From patchwork Tue Dec 15 23:36:59 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Song Liu X-Patchwork-Id: 344298 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=-18.8 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER, INCLUDES_PATCH, MAILING_LIST_MULTI, SPF_HELO_NONE, SPF_PASS, URIBL_BLOCKED, USER_AGENT_GIT 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 8650AC3526A for ; Wed, 16 Dec 2020 00:05:56 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 6623122D02 for ; Wed, 16 Dec 2020 00:05:56 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727811AbgLPABU (ORCPT ); Tue, 15 Dec 2020 19:01:20 -0500 Received: from mx0a-00082601.pphosted.com ([67.231.145.42]:62946 "EHLO mx0a-00082601.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725914AbgLOXh4 (ORCPT ); Tue, 15 Dec 2020 18:37:56 -0500 Received: from pps.filterd (m0109333.ppops.net [127.0.0.1]) by mx0a-00082601.pphosted.com (8.16.0.43/8.16.0.43) with SMTP id 0BFNZEkE019623 for ; Tue, 15 Dec 2020 15:37:16 -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-transfer-encoding : content-type; s=facebook; bh=4HrPklqvodd1+k7+tZn7lCeoz3VJkb2Gyr4ow4hoLB8=; b=SSYTPOWMHd0q67hHT5cA+jHPohiLQgSbHwbxZurv0TfVoj5NapxDwgjx519Al27zPVbl CaU79eWlhxXII8OJXoyWRgY5OGNbKsO8LJzoE/PPX1qObG/jWTKyHiT06H4SpBLJhDlR eTKx8WVMv+46fWfloWPdVX37B9djr9bw6yI= Received: from maileast.thefacebook.com ([163.114.130.16]) by mx0a-00082601.pphosted.com with ESMTP id 35eypsjxts-7 (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128 verify=NOT) for ; Tue, 15 Dec 2020 15:37:16 -0800 Received: from intmgw005.03.ash8.facebook.com (2620:10d:c0a8:1b::d) by mail.thefacebook.com (2620:10d:c0a8:83::5) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.1979.3; Tue, 15 Dec 2020 15:37:11 -0800 Received: by devbig006.ftw2.facebook.com (Postfix, from userid 4523) id 37F8062E56FB; Tue, 15 Dec 2020 15:37:07 -0800 (PST) From: Song Liu To: , CC: , , , , , , Song Liu Subject: [PATCH v2 bpf-next 1/4] bpf: introduce task_vma bpf_iter Date: Tue, 15 Dec 2020 15:36:59 -0800 Message-ID: <20201215233702.3301881-2-songliubraving@fb.com> X-Mailer: git-send-email 2.24.1 In-Reply-To: <20201215233702.3301881-1-songliubraving@fb.com> References: <20201215233702.3301881-1-songliubraving@fb.com> MIME-Version: 1.0 X-FB-Internal: Safe X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:6.0.343, 18.0.737 definitions=2020-12-15_13:2020-12-15,2020-12-15 signatures=0 X-Proofpoint-Spam-Details: rule=fb_default_notspam policy=fb_default score=0 malwarescore=0 phishscore=0 spamscore=0 clxscore=1015 suspectscore=0 adultscore=0 impostorscore=0 lowpriorityscore=0 mlxscore=0 bulkscore=0 mlxlogscore=999 priorityscore=1501 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2009150000 definitions=main-2012150159 X-FB-Internal: deliver Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org Introduce task_vma bpf_iter to print memory information of a process. It can be used to print customized information similar to /proc//maps. task_vma iterator releases mmap_lock before calling the BPF program. Therefore, we cannot pass vm_area_struct directly to the BPF program. A new __vm_area_struct is introduced to keep key information of a vma. On each iteration, task_vma gathers information in __vm_area_struct and passes it to the BPF program. If the vma maps to a file, task_vma also holds a reference to the file while calling the BPF program. Signed-off-by: Song Liu --- include/linux/bpf.h | 2 +- kernel/bpf/task_iter.c | 205 ++++++++++++++++++++++++++++++++++++++++- 2 files