From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753940Ab2FFPKU (ORCPT ); Wed, 6 Jun 2012 11:10:20 -0400 Received: from terminus.zytor.com ([198.137.202.10]:39754 "EHLO terminus.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752173Ab2FFPKS (ORCPT ); Wed, 6 Jun 2012 11:10:18 -0400 Date: Wed, 6 Jun 2012 08:09:11 -0700 From: tip-bot for Oleg Nesterov Message-ID: Cc: linux-kernel@vger.kernel.org, hpa@zytor.com, mingo@kernel.org, torvalds@linux-foundation.org, peterz@infradead.org, ananth@in.ibm.com, anton@redhat.com, masami.hiramatsu.pt@hitachi.com, srikar@linux.vnet.ibm.com, tglx@linutronix.de, oleg@redhat.com Reply-To: mingo@kernel.org, hpa@zytor.com, linux-kernel@vger.kernel.org, torvalds@linux-foundation.org, peterz@infradead.org, ananth@in.ibm.com, anton@redhat.com, masami.hiramatsu.pt@hitachi.com, srikar@linux.vnet.ibm.com, oleg@redhat.com, tglx@linutronix.de In-Reply-To: <20120529192759.GB8057@redhat.com> References: <20120529192759.GB8057@redhat.com> To: linux-tip-commits@vger.kernel.org Subject: [tip:perf/core] uprobes: Change read_opcode() to use FOLL_FORCE Git-Commit-ID: 2c357a15491100e94de8e6105e6046ee3a71e05a 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]); Wed, 06 Jun 2012 08:09:17 -0700 (PDT) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Commit-ID: 2c357a15491100e94de8e6105e6046ee3a71e05a Gitweb: http://git.kernel.org/tip/2c357a15491100e94de8e6105e6046ee3a71e05a Author: Oleg Nesterov AuthorDate: Tue, 29 May 2012 21:27:59 +0200 Committer: Ingo Molnar CommitDate: Wed, 6 Jun 2012 11:30:55 +0200 uprobes: Change read_opcode() to use FOLL_FORCE set_orig_insn()->read_opcode() should not fail if the probed task did mprotect() after uprobe_register(), change it to use FOLL_FORCE. Without FOLL_WRITE this doesn't have any "side" effect but allows to read the !VM_READ memory. There is another reason for this change, we are going to use is_swbp_at_addr() from handle_swbp() which can race with another thread doing mprotect(). Signed-off-by: Oleg Nesterov Acked-by: Srikar Dronamraju Cc: Ananth N Mavinakayanahalli Cc: Anton Arapov Cc: Linus Torvalds Cc: Masami Hiramatsu Cc: Peter Zijlstra Link: http://lkml.kernel.org/r/20120529192759.GB8057@redhat.com Signed-off-by: Ingo Molnar --- kernel/events/uprobes.c | 2 +- 1 files changed, 1 insertions(+), 1 deletions(-) diff --git a/kernel/events/uprobes.c b/kernel/events/uprobes.c index d0f5ec0..a0dbc87 100644 --- a/kernel/events/uprobes.c +++ b/kernel/events/uprobes.c @@ -312,7 +312,7 @@ static int read_opcode(struct mm_struct *mm, unsigned long vaddr, uprobe_opcode_ void *vaddr_new; int ret; - ret = get_user_pages(NULL, mm, vaddr, 1, 0, 0, &page, NULL); + ret = get_user_pages(NULL, mm, vaddr, 1, 0, 1, &page, NULL); if (ret <= 0) return ret;