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

Source file repositories/reference/linux-study-clean/tools/testing/selftests/bpf/prog_tests/get_stack_raw_tp.c

File Facts

System
Linux kernel
Corpus path
tools/testing/selftests/bpf/prog_tests/get_stack_raw_tp.c
Extension
.c
Size
4171 bytes
Lines
150
Domain
Support Tooling And Documentation
Bucket
tools
Inferred role
Support Tooling And Documentation: implementation source
Status
source implementation candidate

Why This File Exists

Repository support layer: documentation, build tooling, samples, user-space helper tools, generated initramfs support, licenses, and validation utilities.

Dependency Surface

Detected Declarations

Annotated Snippet

struct get_stack_trace_t {
	int pid;
	int kern_stack_size;
	int user_stack_size;
	int user_stack_buildid_size;
	__u64 kern_stack[MAX_STACK_RAWTP];
	__u64 user_stack[MAX_STACK_RAWTP];
	struct bpf_stack_build_id user_stack_buildid[MAX_STACK_RAWTP];
};

static void get_stack_print_output(void *ctx, int cpu, void *data, __u32 size)
{
	bool good_kern_stack = false, good_user_stack = false;
	const char *nonjit_func = "___bpf_prog_run";
	/* perfbuf-submitted data is 4-byte aligned, but we need 8-byte
	 * alignment, so copy data into a local variable, for simplicity
	 */
	struct get_stack_trace_t e;
	int i, num_stack;
	struct ksym *ks;

	memset(&e, 0, sizeof(e));
	memcpy(&e, data, size <= sizeof(e) ? size : sizeof(e));

	if (size < sizeof(struct get_stack_trace_t)) {
		__u64 *raw_data = data;
		bool found = false;

		num_stack = size / sizeof(__u64);
		/* If jit is enabled, we do not have a good way to
		 * verify the sanity of the kernel stack. So we
		 * just assume it is good if the stack is not empty.
		 * This could be improved in the future.
		 */
		if (env.jit_enabled) {
			found = num_stack > 0;
		} else {
			for (i = 0; i < num_stack; i++) {
				ks = ksym_search(raw_data[i]);
				if (ks && (strcmp(ks->name, nonjit_func) == 0)) {
					found = true;
					break;
				}
			}
		}
		if (found) {
			good_kern_stack = true;
			good_user_stack = true;
		}
	} else {
		num_stack = e.kern_stack_size / sizeof(__u64);
		if (env.jit_enabled) {
			good_kern_stack = num_stack > 0;
		} else {
			for (i = 0; i < num_stack; i++) {
				ks = ksym_search(e.kern_stack[i]);
				if (ks && (strcmp(ks->name, nonjit_func) == 0)) {
					good_kern_stack = true;
					break;
				}
			}
		}
		if (e.user_stack_size > 0 && e.user_stack_buildid_size > 0)
			good_user_stack = true;
	}

	if (!good_kern_stack)
	    CHECK(!good_kern_stack, "kern_stack", "corrupted kernel stack\n");
	if (!good_user_stack)
	    CHECK(!good_user_stack, "user_stack", "corrupted user stack\n");
}

void test_get_stack_raw_tp(void)
{
	const char *file = "./test_get_stack_rawtp.bpf.o";
	const char *file_err = "./test_get_stack_rawtp_err.bpf.o";
	const char *prog_name = "bpf_prog1";
	int i, err, prog_fd, exp_cnt = MAX_CNT_RAWTP;
	struct perf_buffer *pb = NULL;
	struct bpf_link *link = NULL;
	struct timespec tv = {0, 10};
	struct bpf_program *prog;
	struct bpf_object *obj;
	struct bpf_map *map;
	cpu_set_t cpu_set;

	err = bpf_prog_test_load(file_err, BPF_PROG_TYPE_RAW_TRACEPOINT, &obj, &prog_fd);
	if (CHECK(err >= 0, "prog_load raw tp", "err %d errno %d\n", err, errno))
		return;

Annotation

Implementation Notes