From mboxrd@z Thu Jan 1 00:00:00 1970 From: "H. Peter Anvin" Subject: Re: [PATCH] i386/audit: stop scribbling on the stack frame Date: Fri, 24 Oct 2014 13:19:46 -0700 Message-ID: <544AB462.9070708@zytor.com> References: <1414037043-30647-1-git-send-email-eparis@redhat.com> <54494B74.2080504@amacapital.net> <1414091732.2363.11.camel@redhat.com> <1414092624.2363.13.camel@redhat.com> <1414093104.2363.14.camel@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <1414093104.2363.14.camel@redhat.com> Sender: linux-kernel-owner@vger.kernel.org To: Eric Paris , Andy Lutomirski Cc: Richard Guy Briggs , Thomas Gleixner , Ingo Molnar , X86 ML , "linux-kernel@vger.kernel.org" , linux-audit@redhat.com List-Id: linux-audit@redhat.com On 10/23/2014 12:38 PM, Eric Paris wrote: >> >> After the call __audit_syscall_entry aren't they already polluted? >> Isn't that the reason we need to reload EAX? > > Well, I guess EAX is special... > Because system calls are "asmlinkage", all the parameters are on the stack, but %eax is used as the index into the system call table. This should thus be fine until we get rid of regparm(0) entirely, if that ever happens. -hpa