From 3e5e7f7736b05d5fdf2cc4e0ba4f2d8bc42c630d Mon Sep 17 00:00:00 2001 From: "H. Peter Anvin (Intel)" Date: Mon, 10 May 2021 11:53:11 -0700 Subject: [PATCH] x86/entry: Reverse arguments to do_syscall_64() 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) Signed-off-by: Ingo Molnar Link: https://lore.kernel.org/r/20210510185316.3307264-3-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 #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); -- 2.34.1