From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754734Ab2FMSwe (ORCPT ); Wed, 13 Jun 2012 14:52:34 -0400 Received: from mx1.redhat.com ([209.132.183.28]:64625 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753389Ab2FMSwb (ORCPT ); Wed, 13 Jun 2012 14:52:31 -0400 Date: Wed, 13 Jun 2012 20:50:30 +0200 From: Oleg Nesterov To: Ingo Molnar , Peter Zijlstra , Srikar Dronamraju Cc: Ananth N Mavinakayanahalli , Anton Arapov , Masami Hiramatsu , linux-kernel@vger.kernel.org Subject: [PATCH 3/6] uprobes: no need to re-check vma_address() in write_opcode() Message-ID: <20120613185030.GC13878@redhat.com> References: <20120613184933.GA13870@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20120613184933.GA13870@redhat.com> User-Agent: Mutt/1.5.18 (2008-05-17) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org write_opcode() is called by register_for_each_vma() and uprobe_mmap() paths. In both cases the caller has already verified this vaddr under mmap_sem, no need to re-check. Note also that this check is wrong anyway, we should not truncate loff_t returned by vma_address() if we do not trust this mapping. Signed-off-by: Oleg Nesterov --- kernel/events/uprobes.c | 5 ----- 1 files changed, 0 insertions(+), 5 deletions(-) diff --git a/kernel/events/uprobes.c b/kernel/events/uprobes.c index 9bb5571..799d6ed 100644 --- a/kernel/events/uprobes.c +++ b/kernel/events/uprobes.c @@ -211,7 +211,6 @@ static int write_opcode(struct arch_uprobe *auprobe, struct mm_struct *mm, struct vm_area_struct *vma; struct uprobe *uprobe; unsigned long pgoff; - loff_t addr; int ret; retry: /* Read the page with vaddr into memory */ @@ -235,10 +234,6 @@ retry: if (mapping != vma->vm_file->f_mapping) goto put_out; - addr = vma_address(vma, uprobe->offset); - if (vaddr != (unsigned long)addr) - goto put_out; - ret = -ENOMEM; new_page = alloc_page_vma(GFP_HIGHUSER_MOVABLE, vma, vaddr); if (!new_page) -- 1.5.5.1