From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752590AbeESCrC (ORCPT ); Fri, 18 May 2018 22:47:02 -0400 Received: from mail.kernel.org ([198.145.29.99]:45178 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752562AbeESCq7 (ORCPT ); Fri, 18 May 2018 22:46:59 -0400 From: Frederic Weisbecker To: LKML Cc: 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 , Ingo Molnar , Mark Rutland , Alexander Shishkin , Andy Lutomirski , Arnaldo Carvalho de Melo , Max Filippov Subject: [PATCH 12/12] perf/breakpoint: Clean up and consolidate modify_user_hw_breakpoint_check() Date: Sat, 19 May 2018 04:45:49 +0200 Message-Id: <1526697950-7091-13-git-send-email-frederic@kernel.org> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1526697950-7091-1-git-send-email-frederic@kernel.org> References: <1526697950-7091-1-git-send-email-frederic@kernel.org> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Remove the dance around old and new attributes. Just don't modify the previous breakpoint at all until we have verified everything. 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 | 46 ++++++++++++++++++++++++------------------- 1 file changed, 26 insertions(+), 20 deletions(-) diff --git a/kernel/events/hw_breakpoint.c b/kernel/events/hw_breakpoint.c index 7840746..1af761a 100644 --- a/kernel/events/hw_breakpoint.c +++ b/kernel/events/hw_breakpoint.c @@ -461,37 +461,43 @@ register_user_hw_breakpoint(struct perf_event_attr *attr, } EXPORT_SYMBOL_GPL(register_user_hw_breakpoint); +static void hw_breakpoint_copy_attr(struct perf_event_attr *to, + struct perf_event_attr *from) +{ + to->bp_addr = from->bp_addr; + to->bp_type = from->bp_type; + to->bp_len = from->bp_len; + to->disabled = from->disabled; +} + int modify_user_hw_breakpoint_check(struct perf_event *bp, struct perf_event_attr *attr, bool check) { - u64 old_addr = bp->attr.bp_addr; - 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; - bp->attr.bp_type = attr->bp_type; - bp->attr.bp_len = attr->bp_len; - - if (check && memcmp(&bp->attr, attr, sizeof(*attr))) - return -EINVAL; + int err; err = hw_breakpoint_parse(bp, attr, &hw); - if (!err && modify) - err = modify_bp_slot(bp, old_type, bp->attr.bp_type); - - if (err) { - bp->attr.bp_addr = old_addr; - bp->attr.bp_type = old_type; - bp->attr.bp_len = old_len; + if (err) return err; + + if (check) { + struct perf_event_attr old_attr; + + old_attr = bp->attr; + hw_breakpoint_copy_attr(&old_attr, attr); + if (memcmp(&old_attr, attr, sizeof(*attr))) + return -EINVAL; + } + + if (bp->attr.bp_type != attr->bp_type) { + err = modify_bp_slot(bp, bp->attr.bp_type, attr->bp_type); + if (err) + return err; } + hw_breakpoint_copy_attr(&bp->attr, attr); bp->hw.info = hw; - bp->attr.disabled = attr->disabled; return 0; } -- 2.7.4