From patchwork Wed Jul 22 18:42:07 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Song Liu X-Patchwork-Id: 1334088 X-Patchwork-Delegate: bpf@iogearbox.net Return-Path: X-Original-To: incoming-bpf@patchwork.ozlabs.org Delivered-To: patchwork-incoming-bpf@bilbo.ozlabs.org Authentication-Results: ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=vger.kernel.org (client-ip=23.128.96.18; helo=vger.kernel.org; envelope-from=bpf-owner@vger.kernel.org; receiver=) Authentication-Results: ozlabs.org; dmarc=pass (p=reject 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.a=rsa-sha256 header.s=facebook header.b=SyzWyYKx; dkim-atps=neutral Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by ozlabs.org (Postfix) with ESMTP id 4BBksy1V8xz9sRk for ; Thu, 23 Jul 2020 04:45:10 +1000 (AEST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1732491AbgGVSpJ (ORCPT ); Wed, 22 Jul 2020 14:45:09 -0400 Received: from mx0b-00082601.pphosted.com ([67.231.153.30]:36768 "EHLO mx0b-00082601.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1732488AbgGVSo7 (ORCPT ); Wed, 22 Jul 2020 14:44:59 -0400 Received: from pps.filterd (m0109332.ppops.net [127.0.0.1]) by mx0a-00082601.pphosted.com (8.16.0.42/8.16.0.42) with SMTP id 06MIZJSM000766 for ; Wed, 22 Jul 2020 11:44:58 -0700 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-transfer-encoding : content-type; s=facebook; bh=kLiRNkzTf0D6xXXE4xYsJFN1/otcpDPBRxMJPlWMO1k=; b=SyzWyYKxzV+TF3gkjg3wzsnmg5wuJTMd26e/3f6YHqTW67Jpg6+FN9Q+v5oYqfuXCqTc by9eMGnhYV/adr+9xJ7liUHyi8pS3qY/zZuKXhX/muLFDeMDzYSQpYBcII59PbCSSr8U nL/tP+7PBW3DQEp85cp6lLqSRi+yAGO1iwc= Received: from mail.thefacebook.com ([163.114.132.120]) by mx0a-00082601.pphosted.com with ESMTP id 32esyurd4m-5 (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128 verify=NOT) for ; Wed, 22 Jul 2020 11:44:57 -0700 Received: from intmgw005.03.ash8.facebook.com (2620:10d:c085:208::11) by mail.thefacebook.com (2620:10d:c085:21d::4) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.1979.3; Wed, 22 Jul 2020 11:44:56 -0700 Received: by devbig006.ftw2.facebook.com (Postfix, from userid 4523) id DADC062E4E7F; Wed, 22 Jul 2020 11:42:15 -0700 (PDT) Smtp-Origin-Hostprefix: devbig From: Song Liu Smtp-Origin-Hostname: devbig006.ftw2.facebook.com To: , , CC: , , , , , , , Song Liu Smtp-Origin-Cluster: ftw2c04 Subject: [PATCH v4 bpf-next 1/4] bpf: separate bpf_get_[stack|stackid] for perf events BPF Date: Wed, 22 Jul 2020 11:42:07 -0700 Message-ID: <20200722184210.4078256-2-songliubraving@fb.com> X-Mailer: git-send-email 2.24.1 In-Reply-To: <20200722184210.4078256-1-songliubraving@fb.com> References: <20200722184210.4078256-1-songliubraving@fb.com> MIME-Version: 1.0 X-FB-Internal: Safe X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:6.0.235, 18.0.687 definitions=2020-07-22_10:2020-07-22,2020-07-22 signatures=0 X-Proofpoint-Spam-Details: rule=fb_default_notspam policy=fb_default score=0 mlxscore=0 adultscore=0 suspectscore=0 impostorscore=0 mlxlogscore=999 phishscore=0 spamscore=0 malwarescore=0 bulkscore=0 lowpriorityscore=0 clxscore=1015 priorityscore=1501 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2006250000 definitions=main-2007220119 X-FB-Internal: deliver Sender: bpf-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org Calling get_perf_callchain() on perf_events from PEBS entries may cause unwinder errors. To fix this issue, the callchain is fetched early. Such perf_events are marked with __PERF_SAMPLE_CALLCHAIN_EARLY. Similarly, calling bpf_get_[stack|stackid] on perf_events from PEBS may also cause unwinder errors. To fix this, add separate version of these two helpers, bpf_get_[stack|stackid]_pe. These two hepers use callchain in bpf_perf_event_data_kern->data->callchain. Signed-off-by: