On Sun, 26 Oct 2014, Richard Guy Briggs wrote:
> diff --git a/arch/x86/kernel/entry_32.S b/arch/x86/kernel/entry_32.S
> index b553ed8..344b63f 100644
> --- a/arch/x86/kernel/entry_32.S
> +++ b/arch/x86/kernel/entry_32.S
> @@ -447,15 +447,14 @@ sysenter_exit:
>  sysenter_audit:
>       testl $(_TIF_WORK_SYSCALL_ENTRY & ~_TIF_SYSCALL_AUDIT),TI_flags(%ebp)
>       jnz syscall_trace_entry
> -     addl $4,%esp
> -     CFI_ADJUST_CFA_OFFSET -4
> -     movl %esi,4(%esp)               /* 5th arg: 4th syscall arg */
> -     movl %edx,(%esp)                /* 4th arg: 3rd syscall arg */
> -     /* %ecx already in %ecx            3rd arg: 2nd syscall arg */
> -     movl %ebx,%edx                  /* 2nd arg: 1st syscall arg */
> -     /* %eax already in %eax            1st arg: syscall number */
> +     /* movl PT_ECX(%esp), %ecx      already set, a1: 3nd arg to audit */
> +     /* movl PT_EAX(%esp), %eax      already set, syscall number: 1st arg to 
> audit */
> +     pushl_cfi %esi                  /* a3: 5th arg */
> +     pushl_cfi %edx                  /* a2: 4th arg */
> +     movl %ebx, %edx                 /* ebx/a0: 2nd arg to audit */
>       call __audit_syscall_entry
> -     pushl_cfi %ebx
> +     popl_cfi %ecx /* get that remapped edx off the stack */
> +     popl_cfi %ecx /* get that remapped esi off the stack */

Why use pop instead of simply adjusting esp and CFI by 8?

Thanks,

        tglx
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