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 Content-Type: text/plain Cc: Alexei Starovoitov , Daniel Borkmann , Tejun Heo , To: , , Return-path: Received: from mx0b-00082601.pphosted.com ([67.231.153.30]:58315 "EHLO mx0a-00082601.pphosted.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1751880AbcFVAXf (ORCPT ); Tue, 21 Jun 2016 20:23:35 -0400 Received: from pps.filterd (m0001255.ppops.net [127.0.0.1]) by mx0b-00082601.pphosted.com (8.16.0.11/8.16.0.11) with SMTP id u5M0IobI011316 for ; Tue, 21 Jun 2016 17:23:34 -0700 Received: from mail.thefacebook.com ([199.201.64.23]) by mx0b-00082601.pphosted.com with ESMTP id 23qb3ja3f6-2 (version=TLSv1 cipher=ECDHE-RSA-AES256-SHA bits=256 verify=NOT) for ; Tue, 21 Jun 2016 17:23:34 -0700 Received: from facebook.com (2401:db00:11:d0a6:face:0:33:0) by mx-out.facebook.com (10.212.232.59) with ESMTP id 8d125676380f11e6b75d0002c991e86a-a64f3af0 for ; Tue, 21 Jun 2016 17:23:32 -0700 In-Reply-To: <1466555002-1316296-1-git-send-email-kafai@fb.com> Sender: netdev-owner@vger.kernel.org List-ID: 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