Song Liu --- include/linux/bpf.h | 2 + kernel/bpf/stackmap.c | 184 +++++++++++++++++++++++++++++++++++---- kernel/trace/bpf_trace.c | 4 +- 3 files changed, 170 insertions(+), 20 deletions(-) diff --git a/include/linux/bpf.h b/include/linux/bpf.h index bae557ff2da8b..70e34a0ebbac6 100644 --- a/include/linux/bpf.h +++ b/include/linux/bpf.h @@ -1644,6 +1644,8 @@ extern const struct bpf_func_proto bpf_get_current_comm_proto; extern const struct bpf_func_proto bpf_get_stackid_proto; extern const struct bpf_func_proto bpf_get_stack_proto; extern const struct bpf_func_proto bpf_get_task_stack_proto; +extern const struct bpf_func_proto bpf_get_stackid_proto_pe; +extern const struct bpf_func_proto bpf_get_stack_proto_pe; extern const struct bpf_func_proto bpf_sock_map_update_proto; extern const struct bpf_func_proto bpf_sock_hash_update_proto; extern const struct bpf_func_proto bpf_get_current_cgroup_id_proto; diff --git a/kernel/bpf/stackmap.c b/kernel/bpf/stackmap.c index 48d8e739975fa..5beb2f8c23da1 100644 --- a/kernel/bpf/stackmap.c +++ b/kernel/bpf/stackmap.c @@ -4,6 +4,7 @@ #include #include #include +#include #include #include #include @@ -387,11 +388,10 @@ get_callchain_entry_for_task(struct task_struct *task, u32 init_nr) #endif } -BPF_CALL_3(bpf_get_stackid, struct pt_regs *, regs, struct bpf_map *, map, - u64, flags) +static long __bpf_get_stackid(struct bpf_map *map, + struct perf_callchain_entry *trace, u64 flags) { struct bpf_stack_map *smap = container_of(map, struct bpf_stack_map, map); - struct perf_callchain_entry *trace; struct stack_map_bucket *bucket, *new_bucket, *old_bucket; u32 max_depth = map->value_size / stack_map_data_size(map); /* stack_map_alloc() checks that max_depth <= sysctl_perf_event_max_stack */ @@ -399,21 +399,9 @@ BPF_CALL_3(bpf_get_stackid, struct pt_regs *, regs, struct bpf_map *, map, u32 skip = flags & BPF_F_SKIP_FIELD_MASK; u32 hash, id, trace_nr, trace_len; bool user = flags & BPF_F_USER_STACK; - bool kernel = !user; u64 *ips; bool hash_matches; - if (unlikely(flags & ~(BPF_F_SKIP_FIELD_MASK | BPF_F_USER_STACK | - BPF_F_FAST_STACK_CMP | BPF_F_REUSE_STACKID))) - return -EINVAL; - - trace = get_perf_callchain(regs, init_nr, kernel, user, - sysctl_perf_event_max_stack, false, false); - - if (unlikely(!trace)) - /* couldn't fetch the stack trace */ - return -EFAULT; - /* get_perf_callchain() guarantees that trace->nr >= init_nr * and trace-nr <= sysctl_perf_event_max_stack, so trace_nr <= max_depth */ @@ -478,6 +466,30 @@ BPF_CALL_3(bpf_get_stackid, struct pt_regs *, regs, struct bpf_map *, map, return id; } +BPF_CALL_3(bpf_get_stackid, struct pt_regs *, regs, struct bpf_map *, map, + u64, flags) +{ + u32 max_depth = map->value_size / stack_map_data_size(map); + /* stack_map_alloc() checks that max_depth <= sysctl_perf_event_max_stack */ + u32 init_nr = sysctl_perf_event_max_stack - max_depth; + bool user = flags & BPF_F_USER_STACK; + struct perf_callchain_entry *trace; + bool kernel = !user; + + if (unlikely(flags & ~(BPF_F_SKIP_FIELD_MASK | BPF_F_USER_STACK | + BPF_F_FAST_STACK_CMP | BPF_F_REUSE_STACKID))) + return -EINVAL; + + trace = get_perf_callchain(regs, init_nr, kernel, user, + sysctl_perf_event_max_stack, false, false); + + if (unlikely(!trace)) + /* couldn't fetch the stack trace */ + return -EFAULT; + + return __bpf_get_stackid(map, trace, flags); +} + const struct bpf_func_proto bpf_get_stackid_proto = { .func = bpf_get_stackid, .gpl_only = true, @@ -487,7 +499,77 @@ const struct bpf_func_proto bpf_get_stackid_proto = { .arg3_type = ARG_ANYTHING, }; +static __u64 count_kernel_ip(struct perf_callchain_entry *trace) +{ + __u64 nr_kernel = 0; + + while (nr_kernel < trace->nr) { + if (trace->ip[nr_kernel] == PERF_CONTEXT_USER) + break; + nr_kernel++; + } + return nr_kernel; +} + +BPF_CALL_3(bpf_get_stackid_pe, struct bpf_perf_event_data_kern *, ctx, + struct bpf_map *, map, u64, flags) +{ + struct perf_event *event = ctx->event; + struct perf_callchain_entry *trace; + bool kernel, user; + __u64 nr_kernel; + int ret; + + /* perf_sample_data doesn't have callchain, use bpf_get_stackid */ + if (!