From patchwork Thu Oct 20 22:13:01 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Yonghong Song X-Patchwork-Id: 13014062 X-Patchwork-Delegate: bpf@iogearbox.net Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 21E26C43217 for ; Thu, 20 Oct 2022 22:13:18 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229494AbiJTWNQ (ORCPT ); Thu, 20 Oct 2022 18:13:16 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:38018 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229484AbiJTWNP (ORCPT ); Thu, 20 Oct 2022 18:13:15 -0400 Received: from mx0a-00082601.pphosted.com (mx0a-00082601.pphosted.com [67.231.145.42]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 4E9F71A5B07 for ; Thu, 20 Oct 2022 15:13:15 -0700 (PDT) Received: from pps.filterd (m0044012.ppops.net [127.0.0.1]) by mx0a-00082601.pphosted.com (8.17.1.5/8.17.1.5) with ESMTP id 29KHaCnf009348 for ; Thu, 20 Oct 2022 15:13:15 -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=NUCMZhBtdEFob4Yy2+IoIDADd3grxFGmLtCe9yP2X0I=; b=j5Y73j6zxWfAAwsrAIZ5Hbof2Mp1EcyCKqy1kXbuaKa3vrjocFAyJmQ9VsKoJF8Ys9+g wn7hz8hElWTXl1qe3fXy7OCGVpDwLpf7lWHgbwO2OYcnIemajeEqOsViv/DgEq5oM4PV iKpckp8EwEyvSfVq0Vm9EZky/Je4aQ6YCMc= Received: from maileast.thefacebook.com ([163.114.130.16]) by mx0a-00082601.pphosted.com (PPS) with ESMTPS id 3kb799daxv-15 (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128 verify=NOT) for ; Thu, 20 Oct 2022 15:13:15 -0700 Received: from twshared9088.05.ash9.facebook.com (2620:10d:c0a8:1b::d) by mail.thefacebook.com (2620:10d:c0a8:82::f) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2375.31; Thu, 20 Oct 2022 15:13:11 -0700 Received: by devbig309.ftw3.facebook.com (Postfix, from userid 128203) id 323C610F4EC2C; Thu, 20 Oct 2022 15:13:01 -0700 (PDT) From: Yonghong Song To: CC: Alexei Starovoitov , Andrii Nakryiko , Daniel Borkmann , , KP Singh , Martin KaFai Lau , Tejun Heo Subject: [PATCH bpf-next v2 1/6] bpf: Make struct cgroup btf id global Date: Thu, 20 Oct 2022 15:13:01 -0700 Message-ID: <20221020221301.3554017-1-yhs@fb.com> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20221020221255.3553649-1-yhs@fb.com> References: <20221020221255.3553649-1-yhs@fb.com> MIME-Version: 1.0 X-FB-Internal: Safe X-Proofpoint-GUID: k6nUnIZ3ZfkgZy4JCHc39W0xdwvqYpAm X-Proofpoint-ORIG-GUID: k6nUnIZ3ZfkgZy4JCHc39W0xdwvqYpAm X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.205,Aquarius:18.0.895,Hydra:6.0.545,FMLib:17.11.122.1 definitions=2022-10-20_11,2022-10-20_01,2022-06-22_01 Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org X-Patchwork-Delegate: bpf@iogearbox.net Make struct cgroup btf id global so later patch can reuse the same btf id. Signed-off-by: Yonghong Song --- include/linux/btf_ids.h | 1 + kernel/bpf/cgroup_iter.c | 2 +- 2 files changed, 2 insertions(+), 1 deletion(-) diff --git a/include/linux/btf_ids.h b/include/linux/btf_ids.h index 2aea877d644f..c9744efd202f 100644 --- a/include/linux/btf_ids.h +++ b/include/linux/btf_ids.h @@ -265,5 +265,6 @@ MAX_BTF_TRACING_TYPE, }; extern u32 btf_tracing_ids[]; +extern u32 bpf_cgroup_btf_id[]; #endif diff --git a/kernel/bpf/cgroup_iter.c b/kernel/bpf/cgroup_iter.c index 0d200a993489..c6ffc706d583 100644 --- a/kernel/bpf/cgroup_iter.c +++ b/kernel/bpf/cgroup_iter.c @@ -157,7 +157,7 @@ static const struct seq_operations cgroup_iter_seq_ops = { .show = cgroup_iter_seq_show, }; -BTF_ID_LIST_SINGLE(bpf_cgroup_btf_id, struct, cgroup) +BTF_ID_LIST_GLOBAL_SINGLE(bpf_cgroup_btf_id, struct, cgroup) static int cgroup_iter_seq_init(void *priv, struct bpf_iter_aux_info *aux) { From patchwork Thu Oct 20 22:13:06 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Yonghong Song X-Patchwork-Id: 13014061 X-Patchwork-Delegate: bpf@iogearbox.net Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 7804DC4332F for ; Thu, 20 Oct 2022 22:13:15 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229519AbiJTWNO (ORCPT ); Thu, 20 Oct 2022 18:13:14 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:38012 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229494AbiJTWNN (ORCPT ); Thu, 20 Oct 2022 18:13:13 -0400 Received: from mx0a-00082601.pphosted.com (mx0a-00082601.pphosted.com [67.231.145.42]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 6ABA31DE3F1 for ; Thu, 20 Oct 2022 15:13:11 -0700 (PDT) Received: from pps.filterd (m0044012.ppops.net [127.0.0.1]) by mx0a-00082601.pphosted.com (8.17.1.5/8.17.1.5) with ESMTP id 29KHaAZ9009258 for ; Thu, 20 Oct 2022 15:13:11 -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=1IyHjlM/DTJWEtSqug3clwSqUKQ5DRApkavlleEewp4=; b=nrOrFn5A/LMg3ZbpFoLFKxXghwxwuAK6fgp45EO1cE/PzapsJ8OzmFoY8jSmeRBwJjp5 OtRWPZSwOuAck2ZfY2DCX06KSlr/aWII7W5TusymUi/xf+jvepMpClVBmD5Zw8K1VxVs zUwgUI5qBAh77SSyZ9nYNgKXDH+fix9vurw= Received: from maileast.thefacebook.com ([163.114.130.16]) by mx0a-00082601.pphosted.com (PPS) with ESMTPS id 3kb799dax8-18 (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128 verify=NOT) for ; Thu, 20 Oct 2022 15:13:10 -0700 Received: from twshared0933.07.ash9.facebook.com (2620:10d:c0a8:1b::d) by mail.thefacebook.com (2620:10d:c0a8:83::6) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2375.31; Thu, 20 Oct 2022 15:13:08 -0700 Received: by devbig309.ftw3.facebook.com (Postfix, from userid 128203) id 6D87C10F4EC3E; Thu, 20 Oct 2022 15:13:06 -0700 (PDT) From: Yonghong Song To: CC: Alexei Starovoitov , Andrii Nakryiko , Daniel Borkmann , , KP Singh , Martin KaFai Lau , Tejun Heo Subject: [PATCH bpf-next v2 2/6] bpf: Implement cgroup storage available to non-cgroup-attached bpf progs Date: Thu, 20 Oct 2022 15:13:06 -0700 Message-ID: <20221020221306.3554250-1-yhs@fb.com> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20221020221255.3553649-1-yhs@fb.com> References: <20221020221255.3553649-1-yhs@fb.com> MIME-Version: 1.0 X-FB-Internal: Safe X-Proofpoint-GUID: 9FydCfpcSrqdltozkbauXLfY-xXpehCM X-Proofpoint-ORIG-GUID: 9FydCfpcSrqdltozkbauXLfY-xXpehCM X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.205,Aquarius:18.0.895,Hydra:6.0.545,FMLib:17.11.122.1 definitions=2022-10-20_11,2022-10-20_01,2022-06-22_01 Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org X-Patchwork-Delegate: bpf@iogearbox.net Similar to sk/inode/task storage, implement similar cgroup local storage. There already exists a local storage implementation for cgroup-attached bpf programs. See map type BPF_MAP_TYPE_CGROUP_STORAGE and helper bpf_get_local_storage(). But there are use cases such that non-cgroup attached bpf progs wants to access cgroup local storage data. For example, tc egress prog has access to sk and cgroup. It is possible to use sk local storage to emulate cgroup local storage by storing data in socket. But this is a waste as it could be lots of sockets belonging to a particular cgroup. Alternatively, a separate map can be created with