selftests/bpf: Add arena direct-value one-past-end reject test

tools/testing/selftests/bpf/prog_tests/arena_direct_value.c

@@ -0,0 +1,73 @@
+// SPDX-License-Identifier: GPL-2.0
+
+#include <test_progs.h>
+#include <bpf/bpf.h>
+#include <errno.h>
+#include <sys/mman.h>
+#include <unistd.h>
+
+#define ARENA_PAGES 32
+
+static void test_arena_direct_value_one_past_end(void)
+{
+	char log_buf[16384] = {}, expected[128];
+	__u32 arena_sz = ARENA_PAGES * getpagesize();
+	struct bpf_insn insns[] = {
+		BPF_LD_IMM64_RAW(BPF_REG_1, BPF_PSEUDO_MAP_VALUE, 0),
+		BPF_MOV64_IMM(BPF_REG_0, 0),
+		BPF_EXIT_INSN(),
+	};
+	LIBBPF_OPTS(bpf_map_create_opts, map_opts);
+	LIBBPF_OPTS(bpf_prog_load_opts, prog_opts);
+	void *arena = MAP_FAILED;
+	int map_fd, prog_fd;
+
+	map_opts.map_flags = BPF_F_MMAPABLE;
+	prog_opts.log_buf = log_buf;
+	prog_opts.log_size = sizeof(log_buf);
+	prog_opts.log_level = 1;
+
+	map_fd = bpf_map_create(BPF_MAP_TYPE_ARENA, "arena_direct_value",
+				0, 0, ARENA_PAGES, &map_opts);
+	if (map_fd < 0) {
+		if (errno == EOPNOTSUPP || errno == EINVAL) {
+			test__skip();
+			return;
+		}
+		ASSERT_GE(map_fd, 0, "bpf_map_create");
+		return;
+	}
+
+	arena = mmap(NULL, arena_sz, PROT_READ | PROT_WRITE, MAP_SHARED, map_fd, 0);
+	if (!ASSERT_NEQ(arena, MAP_FAILED, "arena_mmap"))
+		goto cleanup;
+
+	insns[0].imm = map_fd;
+	insns[1].imm = arena_sz;
+
+	prog_fd = bpf_prog_load(BPF_PROG_TYPE_RAW_TRACEPOINT,
+				"arena_direct_value", "GPL", insns,
+				ARRAY_SIZE(insns), &prog_opts);
+	if (!ASSERT_LT(prog_fd, 0, "prog_load")) {
+		if (prog_fd >= 0)
+			close(prog_fd);
+		prog_fd = -1;
+		goto cleanup;
+	}
+
+	snprintf(expected, sizeof(expected),
+		 "invalid access to map value pointer, value_size=0 off=%u",
+		 arena_sz);
+	ASSERT_HAS_SUBSTR(log_buf, expected, "verifier_log");
+
+cleanup:
+	if (arena != MAP_FAILED)
+		munmap(arena, arena_sz);
+	close(map_fd);
+}
+
+void test_arena_direct_value(void)
+{
+	if (test__start_subtest("one_past_end"))
+		test_arena_direct_value_one_past_end();
+}