From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 00D6EC433FE for ; Mon, 17 Oct 2022 18:02:03 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229904AbiJQSCC (ORCPT ); Mon, 17 Oct 2022 14:02:02 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:37626 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229955AbiJQSCB (ORCPT ); Mon, 17 Oct 2022 14:02:01 -0400 Received: from mail-pj1-x104a.google.com (mail-pj1-x104a.google.com [IPv6:2607:f8b0:4864:20::104a]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id EE0ED63FD7 for ; Mon, 17 Oct 2022 11:01:57 -0700 (PDT) Received: by mail-pj1-x104a.google.com with SMTP id z9-20020a17090a468900b00202fdb32ba1so5757199pjf.1 for ; Mon, 17 Oct 2022 11:01:57 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20210112; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:from:to:cc:subject:date:message-id:reply-to; bh=W6fjBqqY6VkpL9tvGHnvdnj91S6p/rXFEdMQ6HbUixg=; b=DC4W32M78PpHr5sBrTLkNTjtMIQy+C3L6A0MTniVieqfyRHwyRIrkLa6yowVw7sjqE /vYCli6HCbi1zo0IpkXNO6ANLrOi1UCKkPkOr2eBKA5Y+58olx6jXQ/5214tODM3IFHY M1es/0vjwhan7WQPbYeDYbk7i7mUt5An8qOl+x3ihopWSSs4EFOMNRmuNasXjGxP30OH 69SxZxOf2z1i/UnmRrwGC/bpmF2Wi2XhGhwlErsZ064JGOmdvmrLU/msomQYfR5b7nGM hTbIiQmdJD85menVWOWdCZVLEy7+N2UuFLeuAhrpdqPOEa7boCs05OqB2P/hHymAtWFD 15Dg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=W6fjBqqY6VkpL9tvGHnvdnj91S6p/rXFEdMQ6HbUixg=; b=oEMvN5NREP2JWBxt1cX2ACDF1Yvtu4DaRTA260jLeqoThCSO4idd8xwc53ZIUWdOTH 8Cdaf9X8DZ20Q2/BabpGDHQbTTcYqf38yXHBot1gnhCP6JtFNVE6PX4RL32cXBzhRqK9 6PX3UhVRAyHLkF0CT5oUT0HG4r7o+QLH5oxiKHxDBpQf2ngcUZDZSK/w8AzmJNHekPrr wE/AwV1KHrVoi4EkmAZaA95VHZQwCsGLxaANG2jZpVl0f0nCa2zuPvmzaZEVGEqadRCV kHNr9FQq8FjJlahMrVPhlDhY70YNXom2qN5goVvvvaoGNCJZvAvYdnyjEbEOKT+AHM7l S24w== X-Gm-Message-State: ACrzQf1USNDPvPy2En7p847W7rXaxJBWI+gIhkMbC+obokUIFukkJpmg gFS8folUT8pEFbarhBzBTFRxcGU= X-Google-Smtp-Source: AMsMyM4D6qQN2JmA3zVXE2HURTBiBJDloAP5PdfESkybPCHSoseGTqI2LEqgrtg1JmC4W4qDZa9/3IY= X-Received: from sdf.c.googlers.com ([fda3:e722:ac3:cc00:7f:e700:c0a8:5935]) (user=sdf job=sendgmr) by 2002:aa7:84ce:0:b0:563:1aaf:81d5 with SMTP id x14-20020aa784ce000000b005631aaf81d5mr13808498pfn.63.1666029717523; Mon, 17 Oct 2022 11:01:57 -0700 (PDT) Date: Mon, 17 Oct 2022 11:01:55 -0700 In-Reply-To: <20221014045630.3311951-1-yhs@fb.com> Mime-Version: 1.0 References: <20221014045619.3309899-1-yhs@fb.com> <20221014045630.3311951-1-yhs@fb.com> Message-ID: Subject: Re: [PATCH bpf-next 2/5] bpf: Implement cgroup storage available to non-cgroup-attached bpf progs From: sdf@google.com To: Yonghong Song Cc: bpf@vger.kernel.org, Alexei Starovoitov , Andrii Nakryiko , Daniel Borkmann , kernel-team@fb.com, KP Singh , Martin KaFai Lau , Tejun Heo Content-Type: text/plain; charset="UTF-8"; format=flowed; delsp=yes Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org On 10/13, Yonghong Song wrote: > 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_cgroup_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. [..] > Since map name BPF_MAP_TYPE_CGROUP_STORAGE has been used for old cgroup > local > storage support, the new map name BPF_MAP_TYPE_CGROUP_LOCAL_STORAGE is > used > for cgroup storage available to non-cgroup-attached bpf programs. The two > helpers are named as bpf_cgroup_local_storage_get() and > bpf_cgroup_local_storage_delete(). Have you considered doing something similar to 7d9c3427894f ("bpf: Make cgroup storages shared between programs on the same cgroup") where the map changes its behavior depending on the key size (see key_size checks in cgroup_storage_map_alloc)? Looks like sizeof(int) for fd still can be used so we can, in theory, reuse the name.. Pros: - no need for a new map name Cons: - existing BPF_MAP_TYPE_CGROUP_STORAGE is already messy; might be not a good idea to add more stuff to it? But, for the very least, should we also extend Documentation/bpf/map_cgroup_storage.rst to cover the new map? We've tried to keep some of the important details in there.. > 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 | 39 +++++ > kernel/bpf/Makefile | 2 +- > kernel/bpf/bpf_cgroup_storage.c | 280 ++++++++++++++++++++++++++++++++ > kernel/bpf/helpers.c | 6 + > kernel/bpf/syscall.c | 3 +- > kernel/bpf/verifier.c | 14 +- > kernel/cgroup/cgroup.c | 4 + > kernel/trace/bpf_trace.c | 4 + > scripts/bpf_doc.py | 2 + > tools/include/uapi/linux/bpf.h | 39 +++++ > 13 files changed, 398 insertions(+), 3 deletions(-) > create mode 100644 kernel/bpf/bpf_cgroup_storage.c > diff --git a/include/linux/bpf.h b/include/linux/bpf.h > index 9e7d46d16032..1395a01c7f18 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_local_cgroup_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_cgroup_storage_get_proto; > +extern const struct bpf_func_proto bpf_cgroup_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..7a0362d7a0aa 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_CGROUP_LOCAL_STORAGE, > cgroup_local_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 4bcf56b3491c..c6f4590dda68 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_BPF_SYSCALL > + struct bpf_local_storage __rcu *bpf_cgroup_storage; > +#endif > + > /* ids of the ancestors at each level including self */ > u64 ancestor_ids[]; > }; > diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h > index 17f61338f8f8..d918b4054297 100644 > --- a/include/uapi/linux/bpf.h > +++ b/include/uapi/linux/bpf.h > @@ -935,6 +935,7 @@ enum bpf_map_type { > BPF_MAP_TYPE_TASK_STORAGE, > BPF_MAP_TYPE_BLOOM_FILTER, > BPF_MAP_TYPE_USER_RINGBUF, > + BPF_MAP_TYPE_CGROUP_LOCAL_STORAGE, > }; > /* Note that tracing related programs such as > @@ -5435,6 +5436,42 @@ 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_cgroup_local_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_CGROUP_LOCAL_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_cgroup_local_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 +5684,8 @@ 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(cgroup_local_storage_get, 210, ##ctx) \ > + FN(cgroup_local_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..b02693f51978 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-$(CONFIG_BPF_SYSCALL) += cgroup_iter.o bpf_cgroup_storage.o > endif > obj-$(CONFIG_CGROUP_BPF) += cgroup.o > ifeq ($(CONFIG_INET),y) > diff --git a/kernel/bpf/bpf_cgroup_storage.c > b/kernel/bpf/bpf_cgroup_storage.c > new file mode 100644 > index 000000000000..9974784822da > --- /dev/null > +++ b/kernel/bpf/bpf_cgroup_storage.c > @@ -0,0 +1,280 @@ > +// 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_cgroup_storage_busy); > + > +static void bpf_cgroup_storage_lock(void) > +{ > + migrate_disable(); > + this_cpu_inc(bpf_cgroup_storage_busy); > +} > + > +static void bpf_cgroup_storage_unlock(void) > +{ > + this_cpu_dec(bpf_cgroup_storage_busy); > + migrate_enable(); > +} > + > +static bool bpf_cgroup_storage_trylock(void) > +{ > + migrate_disable(); > + if (unlikely(this_cpu_inc_return(bpf_cgroup_storage_busy) != 1)) { > + this_cpu_dec(bpf_cgroup_storage_busy); > + migrate_enable(); > + return false; > + } > + return true; > +} Task storage has lock/unlock/trylock; inode storage doesn't; why does cgroup need it as well? > +static struct bpf_local_storage __rcu **cgroup_storage_ptr(void *owner) > +{ > + struct cgroup *cg = owner; > + > + return &cg->bpf_cgroup_storage; > +} > + > +void bpf_local_cgroup_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_cgroup_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_cgroup_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_cgroup_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_cgroup_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_cgroup_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_cgroup_storage_lock(); > + sdata = cgroup_storage_lookup(cgroup, map, true); > + bpf_cgroup_storage_unlock(); > + cgroup_put(cgroup); > + return sdata ? sdata->data : NULL; > +} A lot of the above (free/lookup) seems to be copy-pasted from the task storage; any point in trying to generalize the common parts? > +static int bpf_cgroup_storage_update_elem(struct bpf_map *map, void *key, > + void *value, u64 map_flags) > +{ > + struct bpf_local_storage_data *sdata; > + struct cgroup *cgroup; > + int err, fd; > + > + fd = *(int *)key; > + cgroup = cgroup_get_from_fd(fd); > + if (IS_ERR(cgroup)) > + return PTR_ERR(cgroup); > + > + bpf_cgroup_storage_lock(); > + sdata = bpf_local_storage_update(cgroup, (struct bpf_local_storage_map > *)map, > + value, map_flags, GFP_ATOMIC); > + bpf_cgroup_storage_unlock(); > + err = PTR_ERR_OR_ZERO(sdata); > + cgroup_put(cgroup); > + return