cgroup id as the key. But this will introduce additional overhead to manipulate the new map. A cgroup local storage, similar to existing sk/inode/task storage, should help for this use case. The life-cycle of storage is managed with the life-cycle of the cgroup struct. i.e. the storage is destroyed along with the owning cgroup with a callback to the bpf_cgrp_storage_free when cgroup itself is deleted. The userspace map operations can be done by using a cgroup fd as a key passed to the lookup, update and delete operations. Typically, the following code is used to get the current cgroup: struct task_struct *task = bpf_get_current_task_btf(); ... task->cgroups->dfl_cgrp ... and in structure task_struct definition: struct task_struct { .... struct css_set __rcu *cgroups; .... } With sleepable program, accessing task->cgroups is not protected by rcu_read_lock. So the current implementation only supports non-sleepable program and supporting sleepable program will be the next step together with adding rcu_read_lock protection for rcu tagged structures. Since map name BPF_MAP_TYPE_CGROUP_STORAGE has been used for old cgroup local storage support, the new map name BPF_MAP_TYPE_CGRP_STORAGE is used for cgroup storage available to non-cgroup-attached bpf programs. The old cgroup storage supports bpf_get_local_storage() helper to get the cgroup data. The new cgroup storage helper bpf_cgrp_storage_get() can provide similar functionality. While old cgroup storage pre-allocates storage memory, the new mechanism can also pre-allocate with a user space bpf_map_update_elem() call to avoid potential run-time memory allocaiton failure. Therefore, the new cgroup storage can provide all functionality w.r.t. the old one. So in uapi bpf.h, the old BPF_MAP_TYPE_CGROUP_STORAGE is alias to BPF_MAP_TYPE_CGROUP_STORAGE_DEPRECATED to indicate the old cgroup storage can be deprecated since the new one can provide the same functionality. Signed-off-by: Yonghong Song --- include/linux/bpf.h | 3 + include/linux/bpf_types.h | 1 + include/linux/cgroup-defs.h | 4 + include/uapi/linux/bpf.h | 48 +++++- kernel/bpf/Makefile | 2 +- kernel/bpf/bpf_cgrp_storage.c | 276 +++++++++++++++++++++++++++++++++ kernel/bpf/helpers.c | 6 + kernel/bpf/syscall.c | 3 +- kernel/bpf/verifier.c | 13 +- kernel/cgroup/cgroup.c | 4 + kernel/trace/bpf_trace.c | 4 + scripts/bpf_doc.py | 2 + tools/include/uapi/linux/bpf.h | 48 +++++- 13 files changed, 409 insertions(+), 5 deletions(-) create mode 100644 kernel/bpf/bpf_cgrp_storage.c diff --git a/include/linux/bpf.h b/include/linux/bpf.h index 9e7d46d16032..674da3129248 100644 --- a/include/linux/bpf.h +++ b/include/linux/bpf.h @@ -2045,6 +2045,7 @@ struct bpf_link *bpf_link_by_id(u32 id); const struct bpf_func_proto *bpf_base_func_proto(enum bpf_func_id func_id); void bpf_task_storage_free(struct task_struct *task); +void bpf_cgrp_storage_free(struct cgroup *cgroup); bool bpf_prog_has_kfunc_call(const struct bpf_prog *prog); const struct btf_func_model * bpf_jit_find_kfunc_model(const struct bpf_prog *prog, @@ -2537,6 +2538,8 @@ extern const struct bpf_func_proto bpf_copy_from_user_task_proto; extern const struct bpf_func_proto bpf_set_retval_proto; extern const struct bpf_func_proto bpf_get_retval_proto; extern const struct bpf_func_proto bpf_user_ringbuf_drain_proto; +extern const struct bpf_func_proto bpf_cgrp_storage_get_proto; +extern const struct bpf_func_proto bpf_cgrp_storage_delete_proto; const struct bpf_func_proto *tracing_prog_func_proto( enum bpf_func_id func_id, const struct bpf_prog *prog); diff --git a/include/linux/bpf_types.h b/include/linux/bpf_types.h index 2c6a4f2562a7..f9d5aa62fed0 100644 --- a/include/linux/bpf_types.h +++ b/include/linux/bpf_types.h @@ -90,6 +90,7 @@ BPF_MAP_TYPE(BPF_MAP_TYPE_CGROUP_ARRAY, cgroup_array_map_ops) #ifdef CONFIG_CGROUP_BPF BPF_MAP_TYPE(BPF_MAP_TYPE_CGROUP_STORAGE, cgroup_storage_map_ops) BPF_MAP_TYPE(BPF_MAP_TYPE_PERCPU_CGROUP_STORAGE, cgroup_storage_map_ops) +BPF_MAP_TYPE(BPF_MAP_TYPE_CGRP_STORAGE, cgrp_storage_map_ops) #endif BPF_MAP_TYPE(BPF_MAP_TYPE_HASH, htab_map_ops) BPF_MAP_TYPE(BPF_MAP_TYPE_PERCPU_HASH, htab_percpu_map_ops) diff --git a/include/linux/cgroup-defs.h b/include/linux/cgroup-defs.h index 8f481d1b159a..4a72bc3a0a4e 100644 --- a/include/linux/cgroup-defs.h +++ b/include/linux/cgroup-defs.h @@ -504,6 +504,10 @@ struct cgroup { /* Used to store internal freezer state */ struct cgroup_freezer_state freezer; +#ifdef CONFIG_CGROUP_BPF + struct bpf_local_storage __rcu *bpf_cgrp_storage; +#endif + /* All ancestors including self */ struct cgroup *ancestors[]; }; diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h index 17f61338f8f8..2d7f79bf3500 100644 --- a/include/uapi/linux/bpf.h +++ b/include/uapi/linux/bpf.h @@ -922,7 +922,14 @@ enum bpf_map_type { BPF_MAP_TYPE_CPUMAP, BPF_MAP_TYPE_XSKMAP, BPF_MAP_TYPE_SOCKHASH, - BPF_MAP_TYPE_CGROUP_STORAGE, + BPF_MAP_TYPE_CGROUP_STORAGE_DEPRECATED, + /* BPF_MAP_TYPE_CGROUP_STORAGE is available to bpf programs attaching + * to a cgroup. The newer BPF_MAP_TYPE_CGRP_STORAGE is available to + * both cgroup-attached and other progs and supports all functionality + * provided by BPF_MAP_TYPE_CGROUP_STORAGE. So mark + * BPF_MAP_TYPE_CGROUP_STORAGE deprecated. + */ + BPF_MAP_TYPE_CGROUP_STORAGE = BPF_MAP_TYPE_CGROUP_STORAGE_DEPRECATED, BPF_MAP_TYPE_REUSEPORT_SOCKARRAY, BPF_MAP_TYPE_PERCPU_CGROUP_STORAGE, BPF_MAP_TYPE_QUEUE, @@ -935,6 +942,7 @@ enum bpf_map_type { BPF_MAP_TYPE_TASK_STORAGE, BPF_MAP_TYPE_BLOOM_FILTER, BPF_MAP_TYPE_USER_RINGBUF, + BPF_MAP_TYPE_CGRP_STORAGE, }; /* Note that tracing related programs such as @@ -5435,6 +5443,42 @@ union bpf_attr { * **-E2BIG** if user-space has tried to publish a sample which is * larger than the size of the ring buffer, or which cannot fit * within a struct bpf_dynptr. + * + * void *bpf_cgrp_storage_get(struct bpf_map *map, struct cgroup *cgroup, void *value, u64 flags) + * Description + * Get a bpf_local_storage from the *cgroup*. + * + * Logically, it could be thought of as getting the value from + * a *map* with *cgroup* as the **key**. From this + * perspective, the usage is not much different from + * **bpf_map_lookup_elem**\ (*map*, **&**\ *cgroup*) except this + * helper enforces the key must be a cgroup struct and the map must also + * be a **BPF_MAP_TYPE_CGRP_STORAGE**. + * + * Underneath, the value is stored locally at *cgroup* instead of + * the *map*. The *map* is used as the bpf-local-storage + * "type". The bpf-local-storage "type" (i.e. the *map*) is + * searched against all bpf_local_storage residing at *cgroup*. + * + * An optional *flags* (**BPF_LOCAL_STORAGE_GET_F_CREATE**) can be + * used such that a new bpf_local_storage will be + * created if one does not exist. *value* can be used + * together with **BPF_LOCAL_STORAGE_GET_F_CREATE** to