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=-1.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS,URIBL_BLOCKED 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 6E5A9C4321D for ; Wed, 22 Aug 2018 10:28:39 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 1131A2064A for ; Wed, 22 Aug 2018 10:28:38 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 1131A2064A Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=linux.ibm.com 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 S1728554AbeHVNwy (ORCPT ); Wed, 22 Aug 2018 09:52:54 -0400 Received: from mx0b-001b2d01.pphosted.com ([148.163.158.5]:59478 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726849AbeHVNwy (ORCPT ); Wed, 22 Aug 2018 09:52:54 -0400 Received: from pps.filterd (m0098421.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.16.0.22/8.16.0.22) with SMTP id w7MAODKD077720 for ; Wed, 22 Aug 2018 06:28:35 -0400 Received: from e06smtp01.uk.ibm.com (e06smtp01.uk.ibm.com [195.75.94.97]) by mx0a-001b2d01.pphosted.com with ESMTP id 2m14y9jjme-1 (version=TLSv1.2 cipher=AES256-GCM-SHA384 bits=256 verify=NOT) for ; Wed, 22 Aug 2018 06:28:34 -0400 Received: from localhost by e06smtp01.uk.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Wed, 22 Aug 2018 11:28:33 +0100 Received: from b06cxnps3075.portsmouth.uk.ibm.com (9.149.109.195) by e06smtp01.uk.ibm.com (192.168.101.131) with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted; (version=TLSv1/SSLv3 cipher=AES256-GCM-SHA384 bits=256/256) Wed, 22 Aug 2018 11:28:29 +0100 Received: from d06av21.portsmouth.uk.ibm.com (d06av21.portsmouth.uk.ibm.com [9.149.105.232]) by b06cxnps3075.portsmouth.uk.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id w7MASSYk32964834 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=FAIL); Wed, 22 Aug 2018 10:28:28 GMT Received: from d06av21.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 4F3A452052; Wed, 22 Aug 2018 13:28:28 +0100 (BST) Received: from [9.195.41.244] (unknown [9.195.41.244]) by d06av21.portsmouth.uk.ibm.com (Postfix) with ESMTP id EB2EA52050; Wed, 22 Aug 2018 13:28:24 +0100 (BST) Subject: Re: [PATCH] trace_uprobe: support reference count in fd-based uprobe To: Song Liu , linux-kernel@vger.kernel.org Cc: kernel-team@fb.com, Masami Hiramatsu , Oleg Nesterov , Srikar Dronamraju , "Naveen N . Rao" , Steven Rostedt , Peter Zijlstra , Ingo Molnar , Teng Qin , Ravi Bangoria References: <20180821222307.1071060-1-songliubraving@fb.com> From: Ravi Bangoria Date: Wed, 22 Aug 2018 15:58:20 +0530 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.9.1 MIME-Version: 1.0 In-Reply-To: <20180821222307.1071060-1-songliubraving@fb.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit X-TM-AS-GCONF: 00 x-cbid: 18082210-4275-0000-0000-000002AD92E9 X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 18082210-4276-0000-0000-000037B69786 Message-Id: X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:,, definitions=2018-08-22_06:,, signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 priorityscore=1501 malwarescore=0 suspectscore=0 phishscore=0 bulkscore=0 spamscore=0 clxscore=1015 lowpriorityscore=0 mlxscore=0 impostorscore=0 mlxlogscore=999 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1807170000 definitions=main-1808220106 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 08/22/2018 03:53 AM, Song Liu wrote: > This patch applies on top of Ravi Bangoria's work that enables reference > count for uprobe: > > https://lkml.org/lkml/2018/8/20/37 > > After Ravi's work, the effort to enable it in fd-based uprobe is straight > forward. Highest 40 bits of perf_event_attr.config is used to stored offset > of