1 files changed, 71 insertions, 0 deletions
diff --git a/tools/testing/selftests/bpf/progs/test_ringbuf_map_key.c b/tools/testing/selftests/bpf/progs/test_ringbuf_map_key.c
new file mode 100644
index 000000000000..21bb7da90ea5
--- /dev/null
+++ b/tools/testing/selftests/bpf/progs/test_ringbuf_map_key.c
@@ -0,0 +1,71 @@
+// SPDX-License-Identifier: GPL-2.0
+/* Copyright (c) 2022 Meta Platforms, Inc. and affiliates. */
+
+#include <linux/bpf.h>
+#include <bpf/bpf_helpers.h>
+#include "bpf_misc.h"
+
+char _license[] SEC("license") = "GPL";
+
+struct sample {
+	int pid;
+	int seq;
+	long value;
+	char comm[16];
+};
+
+struct {
+	__uint(type, BPF_MAP_TYPE_RINGBUF);
+} ringbuf SEC(".maps");
+
+struct {
+	__uint(type, BPF_MAP_TYPE_HASH);
+	__uint(max_entries, 1000);
+	__type(key, struct sample);
+	__type(value, int);
+} hash_map SEC(".maps");
+
+/* inputs */
+int pid = 0;
+
+/* inner state */
+long seq = 0;
+
+SEC("fentry/" SYS_PREFIX "sys_getpgid")
+int test_ringbuf_mem_map_key(void *ctx)
+{
+	int cur_pid = bpf_get_current_pid_tgid() >> 32;
+	struct sample *sample, sample_copy;
+	int *lookup_val;
+
+	if (cur_pid != pid)
+		return 0;
+
+	sample = bpf_ringbuf_reserve(&ringbuf, sizeof(*sample), 0);
+	if (!sample)
+		return 0;
+
+	sample->pid = pid;
+	bpf_get_current_comm(sample->comm, sizeof(sample->comm));
+	sample->seq = ++seq;
+	sample->value = 42;
+
+	/* test using 'sample' (PTR_TO_MEM | MEM_ALLOC) as map key arg
+	 */
+	lookup_val = (int *)bpf_map_lookup_elem(&hash_map, sample);
+	__sink(lookup_val);
+
+	/* workaround - memcpy is necessary so that verifier doesn't
+	 * complain with:
+	 *   verifier internal error: more than one arg with ref_obj_id R3
+	 * when trying to do bpf_map_update_elem(&hash_map, sample, &sample->seq, BPF_ANY);
+	 *
+	 * Since bpf_map_lookup_elem above uses 'sample' as key, test using
+	 * sample field as value below
+	 */
+	__builtin_memcpy(&sample_copy, sample, sizeof(struct sample));
+	bpf_map_update_elem(&hash_map, &sample_copy, &sample->seq, BPF_ANY);
+
+	bpf_ringbuf_submit(sample, 0);
+	return 0;
+}