(event->attr.sample_type & __PERF_SAMPLE_CALLCHAIN_EARLY)) + return bpf_get_stackid((unsigned long)(ctx->regs), + (unsigned long) map, flags, 0, 0); + + if (unlikely(flags & ~(BPF_F_SKIP_FIELD_MASK | BPF_F_USER_STACK | + BPF_F_FAST_STACK_CMP | BPF_F_REUSE_STACKID))) + return -EINVAL; + + user = flags & BPF_F_USER_STACK; + kernel = !user; + + trace = ctx->data->callchain; + if (unlikely(!trace)) + return -EFAULT; + + nr_kernel = count_kernel_ip(trace); + + if (kernel) { + __u64 nr = trace->nr; + + trace->nr = nr_kernel; + ret = __bpf_get_stackid(map, trace, flags); + + /* restore nr */ + trace->nr = nr; + } else { /* user */ + u64 skip = flags & BPF_F_SKIP_FIELD_MASK; + + skip += nr_kernel; + if (skip > BPF_F_SKIP_FIELD_MASK) + return -EFAULT; + + flags = (flags & ~BPF_F_SKIP_FIELD_MASK) | skip; + ret = __bpf_get_stackid(map, trace, flags); + } + return ret; +} + +const struct bpf_func_proto bpf_get_stackid_proto_pe = { + .func = bpf_get_stackid_pe, + .gpl_only = false, + .ret_type = RET_INTEGER, + .arg1_type = ARG_PTR_TO_CTX, + .arg2_type = ARG_CONST_MAP_PTR, + .arg3_type = ARG_ANYTHING, +}; + static long __bpf_get_stack(struct pt_regs *regs, struct task_struct *task, + struct perf_callchain_entry *trace_in, void *buf, u32 size, u64 flags) { u32 init_nr, trace_nr, copy_len, elem_size, num_elem; @@ -520,7 +602,9 @@ static long __bpf_get_stack(struct pt_regs *regs, struct task_struct *task, else init_nr = sysctl_perf_event_max_stack - num_elem; - if (kernel && task) + if (trace_in) + trace = trace_in; + else if (kernel && task) trace = get_callchain_entry_for_task(task, init_nr); else trace = get_perf_callchain(regs, init_nr, kernel, user, @@ -556,7 +640,7 @@ static long __bpf_get_stack(struct pt_regs *regs, struct task_struct *task, BPF_CALL_4(bpf_get_stack, struct pt_regs *, regs, void *, buf, u32, size, u64, flags) { - return __bpf_get_stack(regs, NULL, buf, size, flags); + return __bpf_get_stack(regs, NULL, NULL, buf, size, flags); } const struct bpf_func_proto bpf_get_stack_proto = { @@ -574,7 +658,7 @@ BPF_CALL_4(bpf_get_task_stack, struct task_struct *, task, void *, buf, { struct pt_regs *regs = task_pt_regs(task); - return __bpf_get_stack(regs, task, buf, size, flags); + return __bpf_get_stack(regs, task, NULL, buf, size, flags); } BTF_ID_LIST(bpf_get_task_stack_btf_ids) @@ -591,6 +675,70 @@ const struct bpf_func_proto bpf_get_task_stack_proto = { .btf_id = bpf_get_task_stack_btf_ids, }; +BPF_CALL_4(bpf_get_stack_pe, struct bpf_perf_event_data_kern *, ctx, + void *, buf, u32, size, u64, flags) +{ + struct perf_event *event = ctx->event; + struct perf_callchain_entry *trace; + bool kernel, user; + int err = -EINVAL; + __u64 nr_kernel; + + if (!(event->attr.sample_type & __PERF_SAMPLE_CALLCHAIN_EARLY)) + return __bpf_get_stack(ctx->regs, NULL, NULL, buf, size, flags); + + if (unlikely(flags & ~(BPF_F_SKIP_FIELD_MASK | BPF_F_USER_STACK | + BPF_F_USER_BUILD_ID))) + goto clear; + + user = flags & BPF_F_USER_STACK; + kernel = !user; + + err = -EFAULT; + trace = ctx->data->callchain; + if (unlikely(!trace)) + goto clear; + + nr_kernel = count_kernel_ip(trace); + + if (kernel) { + __u64 nr = trace->nr; + + trace->nr = nr_kernel; + err = __bpf_get_stack(ctx->regs, NULL, trace, buf, + size, flags); + + /* restore nr */ + trace->nr = nr; + } else { /* user */ + u64 skip = flags & BPF_F_SKIP_FIELD_MASK; + + skip += nr_kernel; + if (skip > BPF_F_SKIP_FIELD_MASK) + goto clear; + + flags = (flags & ~BPF_F_SKIP_FIELD_MASK) | skip; + err = __bpf_get_stack(ctx->regs, NULL, trace, buf, + size, flags); + } + return err; + +clear: + memset(buf, 0, size); + return err; + +} + +const struct bpf_func_proto bpf_get_stack_proto_pe = { + .func = bpf_get_stack_pe, + .gpl_only = true, + .ret_type = RET_INTEGER, + .arg1_type = ARG_PTR_TO_CTX, + .arg2_type = ARG_PTR_TO_UNINIT_MEM, + .arg3_type = ARG_CONST_SIZE_OR_ZERO, + .arg4_type = ARG_ANYTHING, +}; + /* Called from eBPF program */ static void *stack_map_lookup_elem(struct bpf_map *map, void *key) { diff --git a/kernel/trace/bpf_trace.c b/kernel/trace/bpf_trace.c index 3cc0dcb60ca20..cb91ef902cc43 100644 --- a/kernel/trace/bpf_trace.c +++ b/kernel/trace/bpf_trace.c @@ -1411,9 +1411,9 @@ pe_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) case BPF_FUNC_perf_event_output: return &bpf_perf_event_output_proto_tp; case BPF_FUNC_get_stackid: - return &bpf_get_stackid_proto_tp; + return &bpf_get_stackid_proto_pe; case BPF_FUNC_get_stack: - return &bpf_get_stack_proto_tp; + return &bpf_get_stack_proto_pe; case BPF_FUNC_perf_prog_read_value: return &bpf_perf_prog_read_value_proto; case BPF_FUNC_read_branch_records: From patchwork Wed Jul 22 18:42:08 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Song Liu X-Patchwork-Id: 1334089 X-Patchwork-Delegate: bpf@iogearbox.net Return-Path: X-Original-To: incoming-bpf@patchwork.ozlabs.org Delivered-To: patchwork-incoming-bpf@bilbo.ozlabs.org Authentication-Results: ozlabs.org; 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Wed, 22 Jul 2020 11:42:20 -0700 (PDT) Smtp-Origin-Hostprefix: devbig From: Song Liu Smtp-Origin-Hostname: devbig006.ftw2.facebook.com To: , , CC: , , , , , , , Song Liu Smtp-Origin-Cluster: ftw2c04 Subject: [PATCH v4 bpf-next 2/4] bpf: fail PERF_EVENT_IOC_SET_BPF when bpf_get_[stack|stackid] cannot work Date: Wed, 22 Jul 2020 11:42:08 -0700 Message-ID: <20200722184210.4078256-3-songliubraving@fb.com> X-Mailer: git-send-email 2.24.1 In-Reply-To: <20200722184210.4078256-1-songliubraving@fb.com> References: <20200722184210.4078256-1-songliubraving@fb.com> MIME-Version: 1.0 X-FB-Internal: Safe X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:6.0.235, 18.0.687 definitions=2020-07-22_10:2020-07-22,2020-07-22 signatures=0 X-Proofpoint-Spam-Details: rule=fb_default_notspam policy=fb_default score=0 spamscore=0 clxscore=1015 bulkscore=0 impostorscore=0 lowpriorityscore=0 priorityscore=1501 phishscore=0 adultscore=0 mlxlogscore=999 malwarescore=0 mlxscore=0 suspectscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2006250000 definitions=main-2007220119 X-FB-Internal: deliver Sender: bpf-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org bpf_get_[stack|stackid] on perf_events with precise_ip uses callchain attached to perf_sample_data. If this callchain is not presented, do not allow attaching BPF program that calls bpf_get_[stack|stackid] to this event. Signed-off-by: Song Liu --- include/linux/filter.h | 3 ++- kernel/bpf/verifier.c | 3 +++ kernel/events/core.c | 18 ++++++++++++++++++ 3 files changed, 23 insertions(+), 1 deletion(-) diff --git a/include/linux/filter.h b/include/linux/filter.h index 8252572db918f..582262017a7dd 100644 --- a/include/linux/filter.h +++ b/include/linux/filter.h @@ -534,7 +534,8 @@ struct bpf_prog { is_func:1, /* program is a bpf function */ kprobe_override:1, /* Do we override a kprobe? */ has_callchain_buf:1, /* callchain buffer allocated? */ - enforce_expected_attach_type:1; /* Enforce expected_attach_type checking at attach time */ + enforce_expected_attach_type:1, /* Enforce expected_attach_type checking at attach time */ + call_get_stack:1; /* Do