From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Google-Smtp-Source: AIpwx48qjaUZzWL+OD4DOEr5AHDGfghUjineqyXivQWcUJ44CklKjLAG/7QSEPT1rPuuLaWdYuQk ARC-Seal: i=1; a=rsa-sha256; t=1523021370; cv=none; d=google.com; s=arc-20160816; b=YXMHCawjgJ05Z/O/3WKAHZO4mtNtfpvEwfZGt1VTsWHDM2oTGCKGLqgAYoZLfeti7f SV9ihad725t/pu9QUy5gN3mwmjcq3pcVIIWWbdHkGpvI2aRDdCVGy+0PZZz0/ryODqcp oSDLqiW7RQOI2y8ZLhQ3NQmpt8sMU96kk5lxEwgxBSlr7y/p/8thKxgfkx5zUl4kiiy4 TjvzmjFHThVj1fQGSQSof+qOW5mkiRlTAv1HVeDvS4XwtX4v6nHFmio/G02Kqed4j6MM hQkhlH0Ku3ZbwfiK+bllagGkSrx0x6nWw1+73H0CY9Sv3lZ8qut/ZcLvuoY6pZNx33zO dzXA== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=mime-version:user-agent:references:in-reply-to:message-id:date :subject:cc:to:from:arc-authentication-results; bh=+E28tjGYcGXBW976s0BHJZzX+sn1dSMR3LuBqvb8b88=; b=BHhSeNwD0LAZqAv4u3SW7RO6r3jWuwYXjnDyOZ6Ww9HPbNICnZGUMu6OTpVcf/4j5w gXmAwFpSZ+KwI3wiej7N2/NgNrSTMal9mU3nJFv1zohunvtwO3c/2MDZ/Fe1ci5U3Iuq PxBC7TXSzY7/MSm2bt7km+LMTjcEc1h6vFSY8D1NfSpKFOW/c+KzAuRJz2kCLaTZ2Svq mBGlTdnBqL+0u1ujjWCjxuM8OIICjoRRwP+cxa4Wk8ExfrAjowSCnHAdeNdtyJJgdMpr x154w+McGai/RdcLJiPMK0cZuH/M8MjdyPbIugCdnr3wIju9MA/NcjteTJJjb7IBcYCp oJiw== ARC-Authentication-Results: i=1; mx.google.com; spf=softfail (google.com: domain of transitioning gregkh@linuxfoundation.org does not designate 90.92.61.202 as permitted sender) smtp.mailfrom=gregkh@linuxfoundation.org Authentication-Results: mx.google.com; spf=softfail (google.com: domain of transitioning gregkh@linuxfoundation.org does not designate 90.92.61.202 as permitted sender) smtp.mailfrom=gregkh@linuxfoundation.org From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Linus Torvalds , Thomas Gleixner , Alexander Shishkin , Andy Lutomirski , Arnaldo Carvalho de Melo , Frederic Weisbecker , Jiri Olsa , Peter Zijlstra , Stephane Eranian , Vince Weaver , Ingo Molnar Subject: [PATCH 4.4 04/72] perf/hwbp: Simplify the perf-hwbp code, fix documentation Date: Fri, 6 Apr 2018 15:23:05 +0200 Message-Id: <20180406084305.489020042@linuxfoundation.org> X-Mailer: git-send-email 2.17.0 In-Reply-To: <20180406084305.210085169@linuxfoundation.org> References: <20180406084305.210085169@linuxfoundation.org> User-Agent: quilt/0.65 X-stable: review MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 X-getmail-retrieved-from-mailbox: INBOX X-GMAIL-LABELS: =?utf-8?b?IlxcU2VudCI=?= X-GMAIL-THRID: =?utf-8?q?1597003469119697595?= X-GMAIL-MSGID: =?utf-8?q?1597003656012045716?= X-Mailing-List: linux-kernel@vger.kernel.org List-ID: 4.4-stable review patch. If anyone has any objections, please let me know. ------------------ From: Linus Torvalds commit f67b15037a7a50c57f72e69a6d59941ad90a0f0f upstream. Annoyingly, modify_user_hw_breakpoint() unnecessarily complicates the modification of a breakpoint - simplify it and remove the pointless local variables. Also update the stale Docbook while at it. Signed-off-by: Linus Torvalds Acked-by: Thomas Gleixner Cc: Cc: Alexander Shishkin Cc: Andy Lutomirski Cc: Arnaldo Carvalho de Melo Cc: Frederic Weisbecker Cc: Jiri Olsa Cc: Peter Zijlstra Cc: Stephane Eranian Cc: Vince Weaver Signed-off-by: Ingo Molnar Signed-off-by: Greg Kroah-Hartman --- kernel/events/hw_breakpoint.c | 30 +++++++----------------------- 1 file changed, 7 insertions(+), 23 deletions(-) --- a/kernel/events/hw_breakpoint.c +++ b/kernel/events/hw_breakpoint.c @@ -427,16 +427,9 @@ EXPORT_SYMBOL_GPL(register_user_hw_break * modify_user_hw_breakpoint - modify a user-space hardware breakpoint * @bp: the breakpoint structure to modify * @attr: new breakpoint attributes - * @triggered: callback to trigger when we hit the breakpoint - * @tsk: pointer to 'task_struct' of the process to which the address belongs */ int modify_user_hw_breakpoint(struct perf_event *bp, struct perf_event_attr *attr) { - u64 old_addr = bp->attr.bp_addr; - u64 old_len = bp->attr.bp_len; - int old_type = bp->attr.bp_type; - int err = 0; - /* * modify_user_hw_breakpoint can be invoked with IRQs disabled and hence it * will not be possible to raise IPIs that invoke __perf_event_disable. @@ -451,27 +444,18 @@ int modify_user_hw_breakpoint(struct per bp->attr.bp_addr = attr->bp_addr; bp->attr.bp_type = attr->bp_type; bp->attr.bp_len = attr->bp_len; + bp->attr.disabled = 1; - if (attr->disabled) - goto end; - - err = validate_hw_breakpoint(bp); - if (!err) - perf_event_enable(bp); + if (!attr->disabled) { + int err = validate_hw_breakpoint(bp); - if (err) { - bp->attr.bp_addr = old_addr; - bp->attr.bp_type = old_type; - bp->attr.bp_len = old_len; - if (!bp->attr.disabled) - perf_event_enable(bp); + if (err) + return err; - return err; + perf_event_enable(bp); + bp->attr.disabled = 0; } -end: - bp->attr.disabled = attr->disabled; - return 0; } EXPORT_SYMBOL_GPL(modify_user_hw_breakpoint);