changed, 205 insertions(+), 2 deletions(-) diff --git a/include/linux/bpf.h b/include/linux/bpf.h index 07cb5d15e7439..49dd1e29c8118 100644 --- a/include/linux/bpf.h +++ b/include/linux/bpf.h @@ -1325,7 +1325,7 @@ enum bpf_iter_feature { BPF_ITER_RESCHED = BIT(0), }; -#define BPF_ITER_CTX_ARG_MAX 2 +#define BPF_ITER_CTX_ARG_MAX 3 struct bpf_iter_reg { const char *target; bpf_iter_attach_target_t attach_target; diff --git a/kernel/bpf/task_iter.c b/kernel/bpf/task_iter.c index 0458a40edf10a..15a066b442f75 100644 --- a/kernel/bpf/task_iter.c +++ b/kernel/bpf/task_iter.c @@ -304,9 +304,183 @@ static const struct seq_operations task_file_seq_ops = { .show = task_file_seq_show, }; +/* + * Key information from vm_area_struct. We need this because we cannot + * assume the vm_area_struct is still valid after each iteration. + */ +struct __vm_area_struct { + __u64 start; + __u64 end; + __u64 flags; + __u64 pgoff; +}; + +struct bpf_iter_seq_task_vma_info { + /* The first field must be struct bpf_iter_seq_task_common. + * this is assumed by {init, fini}_seq_pidns() callback functions. + */ + struct bpf_iter_seq_task_common common; + struct task_struct *task; + struct __vm_area_struct vma; + struct file *file; + u32 tid; +}; + +static struct __vm_area_struct * +task_vma_seq_get_next(struct bpf_iter_seq_task_vma_info *info) +{ + struct pid_namespace *ns = info->common.ns; + struct task_struct *curr_task; + struct vm_area_struct *vma; + u32 curr_tid = info->tid; + bool new_task = false; + + /* If this function returns a non-NULL __vm_area_struct, it held + * a reference to the task_struct. If info->file is non-NULL, it + * also holds a reference to the file. If this function returns + * NULL, it does not hold any reference. + */ +again: + if (info->task) { + curr_task = info->task; + } else { + curr_task = task_seq_get_next(ns, &curr_tid, true); + if (!curr_task) { + info->task = NULL; + info->tid++; + return NULL; + } + + if (curr_tid != info->tid) { + info->tid = curr_tid; + new_task = true; + } + + if (!curr_task->mm) + goto next_task; + info->task = curr_task; + } + + mmap_read_lock(curr_task->mm); + if (new_task) { + vma = curr_task->mm->mmap; + } else { + /* We drop the lock between each iteration, so it is + * necessary to use find_vma() to find the next vma. This + * is similar to the mechanism in show_smaps_rollup(). + */ + vma = find_vma(curr_task->mm, info->vma.end - 1); + /* same vma as previous iteration, use vma->next */ + if (vma && (vma->vm_start == info->vma.start)) + vma = vma->vm_next; + } + if (!vma) { + mmap_read_unlock(curr_task->mm); + goto next_task; + } + info->task = curr_task; + info->vma.start = vma->vm_start; + info->vma.end = vma->vm_end; + info->vma.pgoff = vma->vm_pgoff; + info->vma.flags = vma->vm_flags; + if (vma->vm_file) + info->file = get_file(vma->vm_file); + mmap_read_unlock(curr_task->mm); + return &info->vma; + +next_task: + put_task_struct(curr_task); + info->task = NULL; + curr_tid = ++(info->tid); + goto again; +} + +static void *task_vma_seq_start(struct seq_file *seq, loff_t *pos) +{ + struct bpf_iter_seq_task_vma_info *info = seq->private; + struct __vm_area_struct *vma; + + vma = task_vma_seq_get_next(info); + if (vma && *pos == 0) + ++*pos; + + return vma; +} + +static void *task_vma_seq_next(struct seq_file *seq, void *v, loff_t *pos) +{ + struct bpf_iter_seq_task_vma_info *info = seq->private; + + ++*pos; + if (info->file) { + fput(info->file); + info->file = NULL; + } + return task_vma_seq_get_next(info); +} + +struct bpf_iter__task_vma { + __bpf_md_ptr(struct bpf_iter_meta *, meta); + __bpf_md_ptr(struct task_struct *, task); + __bpf_md_ptr(struct __vm_area_struct *, vma); + __bpf_md_ptr(struct file *, file); +}; + +DEFINE_BPF_ITER_FUNC(task_vma, struct bpf_iter_meta *meta, + struct task_struct *task, struct __vm_area_struct *vma, + struct file *file) + +static int __task_vma_seq_show(struct seq_file *seq, bool in_stop) +{ + struct bpf_iter_seq_task_vma_info *info = seq->private; + struct bpf_iter__task_vma ctx; + struct bpf_iter_meta meta; + struct bpf_prog *prog; + + meta.seq = seq; + prog = bpf_iter_get_info(&meta, in_stop); + if (!prog) + return 0; + + ctx.meta = &meta; + ctx.task = info->task; + ctx.vma = &info->vma; + ctx.file = info->file; + return bpf_iter_run_prog(prog, &ctx); +} + +static int task_vma_seq_show(struct seq_file *seq, void *v) +{ + return __task_vma_seq_show(seq, false); +} + +static void task_vma_seq_stop(struct seq_file *seq, void *v) +{ + struct bpf_iter_seq_task_vma_info *info = seq->private; + + if (!v) { + (void)__task_vma_seq_show(seq, true); + } else { + put_task_struct(info->task); + if (info->file) { + fput(info->file); + info->file = NULL; + } + info->task = NULL; + } +} + +static const struct seq_operations task_vma_seq_ops = { + .start = task_vma_seq_start, + .next = task_vma_seq_next, + .stop = task_vma_seq_stop, + .show = task_vma_seq_show, +}; + BTF_ID_LIST(btf_task_file_ids) BTF_ID(struct, task_struct) BTF_ID(struct, file) +BTF_ID(struct, __vm_area_struct) static const struct bpf_iter_seq_info task_seq_info = { .seq_ops = &task_seq_ops, @@ -346,6 +520,28 @@ static struct bpf_iter_reg task_file_reg_info = { .seq_info = &task_file_seq_info, }; +static const struct bpf_iter_seq_info task_vma_seq_info = { + .seq_ops = &task_vma_seq_ops, + .init_seq_private = init_seq_pidns, + .fini_seq_private = fini_seq_pidns, + .seq_priv_size = sizeof(struct bpf_iter_seq_task_vma_info), +}; + +static struct bpf_iter_reg task_vma_reg_info = { + .target = "task_vma", + .feature = BPF_ITER_RESCHED, + .ctx_arg_info_size = 3, + .ctx_arg_info = { + { offsetof(struct bpf_iter__task_vma, task), + PTR_TO_BTF_ID_OR_NULL }, + { offsetof(struct bpf_iter__task_vma, vma), + PTR_TO_BTF_ID_OR_NULL }, + { offsetof(struct bpf_iter__task_vma, file), + PTR_TO_BTF_ID_OR_NULL }, + }, + .seq_info = &task_vma_seq_info, +}; + static int __init task_iter_init(void) { int ret; @@ -357,6 +553,13 @@ static int __init task_iter_init(void) task_file_reg_info.ctx_arg_info[0].btf_id = btf_task_file_ids[0]; task_file_reg_info.ctx_arg_info[1].btf_id = btf_task_file_ids[1]; - return bpf_iter_reg_target(&task_file_reg_info); + ret = bpf_iter_reg_target(&task_file_reg_info); + if (ret) + return ret; + + task_vma_reg_info.ctx_arg_info[0].btf_id = btf_task_file_ids[0]; + task_vma_reg_info.ctx_arg_info[1].btf_id = btf_task_file_ids[2]; + task_vma_reg_info.ctx_arg_info[2].btf_id = btf_task_file_ids[1]; + return bpf_iter_reg_target(&task_vma_reg_info); } late_initcall(task_iter_init); From patchwork Tue Dec 15 23:37:00 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Song Liu X-Patchwork-Id: 344299 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=-18.8 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER, INCLUDES_PATCH, MAILING_LIST_MULTI, SPF_HELO_NONE, SPF_PASS, URIBL_BLOCKED, USER_AGENT_GIT 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 DAF5FC3526D for ; Wed, 16 Dec 2020 00:05:21 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id AD8AF22D05 for ; Wed, 16 Dec 2020 00:05:21 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727855AbgLPABY (ORCPT ); Tue, 15 Dec 2020 19:01:24 -0500 Received: from mx0b-00082601.pphosted.com ([67.231.153.30]:37126 "EHLO mx0b-00082601.