From patchwork Thu Jan 17 16:15:13 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Song Liu X-Patchwork-Id: 1026793 X-Patchwork-Delegate: bpf@iogearbox.net Return-Path: X-Original-To: patchwork-incoming-netdev@ozlabs.org Delivered-To: patchwork-incoming-netdev@ozlabs.org Authentication-Results: ozlabs.org; spf=none (mailfrom) smtp.mailfrom=vger.kernel.org (client-ip=209.132.180.67; helo=vger.kernel.org; envelope-from=netdev-owner@vger.kernel.org; receiver=) Authentication-Results: ozlabs.org; dmarc=pass (p=none dis=none) header.from=fb.com Authentication-Results: ozlabs.org; dkim=pass (1024-bit key; unprotected) header.d=fb.com header.i=@fb.com header.b="Qsfv44wU"; dkim-atps=neutral Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id 43gTjd4Cj7z9sBQ for ; Fri, 18 Jan 2019 03:16:53 +1100 (AEDT) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729176AbfAQQQw (ORCPT ); Thu, 17 Jan 2019 11:16:52 -0500 Received: from mx0b-00082601.pphosted.com ([67.231.153.30]:46542 "EHLO mx0a-00082601.pphosted.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1728747AbfAQQPf (ORCPT ); Thu, 17 Jan 2019 11:15:35 -0500 Received: from pps.filterd (m0001303.ppops.net [127.0.0.1]) by m0001303.ppops.net (8.16.0.27/8.16.0.27) with SMTP id x0HGA1nq006845 for ; Thu, 17 Jan 2019 08:15:34 -0800 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=fb.com; h=from : to : cc : subject : date : message-id : in-reply-to : references : mime-version : content-type; s=facebook; bh=CkzXSFAyDYZyvWONXeZs8oZtSq9F1V6pdhlT+qcMXMs=; b=Qsfv44wUl5CkZgQf7RG0Buwt1hCp7r316/vFtvUGLUzm6qAEfZ+SBIwQm13xmq5mqQNI 4wu1TWtOEp49aWGKkjaYzwVP7oufZCtpjunoibm+srDXM/8w208Th55H3xIm6QLIafse ma+bU4Zdpclt1Wtiof35NlXSzRnFsscPtlA= Received: from mail.thefacebook.com ([199.201.64.23]) by m0001303.ppops.net with ESMTP id 2q2u7vrc98-3 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-SHA384 bits=256 verify=NOT) for ; Thu, 17 Jan 2019 08:15:34 -0800 Received: from mx-out.facebook.com (2620:10d:c081:10::13) by mail.thefacebook.com (2620:10d:c081:35::127) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA) id 15.1.1531.3; Thu, 17 Jan 2019 08:15:31 -0800 Received: by devbig006.ftw2.facebook.com (Postfix, from userid 4523) id A30BF62E19D5; Thu, 17 Jan 2019 08:15:29 -0800 (PST) Smtp-Origin-Hostprefix: devbig From: Song Liu Smtp-Origin-Hostname: devbig006.ftw2.facebook.com To: , CC: Song Liu , , , , , Smtp-Origin-Cluster: ftw2c04 Subject: [PATCH v11 perf, bpf-next 1/9] perf, bpf: Introduce PERF_RECORD_KSYMBOL Date: Thu, 17 Jan 2019 08:15:13 -0800 Message-ID: <20190117161521.1341602-2-songliubraving@fb.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20190117161521.1341602-1-songliubraving@fb.com> References: <20190117161521.1341602-1-songliubraving@fb.com> X-FB-Internal: Safe MIME-Version: 1.0 X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:, , definitions=2019-01-17_05:, , signatures=0 X-Proofpoint-Spam-Reason: safe X-FB-Internal: Safe Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org For better performance analysis of dynamically JITed and loaded kernel functions, such as BPF programs, this patch introduces PERF_RECORD_KSYMBOL, a new perf_event_type that exposes kernel symbol register/unregister information to user