specify + * the initial value of a bpf_local_storage. If *value* is + * **NULL**, the new bpf_local_storage will be zero initialized. + * Return + * A bpf_local_storage pointer is returned on success. + * + * **NULL** if not found or there was an error in adding + * a new bpf_local_storage. + * + * long bpf_cgrp_storage_delete(struct bpf_map *map, struct cgroup *cgroup) + * Description + * Delete a bpf_local_storage from a *cgroup*. + * Return + * 0 on success. + * + * **-ENOENT** if the bpf_local_storage cannot be found. */ #define ___BPF_FUNC_MAPPER(FN, ctx...) \ FN(unspec, 0, ##ctx) \ @@ -5647,6 +5691,8 @@ union bpf_attr { FN(tcp_raw_check_syncookie_ipv6, 207, ##ctx) \ FN(ktime_get_tai_ns, 208, ##ctx) \ FN(user_ringbuf_drain, 209, ##ctx) \ + FN(cgrp_storage_get, 210, ##ctx) \ + FN(cgrp_storage_delete, 211, ##ctx) \ /* */ /* backwards-compatibility macros for users of __BPF_FUNC_MAPPER that don't diff --git a/kernel/bpf/Makefile b/kernel/bpf/Makefile index 341c94f208f4..3a12e6b400a2 100644 --- a/kernel/bpf/Makefile +++ b/kernel/bpf/Makefile @@ -25,7 +25,7 @@ ifeq ($(CONFIG_PERF_EVENTS),y) obj-$(CONFIG_BPF_SYSCALL) += stackmap.o endif ifeq ($(CONFIG_CGROUPS),y) -obj-$(CONFIG_BPF_SYSCALL) += cgroup_iter.o +obj-$(CONFIG_BPF_SYSCALL) += cgroup_iter.o bpf_cgrp_storage.o endif obj-$(CONFIG_CGROUP_BPF) += cgroup.o ifeq ($(CONFIG_INET),y) diff --git a/kernel/bpf/bpf_cgrp_storage.c b/kernel/bpf/bpf_cgrp_storage.c new file mode 100644 index 000000000000..bcc5f0fc20be --- /dev/null +++ b/kernel/bpf/bpf_cgrp_storage.c @@ -0,0 +1,276 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Copyright (c) 2022 Meta Platforms, Inc. and affiliates. + */ + +#include +#include +#include +#include +#include + +DEFINE_BPF_STORAGE_CACHE(cgroup_cache); + +static DEFINE_PER_CPU(int, bpf_cgrp_storage_busy); + +static void bpf_cgrp_storage_lock(void) +{ + migrate_disable(); + this_cpu_inc(bpf_cgrp_storage_busy); +} + +static void bpf_cgrp_storage_unlock(void) +{ + this_cpu_dec(bpf_cgrp_storage_busy); + migrate_enable(); +} + +static bool bpf_cgrp_storage_trylock(void) +{ + migrate_disable(); + if (unlikely(this_cpu_inc_return(bpf_cgrp_storage_busy) != 1)) { + this_cpu_dec(bpf_cgrp_storage_busy); + migrate_enable(); + return false; + } + return true; +} + +static struct bpf_local_storage __rcu **cgroup_storage_ptr(void *owner) +{ + struct cgroup *cg = owner; + + return &cg->bpf_cgrp_storage; +} + +void bpf_cgrp_storage_free(struct cgroup *cgroup) +{ + struct bpf_local_storage *local_storage; + struct bpf_local_storage_elem *selem; + bool free_cgroup_storage = false; + struct hlist_node *n; + unsigned long flags; + + rcu_read_lock(); + local_storage = rcu_dereference(cgroup->bpf_cgrp_storage); + if (!local_storage) { + rcu_read_unlock(); + return; + } + + /* Neither the bpf_prog nor the bpf-map's syscall + * could be modifying the local_storage->list now. + * Thus, no elem can be added-to or deleted-from the + * local_storage->list by the bpf_prog or by the bpf-map's syscall. + * + * It is racing with bpf_local_storage_map_free() alone + * when unlinking elem from the local_storage->list and + * the map's bucket->list. + */ + bpf_cgrp_storage_lock(); + raw_spin_lock_irqsave(&local_storage->lock, flags); + hlist_for_each_entry_safe(selem, n, &local_storage->list, snode) { + bpf_selem_unlink_map(selem); + free_cgroup_storage = + bpf_selem_unlink_storage_nolock(local_storage, selem, false, false); + } + raw_spin_unlock_irqrestore(&local_storage->lock, flags); + bpf_cgrp_storage_unlock(); + rcu_read_unlock(); + + /* free_cgroup_storage should always be true as long as + * local_storage->list was non-empty. + */ + if (free_cgroup_storage) + kfree_rcu(local_storage, rcu); +} + +static struct bpf_local_storage_data * +cgroup_storage_lookup(struct cgroup *cgroup, struct bpf_map *map, bool cacheit_lockit) +{ + struct bpf_local_storage *cgroup_storage; + struct bpf_local_storage_map *smap; + + cgroup_storage = rcu_dereference_check(cgroup->bpf_cgrp_storage, + bpf_rcu_lock_held()); + if (!cgroup_storage) + return NULL; + + smap = (struct bpf_local_storage_map *)map; + return bpf_local_storage_lookup(cgroup_storage, smap, cacheit_lockit); +} + +static void *bpf_cgrp_storage_lookup_elem(struct bpf_map *map, void *key) +{ + struct bpf_local_storage_data *sdata; + struct cgroup *cgroup; + int fd; + + fd = *(int *)key; + cgroup = cgroup_get_from_fd(fd); + if (IS_ERR(cgroup)) + return ERR_CAST(cgroup); + + bpf_cgrp_storage_lock(); + sdata = cgroup_storage_lookup(cgroup, map, true); + bpf_cgrp_storage_unlock(); + cgroup_put(cgroup); + return sdata ? sdata->data : NULL; +} + +static int bpf_cgrp_storage_update_elem(struct bpf_map *map, void *key, + void *value, u64 map_flags) +{ + struct bpf_local_storage_data *sdata; + struct cgroup *cgroup; + int fd; + + fd = *(int *)key; + cgroup = cgroup_get_from_fd(fd); + if (IS_ERR(cgroup)) + return PTR_ERR(cgroup); + + bpf_cgrp_storage_lock(); + sdata = bpf_local_storage_update(cgroup, (struct bpf_local_storage_map *)map, + value, map_flags, GFP_ATOMIC); + bpf_cgrp_storage_unlock(); + cgroup_put(cgroup); + return PTR_ERR_OR_ZERO(sdata); +} + +static int cgroup_storage_delete(struct cgroup *cgroup, struct bpf_map *map) +{ + struct bpf_local_storage_data *sdata; + + sdata = cgroup_storage_lookup(cgroup, map, false); + if (!sdata) + return -ENOENT; + + bpf_selem_unlink(SELEM(sdata), true); + return 0; +} + +static int bpf_cgrp_storage_delete_elem(struct bpf_map *map, void *key) +{ + struct cgroup *cgroup; + int err, fd; + + fd = *(int *)key; + cgroup = cgroup_get_from_fd(fd); + if (IS_ERR(cgroup)) + return PTR_ERR(cgroup); + + bpf_cgrp_storage_lock(); + err = cgroup_storage_delete(cgroup, map); + bpf_cgrp_storage_unlock(); + cgroup_put(cgroup); + return err; +} + +static int notsupp_get_next_key(struct bpf_map *map, void *key, void *next_key) +{ + return -ENOTSUPP; +} + +static struct bpf_map *cgroup_storage_map_alloc(union bpf_attr *attr) +{ + struct bpf_local_storage_map *smap; + + smap = bpf_local_storage_map_alloc(attr); + if (IS_ERR(smap)) + return ERR_CAST(smap); + + smap->cache_idx = bpf_local_storage_cache_idx_get(&cgroup_cache); + return &smap->map; +} + +static void cgroup_storage_map_free(struct bpf_map *map) +{ + struct bpf_local_storage_map *smap; + + smap = (struct bpf_local_storage_map *)map; + bpf_local_storage_cache_idx_free(&cgroup_cache, smap->cache_idx); + bpf_local_storage_map_free(smap, NULL); +} + +/* *gfp_flags* is a hidden argument provided by the verifier */ +BPF_CALL_5(bpf_cgrp_storage_get, struct bpf_map *, map, struct cgroup *, cgroup, + void *, value, u64, flags, gfp_t, gfp_flags) +{ + struct bpf_local_storage_data *sdata; + + WARN_ON_ONCE(!bpf_rcu_lock_held()); + if (flags & ~(BPF_LOCAL_STORAGE_GET_F_CREATE)) + return (unsigned long)NULL; + + if (!cgroup) + return (unsigned long)NULL; + + if (!bpf_cgrp_storage_trylock()) + return (unsigned long)NULL; + + sdata = cgroup_storage_lookup(cgroup, map, true); + if (sdata) + goto unlock; + + /* only allocate new storage, when the cgroup is refcounted */ + if (!percpu_ref_is_dying(&cgroup->self.refcnt) && + (flags & BPF_LOCAL_STORAGE_GET_F_CREATE)) + sdata = bpf_local_storage_update(cgroup, (struct bpf_local_storage_map *)map, + value, BPF_NOEXIST, gfp_flags); + +unlock: + bpf_cgrp_storage_unlock(); + return IS_ERR_OR_NULL(sdata) ? (unsigned long)NULL : (unsigned long)sdata->data; +} + +BPF_CALL_2(bpf_cgrp_storage_delete, struct bpf_map *, map, struct cgroup *, cgroup) +{ + int ret; + + WARN_ON_ONCE(!bpf_rcu_lock_held()); + if (!cgroup) + return -EINVAL; + + if (!bpf_cgrp_storage_trylock()) + return -EBUSY; + + ret = cgroup_storage_delete(cgroup, map); + bpf_cgrp_storage_unlock(); + return ret; +} + +BTF_ID_LIST_SINGLE(cgroup_storage_map_btf_ids, struct, bpf_local_storage_map) +const struct bpf_map_ops cgrp_storage_map_ops = { + .map_meta_equal = bpf_map_meta_equal, + .map_alloc_check = bpf_local_storage_map_alloc_check, + .map_alloc = cgroup_storage_map_alloc, + .map_free = cgroup_storage_map_free, + .map_get_next_key = notsupp_get_next_key, + .map_lookup_elem = bpf_cgrp_storage_lookup_elem, + .map_update_elem = bpf_cgrp_storage_update_elem, + .map_delete_elem = bpf_cgrp_storage_delete_elem, + .map_check_btf = bpf_local_storage_map_check_btf, + .map_btf_id = &cgroup_storage_map_btf_ids[0], + .map_owner_storage_ptr = cgroup_storage_ptr, +}; + +const struct bpf_func_proto bpf_cgrp_storage_get_proto = { + .func = bpf_cgrp_storage_get, + .gpl_only = false, + .ret_type = RET_PTR_TO_MAP_VALUE_OR_NULL, + .arg1_type = ARG_CONST_MAP_PTR, + .arg2_type = ARG_PTR_TO_BTF_ID, + .arg2_btf_id = &bpf_cgroup_btf_id[0], + .arg3_type = ARG_PTR_TO_MAP_VALUE_OR_NULL, + .arg4_type = ARG_ANYTHING, +}; + +const struct bpf_func_proto bpf_cgrp_storage_delete_proto = { + .func = bpf_cgrp_storage_delete, + .gpl_only = false, + .ret_type = RET_INTEGER, + .arg1_type = ARG_CONST_MAP_PTR, + .arg2_type = ARG_PTR_TO_BTF_ID, + .arg2_btf_id = &bpf_cgroup_btf_id[0], +}; diff --git a/kernel/bpf/helpers.c b/kernel/bpf/helpers.c index a6b04faed282..124fd199ce5c 100644 --- a/kernel/bpf/helpers.c +++ b/kernel/bpf/helpers.c @@ -1663,6 +1663,12 @@ bpf_base_func_proto(enum bpf_func_id func_id) return &bpf_dynptr_write_proto; case BPF_FUNC_dynptr_data: return &bpf_dynptr_data_proto; +#ifdef CONFIG_CGROUPS + case BPF_FUNC_cgrp_storage_get: + return &bpf_cgrp_storage_get_proto; + case BPF_FUNC_cgrp_storage_delete: + return &bpf_cgrp_storage_delete_proto; +#endif default: break; } diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c index 7b373a5e861f..b95c276f92e3 100644 --- a/kernel/bpf/syscall.c +++ b/kernel/bpf/syscall.c @@ -1016,7 +1016,8 @@ static int map_check_btf(struct bpf_map *map, const struct btf *btf, map->map_type != BPF_MAP_TYPE_CGROUP_STORAGE && map->map_type != BPF_MAP_TYPE_SK_STORAGE && map->map_type != BPF_MAP_TYPE_INODE_STORAGE && - map->map_type != BPF_MAP_TYPE_TASK_STORAGE) + map->map_type != BPF_MAP_TYPE_TASK_STORAGE && + map->map_type != BPF_MAP_TYPE_CGRP_STORAGE) return -ENOTSUPP; if (map->spin_lock_off + sizeof(struct bpf_spin_lock) > map->value_size) { diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c index 6f6d2d511c06..82bb18d7e881 100644 --- a/kernel/bpf/verifier.c +++ b/kernel/bpf/verifier.c @@ -6360,6 +6360,11 @@ static int check_map_func_compatibility(struct bpf_verifier_env *env, func_id != BPF_FUNC_task_storage_delete) goto error; break; + case BPF_MAP_TYPE_CGRP_STORAGE: + if (func_id != BPF_FUNC_cgrp_storage_get && + func_id != BPF_FUNC_cgrp_storage_delete) + goto error; + break; case BPF_MAP_TYPE_BLOOM_FILTER: if (func_id != BPF_FUNC_map_peek_elem && func_id != BPF_FUNC_map_push_elem) @@ -6472,6 +6477,11 @@ static int check_map_func_compatibility(struct bpf_verifier_env *env, if (map->map_type != BPF_MAP_TYPE_TASK_STORAGE) goto error; break; + case BPF_FUNC_cgrp_storage_get: + case BPF_FUNC_cgrp_storage_delete: + if (map->map_type != BPF_MAP_TYPE_CGRP_STORAGE) + goto error; + break; default: break; } @@ -14149,7 +14159,8 @@ static int do_misc_fixups(struct bpf_verifier_env *env) if (insn->imm == BPF_FUNC_task_storage_get || insn->imm == BPF_FUNC_sk_storage_get || - insn->imm == BPF_FUNC_inode_storage_get) { + insn->imm == BPF_FUNC_inode_storage_get || + insn->imm == BPF_FUNC_cgrp_storage_get) { if (env->prog->aux->sleepable) insn_buf[0] = BPF_MOV64_IMM(BPF_REG_5, (__force __s32)GFP_KERNEL); else diff --git a/kernel/cgroup/cgroup.c b/kernel/cgroup/cgroup.c index 764bdd5fd8d1..7e80e15fae4e 100644 --- a/kernel/cgroup/cgroup.c +++ b/kernel/cgroup/cgroup.c @@ -5227,6 +5227,10 @@ static void css_free_rwork_fn(struct work_struct *work) struct cgroup_subsys *ss = css->ss; struct cgroup *cgrp = css->cgroup; +#ifdef CONFIG_CGROUP_BPF + bpf_cgrp_storage_free(cgrp); +#endif + percpu_ref_exit(&css->refcnt); if (ss) { diff --git a/kernel/trace/bpf_trace.c b/kernel/trace/bpf_trace.c index 49fb9ec8366d..0ddf0834b1b8 100644 --- a/kernel/trace/bpf_trace.c +++ b/kernel/trace/bpf_trace.c @@ -1454,6 +1454,10 @@ bpf_tracing_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) return &bpf_get_current_cgroup_id_proto; case BPF_FUNC_get_current_ancestor_cgroup_id: return &bpf_get_current_ancestor_cgroup_id_proto; + case BPF_FUNC_cgrp_storage_get: + return &bpf_cgrp_storage_get_proto; + case BPF_FUNC_cgrp_storage_delete: + return &bpf_cgrp_storage_delete_proto; #endif case BPF_FUNC_send_signal: return &bpf_send_signal_proto; diff --git a/scripts/bpf_doc.py b/scripts/bpf_doc.py index c0e6690be82a..fdb0aff8cb5a 100755 --- a/scripts/bpf_doc.py +++ b/scripts/bpf_doc.py @@ -685,6 +685,7 @@ class PrinterHelpers(Printer): 'struct udp6_sock', 'struct unix_sock', 'struct task_struct', + 'struct cgroup', 'struct __sk_buff', 'struct sk_msg_md', @@ -742,6 +743,7 @@ class PrinterHelpers(Printer): 'struct udp6_sock', 'struct unix_sock', 'struct task_struct', + 'struct cgroup', 'struct path', 'struct btf_ptr', 'struct inode', diff --git a/tools/include/uapi/linux/bpf.h b/tools/include/uapi/linux/bpf.h index 17f61338f8f8..2d7f79bf3500 100644 --- a/tools/include/uapi/linux/bpf.h +++ b/tools/include/uapi/linux/bpf.h @@ -922,7 +922,14 @@ enum bpf_map_type { BPF_MAP_TYPE_CPUMAP, BPF_MAP_TYPE_XSKMAP, BPF_MAP_TYPE_SOCKHASH, - BPF_MAP_TYPE_CGROUP_STORAGE, + BPF_MAP_TYPE_CGROUP_STORAGE_DEPRECATED, + /* BPF_MAP_TYPE_CGROUP_STORAGE is available to bpf programs attaching + * to a cgroup. The newer BPF_MAP_TYPE_CGRP_STORAGE is available to + * both cgroup-attached and other progs and supports all functionality + * provided by BPF_MAP_TYPE_CGROUP_STORAGE. So mark + * BPF_MAP_TYPE_CGROUP_STORAGE deprecated. + */ + BPF_MAP_TYPE_CGROUP_STORAGE = BPF_MAP_TYPE_CGROUP_STORAGE_DEPRECATED, BPF_MAP_TYPE_REUSEPORT_SOCKARRAY, BPF_MAP_TYPE_PERCPU_CGROUP_STORAGE, BPF_MAP_TYPE_QUEUE, @@ -935,6 +942,7 @@ enum bpf_map_type { BPF_MAP_TYPE_TASK_STORAGE, BPF_MAP_TYPE_BLOOM_FILTER, BPF_MAP_TYPE_USER_RINGBUF, + BPF_MAP_TYPE_CGRP_STORAGE, }; /* Note that tracing related programs such as @@ -5435,6 +5443,42 @@ union bpf_attr { * **-E2BIG** if user-space has tried to publish a sample which is * larger than the size of the ring buffer, or which cannot fit * within a struct bpf_dynptr. + * + * void *bpf_cgrp_storage_get(struct bpf_map *map, struct cgroup *cgroup, void *value, u64 flags) + * Description + * Get a bpf_local_storage from the *cgroup*. + * + * Logically, it could be thought of as getting the value from + * a *map* with *cgroup* as the **key**. From this + * perspective, the usage is not much different from + * **bpf_map_lookup_elem**\ (*map*, **&**\ *cgroup*) except this + * helper enforces the key must be a cgroup struct and the map must also + * be a **BPF_MAP_TYPE_CGRP_STORAGE**. + * + * Underneath, the value is stored locally at *cgroup* instead of + * the *map*. The *map* is used as the bpf-local-storage + * "type". The bpf-local-storage "type" (i.e. the *map*) is + * searched against all bpf_local_storage residing at *cgroup*. + * + * An optional *flags* (**BPF_LOCAL_STORAGE_GET_F_CREATE**) can be + * used such that a new bpf_local_storage will be + * created if one does not exist. *value* can be used + * together with **BPF_LOCAL_STORAGE_GET_F_CREATE** to specify + * the initial value of a bpf_local_storage. If *value* is + * **NULL**, the new bpf_local_storage will be zero initialized. + * Return + * A bpf_local_storage pointer is returned on success. + * + * **NULL** if not found or there was an error in adding + * a new bpf_local_storage. + * + * long bpf_cgrp_storage_delete(struct bpf_map *map, struct cgroup *cgroup) + * Description + * Delete a bpf_local_storage from a *cgroup*. + * Return + * 0 on success. + * + * **-ENOENT** if the bpf_local_storage cannot be found. */ #define ___BPF_FUNC_MAPPER(FN, ctx...) \ FN(unspec, 0, ##ctx) \ @@ -5647,6 +5691,8 @@ union bpf_attr { FN(tcp_raw_check_syncookie_ipv6, 207, ##ctx) \ FN(ktime_get_tai_ns, 208, ##ctx) \ FN(user_ringbuf_drain, 209, ##ctx) \ + FN(cgrp_storage_get, 210, ##ctx) \ + FN(cgrp_storage_delete, 211, ##ctx) \ /* */ /* backwards-compatibility macros for users of __BPF_FUNC_MAPPER that don't From patchwork Thu Oct 20 22:13:11 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Yonghong Song X-Patchwork-Id: 13014063 X-Patchwork-Delegate: bpf@iogearbox.net Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 4957EC433FE for ; Thu, 20 Oct 2022 22:13:21 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229484AbiJTWNU (ORCPT ); Thu, 20 Oct 2022 18:13:20 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:38062 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229587AbiJTWNT (ORCPT ); Thu, 20 Oct 2022 18:13:19 -0400 Received: from mx0b-00082601.pphosted.com (mx0b-00082601.pphosted.com [67.231.153.30]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id C86F71DC4D9 for ; Thu, 20 Oct 2022 15:13:18 -0700 (PDT) Received: from pps.filterd (m0109331.ppops.net [127.0.0.1]) by mx0a-00082601.pphosted.com (8.17.1.5/8.17.1.5) with ESMTP id 29KHZwef010170 for ; Thu, 20 Oct 2022 15:13:18 -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=lSC1mUFyLMFfHenlGM12xTlidbMad6AnT8vuEwb1roo=; b=lub2Y6DKduc7D9U3uXnTrIQo4ZT1F17/2xxTNwxqXPd+sseqilv8mwAI/kNku2kAKU7S QnYCPDuBqpwAb9QxAVM9dvSGyJacysF9k6czvPKZOCt5i0tS9cBliBipHf5z8OJ6kfPX Su/JIUJtn/0VM5bJylpyinqTPo7gKwvL8bE= Received: from maileast.thefacebook.com ([163.114.130.16]) by mx0a-00082601.pphosted.com (PPS) with ESMTPS id 3kb66d64e5-10 (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128 verify=NOT) for ; Thu, 20 Oct 2022 15:13:18 -0700 Received: from twshared9088.05.ash9.facebook.com (2620:10d:c0a8:1b::d) by mail.thefacebook.com (2620:10d:c0a8:83::6) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2375.31; Thu, 20 Oct 2022 15:13:16 -0700 Received: by devbig309.ftw3.facebook.com (Postfix, from userid 128203) id A86AE10F4EC4B; Thu, 20 Oct 2022 15:13:11 -0700 (PDT) From: Yonghong Song To: CC: Alexei Starovoitov , Andrii Nakryiko , Daniel Borkmann , , KP Singh , Martin KaFai Lau , Tejun Heo Subject: [PATCH bpf-next v2 3/6] libbpf: Support new cgroup local storage Date: Thu, 20 Oct 2022 15:13:11 -0700 Message-ID: <20221020221311.3554642-1-yhs@fb.com> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20221020221255.3553649-1-yhs@fb.com> References: <20221020221255.3553649-1-yhs@fb.com> MIME-Version: 1.0 X-FB-Internal: Safe X-Proofpoint-GUID: zSk4XGegQMx6rqIGoIFqjEJMGEVaMfOB X-Proofpoint-ORIG-GUID: zSk4XGegQMx6rqIGoIFqjEJMGEVaMfOB X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.205,Aquarius:18.0.895,Hydra:6.0.545,FMLib:17.11.122.1 definitions=2022-10-20_11,2022-10-20_01,2022-06-22_01 Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org X-Patchwork-Delegate: bpf@iogearbox.net Add support for new cgroup local storage. Signed-off-by: Yonghong Song Acked-by: Andrii Nakryiko --- tools/lib/bpf/libbpf.c | 1 + tools/lib/bpf/libbpf_probes.c | 1 + 2 files changed, 2 insertions(+) diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c index 027fd9565c16..5d7819edf074 100644 --- a/tools/lib/bpf/libbpf.c +++ b/tools/lib/bpf/libbpf.c @@ -164,6 +164,7 @@ static const char * const map_type_name[] = { [BPF_MAP_TYPE_TASK_STORAGE] = "task_storage", [BPF_MAP_TYPE_BLOOM_FILTER] = "bloom_filter", [BPF_MAP_TYPE_USER_RINGBUF] = "user_ringbuf", + [BPF_MAP_TYPE_CGRP_STORAGE] = "cgrp_storage", }; static const char * const prog_type_name[] = { diff --git a/tools/lib/bpf/libbpf_probes.c b/tools/lib/bpf/libbpf_probes.c index f3a8e8e74eb8..bdb83d467f9a 100644 --- a/tools/lib/bpf/libbpf_probes.c +++ b/tools/lib/bpf/libbpf_probes.c @@ -221,6 +221,7 @@ static int probe_map_create(enum bpf_map_type map_type) case BPF_MAP_TYPE_SK_STORAGE: case BPF_MAP_TYPE_INODE_STORAGE: case BPF_MAP_TYPE_TASK_STORAGE: + case BPF_MAP_TYPE_CGRP_STORAGE: btf_key_type_id = 1; btf_value_type_id = 3; value_size = 8; From patchwork Thu Oct 20 22:13:16 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Yonghong Song X-Patchwork-Id: 13014065 X-Patchwork-Delegate: bpf@iogearbox.net Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 2715AC433FE for ; Thu, 20 Oct 2022 22:13:36 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229648AbiJTWNe (ORCPT ); Thu, 20 Oct 2022 18:13:34 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:38400 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229514AbiJTWNd (ORCPT ); Thu, 20 Oct 2022 18:13:33 -0400 Received: from mx0a-00082601.pphosted.com (mx0a-00082601.pphosted.com [67.231.145.42]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id B7BDE215538 for ; Thu, 20 Oct 2022 15:13:30 -0700 (PDT) Received: from pps.filterd (m0148461.ppops.net [127.0.0.1]) by mx0a-00082601.pphosted.com (8.17.1.5/8.17.1.5) with ESMTP id 29KHaCAl023184 for ; Thu, 20 Oct 2022 15:13:29 -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=LZgsahRgS2+ozMpcEZ97QsCPayPMplqJkGhaAaubtkc=; b=Y3DLeJE54qXIm40t/MaD/e2F3Pd74ADFUKwgHdxS+qxm8PdVQNKv/cRBlQthmTSfO/Zk Hh/0qUiYOgKPqlJ7uL6vol2VrzHSstIer1PJrfDg9nesE2gjT84F1qdYJoSA/7qrSoEj 3bTTr5c+8mGAtUWqERocG1lRKF2Pa378rVY= Received: from maileast.thefacebook.com ([163.114.130.16]) by mx0a-00082601.pphosted.com (PPS) with ESMTPS id 3kawj0as1w-9 (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128 verify=NOT) for ; Thu, 20 Oct 2022 15:13:29 -0700 Received: from twshared19720.14.frc2.facebook.com (2620:10d:c0a8:1b::d) by mail.thefacebook.com (2620:10d:c0a8:82::e) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2375.31; Thu, 20 Oct 2022 15:13:23 -0700 Received: by devbig309.ftw3.facebook.com (Postfix, from userid 128203) id EA44410F4EC60; Thu, 20 Oct 2022 15:13:16 -0700 (PDT) From: Yonghong Song To: CC: Alexei Starovoitov , Andrii Nakryiko , Daniel Borkmann , , KP Singh , Martin KaFai Lau , Tejun Heo , Quentin Monnet Subject: [PATCH bpf-next v2 4/6] bpftool: Support new cgroup local storage Date: Thu, 20 Oct 2022 15:13:16 -0700 Message-ID: <20221020221316.3554872-1-yhs@fb.com> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20221020221255.3553649-1-yhs@fb.com> References: <20221020221255.3553649-1-yhs@fb.com> MIME-Version: 1.0 X-FB-Internal: Safe X-Proofpoint-GUID: 4M_Y3TbeIZM1j38vySbFGbQBuAml1ksu X-Proofpoint-ORIG-GUID: 4M_Y3TbeIZM1j38vySbFGbQBuAml1ksu X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.205,Aquarius:18.0.895,Hydra:6.0.545,FMLib:17.11.122.1 definitions=2022-10-20_11,2022-10-20_01,2022-06-22_01 Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org X-Patchwork-Delegate: bpf@iogearbox.net Add support for new cgroup local storage Acked-by: Quentin Monnet Signed-off-by: Yonghong Song --- tools/bpf/bpftool/Documentation/bpftool-map.rst | 2 +- tools/bpf/bpftool/map.c | 2 +- 2 files changed, 2 insertions(+), 2 deletions(-) diff --git a/tools/bpf/bpftool/Documentation/bpftool-map.rst b/tools/bpf/bpftool/Documentation/bpftool-map.rst index 7f3b67a8b48f..11250c4734fe 100644 --- a/tools/bpf/bpftool/Documentation/bpftool-map.rst +++ b/tools/bpf/bpftool/Documentation/bpftool-map.rst @@ -55,7 +55,7 @@ MAP COMMANDS | | **devmap** | **devmap_hash** | **sockmap** | **cpumap** | **xskmap** | **sockhash** | | **cgroup_storage** | **reuseport_sockarray** | **percpu_cgroup_storage** | | **queue** | **stack** | **sk_storage** | **struct_ops** | **ringbuf** | **inode_storage** -| | **task_storage** | **bloom_filter** | **user_ringbuf** } +| | **task_storage** | **bloom_filter** | **user_ringbuf** | **cgrp_storage** } DESCRIPTION =========== diff --git a/tools/bpf/bpftool/map.c b/tools/bpf/bpftool/map.c index 9a6ca9f31133..3a2a89912637 100644 --- a/tools/bpf/bpftool/map.c +++ b/tools/bpf/bpftool/map.c @@ -1459,7 +1459,7 @@ static int do_help(int argc, char **argv) " devmap | devmap_hash | sockmap | cpumap | xskmap | sockhash |\n" " cgroup_storage | reuseport_sockarray | percpu_cgroup_storage |\n" " queue | stack | sk_storage | struct_ops | ringbuf | inode_storage |\n" - " task_storage | bloom_filter | user_ringbuf }\n" + " task_storage | bloom_filter | user_ringbuf | cgrp_storage }\n" " " HELP_SPEC_OPTIONS " |\n" " {-f|--bpffs} | {-n|--nomount} }\n" "", From patchwork Thu Oct 20 22:13:22 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Yonghong Song X-Patchwork-Id: 13014064 X-Patchwork-Delegate: bpf@iogearbox.net Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 18420C4332F for ; Thu, 20 Oct 2022 22:13:30 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229587AbiJTWN2 (ORCPT ); Thu, 20 Oct 2022 18:13:28 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:38242 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229675AbiJTWN2 (ORCPT ); Thu, 20 Oct 2022 18:13:28 -0400 Received: from mx0a-00082601.pphosted.com (mx0a-00082601.pphosted.com [67.231.145.42]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 5360C1F5257 for ; Thu, 20 Oct 2022 15:13:27 -0700 (PDT) Received: from pps.filterd (m0109334.ppops.net [127.0.0.1]) by mx0a-00082601.pphosted.com (8.17.1.5/8.17.1.5) with ESMTP id 29KHa4HS004089 for ; Thu, 20 Oct 2022 15:13:27 -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=/Br7dXNk1OysbH1v0hVWjTAtPPAPbEcjWKvJ2ynHgoM=; b=bXGPHjKENttJbBkKSBnCMn0q+ZTLIIYqdpojI5mt8wXbZ6KYTJyBDNxtmfI5rBnX4ppo 8cS+rpHE5GEXhNq+F/LQLahlpGjhGHCrgunUgFmTKe3Pn6No5c1PN3L2ywEmAX45KoEF mCbASh+c//qvdXb/PNcXdWml07z1oA529mA= Received: from maileast.thefacebook.com ([163.114.130.16]) by mx0a-00082601.pphosted.com (PPS) with ESMTPS id 3kanpvr2md-9 (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128 verify=NOT) for ; Thu, 20 Oct 2022 15:13:27 -0700 Received: from twshared5252.09.ash9.facebook.com (2620:10d:c0a8:1b::d) by mail.thefacebook.com (2620:10d:c0a8:83::7) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2375.31; Thu, 20 Oct 2022 15:13:25 -0700 Received: by devbig309.ftw3.facebook.com (Postfix, from userid 128203) id 3A44B10F4EC7D; Thu, 20 Oct 2022 15:13:22 -0700 (PDT) From: Yonghong Song To: CC: Alexei Starovoitov , Andrii Nakryiko , Daniel Borkmann , , KP Singh , Martin KaFai Lau , Tejun Heo Subject: [PATCH bpf-next v2 5/6] selftests/bpf: Add selftests for cgroup local storage Date: Thu, 20 Oct 2022 15:13:22 -0700 Message-ID: <20221020221322.3556136-1-yhs@fb.com> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20221020221255.3553649-1-yhs@fb.com> References: <20221020221255.3553649-1-yhs@fb.com> MIME-Version: 1.0 X-FB-Internal: Safe X-Proofpoint-ORIG-GUID: TUzJcxPe30o0HJjmtJHPoKbf-SCyNw2j X-Proofpoint-GUID: TUzJcxPe30o0HJjmtJHPoKbf-SCyNw2j X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.205,Aquarius:18.0.895,Hydra:6.0.545,FMLib:17.11.122.1 definitions=2022-10-20_11,2022-10-20_01,2022-06-22_01 Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org X-Patchwork-Delegate: bpf@iogearbox.net Add two tests for cgroup local storage, one to test bpf program helpers and user space map APIs, and the other to test recursive fentry triggering won't deadlock. Signed-off-by: Yonghong Song --- .../bpf/prog_tests/cgroup_local_storage.c | 92 +++++++++++++++++++ .../bpf/progs/cgroup_local_storage.c | 88 ++++++++++++++++++ .../selftests/bpf/progs/cgroup_ls_recursion.c | 70 ++++++++++++++ 3 files changed, 250 insertions(+) create mode 100644 tools/testing/selftests/bpf/prog_tests/cgroup_local_storage.c create mode 100644 tools/testing/selftests/bpf/progs/cgroup_local_storage.c create mode 100644 tools/testing/selftests/bpf/progs/cgroup_ls_recursion.c diff --git a/tools/testing/selftests/bpf/prog_tests/cgroup_local_storage.c b/tools/testing/selftests/bpf/prog_tests/cgroup_local_storage.c new file mode 100644 index 000000000000..69b1abda0d42 --- /dev/null +++ b/tools/testing/selftests/bpf/prog_tests/cgroup_local_storage.c @@ -0,0 +1,92 @@ +// SPDX-License-Identifier: GPL-2.0 +/* Copyright (c) 2022 Meta Platforms, Inc. and affiliates.