we call bpf_get_stack() or bpf_get_stackid() */ enum bpf_prog_type type; /* Type of BPF program */ enum bpf_attach_type expected_attach_type; /* For some prog types */ u32 len; /* Number of filter blocks */ diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c index 9a6703bc3f36f..41c9517a505ff 100644 --- a/kernel/bpf/verifier.c +++ b/kernel/bpf/verifier.c @@ -4887,6 +4887,9 @@ static int check_helper_call(struct bpf_verifier_env *env, int func_id, int insn env->prog->has_callchain_buf = true; } + if (func_id == BPF_FUNC_get_stackid || func_id == BPF_FUNC_get_stack) + env->prog->call_get_stack = true; + if (changes_data) clear_all_pkt_pointers(env); return 0; diff --git a/kernel/events/core.c b/kernel/events/core.c index 856d98c36f562..f77d009fcce95 100644 --- a/kernel/events/core.c +++ b/kernel/events/core.c @@ -9544,6 +9544,24 @@ static int perf_event_set_bpf_handler(struct perf_event *event, u32 prog_fd) if (IS_ERR(prog)) return PTR_ERR(prog); + if (event->attr.precise_ip && + prog->call_get_stack && + (!(event->attr.sample_type & __PERF_SAMPLE_CALLCHAIN_EARLY) || + event->attr.exclude_callchain_kernel || + event->attr.exclude_callchain_user)) { + /* + * On perf_event with precise_ip, calling bpf_get_stack() + * may trigger unwinder warnings and occasional crashes. + * bpf_get_[stack|stackid] works around this issue by using + * callchain attached to perf_sample_data. If the + * perf_event does not full (kernel and user) callchain + * attached to perf_sample_data, do not allow attaching BPF + * program that calls bpf_get_[stack|stackid]. + */ + bpf_prog_put(prog); + return -EINVAL; + } + event->prog = prog; event->orig_overflow_handler = READ_ONCE(event->overflow_handler); WRITE_ONCE(event->overflow_handler, bpf_overflow_handler); From patchwork Wed Jul 22 18:42:09 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Song Liu X-Patchwork-Id: 1334094 X-Patchwork-Delegate: bpf@iogearbox.net Return-Path: X-Original-To: incoming-bpf@patchwork.ozlabs.org Delivered-To: patchwork-incoming-bpf@bilbo.ozlabs.org Authentication-Results: ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=vger.kernel.org (client-ip=23.128.96.18; helo=vger.kernel.org; envelope-from=bpf-owner@vger.kernel.org; receiver=) Authentication-Results: ozlabs.org; dmarc=pass (p=reject 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.a=rsa-sha256 header.s=facebook header.b=fPphctbf; dkim-atps=neutral Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by ozlabs.org (Postfix) with ESMTP id 4BBkx96jCRz9sRW for ; Thu, 23 Jul 2020 04:47:57 +1000 (AEST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730843AbgGVSr4 (ORCPT ); Wed, 22 Jul 2020 14:47:56 -0400 Received: from mx0a-00082601.pphosted.com ([67.231.145.42]:63144 "EHLO mx0a-00082601.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728124AbgGVSr4 (ORCPT ); Wed, 22 Jul 2020 14:47:56 -0400 Received: from pps.filterd (m0109334.ppops.net [127.0.0.1]) by mx0a-00082601.pphosted.com (8.16.0.42/8.16.0.42) with SMTP id 06MIcHXZ002711 for ; Wed, 22 Jul 2020 11:47:56 -0700 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-transfer-encoding : content-type; s=facebook; bh=HC19BocnzqfbZdasNet2djSQezi7uoWDz8ER7wUvdIo=; b=fPphctbfnldciNBDH2k+9Bwe7AyMkEdjuVnfa4LdwaO8PZetnq6RCzeFiqy713Q7914B YI/dAUhA9eY0WNZUG8r0Ef0SWmFrohwOWNPOS9ujsHOamaXaKHhjRag/291WpVYNEMuy jhd+Q0JB7sYGLPNlRsMbcwk0sy0CO5ml/K8= Received: from mail.thefacebook.com ([163.114.132.120]) by mx0a-00082601.pphosted.com with ESMTP id 32esyn8de5-2 (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128 verify=NOT) for ; Wed, 22 Jul 2020 11:47:56 -0700 Received: from intmgw003.03.ash8.facebook.com (2620:10d:c085:208::11) by mail.thefacebook.com (2620:10d:c085:21d::5) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.1979.3; Wed, 