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-rw-r--r--kernel/bpf/core.c71
1 files changed, 70 insertions, 1 deletions
diff --git a/kernel/bpf/core.c b/kernel/bpf/core.c
index 917cc04a0a94..c6be15ae83ee 100644
--- a/kernel/bpf/core.c
+++ b/kernel/bpf/core.c
@@ -1022,7 +1022,7 @@ select_insn:
struct bpf_map *map = (struct bpf_map *) (unsigned long) BPF_R2;
struct bpf_array *array = container_of(map, struct bpf_array, map);
struct bpf_prog *prog;
- u64 index = BPF_R3;
+ u32 index = BPF_R3;
if (unlikely(index >= array->map.max_entries))
goto out;
@@ -1381,6 +1381,75 @@ struct bpf_prog *bpf_prog_select_runtime(struct bpf_prog *fp, int *err)
}
EXPORT_SYMBOL_GPL(bpf_prog_select_runtime);
+/* to avoid allocating empty bpf_prog_array for cgroups that
+ * don't have bpf program attached use one global 'empty_prog_array'
+ * It will not be modified the caller of bpf_prog_array_alloc()
+ * (since caller requested prog_cnt == 0)
+ * that pointer should be 'freed' by bpf_prog_array_free()
+ */
+static struct {
+ struct bpf_prog_array hdr;
+ struct bpf_prog *null_prog;
+} empty_prog_array = {
+ .null_prog = NULL,
+};
+
+struct bpf_prog_array __rcu *bpf_prog_array_alloc(u32 prog_cnt, gfp_t flags)
+{
+ if (prog_cnt)
+ return kzalloc(sizeof(struct bpf_prog_array) +
+ sizeof(struct bpf_prog *) * (prog_cnt + 1),
+ flags);
+
+ return &empty_prog_array.hdr;
+}
+
+void bpf_prog_array_free(struct bpf_prog_array __rcu *progs)
+{
+ if (!progs ||
+ progs == (struct bpf_prog_array __rcu *)&empty_prog_array.hdr)
+ return;
+ kfree_rcu(progs, rcu);
+}
+
+int bpf_prog_array_length(struct bpf_prog_array __rcu *progs)
+{
+ struct bpf_prog **prog;
+ u32 cnt = 0;
+
+ rcu_read_lock();
+ prog = rcu_dereference(progs)->progs;
+ for (; *prog; prog++)
+ cnt++;
+ rcu_read_unlock();
+ return cnt;
+}
+
+int bpf_prog_array_copy_to_user(struct bpf_prog_array __rcu *progs,
+ __u32 __user *prog_ids, u32 cnt)
+{
+ struct bpf_prog **prog;
+ u32 i = 0, id;
+
+ rcu_read_lock();
+ prog = rcu_dereference(progs)->progs;
+ for (; *prog; prog++) {
+ id = (*prog)->aux->id;
+ if (copy_to_user(prog_ids + i, &id, sizeof(id))) {
+ rcu_read_unlock();
+ return -EFAULT;
+ }
+ if (++i == cnt) {
+ prog++;
+ break;
+ }
+ }
+ rcu_read_unlock();
+ if (*prog)
+ return -ENOSPC;
+ return 0;
+}
+
static void bpf_prog_free_deferred(struct work_struct *work)
{
struct bpf_prog_aux *aux;