From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-3.1 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,MAILING_LIST_MULTI,SPF_PASS,T_DKIMWL_WL_HIGH,URIBL_BLOCKED, USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id A5E30C43142 for ; Tue, 26 Jun 2018 02:59:30 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 5782226471 for ; Tue, 26 Jun 2018 02:59:30 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="ZwFSDG7+" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 5782226471 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S965299AbeFZC70 (ORCPT ); Mon, 25 Jun 2018 22:59:26 -0400 Received: from mail.kernel.org ([198.145.29.99]:60674 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S965232AbeFZC7Y (ORCPT ); Mon, 25 Jun 2018 22:59:24 -0400 Received: from localhost.localdomain (h2133.porttelecom.ru [193.189.69.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 978BD2646C; Tue, 26 Jun 2018 02:59:18 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1529981963; bh=UAkgJk305p84rl6vpzKEz9bcWLq3QcQs6m/HrVDGqX8=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=ZwFSDG7+aNzuwztcMvuTJ2K0TzHoyA37W24rYpnNQgol2+MQfwJtRnqpPNSesfpV2 wdV8MOJiO/4FrVtnmJwqhPIkxRYBjiutfTYoIbxTGjebGjslF2cXpIgt08F/OT1MdO H/bgSQY5pOo/AZ3Hx2lqyqEofHkTFu7lZGxpm6Ag= From: Frederic Weisbecker To: Ingo Molnar Cc: LKML , Frederic Weisbecker , Jiri Olsa , Namhyung Kim , Joel Fernandes , Peter Zijlstra , Linus Torvalds , Yoshinori Sato , Benjamin Herrenschmidt , Catalin Marinas , Chris Zankel , Paul Mackerras , Thomas Gleixner , Will Deacon , Michael Ellerman , Rich Felker , Mark Rutland , Alexander Shishkin , Andy Lutomirski , Arnaldo Carvalho de Melo , Max Filippov Subject: [PATCH 01/12] perf/breakpoint: Split attribute parse and commit Date: Tue, 26 Jun 2018 04:58:48 +0200 Message-Id: <1529981939-8231-2-git-send-email-frederic@kernel.org> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1529981939-8231-1-git-send-email-frederic@kernel.org> References: <1529981939-8231-1-git-send-email-frederic@kernel.org> Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org arch_validate_hwbkpt_settings() mixes up attribute check and commit into a single code entity. Therefore the validation may return an error due to incorrect atributes while still leaving halfway modified architecture breakpoint data. This is harmless when we deal with a new breakpoint but it becomes a problem when we modify an existing breakpoint. Split attribute parse and commit to fix that. The architecture is passed a "struct arch_hw_breakpoint" to fill on top of the new attr and the core takes care about copying the backend data once it's fully validated. The architectures then need to implement the new API. Reported-by: Linus Torvalds Original-patch-by: Andy Lutomirski Signed-off-by: Frederic Weisbecker Cc: Linus Torvalds Cc: Andy Lutomirski Cc: Yoshinori Sato Cc: Rich Felker Cc: Ingo Molnar Cc: Thomas Gleixner Cc: Will Deacon Cc: Mark Rutland Cc: Max Filippov Cc: Chris Zankel Cc: Catalin Marinas Cc: Benjamin Herrenschmidt Cc: Paul Mackerras Cc: Michael Ellerman Cc: Peter Zijlstra Cc: Arnaldo Carvalho de Melo Cc: Alexander Shishkin Cc: Jiri Olsa Cc: Namhyung Kim Cc: Joel Fernandes --- kernel/events/hw_breakpoint.c | 57 +++++++++++++++++++++++++++++++------------ 1 file changed, 41 insertions(+), 16 deletions(-) diff --git a/kernel/events/hw_breakpoint.c b/kernel/events/hw_breakpoint.c index 6e28d28..314e2a9 100644 --- a/kernel/events/hw_breakpoint.c +++ b/kernel/events/hw_breakpoint.c @@ -400,16 +400,35 @@ int dbg_release_bp_slot(struct perf_event *bp) return 0; } -static int validate_hw_breakpoint(struct perf_event *bp) +#ifndef hw_breakpoint_arch_parse +int hw_breakpoint_arch_parse(struct perf_event *bp, + const struct perf_event_attr *attr, + struct arch_hw_breakpoint *hw) { - int ret; + int err; - ret = arch_validate_hwbkpt_settings(bp); - if (ret) - return ret; + err = arch_validate_hwbkpt_settings(bp); + if (err) + return err; + + *hw = bp->hw.info; + + return 0; +} +#endif + +static int hw_breakpoint_parse(struct perf_event *bp, + const struct perf_event_attr *attr, + struct arch_hw_breakpoint *hw) +{ + int err; + + err = hw_breakpoint_arch_parse(bp, attr, hw); + if (err) + return err; if (arch_check_bp_in_kernelspace(bp)) { - if (bp->attr.exclude_kernel) + if (attr->exclude_kernel) return -EINVAL; /* * Don't let unprivileged users set a breakpoint in the trap @@ -424,19 +443,22 @@ static int validate_hw_breakpoint(struct perf_event *bp) int register_perf_hw_breakpoint(struct perf_event *bp) { - int ret; + struct arch_hw_breakpoint hw; + int err; - ret = reserve_bp_slot(bp); - if (ret) - return ret; + err = reserve_bp_slot(bp); + if (err) + return err; - ret = validate_hw_breakpoint(bp); - - /* if arch_validate_hwbkpt_settings() fails then release bp slot */ - if (ret) + err = hw_breakpoint_parse(bp, &bp->attr, &hw); + if (err) { release_bp_slot(bp); + return err; + } - return ret; + bp->hw.info = hw; + + return 0; } /** @@ -464,6 +486,7 @@ modify_user_hw_breakpoint_check(struct perf_event *bp, struct perf_event_attr *a u64 old_len = bp->attr.bp_len; int old_type = bp->attr.bp_type; bool modify = attr->bp_type != old_type; + struct arch_hw_breakpoint hw; int err = 0; bp->attr.bp_addr = attr->bp_addr; @@ -473,7 +496,7 @@ modify_user_hw_breakpoint_check(struct perf_event *bp, struct perf_event_attr *a if (check && memcmp(&bp->attr, attr, sizeof(*attr))) return -EINVAL; - err = validate_hw_breakpoint(bp); + err = hw_breakpoint_parse(bp, attr, &hw); if (!err && modify) err = modify_bp_slot(bp, old_type); @@ -484,7 +507,9 @@ modify_user_hw_breakpoint_check(struct perf_event *bp, struct perf_event_attr *a return err; } + bp->hw.info = hw; bp->attr.disabled = attr->disabled; + return 0; } -- 2.7.4