22 Jul 2020 11:47:55 -0700 Received: by devbig006.ftw2.facebook.com (Postfix, from userid 4523) id 76F7562E5024; Wed, 22 Jul 2020 11:42:24 -0700 (PDT) Smtp-Origin-Hostprefix: devbig From: Song Liu Smtp-Origin-Hostname: devbig006.ftw2.facebook.com To: , , CC: , , , , , , , Song Liu , Andrii Nakryiko Smtp-Origin-Cluster: ftw2c04 Subject: [PATCH v4 bpf-next 3/4] selftests/bpf: add callchain_stackid Date: Wed, 22 Jul 2020 11:42:09 -0700 Message-ID: <20200722184210.4078256-4-songliubraving@fb.com> X-Mailer: git-send-email 2.24.1 In-Reply-To: <20200722184210.4078256-1-songliubraving@fb.com> References: <20200722184210.4078256-1-songliubraving@fb.com> MIME-Version: 1.0 X-FB-Internal: Safe X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:6.0.235, 18.0.687 definitions=2020-07-22_10:2020-07-22,2020-07-22 signatures=0 X-Proofpoint-Spam-Details: rule=fb_default_notspam policy=fb_default score=0 spamscore=0 clxscore=1015 bulkscore=0 impostorscore=0 lowpriorityscore=0 priorityscore=1501 phishscore=0 adultscore=0 mlxlogscore=999 malwarescore=0 mlxscore=0 suspectscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2006250000 definitions=main-2007220119 X-FB-Internal: deliver Sender: bpf-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org This tests new helper function bpf_get_stackid_pe and bpf_get_stack_pe. These two helpers have different implementation for perf_event with PEB entries. Acked-by: Andrii Nakryiko Signed-off-by: Song Liu --- .../bpf/prog_tests/perf_event_stackmap.c | 116 ++++++++++++++++++ .../selftests/bpf/progs/perf_event_stackmap.c | 59 +++++++++ 2 files changed, 175 insertions(+) create mode 100644 tools/testing/selftests/bpf/prog_tests/perf_event_stackmap.c create mode 100644 tools/testing/selftests/bpf/progs/perf_event_stackmap.c diff --git a/tools/testing/selftests/bpf/prog_tests/perf_event_stackmap.c b/tools/testing/selftests/bpf/prog_tests/perf_event_stackmap.c new file mode 100644 index 0000000000000..72c3690844fba --- /dev/null +++ b/tools/testing/selftests/bpf/prog_tests/perf_event_stackmap.c @@ -0,0 +1,116 @@ +// SPDX-License-Identifier: GPL-2.0 +// Copyright (c) 2020 Facebook +#define _GNU_SOURCE +#include +#include +#include +#include "perf_event_stackmap.skel.h" + +#ifndef noinline +#define noinline __attribute__((noinline)) +#endif + +noinline int func_1(void) +{ + static int val = 1; + + val += 1; + + usleep(100); + return val; +} + +noinline int func_2(void) +{ + return func_1(); +} + +noinline int func_3(void) +{ + return func_2(); +} + +noinline int func_4(void) +{ + return func_3(); +} + +noinline int func_5(void) +{ + return func_4(); +} + +noinline int func_6(void) +{ + int i, val = 1; + + for (i = 0; i < 100; i++) + val += func_5(); + + return val; +} + +void test_perf_event_stackmap(void) +{ + struct perf_event_attr attr = { + /* .type = PERF_TYPE_SOFTWARE, */ + .type = PERF_TYPE_HARDWARE, + .config = PERF_COUNT_HW_CPU_CYCLES, + .precise_ip = 2, + .sample_type = PERF_SAMPLE_IP | PERF_SAMPLE_BRANCH_STACK | + PERF_SAMPLE_CALLCHAIN, + .branch_sample_type = PERF_SAMPLE_BRANCH_USER | + PERF_SAMPLE_BRANCH_NO_FLAGS | + PERF_SAMPLE_BRANCH_NO_CYCLES | + PERF_SAMPLE_BRANCH_CALL_STACK, + .sample_period = 5000, + .size = sizeof(struct perf_event_attr), + }; + struct perf_event_stackmap *skel; + __u32 duration = 0; + cpu_set_t cpu_set; + int pmu_fd, err; + + skel = perf_event_stackmap__open(); + + if (CHECK(!skel, "skel_open", "skeleton open failed\n")) + return; + + err = perf_event_stackmap__load(skel); + if (CHECK(err, "skel_load", "skeleton load failed: %d\n", err)) + goto cleanup; + + CPU_ZERO(&cpu_set); + CPU_SET(0, &cpu_set); + err = pthread_setaffinity_np(pthread_self(), sizeof(cpu_set), &cpu_set); + if (CHECK(err, "set_affinity", "err %d, errno %d\n", err, errno)) + goto cleanup; + + pmu_fd = syscall(__NR_perf_event_open, &attr, -1 /* pid */, + 0 /* cpu 0 */, -1 /* group id */, + 0 /* flags */); + if (pmu_fd < 0) { + printf("%s:SKIP:cpu doesn't support the event\n", __func__); + test__skip(); + goto cleanup; + } + + skel->links.oncpu = bpf_program__attach_perf_event(skel->progs.oncpu, + pmu_fd); + if (CHECK(IS_ERR(skel->links.oncpu), "attach_perf_event", + "err %ld\n", PTR_ERR(skel->links.oncpu))) { + close(pmu_fd); + goto cleanup; + } + + /* create kernel and user stack traces for testing */ + func_6(); + + CHECK(skel->data->stackid_kernel != 2, "get_stackid_kernel", "failed\n"); + CHECK(skel->data->stackid_user != 2, "get_stackid_user", "failed\n"); + CHECK(skel->data->stack_kernel != 2, "get_stack_kernel", "failed\n"); + CHECK(skel->data->stack_user != 2, "get_stack_user", "failed\n"); + +cleanup: + perf_event_stackmap__destroy(skel); +} diff --git a/tools/testing/selftests/bpf/progs/perf_event_stackmap.c b/tools/testing/selftests/bpf/progs/perf_event_stackmap.c new file mode 100644 index 0000000000000..25467d13c356a --- /dev/null +++ b/tools/testing/selftests/bpf/progs/perf_event_stackmap.c @@ -0,0 +1,59 @@ +// SPDX-License-Identifier: GPL-2.0 +// Copyright (c) 2020 Facebook +#include "vmlinux.h" +#include + +#ifndef PERF_MAX_STACK_DEPTH +#define PERF_MAX_STACK_DEPTH 127 +#endif + +typedef __u64 stack_trace_t[PERF_MAX_STACK_DEPTH]; +struct { + __uint(type, BPF_MAP_TYPE_STACK_TRACE); + __uint(max_entries, 16384); + __uint(key_size, sizeof(__u32)); + __uint(value_size, sizeof(stack_trace_t)); +} stackmap SEC(".maps"); + +struct { + __uint(type, BPF_MAP_TYPE_PERCPU_ARRAY); + __uint(max_entries, 1); + __type(key, __u32); + __type(value, stack_trace_t); +} stackdata_map SEC(".maps"); + +long stackid_kernel = 1; +long stackid_user = 1; +long stack_kernel = 1; +long stack_user = 1; + +SEC("perf_event") +int oncpu(void *ctx) +{ + stack_trace_t *trace; + __u32 key = 0; + long val; + + val = bpf_get_stackid(ctx, &stackmap, 0); + if (val > 0) + stackid_kernel = 2; + val = bpf_get_stackid(ctx, &stackmap, BPF_F_USER_STACK); + if (val > 0) + stackid_user = 2; + + trace = bpf_map_lookup_elem(&stackdata_map, &key); + if (!trace) + return 0; + + val = bpf_get_stack(ctx, trace, sizeof(stack_trace_t), 0); + if (val > 0) + stack_kernel = 2; + + val = bpf_get_stack(ctx, trace, sizeof(stack_trace_t), BPF_F_USER_STACK); + if (val > 0) + stack_user = 2; + + return 0; +} + +char LICENSE[] SEC("license") = "GPL"; From patchwork Wed Jul 22 18:42:10 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Song Liu X-Patchwork-Id: 1334090 X-Patchwork-Delegate: bpf@iogearbox.net Return-Path: X-Original-To: incoming-bpf@patchwork.ozlabs.org Delivered-To: patchwork-incoming-bpf@bilbo.ozlabs.org Authentication-Results: ozlabs.org; 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Wed, 22 Jul 2020 11:42:29 -0700 (PDT) Smtp-Origin-Hostprefix: devbig From: Song Liu Smtp-Origin-Hostname: devbig006.ftw2.facebook.com To: , , CC: , , , , , , , Song Liu Smtp-Origin-Cluster: ftw2c04 Subject: [PATCH v4 bpf-next 4/4] selftests/bpf: add get_stackid_cannot_attach Date: Wed, 22 Jul 2020 11:42:10 -0700 Message-ID: <20200722184210.4078256-5-songliubraving@fb.com> X-Mailer: git-send-email 2.24.1 In-Reply-To: <20200722184210.4078256-1-songliubraving@fb.com> References: <20200722184210.4078256-1-songliubraving@fb.com> MIME-Version: 1.0 X-FB-Internal: Safe X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:6.0.235, 18.0.687 definitions=2020-07-22_10:2020-07-22,2020-07-22 signatures=0 X-Proofpoint-Spam-Details: rule=fb_default_notspam policy=fb_default score=0 mlxscore=0 clxscore=1015 malwarescore=0 spamscore=0 