err; > +} > + > +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_cgroup_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_cgroup_storage_lock(); > + err = cgroup_storage_delete(cgroup, map); > + bpf_cgroup_storage_unlock(); > + if (err) > + return err; > + > + cgroup_put(cgroup); > + return 0; > +} > + > +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_cgroup_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_cgroup_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_cgroup_storage_unlock(); > + return IS_ERR_OR_NULL(sdata) ? (unsigned long)NULL : (unsigned > long)sdata->data; > +} > + > +BPF_CALL_2(bpf_cgroup_storage_delete, struct bpf_map *, map, struct > cgroup *, cgroup) > +{ > + int ret; > + > + WARN_ON_ONCE(!bpf_rcu_lock_held()); > + if (!cgroup) > + return -EINVAL; > + > + if (!bpf_cgroup_storage_trylock()) > + return -EBUSY; > + > + ret = cgroup_storage_delete(cgroup, map); > + bpf_cgroup_storage_unlock(); > + return ret; > +} > + > +BTF_ID_LIST_SINGLE(cgroup_storage_map_btf_ids, struct, > bpf_local_storage_map) > +const struct bpf_map_ops cgroup_local_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_cgroup_storage_lookup_elem, > + .map_update_elem = bpf_cgroup_storage_update_elem, > + .map_delete_elem = bpf_cgroup_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_cgroup_storage_get_proto = { > + .func = bpf_cgroup_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_cgroup_storage_delete_proto = { > + .func = bpf_cgroup_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..5c5bb08832ec 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_cgroup_local_storage_get: > + return &bpf_cgroup_storage_get_proto; > + case BPF_FUNC_cgroup_local_storage_delete: > + return &bpf_cgroup_storage_delete_proto; > +#endif > default: > break; > } > diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c > index 7b373a5e861f..e53c7fae6e22 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_CGROUP_LOCAL_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..f36f6a3c0d50 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_CGROUP_LOCAL_STORAGE: > + if (func_id != BPF_FUNC_cgroup_local_storage_get && > + func_id != BPF_FUNC_cgroup_local_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_cgroup_local_storage_get: > + case BPF_FUNC_cgroup_local_storage_delete: > + if (map->map_type != BPF_MAP_TYPE_CGROUP_LOCAL_STORAGE) > + goto error; > + break; > default: > break; > } > @@ -12713,6 +12723,7 @@ static int check_map_prog_compatibility(struct > bpf_verifier_env *env, > case BPF_MAP_TYPE_INODE_STORAGE: > case BPF_MAP_TYPE_SK_STORAGE: > case BPF_MAP_TYPE_TASK_STORAGE: > + case BPF_MAP_TYPE_CGROUP_LOCAL_STORAGE: > break; > default: > verbose(env, > @@ -14149,7 +14160,8 @@ 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_cgroup_local_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 8ad2c267ff47..2fa2c950c7fb 100644 > --- a/kernel/cgroup/cgroup.c > +++ b/kernel/cgroup/cgroup.c > @@ -985,6 +985,10 @@ void put_css_set_locked(struct css_set *cset) > put_css_set_locked(cset->dom_cset); > } > +#ifdef CONFIG_BPF_SYSCALL > + bpf_local_cgroup_storage_free(cset->dfl_cgrp); > +#endif > + > kfree_rcu(cset, rcu_head); > } > diff --git a/kernel/trace/bpf_trace.c b/kernel/trace/bpf_trace.c > index 688552df95ca..179adaae4a9f 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_cgroup_local_storage_get: > + return &bpf_cgroup_storage_get_proto; > + case BPF_FUNC_cgroup_local_storage_delete: > + return &bpf_cgroup_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..d918b4054297 100644 > --- a/tools/include/uapi/linux/bpf.h > +++ b/tools/include/uapi/linux/bpf.h > @@ -935,6 +935,7 @@ enum bpf_map_type { > BPF_MAP_TYPE_TASK_STORAGE, > BPF_MAP_TYPE_BLOOM_FILTER, > BPF_MAP_TYPE_USER_RINGBUF, > + BPF_MAP_TYPE_CGROUP_LOCAL_STORAGE, > }; > /* Note that tracing related programs such as > @@ -5435,6 +5436,42 @@ 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_cgroup_local_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_CGROUP_LOCAL_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_cgroup_local_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 +5684,8 @@ 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(cgroup_local_storage_get, 210, ##ctx) \ > + FN(cgroup_local_storage_delete, 211, ##ctx) \ > /* */ > /* backwards-compatibility macros for users of __BPF_FUNC_MAPPER that > don't > -- > 2.30.2