bpf/test_run: support cgroup local storage

Allocate a temporary cgroup storage to use for bpf program test runs.

Because the test program is not actually attached to a cgroup,
the storage is allocated manually just for the execution
of the bpf program.

If the program is executed multiple times, the storage is not zeroed
on each run, emulating multiple runs of the program, attached to
a real cgroup.

Signed-off-by: Roman Gushchin <guro@fb.com>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Martin KaFai Lau <kafai@fb.com>

net/bpf/test_run.c

@@ -11,12 +11,14 @@
 #include <linux/filter.h>
 #include <linux/sched/signal.h>
 
-static __always_inline u32 bpf_test_run_one(struct bpf_prog *prog, void *ctx)
+static __always_inline u32 bpf_test_run_one(struct bpf_prog *prog, void *ctx,
+					    struct bpf_cgroup_storage *storage)
 {
 	u32 ret;
 
 	preempt_disable();
 	rcu_read_lock();
+	bpf_cgroup_storage_set(storage);
 	ret = BPF_PROG_RUN(prog, ctx);
 	rcu_read_unlock();
 	preempt_enable();
@@ -26,14 +28,19 @@ static __always_inline u32 bpf_test_run_one(struct bpf_prog *prog, void *ctx)
 
 static u32 bpf_test_run(struct bpf_prog *prog, void *ctx, u32 repeat, u32 *time)
 {
+	struct bpf_cgroup_storage *storage = NULL;
 	u64 time_start, time_spent = 0;
 	u32 ret = 0, i;
 
+	storage = bpf_cgroup_storage_alloc(prog);
+	if (IS_ERR(storage))
+		return PTR_ERR(storage);
+
 	if (!repeat)
 		repeat = 1;
 	time_start = ktime_get_ns();
 	for (i = 0; i < repeat; i++) {
-		ret = bpf_test_run_one(prog, ctx);
+		ret = bpf_test_run_one(prog, ctx, storage);
 		if (need_resched()) {
 			if (signal_pending(current))
 				break;
@@ -46,6 +53,8 @@ static u32 bpf_test_run(struct bpf_prog *prog, void *ctx, u32 repeat, u32 *time)
 	do_div(time_spent, repeat);
 	*time = time_spent > U32_MAX ? U32_MAX : (u32)time_spent;
 
+	bpf_cgroup_storage_free(storage);
+
 	return ret;
 }