adultscore=0 impostorscore=0 phishscore=0 suspectscore=0 bulkscore=0 priorityscore=1501 mlxlogscore=999 lowpriorityscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2006250000 definitions=main-2007220119 X-FB-Internal: deliver Sender: bpf-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org This test confirms that BPF program that calls bpf_get_stackid() cannot attach to perf_event with precise_ip > 0 but not PERF_SAMPLE_CALLCHAIN; and cannot attach if the perf_event has exclude_callchain_kernel. Signed-off-by: Song Liu --- .../prog_tests/get_stackid_cannot_attach.c | 91 +++++++++++++++++++ 1 file changed, 91 insertions(+) create mode 100644 tools/testing/selftests/bpf/prog_tests/get_stackid_cannot_attach.c diff --git a/tools/testing/selftests/bpf/prog_tests/get_stackid_cannot_attach.c b/tools/testing/selftests/bpf/prog_tests/get_stackid_cannot_attach.c new file mode 100644 index 0000000000000..f13149d279bc9 --- /dev/null +++ b/tools/testing/selftests/bpf/prog_tests/get_stackid_cannot_attach.c @@ -0,0 +1,91 @@ +// SPDX-License-Identifier: GPL-2.0 +// Copyright (c) 2020 Facebook +#include +#include "test_stacktrace_build_id.skel.h" + +void test_get_stackid_cannot_attach(void) +{ + struct perf_event_attr attr = { + /* .type = PERF_TYPE_SOFTWARE, */ + .type = PERF_TYPE_HARDWARE, + .config = PERF_COUNT_HW_CPU_CYCLES, + .precise_ip = 1, + .sample_type = PERF_SAMPLE_IP | PERF_SAMPLE_BRANCH_STACK, + .branch_sample_type = PERF_SAMPLE_BRANCH_USER | + PERF_SAMPLE_BRANCH_NO_FLAGS | + PERF_SAMPLE_BRANCH_NO_CYCLES | + PERF_SAMPLE_BRANCH_CALL_STACK, + .sample_period = 5000, + .size = sizeof(struct perf_event_attr), + }; + struct test_stacktrace_build_id *skel; + __u32 duration = 0; + int pmu_fd, err; + + skel = test_stacktrace_build_id__open(); + if (CHECK(!skel, "skel_open", "skeleton open failed\n")) + return; + + /* override program type */ + bpf_program__set_perf_event(skel->progs.oncpu); + + err = test_stacktrace_build_id__load(skel); + if (CHECK(err, "skel_load", "skeleton load failed: %d\n", err)) + goto cleanup; + + pmu_fd = syscall(__NR_perf_event_open, &attr, -1 /* pid */, + 0 /* cpu 0 */, -1 /* group id */, + 0 /* flags */); + if (pmu_fd < 0 && errno == ENOENT) { + printf("%s:SKIP:cannot open PERF_COUNT_HW_CPU_CYCLES with precise_ip > 0\n", + __func__); + test__skip(); + goto cleanup; + } + if (CHECK(pmu_fd < 0, "perf_event_open", "err %d errno %d\n", + pmu_fd, errno)) + goto cleanup; + + skel->links.oncpu = bpf_program__attach_perf_event(skel->progs.oncpu, + pmu_fd); + CHECK(!IS_ERR(skel->links.oncpu), "attach_perf_event_no_callchain", + "should have failed\n"); + close(pmu_fd); + + /* add PERF_SAMPLE_CALLCHAIN, attach should succeed */ + attr.sample_type |= PERF_SAMPLE_CALLCHAIN; + + pmu_fd = syscall(__NR_perf_event_open, &attr, -1 /* pid */, + 0 /* cpu 0 */, -1 /* group id */, + 0 /* flags */); + + if (CHECK(pmu_fd < 0, "perf_event_open", "err %d errno %d\n", + pmu_fd, errno)) + goto cleanup; + + skel->links.oncpu = bpf_program__attach_perf_event(skel->progs.oncpu, + pmu_fd); + CHECK(IS_ERR(skel->links.oncpu), "attach_perf_event_callchain", + "err: %ld\n", PTR_ERR(skel->links.oncpu)); + close(pmu_fd); + + /* add exclude_callchain_kernel, attach should fail */ + attr.exclude_callchain_kernel = 1; + + pmu_fd = syscall(__NR_perf_event_open, &attr, -1 /* pid */, + 0 /* cpu 0 */, -1 /* group id */, + 0 /* flags */); + + if (CHECK(pmu_fd < 0, "perf_event_open", "err %d errno %d\n", + pmu_fd, errno)) + goto cleanup; + + skel->links.oncpu = bpf_program__attach_perf_event(skel->progs.oncpu, + pmu_fd); + CHECK(!IS_ERR(skel->links.oncpu), "attach_perf_event_exclude_callchain_kernel", + "should have failed\n"); + close(pmu_fd); + +cleanup: + test_stacktrace_build_id__destroy(skel); +}