space. The following data structure is used for PERF_RECORD_KSYMBOL. /* * struct { * struct perf_event_header header; * u64 addr; * u32 len; * u16 ksym_type; * u16 flags; * char name[]; * struct sample_id sample_id; * }; */ Reviewed-by: Arnaldo Carvalho de Melo Acked-by: Peter Zijlstra (Intel) Signed-off-by: Song Liu --- include/linux/perf_event.h | 8 +++ include/uapi/linux/perf_event.h | 26 ++++++++- kernel/events/core.c | 98 ++++++++++++++++++++++++++++++++- 3 files changed, 130 insertions(+), 2 deletions(-) diff --git a/include/linux/perf_event.h b/include/linux/perf_event.h index 1d5c551a5add..b46d11d8d79c 100644 --- a/include/linux/perf_event.h +++ b/include/linux/perf_event.h @@ -1113,6 +1113,10 @@ static inline void perf_event_task_sched_out(struct task_struct *prev, } extern void perf_event_mmap(struct vm_area_struct *vma); + +extern void perf_event_ksymbol(u16 ksym_type, u64 addr, u32 len, + bool unregister, const char *sym); + extern struct perf_guest_info_callbacks *perf_guest_cbs; extern int perf_register_guest_info_callbacks(struct perf_guest_info_callbacks *callbacks); extern int perf_unregister_guest_info_callbacks(struct perf_guest_info_callbacks *callbacks); @@ -1333,6 +1337,10 @@ static inline int perf_unregister_guest_info_callbacks (struct perf_guest_info_callbacks *callbacks) { return 0; } static inline void perf_event_mmap(struct vm_area_struct *vma) { } + +typedef int (perf_ksymbol_get_name_f)(char *name, int name_len, void *data); +static inline void perf_event_ksymbol(u16 ksym_type, u64 addr, u32 len, + bool unregister, const char *sym) { } static inline void perf_event_exec(void) { } static inline void perf_event_comm(struct task_struct *tsk, bool exec) { } static inline void perf_event_namespaces(struct task_struct *tsk) { } diff --git a/include/uapi/linux/perf_event.h b/include/uapi/linux/perf_event.h index 9de8780ac8d9..68c4da0227c5 100644 --- a/include/uapi/linux/perf_event.h +++ b/include/uapi/linux/perf_event.h @@ -372,7 +372,8 @@ struct perf_event_attr { context_switch : 1, /* context switch data */ write_backward : 1, /* Write ring buffer from end to beginning */ namespaces : 1, /* include namespaces data */ - __reserved_1 : 35; + ksymbol : 1, /* include ksymbol events */ + __reserved_1 : 34; union { __u32 wakeup_events; /* wakeup every n events */ @@ -965,9 +966,32 @@ enum perf_event_type { */ PERF_RECORD_NAMESPACES = 16, + /* + * Record ksymbol register/unregister events: + * + * struct { + * struct perf_event_header header; + * u64 addr; + * u32 len; + * u16 ksym_type; + * u16 flags; + * char name[]; + * struct sample_id sample_id; + * }; + */ + PERF_RECORD_KSYMBOL = 17, + PERF_RECORD_MAX, /* non-ABI */ }; +enum perf_record_ksymbol_type { + PERF_RECORD_KSYMBOL_TYPE_UNKNOWN = 0, + PERF_RECORD_KSYMBOL_TYPE_BPF = 1, + PERF_RECORD_KSYMBOL_TYPE_MAX /* non-ABI */ +}; + +#define PERF_RECORD_KSYMBOL_FLAGS_UNREGISTER (1 << 0) + #define PERF_MAX_STACK_DEPTH 127 #define PERF_MAX_CONTEXTS_PER_STACK 8 diff --git a/kernel/events/core.c b/kernel/events/core.c index 3cd13a30f732..64480a4ae2e2 100644 --- a/kernel/events/core.c +++ b/kernel/events/core.c @@ -385,6 +385,7 @@ static atomic_t nr_namespaces_events __read_mostly; static atomic_t nr_task_events __read_mostly; static atomic_t nr_freq_events __read_mostly; static atomic_t nr_switch_events __read_mostly; +static atomic_t nr_ksymbol_events __read_mostly; static LIST_HEAD(pmus); static DEFINE_MUTEX(pmus_lock); @@ -4235,7 +4236,7 @@ static bool is_sb_event(struct perf_event *event) if (attr->mmap || attr->mmap_data || attr->mmap2 || attr->comm || attr->comm_exec || - attr->task || + attr->task || attr->ksymbol || attr->context_switch) return true; return false; @@ -4305,6 +4306,8 @@ static void unaccount_event(struct perf_event *event) dec = true; if (has_branch_stack(event)) dec = true; + if (event->attr.ksymbol) + atomic_dec(&nr_ksymbol_events); if (dec) { if (!atomic_add_unless(&perf_sched_count, -1, 1)) @@ -7650,6 +7653,97 @@ static void perf_log_throttle(struct perf_event *event, int enable) perf_output_end(&handle); } +/* + * ksymbol register/unregister tracking + */ + +struct perf_ksymbol_event { + const char *name; + int name_len; + struct { + struct perf_event_header header; + u64 addr; + u32 len; + u16 ksym_type; + u16 flags; + } event_id; +}; + +static int perf_event_ksymbol_match(struct perf_event *event) +{ + return event->attr.ksymbol; +} + +static void perf_event_ksymbol_output(struct perf_event *event, void *data) +{ + struct perf_ksymbol_event *ksymbol_event = data; + struct perf_output_handle handle; + struct perf_sample_data sample; + int ret; + + if (!perf_event_ksymbol_match(event)) + return; + + perf_event_header__init_id(&ksymbol_event->event_id.header, + &sample, event); + ret = perf_output_begin(&handle, event, + ksymbol_event->event_id.header.size); + if (ret) + return; + + perf_output_put(&handle, ksymbol_event->event_id); + __output_copy(&handle, ksymbol_event->name, ksymbol_event->name_len); + perf_event__output_id_sample(event, &handle, &sample); + + perf_output_end(&handle); +} + +void perf_event_ksymbol(u16 ksym_type, u64 addr, u32 len, bool unregister, + const char *sym) +{ + struct perf_ksymbol_event ksymbol_event; + char name[KSYM_NAME_LEN]; + u16 flags = 0; + int name_len; + + if (!atomic_read(&nr_ksymbol_events)) + return; + + if (ksym_type >= PERF_RECORD_KSYMBOL_TYPE_MAX || + ksym_type == PERF_RECORD_KSYMBOL_TYPE_UNKNOWN) + goto err; + + strlcpy(name, sym, KSYM_NAME_LEN); + name_len = strlen(name) + 1; + while (!IS_ALIGNED(name_len, sizeof(u64))) + name[name_len++] = '\0'; + BUILD_BUG_ON(KSYM_NAME_LEN % sizeof(u64)); + + if (unregister) + flags |= PERF_RECORD_KSYMBOL_FLAGS_UNREGISTER; + + ksymbol_event = (struct perf_ksymbol_event){ + .name = name, + .name_len = name_len, + .event_id = { + .header = { + .type = PERF_RECORD_KSYMBOL, + .size = sizeof(ksymbol_event.event_id) + + name_len, + }, + .addr = addr, + .len = len, + .ksym_type = ksym_type, + .flags = flags, + }, + }; + + perf_iterate_sb(perf_event_ksymbol_output, &ksymbol_event, NULL); + return; +err: + WARN_ONCE(1, "%s: Invalid KSYMBOL type 0x%x\n", __func__, ksym_type); +} + void perf_event_itrace_started(struct perf_event *event) { event->attach_state |= PERF_ATTACH_ITRACE; @@ -9900,6 +9994,8 @@ static void account_event(struct perf_event *event) inc = true; if (is_cgroup_event(event)) inc = true; + if (event->attr.ksymbol) + atomic_inc(&nr_ksymbol_events); if (inc) { /*