From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754511Ab2G3OKE (ORCPT ); Mon, 30 Jul 2012 10:10:04 -0400 Received: from terminus.zytor.com ([198.137.202.10]:45522 "EHLO terminus.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754403Ab2G3OKB (ORCPT ); Mon, 30 Jul 2012 10:10:01 -0400 Date: Mon, 30 Jul 2012 07:09:40 -0700 From: tip-bot for Oleg Nesterov Message-ID: Cc: linux-kernel@vger.kernel.org, anton@redhat.com, hpa@zytor.com, mingo@kernel.org, srikar@linux.vnet.ibm.com, oleg@redhat.com, tglx@linutronix.de Reply-To: mingo@kernel.org, hpa@zytor.com, anton@redhat.com, linux-kernel@vger.kernel.org, srikar@linux.vnet.ibm.com, tglx@linutronix.de, oleg@redhat.com In-Reply-To: <20120729182212.GA20304@redhat.com> References: <20120729182212.GA20304@redhat.com> To: linux-tip-commits@vger.kernel.org Subject: [tip:perf/core] uprobes: Don't recheck vma/ f_mapping in write_opcode() Git-Commit-ID: f403072c6108e15f319a4a5036b650c77760522c X-Mailer: tip-git-log-daemon Robot-ID: Robot-Unsubscribe: Contact to get blacklisted from these emails MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Content-Type: text/plain; charset=UTF-8 Content-Disposition: inline X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.2.6 (terminus.zytor.com [127.0.0.1]); Mon, 30 Jul 2012 07:09:45 -0700 (PDT) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Commit-ID: f403072c6108e15f319a4a5036b650c77760522c Gitweb: http://git.kernel.org/tip/f403072c6108e15f319a4a5036b650c77760522c Author: Oleg Nesterov AuthorDate: Sun, 29 Jul 2012 20:22:12 +0200 Committer: Ingo Molnar CommitDate: Mon, 30 Jul 2012 11:27:18 +0200 uprobes: Don't recheck vma/f_mapping in write_opcode() write_opcode() rechecks valid_vma() and ->f_mapping, this is pointless. The caller, register_for_each_vma() or uprobe_mmap(), has already done these checks under mmap_sem. To clarify, uprobe_mmap() checks valid_vma() only, but we can rely on build_probe_list(vm_file->f_mapping->host). Signed-off-by: Oleg Nesterov Acked-by: Srikar Dronamraju Cc: Anton Arapov Cc: Srikar Dronamraju Link: http://lkml.kernel.org/r/20120729182212.GA20304@redhat.com Signed-off-by: Ingo Molnar --- kernel/events/uprobes.c | 19 +------------------ 1 files changed, 1 insertions(+), 18 deletions(-) diff --git a/kernel/events/uprobes.c b/kernel/events/uprobes.c index f935327..a2b32a5 100644 --- a/kernel/events/uprobes.c +++ b/kernel/events/uprobes.c @@ -206,33 +206,16 @@ static int write_opcode(struct arch_uprobe *auprobe, struct mm_struct *mm, unsigned long vaddr, uprobe_opcode_t opcode) { struct page *old_page, *new_page; - struct address_space *mapping; void *vaddr_old, *vaddr_new; struct vm_area_struct *vma; - struct uprobe *uprobe; int ret; + retry: /* Read the page with vaddr into memory */ ret = get_user_pages(NULL, mm, vaddr, 1, 0, 0, &old_page, &vma); if (ret <= 0) return ret; - ret = -EINVAL; - - /* - * We are interested in text pages only. Our pages of interest - * should be mapped for read and execute only. We desist from - * adding probes in write mapped pages since the breakpoints - * might end up in the file copy. - */ - if (!valid_vma(vma, is_swbp_insn(&opcode))) - goto put_out; - - uprobe = container_of(auprobe, struct uprobe, arch); - mapping = uprobe->inode->i_mapping; - if (mapping != vma->vm_file->f_mapping) - goto put_out; - ret = -ENOMEM; new_page = alloc_page_vma(GFP_HIGHUSER_MOVABLE, vma, vaddr); if (!new_page)