1 files changed, 123 insertions, 0 deletions
diff --git a/tools/testing/selftests/bpf/progs/bpf_iter_bpf_hash_map.c b/tools/testing/selftests/bpf/progs/bpf_iter_bpf_hash_map.c
new file mode 100644
index 000000000000..d7a69217fb68
--- /dev/null
+++ b/tools/testing/selftests/bpf/progs/bpf_iter_bpf_hash_map.c
@@ -0,0 +1,123 @@
+// SPDX-License-Identifier: GPL-2.0
+/* Copyright (c) 2020 Facebook */
+#include "bpf_iter.h"
+#include <bpf/bpf_helpers.h>
+
+char _license[] SEC("license") = "GPL";
+
+struct key_t {
+	int a;
+	int b;
+	int c;
+};
+
+struct {
+	__uint(type, BPF_MAP_TYPE_HASH);
+	__uint(max_entries, 3);
+	__type(key, struct key_t);
+	__type(value, __u64);
+} hashmap1 SEC(".maps");
+
+struct {
+	__uint(type, BPF_MAP_TYPE_HASH);
+	__uint(max_entries, 3);
+	__type(key, __u64);
+	__type(value, __u64);
+} hashmap2 SEC(".maps");
+
+struct {
+	__uint(type, BPF_MAP_TYPE_HASH);
+	__uint(max_entries, 3);
+	__type(key, struct key_t);
+	__type(value, __u32);
+} hashmap3 SEC(".maps");
+
+/* will set before prog run */
+bool in_test_mode = 0;
+
+/* will collect results during prog run */
+__u32 key_sum_a = 0, key_sum_b = 0, key_sum_c = 0;
+__u64 val_sum = 0;
+
+SEC("iter/bpf_map_elem")
+int dump_bpf_hash_map(struct bpf_iter__bpf_map_elem *ctx)
+{
+	struct seq_file *seq = ctx->meta->seq;
+	__u32 seq_num = ctx->meta->seq_num;
+	struct bpf_map *map = ctx->map;
+	struct key_t *key = ctx->key;
+	struct key_t tmp_key;
+	__u64 *val = ctx->value;
+	__u64 tmp_val = 0;
+	int ret;
+
+	if (in_test_mode) {
+		/* test mode is used by selftests to
+		 * test functionality of bpf_hash_map iter.
+		 *
+		 * the above hashmap1 will have correct size
+		 * and will be accepted, hashmap2 and hashmap3
+		 * should be rejected due to smaller key/value
+		 * size.
+		 */
+		if (key == (void *)0 || val == (void *)0)
+			return 0;
+
+		/* update the value and then delete the <key, value> pair.
+		 * it should not impact the existing 'val' which is still
+		 * accessible under rcu.
+		 */
+		__builtin_memcpy(&tmp_key, key, sizeof(struct key_t));
+		ret = bpf_map_update_elem(&hashmap1, &tmp_key, &tmp_val, 0);
+		if (ret)
+			return 0;
+		ret = bpf_map_delete_elem(&hashmap1, &tmp_key);
+		if (ret)
+			return 0;
+
+		key_sum_a += key->a;
+		key_sum_b += key->b;
+		key_sum_c += key->c;
+		val_sum += *val;
+		return 0;
+	}
+
+	/* non-test mode, the map is prepared with the
+	 * below bpftool command sequence:
+	 *   bpftool map create /sys/fs/bpf/m1 type hash \
+	 *   	key 12 value 8 entries 3 name map1
+	 *   bpftool map update id 77 key 0 0 0 1 0 0 0 0 0 0 0 1 \
+	 *   	value 0 0 0 1 0 0 0 1
+	 *   bpftool map update id 77 key 0 0 0 1 0 0 0 0 0 0 0 2 \
+	 *   	value 0 0 0 1 0 0 0 2
+	 * The bpftool iter command line:
+	 *   bpftool iter pin ./bpf_iter_bpf_hash_map.o /sys/fs/bpf/p1 \
+	 *   	map id 77
+	 * The below output will be:
+	 *   map dump starts
+	 *   77: (1000000 0 2000000) (200000001000000)
+	 *   77: (1000000 0 1000000) (100000001000000)
+	 *   map dump ends
+	 */
+	if (seq_num == 0)
+		BPF_SEQ_PRINTF(seq, "map dump starts\n");
+
+	if (key == (void *)0 || val == (void *)0) {
+		BPF_SEQ_PRINTF(seq, "map dump ends\n");
+		return 0;
+	}
+
+	BPF_SEQ_PRINTF(seq, "%d: (%x %d %x) (%llx)\n", map->id,
+		       key->a, key->b, key->c, *val);
+
+	return 0;
+}
+
+SEC("iter.s/bpf_map_elem")
+int sleepable_dummy_dump(struct bpf_iter__bpf_map_elem *ctx)
+{
+	if (ctx->meta->seq_num == 0)
+		BPF_SEQ_PRINTF(ctx->meta->seq, "map dump starts\n");
+
+	return 0;
+}