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726221AbgLOXiA (ORCPT ); Tue, 15 Dec 2020 18:38:00 -0500 Received: from pps.filterd (m0109331.ppops.net [127.0.0.1]) by mx0a-00082601.pphosted.com (8.16.0.43/8.16.0.43) with SMTP id 0BFNWulE008132 for ; Tue, 15 Dec 2020 15:37:19 -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-transfer-encoding : content-type; s=facebook; bh=+UK0j/mFombeFsFq0Rpm6Ff6mQdxwD/eCrgr4iYJQPk=; b=IeYinZqq+7GvLLtRv6oilJWPpAHiFhLWeTvoGgetEv023DHPXAoUgfCXUy7E5xwzCxYY yvI89CYmNbT2xxYofWoOjIB8uweiuc7aA0oZMTS83Q8TPaRA3G6ROl8tQwd49SWIfYXr pc4xCNqsx+jAvYLZYMy+XbB1IZKtzZzylBo= Received: from mail.thefacebook.com ([163.114.132.120]) by mx0a-00082601.pphosted.com with ESMTP id 35ej69p7ak-5 (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128 verify=NOT) for ; Tue, 15 Dec 2020 15:37:19 -0800 Received: from intmgw003.08.frc2.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; Tue, 15 Dec 2020 15:37:15 -0800 Received: by devbig006.ftw2.facebook.com (Postfix, from userid 4523) id 3FA7462E56FB; Tue, 15 Dec 2020 15:37:09 -0800 (PST) From: Song Liu To: , CC: , , , , , , Song Liu Subject: [PATCH v2 bpf-next 2/4] bpf: allow bpf_d_path in sleepable bpf_iter program Date: Tue, 15 Dec 2020 15:37:00 -0800 Message-ID: <20201215233702.3301881-3-songliubraving@fb.com> X-Mailer: git-send-email 2.24.1 In-Reply-To: <20201215233702.3301881-1-songliubraving@fb.com> References: <20201215233702.3301881-1-songliubraving@fb.com> MIME-Version: 1.0 X-FB-Internal: Safe X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:6.0.343, 18.0.737 definitions=2020-12-15_13:2020-12-15,2020-12-15 signatures=0 X-Proofpoint-Spam-Details: rule=fb_default_notspam policy=fb_default score=0 mlxscore=0 bulkscore=0 impostorscore=0 lowpriorityscore=0 priorityscore=1501 phishscore=0 mlxlogscore=680 malwarescore=0 spamscore=0 suspectscore=0 adultscore=0 clxscore=1015 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2009150000 definitions=main-2012150159 X-FB-Internal: deliver Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org task_file and task_vma iter programs have access to file->f_path. Enable bpf_d_path to print paths of these file. bpf_iter programs are generally called in sleepable context. However, it is still necessary to diffientiate sleepable and non-sleepable bpf_iter programs: sleepable programs have access to bpf_d_path; non-sleepable programs have access to bpf_spin_lock. Signed-off-by: Song Liu Acked-by: Yonghong Song Tested-by: Jiri Olsa --- kernel/trace/bpf_trace.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/kernel/trace/bpf_trace.c b/kernel/trace/bpf_trace.c index 4be771df5549a..9e5f9b968355f 100644 --- a/kernel/trace/bpf_trace.c +++ b/kernel/trace/bpf_trace.c @@ -1191,6 +1191,11 @@ BTF_SET_END(btf_allowlist_d_path) static bool bpf_d_path_allowed(const struct bpf_prog *prog) { + if (prog->type == BPF_PROG_TYPE_TRACING && + prog->expected_attach_type == BPF_TRACE_ITER && + prog->aux->sleepable) + return true; + if (prog->type == BPF_PROG_TYPE_LSM) return bpf_lsm_is_sleepable_hook(prog->aux->attach_btf_id); From patchwork Tue Dec 15 23:37:01 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Song Liu X-Patchwork-Id: 344858 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=-18.8 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER, INCLUDES_PATCH, MAILING_LIST_MULTI, SPF_HELO_NONE, SPF_PASS, URIBL_BLOCKED, USER_AGENT_GIT 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 5605EC35273 for ; Wed, 16 Dec 2020 00:05:57 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 34AA522D02 for ; Wed, 16 Dec 2020 00:05:57 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727840AbgLPABV (ORCPT ); Tue, 15 Dec 2020 19:01:21 -0500 Received: from mx0a-00082601.pphosted.com ([67.231.145.42]:53870 "EHLO mx0a-00082601.