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// SPDX-License-Identifier: GPL-2.0
#include <test_progs.h>
#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 LIBBPF_PERF_EVENT_ERROR;
if (cnt == MAX_CNT_RAWTP)
return LIBBPF_PERF_EVENT_DONE;
return LIBBPF_PERF_EVENT_CONT;
}
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);
}
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