From: "H. Peter Anvin" <hpa@zytor.com>
To: Ingo Molnar <mingo@redhat.com>,
Thomas Gleixner <tglx@linutronix.de>,
Andy Lutomirski <luto@kernel.org>, Borislav Petkov <bp@alien8.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>,
Linux Kernel Mailing List <linux-kernel@vger.kernel.org>
Subject: [RFC PATCH 2/6] x86/entry: reverse arguments to do_syscall_64()
Date: Mon, 10 May 2021 10:45:05 -0700 [thread overview]
Message-ID: <20210510174509.3039991-3-hpa@zytor.com> (raw)
In-Reply-To: <20210510174509.3039991-1-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
next prev parent reply other threads:[~2021-05-10 17:46 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-05-10 17:45 [RFC PATCH 0/6] x86/entry: cleanups and consistent syscall number handling H. Peter Anvin
2021-05-10 17:45 ` [RFC PATCH 1/6] x86/entry: unify definitions from calling.h and ptrace-abi.h H. Peter Anvin
2021-05-10 17:45 ` H. Peter Anvin [this message]
2021-05-10 17:45 ` [RFC PATCH 3/6] x86/syscall: unconditionally prototype {ia32,x32}_sys_call_table[] H. Peter Anvin
2021-05-10 17:45 ` [RFC PATCH 4/6] x86/syscall: maximize MSR_SYSCALL_MASK H. Peter Anvin
2021-05-10 17:45 ` [RFC PATCH 5/6] x86/entry: use int for syscall number; handle all invalid syscall nrs H. Peter Anvin
2021-05-13 7:39 ` [x86/entry] 55b7c6747c: kernel-selftests.x86.syscall_numbering_64.fail kernel test robot
2021-05-10 17:45 ` [RFC PATCH 6/6] x86/entry: split PUSH_AND_CLEAR_REGS into two submacros H. Peter Anvin
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