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726177AbgLOXh7 (ORCPT ); Tue, 15 Dec 2020 18:37:59 -0500 Received: from pps.filterd (m0109333.ppops.net [127.0.0.1]) by mx0a-00082601.pphosted.com (8.16.0.43/8.16.0.43) with SMTP id 0BFNZEkK019623 for ; Tue, 15 Dec 2020 15:37:18 -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-transfer-encoding : content-type; s=facebook; bh=Pvz7Me3uWv3Bgg8leBWmu6W1S9zf+6E28CBDJrJbUcI=; b=bOBucWjz0A1rB82AxfYWp/bWVld011AkOXyeuedjjkw9JXMfSuk5Fc8rzjf0cDfNUi2y lm4qNbhuXZe1VqoXp5jInoRMGMau8iwvqnI6Wsi0dOSw6A5A8feNLESqG1RywTC2lxyI HLyBWuMou4ATf470GL53oncCvoDm3bdOa+Q= Received: from maileast.thefacebook.com ([163.114.130.16]) by mx0a-00082601.pphosted.com with ESMTP id 35eypsjxts-13 (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128 verify=NOT) for ; Tue, 15 Dec 2020 15:37:18 -0800 Received: from intmgw005.03.ash8.facebook.com (2620:10d:c0a8:1b::d) by mail.thefacebook.com (2620:10d:c0a8:83::5) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.1979.3; Tue, 15 Dec 2020 15:37:12 -0800 Received: by devbig006.ftw2.facebook.com (Postfix, from userid 4523) id 55B0F62E56FB; Tue, 15 Dec 2020 15:37:11 -0800 (PST) From: Song Liu To: , CC: , , , , , , Song Liu Subject: [PATCH v2 bpf-next 3/4] libbpf: introduce section "iter.s/" for sleepable bpf_iter program Date: Tue, 15 Dec 2020 15:37:01 -0800 Message-ID: <20201215233702.3301881-4-songliubraving@fb.com> X-Mailer: git-send-email 2.24.1 In-Reply-To: <20201215233702.3301881-1-songliubraving@fb.com> References: <20201215233702.3301881-1-songliubraving@fb.com> MIME-Version: 1.0 X-FB-Internal: Safe X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:6.0.343, 18.0.737 definitions=2020-12-15_13:2020-12-15,2020-12-15 signatures=0 X-Proofpoint-Spam-Details: rule=fb_default_notspam policy=fb_default score=0 malwarescore=0 phishscore=0 spamscore=0 clxscore=1015 suspectscore=0 adultscore=0 impostorscore=0 lowpriorityscore=0 mlxscore=0 bulkscore=0 mlxlogscore=809 priorityscore=1501 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2009150000 definitions=main-2012150159 X-FB-Internal: deliver Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org Sleepable iterator program have access to helper functions like bpf_d_path. Signed-off-by: Song Liu --- tools/lib/bpf/libbpf.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c index 6ae748f6ea118..12ad4593a91cb 100644 --- a/tools/lib/bpf/libbpf.c +++ b/tools/lib/bpf/libbpf.c @@ -8541,6 +8541,11 @@ static const struct bpf_sec_def section_defs[] = { .expected_attach_type = BPF_TRACE_ITER, .is_attach_btf = true, .attach_fn = attach_iter), + SEC_DEF("iter.s/", TRACING, + .expected_attach_type = BPF_TRACE_ITER, + .is_attach_btf = true, + .is_sleepable = true, + .attach_fn = attach_iter), BPF_EAPROG_SEC("xdp_devmap/", BPF_PROG_TYPE_XDP, BPF_XDP_DEVMAP), BPF_EAPROG_SEC("xdp_cpumap/", BPF_PROG_TYPE_XDP, From patchwork Tue Dec 15 23:37:02 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Song Liu X-Patchwork-Id: 344300 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=-16.0 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER, INCLUDES_PATCH, MAILING_LIST_MULTI, SPF_HELO_NONE, SPF_PASS, UNWANTED_LANGUAGE_BODY,URIBL_BLOCKED,USER_AGENT_GIT 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 9C10FC2BBCA for ; Wed, 16 Dec 2020 00:05:20 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 632BE22D07 for ; Wed, 16 Dec 2020 00:05:20 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727892AbgLPAB0 (ORCPT ); Tue, 15 Dec 2020 19:01:26 -0500 Received: from mx0b-00082601.pphosted.com ([67.231.153.30]:61498 "EHLO mx0b-00082601.