the reference count (semaphore). > > Format information in /sys/bus/event_source/devices/uprobe/format/ is > updated to reflect this new feature. LGTM Reviewed-and-tested-by: Ravi Bangoria > > Signed-off-by: Song Liu > Cc: Ravi Bangoria > Cc: Masami Hiramatsu > Cc: Oleg Nesterov > Cc: Srikar Dronamraju > Cc: Naveen N. Rao > Cc: Steven Rostedt (VMware) > Cc: Peter Zijlstra > Cc: Ingo Molnar > Cc: Teng Qin > --- > include/linux/trace_events.h | 3 +- > kernel/events/core.c | 49 ++++++++++++++++++++++++++------- > kernel/trace/trace_event_perf.c | 7 +++-- > kernel/trace/trace_probe.h | 3 +- > kernel/trace/trace_uprobe.c | 4 ++- > 5 files changed, 50 insertions(+), 16 deletions(-) > > diff --git a/include/linux/trace_events.h b/include/linux/trace_events.h > index 78a010e19ed4..4130a5497d40 100644 > --- a/include/linux/trace_events.h > +++ b/include/linux/trace_events.h > @@ -575,7 +575,8 @@ extern int bpf_get_kprobe_info(const struct perf_event *event, > bool perf_type_tracepoint); > #endif > #ifdef CONFIG_UPROBE_EVENTS > -extern int perf_uprobe_init(struct perf_event *event, bool is_retprobe); > +extern int perf_uprobe_init(struct perf_event *event, > + unsigned long ref_ctr_offset, bool is_retprobe); > extern void perf_uprobe_destroy(struct perf_event *event); > extern int bpf_get_uprobe_info(const struct perf_event *event, > u32 *fd_type, const char **filename, > diff --git a/kernel/events/core.c b/kernel/events/core.c > index 8f0434a9951a..75a0219be420 100644 > --- a/kernel/events/core.c > +++ b/kernel/events/core.c > @@ -8363,30 +8363,39 @@ static struct pmu perf_tracepoint = { > * > * PERF_PROBE_CONFIG_IS_RETPROBE if set, create kretprobe/uretprobe > * if not set, create kprobe/uprobe > + * > + * The following values specify a reference counter (or semaphore in the > + * terminology of tools like dtrace, systemtap, etc.) Userspace Statically > + * Defined Tracepoints (USDT). Currently, we use 40 bit for the offset. > + * > + * PERF_UPROBE_REF_CTR_OFFSET_BITS # of bits in config as th offset > + * PERF_UPROBE_REF_CTR_OFFSET_SHIFT # of bits to shift left > */ > enum perf_probe_config { > PERF_PROBE_CONFIG_IS_RETPROBE = 1U << 0, /* [k,u]retprobe */ > + PERF_UPROBE_REF_CTR_OFFSET_BITS = 40, > + PERF_UPROBE_REF_CTR_OFFSET_SHIFT = 64 - PERF_UPROBE_REF_CTR_OFFSET_BITS, > }; > > PMU_FORMAT_ATTR(retprobe, "config:0"); > +#endif > > -static struct attribute *probe_attrs[] = { > +#ifdef CONFIG_KPROBE_EVENTS > +static struct attribute *kprobe_attrs[] = { > &format_attr_retprobe.attr, > NULL, > }; > > -static struct attribute_group probe_format_group = { > +static struct attribute_group kprobe_format_group = { > .name = "format", > - .attrs = probe_attrs, > + .attrs = kprobe_attrs, > }; > > -static const struct attribute_group *probe_attr_groups[] = { > - &probe_format_group, > +static const struct attribute_group *kprobe_attr_groups[] = { > + &kprobe_format_group, > NULL, > }; > -#endif > > -#ifdef CONFIG_KPROBE_EVENTS > static int perf_kprobe_event_init(struct perf_event *event); > static struct pmu perf_kprobe = { > .task_ctx_nr = perf_sw_context, > @@ -8396,7 +8405,7 @@ static struct pmu perf_kprobe = { > .start = perf_swevent_start, > .stop = perf_swevent_stop, > .read = perf_swevent_read, > - .attr_groups = probe_attr_groups, > + .attr_groups = kprobe_attr_groups, > }; > > static int perf_kprobe_event_init(struct perf_event *event) > @@ -8428,6 +8437,24 @@ static int perf_kprobe_event_init(struct perf_event *event) > #endif /* CONFIG_KPROBE_EVENTS */ > > #ifdef CONFIG_UPROBE_EVENTS > +PMU_FORMAT_ATTR(ref_ctr_offset, "config:63-24"); > + > +static struct attribute *uprobe_attrs[] = { > + &format_attr_retprobe.attr, > + &format_attr_ref_ctr_offset.attr, > + NULL, > +}; > + > +static struct attribute_group uprobe_format_group = { > + .name = "format", > + .attrs = uprobe_attrs, > +}; > + > +static const struct attribute_group *uprobe_attr_groups[] = { > + &uprobe_format_group, > + NULL, > +}; > + > static int perf_uprobe_event_init(struct perf_event *event); > static struct pmu perf_uprobe = { > .task_ctx_nr = perf_sw_context, > @@ -8437,12 +8464,13 @@ static struct pmu perf_uprobe = { > .start = perf_swevent_start, > .stop = perf_swevent_stop, > .read = perf_swevent_read, > - .attr_groups = probe_attr_groups, > + .attr_groups = uprobe_attr_groups, > }; > > static int perf_uprobe_event_init(struct perf_event *event) > { > int err; > + unsigned long ref_ctr_offset; > bool is_retprobe; > > if (event->attr.type != perf_uprobe.type) > @@ -8458,7 +8486,8 @@ static int perf_uprobe_event_init(struct perf_event *event) > return -EOPNOTSUPP; > > is_retprobe = event->attr.config & PERF_PROBE_CONFIG_IS_RETPROBE; > - err = perf_uprobe_init(event, is_retprobe); > + ref_ctr_offset = event->attr.config >> PERF_UPROBE_REF_CTR_OFFSET_SHIFT; > + err = perf_uprobe_init(event, ref_ctr_offset, is_retprobe); > if (err) > return err; > > diff --git a/kernel/trace/trace_event_perf.c b/kernel/trace/trace_event_perf.c > index 69a3fe926e8c..76217bbef815 100644 > --- a/kernel/trace/trace_event_perf.c > +++ b/kernel/trace/trace_event_perf.c > @@ -290,7 +290,8 @@ void perf_kprobe_destroy(struct perf_event *p_event) > #endif /* CONFIG_KPROBE_EVENTS */ > > #ifdef CONFIG_UPROBE_EVENTS > -int perf_uprobe_init(struct perf_event *p_event, bool is_retprobe) > +int perf_uprobe_init(struct perf_event *p_event, > + unsigned long ref_ctr_offset, bool is_retprobe) > { > int ret; > char *path = NULL; > @@ -312,8 +313,8 @@ int perf_uprobe_init(struct perf_event *p_event, bool is_retprobe) > goto out; > } > > - tp_event = create_local_trace_uprobe( > - path, p_event->attr.probe_offset, is_retprobe); > + tp_event = create_local_trace_uprobe(path, p_event->attr.probe_offset, > + ref_ctr_offset, is_retprobe); > if (IS_ERR(tp_event)) { > ret = PTR_ERR(tp_event); > goto out; > diff --git a/kernel/trace/trace_probe.h b/kernel/trace/trace_probe.h > index 5f52668e165d..03b10f3201a5 100644 > --- a/kernel/trace/trace_probe.h > +++ b/kernel/trace/trace_probe.h > @@ -412,6 +412,7 @@ create_local_trace_kprobe(char *func, void *addr, unsigned long offs, > extern void destroy_local_trace_kprobe(struct trace_event_call *event_call); > > extern struct trace_event_call * > -create_local_trace_uprobe(char *name, unsigned long offs, bool is_return); > +create_local_trace_uprobe(char *name, unsigned long offs, > + unsigned long ref_ctr_offset, bool is_return); > extern void destroy_local_trace_uprobe(struct trace_event_call *event_call); > #endif > diff --git a/kernel/trace/trace_uprobe.c b/kernel/trace/trace_uprobe.c > index 3a7c73c40007..d09638706fe0 100644 > --- a/kernel/trace/trace_uprobe.c > +++ b/kernel/trace/trace_uprobe.c > @@ -1405,7 +1405,8 @@ static int unregister_uprobe_event(struct trace_uprobe *tu) > > #ifdef CONFIG_PERF_EVENTS > struct trace_event_call * > -create_local_trace_uprobe(char *name, unsigned long offs, bool is_return) > +create_local_trace_uprobe(char *name, unsigned long offs, > + unsigned long ref_ctr_offset, bool is_return) > { > struct trace_uprobe *tu; > struct path path; > @@ -1437,6 +1438,7 @@ create_local_trace_uprobe(char *name, unsigned long offs, bool is_return) > > tu->offset = offs; > tu->path = path; > + tu->ref_ctr_offset = ref_ctr_offset; > tu->filename = kstrdup(name, GFP_KERNEL); > init_trace_event_call(tu, &tu->tp.call); > >