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: Mon, 27 Oct 2014 10:02:05 -0700 Message-ID: <544E7A8D.1030909@zytor.com> References: <1414037043-30647-1-git-send-email-eparis@redhat.com> <20141027023457.GY15532@madcap2.tricolour.ca> <1414418157.24347.1.camel@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <1414418157.24347.1.camel@redhat.com> Sender: linux-kernel-owner@vger.kernel.org To: Eric Paris , Richard Guy Briggs Cc: Thomas Gleixner , linux-kernel@vger.kernel.org, przanoni@gmail.com, mingo@kernel.org, hpa@linux.intel.com, linux-tip-commits@vger.kernel.org, linux-audit@redhat.com List-Id: linux-audit@redhat.com On 10/27/2014 06:55 AM, Eric Paris wrote: > My patch was already committed to the -tip urgent branch. I believe any > optimization should be based on that branch, Richard. If you are trying > to wrangle every bit of speed out of this, should you > > push %esi; > push %edi; > CFI_ADJUST_CFA_OFFSET 8 > call __audit_syscall_entry > pop; > pop; > CFI_ADJUST_CFA_OFFSET -8 > > Instead of using the pushl_cfi and popl_cfi macros? > > I wrote my patch to be obviously correct, but agree there are certainly > some speedups possible. > Uh... not only is that plain wrong (the CFI should be adjusted after each instruction that changes the stack pointer), but what the heck is wrong with using the macros? -hpa