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726275AbgLOXiC (ORCPT ); Tue, 15 Dec 2020 18:38:02 -0500 Received: from pps.filterd (m0109331.ppops.net [127.0.0.1]) by mx0a-00082601.pphosted.com (8.16.0.43/8.16.0.43) with SMTP id 0BFNWvVK008171 for ; Tue, 15 Dec 2020 15:37:20 -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-transfer-encoding : content-type; s=facebook; bh=S+EA0I96zi5nkyHqlKPU2+dcHKzq+z+TYfraL6H8TQw=; b=fsmBOMLRlZJPayU3mlZBmXv2MmhyKt8yuV9cfhjQsFH0qNxX7LWQ1DDS42M5aTNrk/nR +Otb/UPr7DTgsMEGURv7EoLhfKNpQvVabBgZ1ts6fYCocfCFhpimoVXeB3+KNEd4L4P5 NpJAOh0Qbo73NH8TFgMdfRMgkrERr6607Hc= Received: from mail.thefacebook.com ([163.114.132.120]) by mx0a-00082601.pphosted.com with ESMTP id 35ej69p7af-8 (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128 verify=NOT) for ; Tue, 15 Dec 2020 15:37:20 -0800 Received: from intmgw001.03.ash8.facebook.com (2620:10d:c085:208::f) 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; Tue, 15 Dec 2020 15:37:16 -0800 Received: by devbig006.ftw2.facebook.com (Postfix, from userid 4523) id 3AFB962E56FB; Tue, 15 Dec 2020 15:37:13 -0800 (PST) From: Song Liu To: , CC: , , , , , , Song Liu Subject: [PATCH v2 bpf-next 4/4] selftests/bpf: add test for bpf_iter_task_vma Date: Tue, 15 Dec 2020 15:37:02 -0800 Message-ID: <20201215233702.3301881-5-songliubraving@fb.com> X-Mailer: git-send-email 2.24.1 In-Reply-To: <20201215233702.3301881-1-songliubraving@fb.com> References: <20201215233702.3301881-1-songliubraving@fb.com> MIME-Version: 1.0 X-FB-Internal: Safe X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:6.0.343, 18.0.737 definitions=2020-12-15_13:2020-12-15,2020-12-15 signatures=0 X-Proofpoint-Spam-Details: rule=fb_default_notspam policy=fb_default score=0 mlxscore=0 bulkscore=0 impostorscore=0 lowpriorityscore=0 priorityscore=1501 phishscore=0 mlxlogscore=999 malwarescore=0 spamscore=0 suspectscore=0 adultscore=0 clxscore=1015 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2009150000 definitions=main-2012150159 X-FB-Internal: deliver Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org The test dumps information similar to /proc/pid/maps. The first line of the output is compared against the /proc file to make sure they match. Signed-off-by: Song Liu --- .../selftests/bpf/prog_tests/bpf_iter.c | 106 ++++++++++++++++-- tools/testing/selftests/bpf/progs/bpf_iter.h | 9 ++ .../selftests/bpf/progs/bpf_iter_task_vma.c | 55 +++++++++ 3 files changed, 160 insertions(+), 10 deletions(-) create mode 100644 tools/testing/selftests/bpf/progs/bpf_iter_task_vma.c diff --git a/tools/testing/selftests/bpf/prog_tests/bpf_iter.c b/tools/testing/selftests/bpf/prog_tests/bpf_iter.c index 0e586368948dd..7afd3abae1899 100644 --- a/tools/testing/selftests/bpf/prog_tests/bpf_iter.c +++ b/tools/testing/selftests/bpf/prog_tests/bpf_iter.c @@ -7,6 +7,7 @@ #include "bpf_iter_task.skel.h" #include "bpf_iter_task_stack.skel.h" #include "bpf_iter_task_file.skel.h" +#include "bpf_iter_task_vma.skel.h" #include "bpf_iter_task_btf.skel.h" #include "bpf_iter_tcp4.skel.h" #include "bpf_iter_tcp6.skel.h" @@ -64,6 +65,22 @@ static void do_dummy_read(struct bpf_program *prog) bpf_link__destroy(link); } +static int read_fd_into_buffer(int fd, char *buf, int size) +{ + int bufleft = size; + int len; + + do { + len = read(fd, buf, bufleft); + if (len > 0) { + buf += len; + bufleft -= len; + } + } while (len > 0); + + return len; +} + static void test_ipv6_route(void) { struct bpf_iter_ipv6_route *skel; @@ -177,7 +194,7 @@ static int do_btf_read(struct bpf_iter_task_btf *skel) { struct bpf_program *prog = skel->progs.dump_task_struct; struct bpf_iter_task_btf__bss *bss = skel->bss; - int iter_fd = -1, len = 0, bufleft = TASKBUFSZ; + int iter_fd = -1, err; struct bpf_link *link; char *buf = taskbuf; int ret = 0; @@ -190,14 +207,7 @@ static int do_btf_read(struct bpf_iter_task_btf *skel) if (CHECK(iter_fd < 0, "create_iter", "create_iter failed\n")) goto free_link; - do { - len = read(iter_fd, buf, bufleft); - if (len > 0) { - buf += len; - bufleft -= len; - } - } while (len > 0); - + err = read_fd_into_buffer(iter_fd, buf, TASKBUFSZ); if (bss->skip) { printf("%s:SKIP:no __builtin_btf_type_id\n", __func__); ret = 1; @@ -205,7 +215,7 @@ static int do_btf_read(struct bpf_iter_task_btf *skel) goto free_link; } - if (CHECK(len < 0, "read", "read failed: %s\n", strerror(errno))) + if (CHECK(err < 0, "read", "read failed: %s\n", strerror(errno))) goto free_link; CHECK(strstr(taskbuf, "(struct task_struct)") == NULL, @@ -1133,6 +1143,80 @@ static void test_buf_neg_offset(void) bpf_iter_test_kern6__destroy(skel); } +#define CMP_BUFFER_SIZE 1024 +char task_vma_output[CMP_BUFFER_SIZE]; +char proc_maps_output[CMP_BUFFER_SIZE]; + +/* remove \0 and \t from str, and only keep the first line */ +static void str_strip_first_line(char *str) +{ + char *dst = str, *src = str; + + do { + if (*src == ' ' || *src == '\t') + src++; + else + *(dst++) = *(src++); + + } while (*src != '\0' && *src != '\n'); + + *dst = '\0'; +} + +static void test_task_vma(void) +{ + int err, iter_fd = -1, proc_maps_fd = -1; + struct bpf_iter_task_vma *skel; + char maps_path[64]; + + skel = bpf_iter_task_vma__open(); + if (CHECK(!skel, "bpf_iter_task_vma__open", "skeleton open failed\n")) + return; + + skel->bss->pid = getpid(); + + err = bpf_iter_task_vma__load(skel); + if (CHECK(err, "bpf_iter_task_vma__load", "skeleton load failed\n")) + goto out; + + do_dummy_read(skel->progs.proc_maps); + + skel->links.proc_maps = bpf_program__attach_iter( + skel->progs.proc_maps, NULL); + + if (CHECK(IS_ERR(skel->links.proc_maps), "bpf_program__attach_iter", + "attach iterator failed\n")) + goto out; + + /* read 1kB from bpf_iter */ + iter_fd = bpf_iter_create(bpf_link__fd(skel->links.proc_maps)); + if (CHECK(iter_fd < 0, "create_iter", "create_iter failed\n")) + goto out; + err = read_fd_into_buffer(iter_fd, task_vma_output, CMP_BUFFER_SIZE); + if (CHECK(err < 0, "read_iter_fd", "read_iter_fd failed\n")) + goto out; + + /* read 1kB from /proc/pid/maps */ + snprintf(maps_path, 64, "/proc/%u/maps", skel->bss->pid); + proc_maps_fd = open(maps_path, O_RDONLY); + if (CHECK(proc_maps_fd < 0, "open_proc_maps", "open_proc_maps failed\n")) + goto out; + err = read_fd_into_buffer(proc_maps_fd, proc_maps_output, CMP_BUFFER_SIZE); + if (CHECK(err < 0, "read_prog_maps_fd", "read_prog_maps_fd failed\n")) + goto out; + + /* strip and compare the first line of the two files */ + str_strip_first_line(task_vma_output); + str_strip_first_line(proc_maps_output); + + CHECK(strcmp(task_vma_output, proc_maps_output), "compare_output", + "found