Check that verifier rejects BPF program containing relocation
pointing to non-existent BTF type.
To force relocation resolution on kernel side test case uses
bpf_attr->core_relos field. This field is not exposed by libbpf,
so directly do BPF system call in the test.
Signed-off-by: Eduard Zingerman <eddyz87@xxxxxxxxx>
---
.../selftests/bpf/prog_tests/core_reloc_raw.c | 125 ++++++++++++++++++
1 file changed, 125 insertions(+)
create mode 100644 tools/testing/selftests/bpf/prog_tests/core_reloc_raw.c
diff --git a/tools/testing/selftests/bpf/prog_tests/core_reloc_raw.c b/tools/testing/selftests/bpf/prog_tests/core_reloc_raw.c
new file mode 100644
index 000000000000..a18d3680fb16
--- /dev/null
+++ b/tools/testing/selftests/bpf/prog_tests/core_reloc_raw.c
@@ -0,0 +1,125 @@
+// SPDX-License-Identifier: GPL-2.0
+
+/* Test cases that can't load programs using libbpf and need direct
+ * BPF syscall access
+ */
+
+#include <sys/syscall.h>
+#include <bpf/libbpf.h>
+#include <bpf/btf.h>
+
+#include "test_progs.h"
+#include "test_btf.h"
+#include "bpf/libbpf_internal.h"
+
+static char log[16 * 1024];
+
+/* Check that verifier rejects BPF program containing relocation
+ * pointing to non-existent BTF type.
+ */
+static void test_bad_local_id(void)
+{
+ struct test_btf {
+ struct btf_header hdr;
+ __u32 types[15];
+ char strings[128];
+ } raw_btf = {
+ .hdr = {
+ .magic = BTF_MAGIC,
+ .version = BTF_VERSION,
+ .hdr_len = sizeof(struct btf_header),
+ .type_off = 0,
+ .type_len = sizeof(raw_btf.types),
+ .str_off = offsetof(struct test_btf, strings) -
+ offsetof(struct test_btf, types),
+ .str_len = sizeof(raw_btf.strings),
+ },
+ .types = {
+ BTF_PTR_ENC(0), /* [1] void* */
+ BTF_TYPE_INT_ENC(1, BTF_INT_SIGNED, 0, 32, 4), /* [2] int */
+ BTF_FUNC_PROTO_ENC(2, 1), /* [3] int (*)(void*) */
+ BTF_FUNC_PROTO_ARG_ENC(8, 1),
+ BTF_FUNC_ENC(8, 3) /* [4] FUNC 'foo' type_id=2 */
+ },
+ .strings = "\0int\0 0\0foo\0"
+ };
+ __u32 log_level = 1 | 2 | 4;
+ LIBBPF_OPTS(bpf_btf_load_opts, opts,
+ .log_buf = log,
+ .log_size = sizeof(log),
+ .log_level = log_level,
+ );
+ struct bpf_insn insns[] = {
+ BPF_ALU64_IMM(BPF_MOV, BPF_REG_0, 0),
+ BPF_EXIT_INSN(),
+ };
+ struct bpf_func_info funcs[] = {
+ {
+ .insn_off = 0,
+ .type_id = 4,
+ }
+ };
+ struct bpf_core_relo relos[] = {
+ {
+ .insn_off = 0, /* patch first instruction (r0 = 0) */
+ .type_id = 100500, /* !!! this type id does not exist */
+ .access_str_off = 6, /* offset of "0" */
+ .kind = BPF_CORE_TYPE_ID_LOCAL,
+ }
+ };
+ union bpf_attr attr;
+ int saved_errno;
+ int prog_fd = -1;
+ int btf_fd = -1;
+
+ btf_fd = bpf_btf_load(&raw_btf, sizeof(raw_btf), &opts);
+ saved_errno = errno;
+ if (btf_fd < 0 || env.verbosity > VERBOSE_NORMAL) {
+ printf("-------- BTF load log start --------\n");
+ printf("%s", log);
+ printf("-------- BTF load log end ----------\n");
+ }
+ if (btf_fd < 0) {
+ PRINT_FAIL("bpf_btf_load() failed, errno=%d\n", saved_errno);
+ return;
+ }
+
+ log[0] = 0;
+ memset(&attr, 0, sizeof(attr));
+ attr.prog_btf_fd = btf_fd;
+ attr.prog_type = BPF_TRACE_RAW_TP;
+ attr.license = (__u64)"GPL";
+ attr.insns = (__u64)&insns;
+ attr.insn_cnt = sizeof(insns) / sizeof(*insns);
+ attr.log_buf = (__u64)log;
+ attr.log_size = sizeof(log);
+ attr.log_level = log_level;
+ attr.func_info = (__u64)funcs;
+ attr.func_info_cnt = sizeof(funcs) / sizeof(*funcs);
+ attr.func_info_rec_size = sizeof(*funcs);
+ attr.core_relos = (__u64)relos;
+ attr.core_relo_cnt = sizeof(relos) / sizeof(*relos);
+ attr.core_relo_rec_size = sizeof(*relos);
+ prog_fd = sys_bpf_prog_load(&attr, sizeof(attr), 1);
+ saved_errno = errno;
+ if (prog_fd < 0 || env.verbosity > VERBOSE_NORMAL) {
+ printf("-------- program load log start --------\n");
+ printf("%s", log);
+ printf("-------- program load log end ----------\n");
+ }
+ if (prog_fd >= 0) {
+ PRINT_FAIL("sys_bpf_prog_load() expected to fail\n");
+ goto out;
+ }
+ ASSERT_HAS_SUBSTR(log, "relo #0: bad type id 100500", "program load log");
+
+out:
+ close(prog_fd);
+ close(btf_fd);
+}
+
+void test_core_reloc_raw(void)
+{
+ if (test__start_subtest("bad_local_id"))
+ test_bad_local_id();
+}
--
2.45.2
