--- /dev/null
+// SPDX-License-Identifier: GPL-2.0
+
+#include <linux/bpf.h>
+#include "bpf_helpers.h"
+
+/* Permit pretty deep stack traces */
+#define MAX_STACK_RAWTP 100
+struct 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];
+};
+
+struct bpf_map_def SEC("maps") perfmap = {
+ .type = BPF_MAP_TYPE_PERF_EVENT_ARRAY,
+ .key_size = sizeof(int),
+ .value_size = sizeof(__u32),
+ .max_entries = 2,
+};
+
+struct bpf_map_def SEC("maps") stackdata_map = {
+ .type = BPF_MAP_TYPE_PERCPU_ARRAY,
+ .key_size = sizeof(__u32),
+ .value_size = sizeof(struct stack_trace_t),
+ .max_entries = 1,
+};
+
+/* Allocate per-cpu space twice the needed. For the code below
+ * usize = bpf_get_stack(ctx, raw_data, max_len, BPF_F_USER_STACK);
+ * if (usize < 0)
+ * return 0;
+ * ksize = bpf_get_stack(ctx, raw_data + usize, max_len - usize, 0);
+ *
+ * If we have value_size = MAX_STACK_RAWTP * sizeof(__u64),
+ * verifier will complain that access "raw_data + usize"
+ * with size "max_len - usize" may be out of bound.
+ * The maximum "raw_data + usize" is "raw_data + max_len"
+ * and the maximum "max_len - usize" is "max_len", verifier
+ * concludes that the maximum buffer access range is
+ * "raw_data[0...max_len * 2 - 1]" and hence reject the program.
+ *
+ * Doubling the to-be-used max buffer size can fix this verifier
+ * issue and avoid complicated C programming massaging.
+ * This is an acceptable workaround since there is one entry here.
+ */
+struct bpf_map_def SEC("maps") rawdata_map = {
+ .type = BPF_MAP_TYPE_PERCPU_ARRAY,
+ .key_size = sizeof(__u32),
+ .value_size = MAX_STACK_RAWTP * sizeof(__u64) * 2,
+ .max_entries = 1,
+};
+
+SEC("tracepoint/raw_syscalls/sys_enter")
+int bpf_prog1(void *ctx)
+{
+ int max_len, max_buildid_len, usize, ksize, total_size;
+ struct stack_trace_t *data;
+ void *raw_data;
+ __u32 key = 0;
+
+ data = bpf_map_lookup_elem(&stackdata_map, &key);
+ if (!data)
+ return 0;
+
+ max_len = MAX_STACK_RAWTP * sizeof(__u64);
+ max_buildid_len = MAX_STACK_RAWTP * sizeof(struct bpf_stack_build_id);
+ data->pid = bpf_get_current_pid_tgid();
+ data->kern_stack_size = bpf_get_stack(ctx, data->kern_stack,
+ max_len, 0);
+ data->user_stack_size = bpf_get_stack(ctx, data->user_stack, max_len,
+ BPF_F_USER_STACK);
+ data->user_stack_buildid_size = bpf_get_stack(
+ ctx, data->user_stack_buildid, max_buildid_len,
+ BPF_F_USER_STACK | BPF_F_USER_BUILD_ID);
+ bpf_perf_event_output(ctx, &perfmap, 0, data, sizeof(*data));
+
+ /* write both kernel and user stacks to the same buffer */
+ raw_data = bpf_map_lookup_elem(&rawdata_map, &key);
+ if (!raw_data)
+ return 0;
+
+ usize = bpf_get_stack(ctx, raw_data, max_len, BPF_F_USER_STACK);
+ if (usize < 0)
+ return 0;
+
+ ksize = bpf_get_stack(ctx, raw_data + usize, max_len - usize, 0);
+ if (ksize < 0)
+ return 0;
+
+ total_size = usize + ksize;
+ if (total_size > 0 && total_size <= max_len)
+ bpf_perf_event_output(ctx, &perfmap, 0, raw_data, total_size);
+
+ return 0;
+}
+
+char _license[] SEC("license") = "GPL";
+__u32 _version SEC("version") = 1; /* ignored by tracepoints, required by libbpf.a */
#include "bpf_util.h"
#include "bpf_endian.h"
#include "bpf_rlimit.h"
+#include "trace_helpers.h"
static int error_cnt, pass_cnt;
+static bool jit_enabled;
#define MAGIC_BYTES 123
return (__u64) (unsigned long) ptr;
}
+static bool is_jit_enabled(void)
+{
+ const char *jit_sysctl = "/proc/sys/net/core/bpf_jit_enable";
+ bool enabled = false;
+ int sysctl_fd;
+
+ sysctl_fd = open(jit_sysctl, 0, O_RDONLY);
+ if (sysctl_fd != -1) {
+ char tmpc;
+
+ if (read(sysctl_fd, &tmpc, sizeof(tmpc)) == 1)
+ enabled = (tmpc != '0');
+ close(sysctl_fd);
+ }
+
+ return enabled;
+}
+
static void test_bpf_obj_id(void)
{
const __u64 array_magic_value = 0xfaceb00c;
const __u32 array_key = 0;
const int nr_iters = 2;
const char *file = "./test_obj_id.o";
- const char *jit_sysctl = "/proc/sys/net/core/bpf_jit_enable";
const char *expected_prog_name = "test_obj_id";
const char *expected_map_name = "test_map_id";
