Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755843AbbHDIzg (ORCPT ); Tue, 4 Aug 2015 04:55:36 -0400 Received: from terminus.zytor.com ([198.137.202.10]:50084 "EHLO terminus.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755804AbbHDIzb (ORCPT ); Tue, 4 Aug 2015 04:55:31 -0400 Date: Tue, 4 Aug 2015 01:54:35 -0700 From: tip-bot for Andy Lutomirski Message-ID: Cc: tglx@linutronix.de, rostedt@goodmis.org, hpa@zytor.com, peterz@infradead.org, bp@alien8.de, brgerst@gmail.com, linux-kernel@vger.kernel.org, masami.hiramatsu.pt@hitachi.com, torvalds@linux-foundation.org, luto@kernel.org, mingo@kernel.org Reply-To: linux-kernel@vger.kernel.org, torvalds@linux-foundation.org, masami.hiramatsu.pt@hitachi.com, luto@kernel.org, mingo@kernel.org, rostedt@goodmis.org, tglx@linutronix.de, hpa@zytor.com, peterz@infradead.org, bp@alien8.de, brgerst@gmail.com In-Reply-To: References: To: linux-tip-commits@vger.kernel.org Subject: [tip:perf/core] perf/x86/hw_breakpoints: Improve range breakpoint validation Git-Commit-ID: ab513927ab449af00cc70b0269e15ee80dd537f9 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 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2250 Lines: 56 Commit-ID: ab513927ab449af00cc70b0269e15ee80dd537f9 Gitweb: http://git.kernel.org/tip/ab513927ab449af00cc70b0269e15ee80dd537f9 Author: Andy Lutomirski AuthorDate: Thu, 30 Jul 2015 20:32:41 -0700 Committer: Ingo Molnar CommitDate: Tue, 4 Aug 2015 10:16:54 +0200 perf/x86/hw_breakpoints: Improve range breakpoint validation Range breakpoints will do the wrong thing if the address isn't aligned. While we're there, add comments about why it's safe for instruction breakpoints. Signed-off-by: Andy Lutomirski Signed-off-by: Peter Zijlstra (Intel) Cc: Borislav Petkov Cc: Brian Gerst Cc: Linus Torvalds Cc: Masami Hiramatsu Cc: Peter Zijlstra Cc: Steven Rostedt Cc: Thomas Gleixner Link: http://lkml.kernel.org/r/ae25d14d61f2f43b78e0a247e469f3072df7e201.1438312874.git.luto@kernel.org Signed-off-by: Ingo Molnar --- arch/x86/kernel/hw_breakpoint.c | 10 ++++++++++ 1 file changed, 10 insertions(+) diff --git a/arch/x86/kernel/hw_breakpoint.c b/arch/x86/kernel/hw_breakpoint.c index 78f3e90..6f345d3 100644 --- a/arch/x86/kernel/hw_breakpoint.c +++ b/arch/x86/kernel/hw_breakpoint.c @@ -291,8 +291,18 @@ static int arch_build_bp_info(struct perf_event *bp) break; #endif default: + /* AMD range breakpoint */ if (!is_power_of_2(bp->attr.bp_len)) return -EINVAL; + if (bp->attr.bp_addr & (bp->attr.bp_len - 1)) + return -EINVAL; + /* + * It's impossible to use a range breakpoint to fake out + * user vs kernel detection because bp_len - 1 can't + * have the high bit set. If we ever allow range instruction + * breakpoints, then we'll have to check for kprobe-blacklisted + * addresses anywhere in the range. + */ if (!cpu_has_bpext) return -EOPNOTSUPP; info->mask = bp->attr.bp_len - 1; -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/