From mboxrd@z Thu Jan 1 00:00:00 1970 From: Martin KaFai Lau Subject: [PATCH -next 2/4] cgroup: bpf: Add BPF_MAP_TYPE_CGROUP_ARRAY Date: Tue, 21 Jun 2016 17:23:20 -0700 Message-ID: <1466555002-1316296-3-git-send-email-kafai@fb.com> References: <1466555002-1316296-1-git-send-email-kafai@fb.com> Mime-Version: 1.0 Return-path: DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=fb.com; h=from : to : cc : subject : date : message-id : in-reply-to : references : mime-version : content-type; s=facebook; bh=K7+FBwRjrgOIVeEQxK0Su+ogoAQcJf9ZFW2q1Z4xQzI=; b=JcE5pircfN2A5II7bKGnIe9JD18f2syTRdXv2RU2F8YH4fe8gXrA1OLlRE6ai517RxsU /ExWXdnTKLOMnugXsMsIOZvcpEQJArHm+sfrRMH05GM6fQmO6qDabgoHrQfLkQ47thZv 6GeZKkpOJwnG+j/JvXNKYcKGTvvuyCkpC+c= In-Reply-To: <1466555002-1316296-1-git-send-email-kafai@fb.com> Sender: netdev-owner@vger.kernel.org List-ID: Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: cgroups@vger.kernel.org, linux-kernel@vger.kernel.org, netdev@vger.kernel.org Cc: Alexei Starovoitov , Daniel Borkmann , Tejun Heo , kernel-team@fb.com Add a BPF_MAP_TYPE_CGROUP_ARRAY and its bpf_map_ops's implementations. To update an element, the caller is expected to obtain a cgroup2 backed fd by open(cgroup2_dir) and then update the array with that fd. Signed-off-by: Martin KaFai Lau Cc: Alexei Starovoitov Cc: Daniel Borkmann Cc: Tejun Heo --- include/uapi/linux/bpf.h | 1 + kernel/bpf/arraymap.c | 41 +++++++++++++++++++++++++++++++++++++++++ kernel/bpf/syscall.c | 3 ++- 3 files changed, 44 insertions(+), 1 deletion(-) diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h index 406459b..ef4e386 100644 --- a/include/uapi/linux/bpf.h +++ b/include/uapi/linux/bpf.h @@ -84,6 +84,7 @@ enum bpf_map_type { BPF_MAP_TYPE_PERCPU_HASH, BPF_MAP_TYPE_PERCPU_ARRAY, BPF_MAP_TYPE_STACK_TRACE, + BPF_MAP_TYPE_CGROUP_ARRAY, }; enum bpf_prog_type { diff --git a/kernel/bpf/arraymap.c b/kernel/bpf/arraymap.c index 5af3073..5e279ec 100644 --- a/kernel/bpf/arraymap.c +++ b/kernel/bpf/arraymap.c @@ -539,3 +539,44 @@ static int __init register_perf_event_array_map(void) return 0; } late_initcall(register_perf_event_array_map); + +static void *cgroup_fd_array_get_ptr(struct bpf_map *map, + struct file *map_file /* not used */, + int fd) +{ + return cgroup_get_from_fd(fd); +} + +static void cgroup_fd_array_put_ptr(void *ptr) +{ + /* cgroup_put free cgrp after a rcu grace period */ + cgroup_put(ptr); +} + +static void cgroup_fd_array_free(struct bpf_map *map) +{ + bpf_fd_array_map_clear(map); + fd_array_map_free(map); +} + +static const struct bpf_map_ops cgroup_array_ops = { + .map_alloc = fd_array_map_alloc, + .map_free = cgroup_fd_array_free, + .map_get_next_key = array_map_get_next_key, + .map_lookup_elem = fd_array_map_lookup_elem, + .map_delete_elem = fd_array_map_delete_elem, + .map_fd_get_ptr = cgroup_fd_array_get_ptr, + .map_fd_put_ptr = cgroup_fd_array_put_ptr, +}; + +static struct bpf_map_type_list cgroup_array_type __read_mostly = { + .ops = &cgroup_array_ops, + .type = BPF_MAP_TYPE_CGROUP_ARRAY, +}; + +static int __init register_cgroup_array_map(void) +{ + bpf_register_map_type(&cgroup_array_type); + return 0; +} +late_initcall(register_cgroup_array_map); diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c index c23a4e93..cac13f1 100644 --- a/kernel/bpf/syscall.c +++ b/kernel/bpf/syscall.c @@ -393,7 +393,8 @@ static int map_update_elem(union bpf_attr *attr) } else if (map->map_type == BPF_MAP_TYPE_PERCPU_ARRAY) { err = bpf_percpu_array_update(map, key, value, attr->flags); } else if (map->map_type == BPF_MAP_TYPE_PERF_EVENT_ARRAY || - map->map_type == BPF_MAP_TYPE_PROG_ARRAY) { + map->map_type == BPF_MAP_TYPE_PROG_ARRAY || + map->map_type == BPF_MAP_TYPE_CGROUP_ARRAY) { rcu_read_lock(); err = bpf_fd_array_map_update_elem(map, f.file, key, value, attr->flags); -- 2.5.1