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authorAndré Fabian Silva Delgado <emulatorman@parabola.nu>2015-09-08 01:01:14 -0300
committerAndré Fabian Silva Delgado <emulatorman@parabola.nu>2015-09-08 01:01:14 -0300
commite5fd91f1ef340da553f7a79da9540c3db711c937 (patch)
treeb11842027dc6641da63f4bcc524f8678263304a3 /kernel/bpf/arraymap.c
parent2a9b0348e685a63d97486f6749622b61e9e3292f (diff)
Linux-libre 4.2-gnu
Diffstat (limited to 'kernel/bpf/arraymap.c')
-rw-r--r--kernel/bpf/arraymap.c113
1 files changed, 107 insertions, 6 deletions
diff --git a/kernel/bpf/arraymap.c b/kernel/bpf/arraymap.c
index 8a6616583..cb31229a6 100644
--- a/kernel/bpf/arraymap.c
+++ b/kernel/bpf/arraymap.c
@@ -14,12 +14,7 @@
#include <linux/vmalloc.h>
#include <linux/slab.h>
#include <linux/mm.h>
-
-struct bpf_array {
- struct bpf_map map;
- u32 elem_size;
- char value[0] __aligned(8);
-};
+#include <linux/filter.h>
/* Called from syscall */
static struct bpf_map *array_map_alloc(union bpf_attr *attr)
@@ -154,3 +149,109 @@ static int __init register_array_map(void)
return 0;
}
late_initcall(register_array_map);
+
+static struct bpf_map *prog_array_map_alloc(union bpf_attr *attr)
+{
+ /* only bpf_prog file descriptors can be stored in prog_array map */
+ if (attr->value_size != sizeof(u32))
+ return ERR_PTR(-EINVAL);
+ return array_map_alloc(attr);
+}
+
+static void prog_array_map_free(struct bpf_map *map)
+{
+ struct bpf_array *array = container_of(map, struct bpf_array, map);
+ int i;
+
+ synchronize_rcu();
+
+ /* make sure it's empty */
+ for (i = 0; i < array->map.max_entries; i++)
+ BUG_ON(array->prog[i] != NULL);
+ kvfree(array);
+}
+
+static void *prog_array_map_lookup_elem(struct bpf_map *map, void *key)
+{
+ return NULL;
+}
+
+/* only called from syscall */
+static int prog_array_map_update_elem(struct bpf_map *map, void *key,
+ void *value, u64 map_flags)
+{
+ struct bpf_array *array = container_of(map, struct bpf_array, map);
+ struct bpf_prog *prog, *old_prog;
+ u32 index = *(u32 *)key, ufd;
+
+ if (map_flags != BPF_ANY)
+ return -EINVAL;
+
+ if (index >= array->map.max_entries)
+ return -E2BIG;
+
+ ufd = *(u32 *)value;
+ prog = bpf_prog_get(ufd);
+ if (IS_ERR(prog))
+ return PTR_ERR(prog);
+
+ if (!bpf_prog_array_compatible(array, prog)) {
+ bpf_prog_put(prog);
+ return -EINVAL;
+ }
+
+ old_prog = xchg(array->prog + index, prog);
+ if (old_prog)
+ bpf_prog_put_rcu(old_prog);
+
+ return 0;
+}
+
+static int prog_array_map_delete_elem(struct bpf_map *map, void *key)
+{
+ struct bpf_array *array = container_of(map, struct bpf_array, map);
+ struct bpf_prog *old_prog;
+ u32 index = *(u32 *)key;
+
+ if (index >= array->map.max_entries)
+ return -E2BIG;
+
+ old_prog = xchg(array->prog + index, NULL);
+ if (old_prog) {
+ bpf_prog_put_rcu(old_prog);
+ return 0;
+ } else {
+ return -ENOENT;
+ }
+}
+
+/* decrement refcnt of all bpf_progs that are stored in this map */
+void bpf_prog_array_map_clear(struct bpf_map *map)
+{
+ struct bpf_array *array = container_of(map, struct bpf_array, map);
+ int i;
+
+ for (i = 0; i < array->map.max_entries; i++)
+ prog_array_map_delete_elem(map, &i);
+}
+
+static const struct bpf_map_ops prog_array_ops = {
+ .map_alloc = prog_array_map_alloc,
+ .map_free = prog_array_map_free,
+ .map_get_next_key = array_map_get_next_key,
+ .map_lookup_elem = prog_array_map_lookup_elem,
+ .map_update_elem = prog_array_map_update_elem,
+ .map_delete_elem = prog_array_map_delete_elem,
+};
+
+static struct bpf_map_type_list prog_array_type __read_mostly = {
+ .ops = &prog_array_ops,
+ .type = BPF_MAP_TYPE_PROG_ARRAY,
+};
+
+static int __init register_prog_array_map(void)
+{
+ bpf_register_map_type(&prog_array_type);
+ return 0;
+}
+late_initcall(register_prog_array_map);