const __u64 nsec_per_sec = 1000000000;
char jited_insns[128], xlated_insns[128], zeros[128];
__u32 i, next_id, info_len, nr_id_found, duration = 0;
struct timespec real_time_ts, boot_time_ts;
- int sysctl_fd, jit_enabled = 0, err = 0;
+ int err = 0;
__u64 array_value;
uid_t my_uid = getuid();
time_t now, load_time;
- sysctl_fd = open(jit_sysctl, 0, O_RDONLY);
- if (sysctl_fd != -1) {
- char tmpc;
-
- if (read(sysctl_fd, &tmpc, sizeof(tmpc)) == 1)
- jit_enabled = (tmpc != '0');
- close(sysctl_fd);
- }
-
err = bpf_prog_get_fd_by_id(0);
CHECK(err >= 0 || errno != ENOENT,
"get-fd-by-notexist-prog-id", "err %d errno %d\n", err, errno);
return;
}
+#define MAX_CNT_RAWTP 10ull
+#define MAX_STACK_RAWTP 100
+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 int get_stack_print_output(void *data, int size)
+{
+ bool good_kern_stack = false, good_user_stack = false;
+ const char *nonjit_func = "___bpf_prog_run";
+ struct get_stack_trace_t *e = data;
+ int i, num_stack;
+ static __u64 cnt;
+ struct ksym *ks;
+
+ cnt++;
+
+ 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 (jit_enabled) {
+ found = num_stack > 0;
+ } else {
+ for (i = 0; i < num_stack; i++) {
+ ks = ksym_search(raw_data[i]);
+ if (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 (jit_enabled) {
+ good_kern_stack = num_stack > 0;
+ } else {
+ for (i = 0; i < num_stack; i++) {
+ ks = ksym_search(e->kern_stack[i]);
+ if (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 || !good_user_stack)
+ return PERF_EVENT_ERROR;
+
+ if (cnt == MAX_CNT_RAWTP)
+ return PERF_EVENT_DONE;
+
+ return PERF_EVENT_CONT;
+}
+
+static void test_get_stack_raw_tp(void)
+{
+ const char *file = "./test_get_stack_rawtp.o";
+ int i, efd, err, prog_fd, pmu_fd, perfmap_fd;
+ struct perf_event_attr attr = {};
+ struct timespec tv = {0, 10};
+ __u32 key = 0, duration = 0;
+ struct bpf_object *obj;
+
+ err = bpf_prog_load(file, BPF_PROG_TYPE_RAW_TRACEPOINT, &obj, &prog_fd);
+ if (CHECK(err, "prog_load raw tp", "err %d errno %d\n", err, errno))
+ return;
+
+ efd = bpf_raw_tracepoint_open("sys_enter", prog_fd);
+ if (CHECK(efd < 0, "raw_tp_open", "err %d errno %d\n", efd, errno))
+ goto close_prog;
+
+ perfmap_fd = bpf_find_map(__func__, obj, "perfmap");
+ if (CHECK(perfmap_fd < 0, "bpf_find_map", "err %d errno %d\n",
+ perfmap_fd, errno))
+ goto close_prog;
+
+ err = load_kallsyms();
+ if (CHECK(err < 0, "load_kallsyms", "err %d errno %d\n", err, errno))
+ goto close_prog;
+
+ attr.sample_type = PERF_SAMPLE_RAW;
+ attr.type = PERF_TYPE_SOFTWARE;
+ attr.config = PERF_COUNT_SW_BPF_OUTPUT;
+ pmu_fd = syscall(__NR_perf_event_open, &attr, getpid()/*pid*/, -1/*cpu*/,
+ -1/*group_fd*/, 0);
+ if (CHECK(pmu_fd < 0, "perf_event_open", "err %d errno %d\n", pmu_fd,
+ errno))
+ goto close_prog;
+
+ err = bpf_map_update_elem(perfmap_fd, &key, &pmu_fd, BPF_ANY);
+ if (CHECK(err < 0, "bpf_map_update_elem", "err %d errno %d\n", err,
+ errno))
+ goto close_prog;
+
+ err = ioctl(pmu_fd, PERF_EVENT_IOC_ENABLE, 0);
+ if (CHECK(err < 0, "ioctl PERF_EVENT_IOC_ENABLE", "err %d errno %d\n",
+ err, errno))
+ goto close_prog;
+
+ err = perf_event_mmap(pmu_fd);
+ if (CHECK(err < 0, "perf_event_mmap", "err %d errno %d\n", err, errno))
+ goto close_prog;
+
+ /* trigger some syscall action */
+ for (i = 0; i < MAX_CNT_RAWTP; i++)
+ nanosleep(&tv, NULL);
+
+ err = perf_event_poller(pmu_fd, get_stack_print_output);
+ if (CHECK(err < 0, "perf_event_poller", "err %d errno %d\n", err, errno))
+ goto close_prog;
+
+ goto close_prog_noerr;
+close_prog:
+ error_cnt++;
+close_prog_noerr:
+ bpf_object__close(obj);
+}
+
int main(void)
{
+ jit_enabled = is_jit_enabled();
+
test_pkt_access();
test_xdp();
test_xdp_adjust_tail();
test_stacktrace_map();
test_stacktrace_build_id();
test_stacktrace_map_raw_tp();
+ test_get_stack_raw_tp();
printf("Summary: %d PASSED, %d FAILED\n", pass_cnt, error_cnt);
return error_cnt ? EXIT_FAILURE : EXIT_SUCCESS;
projects / openwrt / staging / blogic.git / commitdiff