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From: "H. Peter Anvin" <hpa@zytor.com>
To: Ingo Molnar <mingo@redhat.com>,
	Thomas Gleixner <tglx@linutronix.de>,
	Borislav Petkov <bp@alien8.de>, Andy Lutomirski <luto@kernel.org>
Cc: "H. Peter Anvin" <hpa@zytor.com>,
	Linux Kernel Mailing List <linux-kernel@vger.kernel.org>
Subject: [RFC v2 PATCH 2/7] x86/entry: reverse arguments to do_syscall_64()
Date: Mon, 10 May 2021 11:53:11 -0700	[thread overview]
Message-ID: <20210510185316.3307264-3-hpa@zytor.com> (raw)
In-Reply-To: <20210510185316.3307264-1-hpa@zytor.com>

From: "H. Peter Anvin (Intel)" <hpa@zytor.com>

Reverse the order of arguments to do_syscall_64() so that the first
argument is the pt_regs pointer. This is not only consistent with
*all* other entry points from assembly, but it actually makes the
compiled code slightly better.

Signed-off-by: H. Peter Anvin (Intel) <hpa@zytor.com>
---
 arch/x86/entry/common.c        | 2 +-
 arch/x86/entry/entry_64.S      | 4 ++--
 arch/x86/include/asm/syscall.h | 2 +-
 3 files changed, 4 insertions(+), 4 deletions(-)

diff --git a/arch/x86/entry/common.c b/arch/x86/entry/common.c
index 7b2542b13ebd..00da0f5420de 100644
--- a/arch/x86/entry/common.c
+++ b/arch/x86/entry/common.c
@@ -36,7 +36,7 @@
 #include <asm/irq_stack.h>
 
 #ifdef CONFIG_X86_64
-__visible noinstr void do_syscall_64(unsigned long nr, struct pt_regs *regs)
+__visible noinstr void do_syscall_64(struct pt_regs *regs, unsigned long nr)
 {
 	add_random_kstack_offset();
 	nr = syscall_enter_from_user_mode(regs, nr);
diff --git a/arch/x86/entry/entry_64.S b/arch/x86/entry/entry_64.S
index a16a5294d55f..1d9db15fdc69 100644
--- a/arch/x86/entry/entry_64.S
+++ b/arch/x86/entry/entry_64.S
@@ -107,8 +107,8 @@ SYM_INNER_LABEL(entry_SYSCALL_64_after_hwframe, SYM_L_GLOBAL)
 	PUSH_AND_CLEAR_REGS rax=$-ENOSYS
 
 	/* IRQs are off. */
-	movq	%rax, %rdi
-	movq	%rsp, %rsi
+	movq	%rsp, %rdi
+	movq	%rax, %rsi
 	call	do_syscall_64		/* returns with IRQs disabled */
 
 	/*
diff --git a/arch/x86/include/asm/syscall.h b/arch/x86/include/asm/syscall.h
index 7cbf733d11af..4e20054d7533 100644
--- a/arch/x86/include/asm/syscall.h
+++ b/arch/x86/include/asm/syscall.h
@@ -160,7 +160,7 @@ static inline int syscall_get_arch(struct task_struct *task)
 		? AUDIT_ARCH_I386 : AUDIT_ARCH_X86_64;
 }
 
-void do_syscall_64(unsigned long nr, struct pt_regs *regs);
+void do_syscall_64(struct pt_regs *regs, unsigned long nr);
 void do_int80_syscall_32(struct pt_regs *regs);
 long do_fast_syscall_32(struct pt_regs *regs);
 
-- 
2.31.1


  parent reply	other threads:[~2021-05-10 18:53 UTC|newest]

Thread overview: 25+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-05-10 18:53 [RFC v2 PATCH 0/6] x86/entry: cleanups and consistent syscall number handling H. Peter Anvin
2021-05-10 18:53 ` [RFC v2 PATCH 1/7] x86/entry: unify definitions from calling.h and ptrace-abi.h H. Peter Anvin
2021-05-12  9:23   ` [tip: x86/asm] x86/entry: Unify definitions from <asm/calling.h> and <asm/ptrace-abi.h> tip-bot2 for H. Peter Anvin (Intel)
2021-05-10 18:53 ` H. Peter Anvin [this message]
2021-05-12  9:23   ` [tip: x86/asm] x86/entry: Reverse arguments to do_syscall_64() tip-bot2 for H. Peter Anvin (Intel)
2021-05-10 18:53 ` [RFC v2 PATCH 3/7] x86/syscall: unconditionally prototype {ia32,x32}_sys_call_table[] H. Peter Anvin
2021-05-12  9:23   ` [tip: x86/asm] x86/syscall: Unconditionally " tip-bot2 for H. Peter Anvin (Intel)
2021-05-10 18:53 ` [RFC v2 PATCH 4/7] x86/syscall: maximize MSR_SYSCALL_MASK H. Peter Anvin
2021-05-12  9:23   ` [tip: x86/asm] x86/syscall: Maximize MSR_SYSCALL_MASK tip-bot2 for H. Peter Anvin (Intel)
2021-05-10 18:53 ` [RFC v2 PATCH 5/7] x86/entry: split PUSH_AND_CLEAR_REGS into two submacros H. Peter Anvin
2021-05-12  9:23   ` [tip: x86/asm] x86/entry: Split " tip-bot2 for H. Peter Anvin (Intel)
2021-05-10 18:53 ` [RFC v2 PATCH 6/7] x86/regs: syscall_get_nr() returns -1 for a non-system call H. Peter Anvin
2021-05-12  9:23   ` [tip: x86/asm] x86/regs: Syscall_get_nr() " tip-bot2 for H. Peter Anvin
2021-05-10 18:53 ` [RFC v2 PATCH 7/7] x86/entry: use int for syscall number; handle all invalid syscall nrs H. Peter Anvin
2021-05-12  8:51   ` Ingo Molnar
2021-05-12 17:50     ` H. Peter Anvin
2021-05-12 12:09   ` Thomas Gleixner
2021-05-12 18:21     ` H. Peter Anvin
2021-05-12 18:34       ` Thomas Gleixner
2021-05-12 22:09         ` H. Peter Anvin
2021-05-12 22:22           ` Thomas Gleixner
2021-05-12 22:24             ` H. Peter Anvin
2021-05-14  0:38             ` H. Peter Anvin
2021-05-14  3:18               ` Andy Lutomirski
2021-05-14  3:23                 ` H. Peter Anvin

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