*/ + +#define _GNU_SOURCE +#include +#include +#include +#include +#include "cgroup_local_storage.skel.h" +#include "cgroup_ls_recursion.skel.h" + +static void test_sys_enter_exit(int cgroup_fd) +{ + struct cgroup_local_storage *skel; + long val1 = 1, val2 = 0; + int err; + + skel = cgroup_local_storage__open_and_load(); + if (!ASSERT_OK_PTR(skel, "skel_open_and_load")) + return; + + /* populate a value in cgrp_storage_2 */ + err = bpf_map_update_elem(bpf_map__fd(skel->maps.cgrp_storage_2), &cgroup_fd, &val1, BPF_ANY); + if (!ASSERT_OK(err, "map_update_elem")) + goto out; + + /* check value */ + err = bpf_map_lookup_elem(bpf_map__fd(skel->maps.cgrp_storage_2), &cgroup_fd, &val2); + if (!ASSERT_OK(err, "map_lookup_elem")) + goto out; + if (!ASSERT_EQ(val2, 1, "map_lookup_elem, invalid val")) + goto out; + + /* delete value */ + err = bpf_map_delete_elem(bpf_map__fd(skel->maps.cgrp_storage_2), &cgroup_fd); + if (!ASSERT_OK(err, "map_delete_elem")) + goto out; + + skel->bss->target_pid = syscall(SYS_gettid); + + err = cgroup_local_storage__attach(skel); + if (!ASSERT_OK(err, "skel_attach")) + goto out; + + syscall(SYS_gettid); + syscall(SYS_gettid); + + skel->bss->target_pid = 0; + + /* 3x syscalls: 1x attach and 2x gettid */ + ASSERT_EQ(skel->bss->enter_cnt, 3, "enter_cnt"); + ASSERT_EQ(skel->bss->exit_cnt, 3, "exit_cnt"); + ASSERT_EQ(skel->bss->mismatch_cnt, 0, "mismatch_cnt"); +out: + cgroup_local_storage__destroy(skel); +} + +static void test_recursion(int cgroup_fd) +{ + struct cgroup_ls_recursion *skel; + int err; + + skel = cgroup_ls_recursion__open_and_load(); + if (!ASSERT_OK_PTR(skel, "skel_open_and_load")) + return; + + err = cgroup_ls_recursion__attach(skel); + if (!ASSERT_OK(err, "skel_attach")) + goto out; + + /* trigger sys_enter, make sure it does not cause deadlock */ + syscall(SYS_gettid); + +out: + cgroup_ls_recursion__destroy(skel); +} + +void test_cgroup_local_storage(void) +{ + int cgroup_fd; + + cgroup_fd = test__join_cgroup("/cgroup_local_storage"); + if (!ASSERT_GE(cgroup_fd, 0, "join_cgroup /cgroup_local_storage")) + return; + + if (test__start_subtest("sys_enter_exit")) + test_sys_enter_exit(cgroup_fd); + if (test__start_subtest("recursion")) + test_recursion(cgroup_fd); + + close(cgroup_fd); +} diff --git a/tools/testing/selftests/bpf/progs/cgroup_local_storage.c b/tools/testing/selftests/bpf/progs/cgroup_local_storage.c new file mode 100644 index 000000000000..dee63d4c1512 --- /dev/null +++ b/tools/testing/selftests/bpf/progs/cgroup_local_storage.c @@ -0,0 +1,88 @@ +// SPDX-License-Identifier: GPL-2.0 +/* Copyright (c) 2022 Meta Platforms, Inc. and affiliates. */ + +#include "vmlinux.h" +#include +#include + +char _license[] SEC("license") = "GPL"; + +struct { + __uint(type, BPF_MAP_TYPE_CGRP_STORAGE); + __uint(map_flags, BPF_F_NO_PREALLOC); + __type(key, int); + __type(value, long); +} cgrp_storage_1 SEC(".maps"); + +struct { + __uint(type, BPF_MAP_TYPE_CGRP_STORAGE); + __uint(map_flags, BPF_F_NO_PREALLOC); + __type(key, int); + __type(value, long); +} cgrp_storage_2 SEC(".maps"); + +#define MAGIC_VALUE 0xabcd1234 + +pid_t target_pid = 0; +int mismatch_cnt = 0; +int enter_cnt = 0; +int exit_cnt = 0; + +SEC("tp_btf/sys_enter") +int BPF_PROG(on_enter, struct pt_regs *regs, long id) +{ + struct task_struct *task; + long *ptr; + int err; + + task = bpf_get_current_task_btf(); + if (task->pid != target_pid) + return 0; + + /* populate value 0 */ + ptr = bpf_cgrp_storage_get(&cgrp_storage_1, task->cgroups->dfl_cgrp, 0, + BPF_LOCAL_STORAGE_GET_F_CREATE); + if (!ptr) + return 0; + + /* delete value 0 */ + err = bpf_cgrp_storage_delete(&cgrp_storage_1, task->cgroups->dfl_cgrp); + if (err) + return 0; + + /* value is not available */ + ptr = bpf_cgrp_storage_get(&cgrp_storage_1, task->cgroups->dfl_cgrp, 0, 0); + if (ptr) + return 0; + + /* re-populate the value */ + ptr = bpf_cgrp_storage_get(&cgrp_storage_1, task->cgroups->dfl_cgrp, 0, + BPF_LOCAL_STORAGE_GET_F_CREATE); + if (!ptr) + return 0; + __sync_fetch_and_add(&enter_cnt, 1); + *ptr = MAGIC_VALUE + enter_cnt; + + return 0; +} + +SEC("tp_btf/sys_exit") +int BPF_PROG(on_exit, struct pt_regs *regs, long id) +{ + struct task_struct *task; + long *ptr; + + task = bpf_get_current_task_btf(); + if (task->pid != target_pid) + return 0; + + ptr = bpf_cgrp_storage_get(&cgrp_storage_1, task->cgroups->dfl_cgrp, 0, + BPF_LOCAL_STORAGE_GET_F_CREATE); + if (!ptr) + return 0; + + __sync_fetch_and_add(&exit_cnt, 1); + if (*ptr != MAGIC_VALUE + exit_cnt) + __sync_fetch_and_add(&mismatch_cnt, 1); + return 0; +} diff --git a/tools/testing/selftests/bpf/progs/cgroup_ls_recursion.c b/tools/testing/selftests/bpf/progs/cgroup_ls_recursion.c new file mode 100644 index 000000000000..a043d8fefdac --- /dev/null +++ b/tools/testing/selftests/bpf/progs/cgroup_ls_recursion.c @@ -0,0 +1,70 @@ +// SPDX-License-Identifier: GPL-2.0 +/* Copyright (c) 2022 Meta Platforms, Inc. and affiliates. */ + +#include "vmlinux.h" +#include +#include + +char _license[] SEC("license") = "GPL"; + +struct { + __uint(type, BPF_MAP_TYPE_CGRP_STORAGE); + __uint(map_flags, BPF_F_NO_PREALLOC); + __type(key, int); + __type(value, long); +} map_a SEC(".maps"); + +struct { + __uint(type, BPF_MAP_TYPE_CGRP_STORAGE); + __uint(map_flags, BPF_F_NO_PREALLOC); + __type(key, int); + __type(value, long); +} map_b SEC(".maps"); + +SEC("fentry/bpf_local_storage_lookup") +int BPF_PROG(on_lookup) +{ + struct task_struct *task = bpf_get_current_task_btf(); + + bpf_cgrp_storage_delete(&map_a, task->cgroups->dfl_cgrp); + bpf_cgrp_storage_delete(&map_b, task->cgroups->dfl_cgrp); + return 0; +} + +SEC("fentry/bpf_local_storage_update") +int BPF_PROG(on_update) +{ + struct task_struct *task = bpf_get_current_task_btf(); + long *ptr; + + ptr = bpf_cgrp_storage_get(&map_a, task->cgroups->dfl_cgrp, 0, + BPF_LOCAL_STORAGE_GET_F_CREATE); + if (ptr) + *ptr += 1; + + ptr = bpf_cgrp_storage_get(&map_b, task->cgroups->dfl_cgrp, 0, + BPF_LOCAL_STORAGE_GET_F_CREATE); + if (ptr) + *ptr += 1; + + return 0; +} + +SEC("tp_btf/sys_enter") +int BPF_PROG(on_enter, struct pt_regs *regs, long id) +{ + struct task_struct *task; + long *ptr; + + task = bpf_get_current_task_btf(); + ptr = bpf_cgrp_storage_get(&map_a, task->cgroups->dfl_cgrp, 0, + BPF_LOCAL_STORAGE_GET_F_CREATE); + if (ptr) + *ptr = 200; + + ptr = bpf_cgrp_storage_get(&map_b, task->cgroups->dfl_cgrp, 0, + BPF_LOCAL_STORAGE_GET_F_CREATE); + if (ptr) + *ptr = 100; + return 0; +} From patchwork Thu Oct 20 22:13:27 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Yonghong Song X-Patchwork-Id: 13014066 X-Patchwork-Delegate: bpf@iogearbox.net Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 48737C433FE for ; Thu, 20 Oct 2022 22:13:41 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229678AbiJTWNi (ORCPT ); Thu, 20 Oct 2022 18:13:38 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:38508 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229629AbiJTWNi (ORCPT ); Thu, 20 Oct 2022 18:13:38 -0400 Received: from mx0a-00082601.pphosted.com (mx0a-00082601.pphosted.com [67.231.145.42]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 3F2102112B9 for ; Thu, 20 Oct 2022 15:13:37 -0700 (PDT) Received: from pps.filterd (m0044012.ppops.net [127.0.0.1]) by mx0a-00082601.pphosted.com (8.17.1.5/8.17.1.5) with ESMTP id 29KHaCSp009412 for ; Thu, 20 Oct 2022 15:13:36 -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=vTr6RbKSp5SXWBQZQ7WTsQB9FAwJtccH55Rr7CWZNCw=; b=GxUpzrKyYzB4OQvNdz2tLnuB+YrvfzqvhPozdjMbCtA0dW43t9cO+zqmMz+lALJOfiFX C1uYUvrMEszUVSfq4EmM73+BUVNLEtfC02d86LokCD9arqW1ir9UFbqlwUJo4x71LxLJ EGoYaW/oXE2FOQcLP7JB/C55zGbVvDUp0JI= Received: from mail.thefacebook.com ([163.114.132.120]) by mx0a-00082601.pphosted.com (PPS) with ESMTPS id 3kb799db4n-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128 verify=NOT) for ; Thu, 20 Oct 2022 15:13:36 -0700 Received: from twshared17038.18.frc3.facebook.com (2620:10d:c085:208::11) by mail.thefacebook.com (2620:10d:c085:21d::6) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2375.31; Thu, 20 Oct 2022 15:13:35 -0700 Received: by devbig309.ftw3.facebook.com (Postfix, from userid 128203) id B6D2C10F4ECA8; Thu, 20 Oct 2022 15:13:27 -0700 (PDT) From: Yonghong Song To: CC: Alexei Starovoitov , Andrii Nakryiko , Daniel Borkmann , , KP Singh , Martin KaFai Lau , Tejun Heo Subject: [PATCH bpf-next v2 6/6] docs/bpf: Add documentation for map type BPF_MAP_TYPE_CGRP_STROAGE Date: Thu, 20 Oct 2022 15:13:27 -0700 Message-ID: <20221020221327.3557258-1-yhs@fb.com> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20221020221255.3553649-1-yhs@fb.com> References: <20221020221255.3553649-1-yhs@fb.com> MIME-Version: 1.0 X-FB-Internal: Safe X-Proofpoint-GUID: o-RuAa5u4arVZMvWqw6DYvsqpvVAdc5Q X-Proofpoint-ORIG-GUID: o-RuAa5u4arVZMvWqw6DYvsqpvVAdc5Q X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.205,Aquarius:18.0.895,Hydra:6.0.545,FMLib:17.11.122.1 definitions=2022-10-20_11,2022-10-20_01,2022-06-22_01 Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org X-Patchwork-Delegate: bpf@iogearbox.net Add some descriptions and examples for BPF_MAP_TYPE_CGRP_STROAGE. Also illustate the major difference between BPF_MAP_TYPE_CGRP_STROAGE and BPF_MAP_TYPE_CGROUP_STORAGE and recommend to use BPF_MAP_TYPE_CGRP_STROAGE instead of BPF_MAP_TYPE_CGROUP_STORAGE in the end. Signed-off-by: Yonghong Song --- Documentation/bpf/map_cgrp_storage.rst | 104 +++++++++++++++++++++++++ 1 file changed, 104 insertions(+) create mode 100644 Documentation/bpf/map_cgrp_storage.rst diff --git a/Documentation/bpf/map_cgrp_storage.rst b/Documentation/bpf/map_cgrp_storage.rst new file mode 100644 index 000000000000..15691aab7fc7 --- /dev/null +++ b/Documentation/bpf/map_cgrp_storage.rst @@ -0,0 +1,104 @@ +.. SPDX-License-Identifier: GPL-2.0-only +.. Copyright (C) 2022 Meta Platforms, Inc. and affiliates. + +=========================== +BPF_MAP_TYPE_CGRP_STORAGE +=========================== + +The ``BPF_MAP_TYPE_CGRP_STORAGE`` map type represents a local fix-sized +storage for cgroups. It is only available with ``CONFIG_CGROUP_BPF``. +The programs are made available by the same Kconfig. The +data for a particular cgroup can be retrieved by looking up the map +with that cgroup. + +This document describes the usage and semantics of the +``BPF_MAP_TYPE_CGRP_STORAGE`` map type. + +Usage +===== + +The map key must be ``sizeof(int)`` representing a cgroup fd. +To access the storage in a program, use ``bpf_cgrp_storage_get``:: + + void *bpf_cgrp_storage_get(struct bpf_map *map, struct cgroup *cgroup, void *value, u64 flags) + +``flags`` could be 0 or ``BPF_LOCAL_STORAGE_GET_F_CREATE`` which indicates that +a new local storage will be created if one does not exist. + +The local storage can be removed with ``bpf_cgrp_storage_delete``:: + + long bpf_cgrp_storage_delete(struct bpf_map *map, struct cgruop *cgroup) + +The map is available to all program types. + +Examples +======== + +An bpf-program example with BPF_MAP_TYPE_CGRP_STORAGE:: + + #include + #include + #include + + struct { + __uint(type, BPF_MAP_TYPE_CGRP_STORAGE); + __uint(map_flags, BPF_F_NO_PREALLOC); + __type(key, int); + __type(value, long); + } cgrp_storage SEC(".maps"); + + SEC("tp_btf/sys_enter") + int BPF_PROG(on_enter, struct pt_regs *regs, long id) + { + struct task_struct *task = bpf_get_current_task_btf(); + long *ptr; + + ptr = bpf_cgrp_storage_get(&cgrp_storage, task->cgroups->dfl_cgrp, 0, + BPF_LOCAL_STORAGE_GET_F_CREATE); + if (ptr) + __sync_fetch_and_add(ptr, 1); + + return 0; + } + +Userspace accessing map declared above:: + + #include + #include + + __u32 map_lookup(struct bpf_map *map, int cgrp_fd) + { + __u32 *value; + value = bpf_map_lookup_elem(bpf_map__fd(map), &cgrp_fd); + if (value) + return *value; + return 0; + } + +Difference Between BPF_MAP_TYPE_CGRP_STORAGE and BPF_MAP_TYPE_CGROUP_STORAGE +============================================================================ + +The main difference between ``BPF_MAP_TYPE_CGRP_STORAGE`` and ``BPF_MAP_TYPE_CGROUP_STORAGE`` +is that ``BPF_MAP_TYPE_CGRP_STORAGE`` can be used by all program types while +``BPF_MAP_TYPE_CGROUP_STORAGE`` is available only to cgroup program types. + +There are some other differences as well. + +(1). ``BPF_MAP_TYPE_CGRP_STORAGE`` supports local storage for more than one + cgroups while ``BPF_MAP_TYPE_CGROUP_STORAGE`` only support one, the one attached + by the bpf program. + +(2). ``BPF_MAP_TYPE_CGROUP_STORAGE`` allocates local storage at attach time so + ``bpf_get_local_storage()`` always returns non-null local storage. + ``BPF_MAP_TYPE_CGRP_STORAGE`` allocates local storage at runtime so + it is possible that ``bpf_cgrp_storage_get()`` may return null local storage. + To avoid such null local storage issue, user space can do + ``bpf_map_update_elem()`` to pre-allocate local storage. + +(3). ``BPF_MAP_TYPE_CGRP_STORAGE`` supports de-allocating local storage by bpf program + while ``BPF_MAP_TYPE_CGROUP_STORAGE`` only de-allocates storage during + prog detach time. + +So overall, ``BPF_MAP_TYPE_CGRP_STORAGE`` supports all ``BPF_MAP_TYPE_CGROUP_STORAGE`` +functionality and beyond. It is recommended to use ``BPF_MAP_TYPE_CGRP_STORAGE`` +instead of ``BPF_MAP_TYPE_CGROUP_STORAGE``.