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authorMartin KaFai Lau <kafai@fb.com>2016-06-30 17:28:43 (GMT)
committerDavid S. Miller <davem@davemloft.net>2016-07-01 20:30:38 (GMT)
commit4ed8ec521ed57c4e207ad464ca0388776de74d4b (patch)
treef656cf08ee272920b26cad8a91ae8d315242b5cd /kernel
parent1f3fe7ebf6136c341012db9f554d4caa566fcbaa (diff)
downloadlinux-4ed8ec521ed57c4e207ad464ca0388776de74d4b.tar.xz
cgroup: bpf: Add BPF_MAP_TYPE_CGROUP_ARRAY
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 <kafai@fb.com> Cc: Alexei Starovoitov <ast@fb.com> Cc: Daniel Borkmann <daniel@iogearbox.net> Cc: Tejun Heo <tj@kernel.org> Acked-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'kernel')
-rw-r--r--kernel/bpf/arraymap.c43
-rw-r--r--kernel/bpf/syscall.c3
-rw-r--r--kernel/bpf/verifier.c2
3 files changed, 47 insertions, 1 deletions
diff --git a/kernel/bpf/arraymap.c b/kernel/bpf/arraymap.c
index 4ec57a6..db1a743 100644
--- a/kernel/bpf/arraymap.c
+++ b/kernel/bpf/arraymap.c
@@ -537,3 +537,46 @@ static int __init register_perf_event_array_map(void)
return 0;
}
late_initcall(register_perf_event_array_map);
+
+#ifdef CONFIG_SOCK_CGROUP_DATA
+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);
+#endif
diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c
index 22863d9..96d938a 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);
diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c
index eec9f90..69ba225 100644
--- a/kernel/bpf/verifier.c
+++ b/kernel/bpf/verifier.c
@@ -1035,6 +1035,8 @@ static int check_map_func_compatibility(struct bpf_map *map, int func_id)
if (func_id != BPF_FUNC_get_stackid)
goto error;
break;
+ case BPF_MAP_TYPE_CGROUP_ARRAY:
+ goto error;
default:
break;
}