Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752566AbaJ0UwX (ORCPT ); Mon, 27 Oct 2014 16:52:23 -0400 Received: from www.linutronix.de ([62.245.132.108]:40621 "EHLO Galois.linutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751605AbaJ0UwW (ORCPT ); Mon, 27 Oct 2014 16:52:22 -0400 Date: Mon, 27 Oct 2014 21:52:16 +0100 (CET) From: Thomas Gleixner To: Richard Guy Briggs cc: linux-kernel@vger.kernel.org, eparis@redhat.com, przanoni@gmail.com, mingo@kernel.org, hpa@linux.intel.com, hpa@zytor.com, linux-tip-commits@vger.kernel.org, linux-audit@redhat.com Subject: Re: [PATCH] i386/audit: stop scribbling on the stack frame In-Reply-To: <20141027023457.GY15532@madcap2.tricolour.ca> Message-ID: References: <1414037043-30647-1-git-send-email-eparis@redhat.com> <20141027023457.GY15532@madcap2.tricolour.ca> User-Agent: Alpine 2.11 (DEB 23 2013-08-11) MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII X-Linutronix-Spam-Score: -1.0 X-Linutronix-Spam-Level: - X-Linutronix-Spam-Status: No , -1.0 points, 5.0 required, ALL_TRUSTED=-1,SHORTCIRCUIT=-0.0001 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/