mismatch\n"); +out: + close(proc_maps_fd); + close(iter_fd); + bpf_iter_task_vma__destroy(skel); +} + void test_bpf_iter(void) { if (test__start_subtest("btf_id_or_null")) @@ -1149,6 +1233,8 @@ void test_bpf_iter(void) test_task_stack(); if (test__start_subtest("task_file")) test_task_file(); + if (test__start_subtest("task_vma")) + test_task_vma(); if (test__start_subtest("task_btf")) test_task_btf(); if (test__start_subtest("tcp4")) diff --git a/tools/testing/selftests/bpf/progs/bpf_iter.h b/tools/testing/selftests/bpf/progs/bpf_iter.h index 6a1255465fd6d..4dab0869c4fcb 100644 --- a/tools/testing/selftests/bpf/progs/bpf_iter.h +++ b/tools/testing/selftests/bpf/progs/bpf_iter.h @@ -7,6 +7,7 @@ #define bpf_iter__netlink bpf_iter__netlink___not_used #define bpf_iter__task bpf_iter__task___not_used #define bpf_iter__task_file bpf_iter__task_file___not_used +#define bpf_iter__task_vma bpf_iter__task_vma___not_used #define bpf_iter__tcp bpf_iter__tcp___not_used #define tcp6_sock tcp6_sock___not_used #define bpf_iter__udp bpf_iter__udp___not_used @@ -26,6 +27,7 @@ #undef bpf_iter__netlink #undef bpf_iter__task #undef bpf_iter__task_file +#undef bpf_iter__task_vma #undef bpf_iter__tcp #undef tcp6_sock #undef bpf_iter__udp @@ -67,6 +69,13 @@ struct bpf_iter__task_file { struct file *file; } __attribute__((preserve_access_index)); +struct bpf_iter__task_vma { + struct bpf_iter_meta *meta; + struct task_struct *task; + struct __vm_area_struct *vma; + struct file *file; +} __attribute__((preserve_access_index)); + struct bpf_iter__bpf_map { struct bpf_iter_meta *meta; struct bpf_map *map; diff --git a/tools/testing/selftests/bpf/progs/bpf_iter_task_vma.c b/tools/testing/selftests/bpf/progs/bpf_iter_task_vma.c new file mode 100644 index 0000000000000..ba87afe01024c --- /dev/null +++ b/tools/testing/selftests/bpf/progs/bpf_iter_task_vma.c @@ -0,0 +1,55 @@ +// SPDX-License-Identifier: GPL-2.0 +/* Copyright (c) 2020 Facebook */ +#include "bpf_iter.h" +#include +#include + +char _license[] SEC("license") = "GPL"; + +/* Copied from mm.h */ +#define VM_READ 0x00000001 +#define VM_WRITE 0x00000002 +#define VM_EXEC 0x00000004 +#define VM_MAYSHARE 0x00000080 + +/* Copied from kdev_t.h */ +#define MINORBITS 20 +#define MINORMASK ((1U << MINORBITS) - 1) +#define MAJOR(dev) ((unsigned int) ((dev) >> MINORBITS)) +#define MINOR(dev) ((unsigned int) ((dev) & MINORMASK)) + +#define D_PATH_BUF_SIZE 1024 +char d_path_buf[D_PATH_BUF_SIZE]; +__u32 pid; + +SEC("iter.s/task_vma") int proc_maps(struct bpf_iter__task_vma *ctx) +{ + struct __vm_area_struct *vma = ctx->vma; + struct seq_file *seq = ctx->meta->seq; + struct task_struct *task = ctx->task; + struct file *file = ctx->file; + char perm_str[] = "----"; + + if (task == (void *)0 || vma == (void *)0 || task->pid != pid) + return 0; + + perm_str[0] = (vma->flags & VM_READ) ? 'r' : '-'; + perm_str[1] = (vma->flags & VM_WRITE) ? 'w' : '-'; + perm_str[2] = (vma->flags & VM_EXEC) ? 'x' : '-'; + perm_str[3] = (vma->flags & VM_MAYSHARE) ? 's' : 'p'; + BPF_SEQ_PRINTF(seq, "%08llx-%08llx %s ", vma->start, vma->end, perm_str); + + if (file) { + __u32 dev = file->f_inode->i_sb->s_dev; + + bpf_d_path(&file->f_path, d_path_buf, D_PATH_BUF_SIZE); + + BPF_SEQ_PRINTF(seq, "%08llx ", vma->pgoff << 12); + BPF_SEQ_PRINTF(seq, "%02x:%02x %u", MAJOR(dev), MINOR(dev), + file->f_inode->i_ino); + BPF_SEQ_PRINTF(seq, "\t%s\n", d_path_buf); + } else { + BPF_SEQ_PRINTF(seq, "%08llx 00:00 0\n", 0ULL); + } + return 0; +}