diff options
Diffstat (limited to 'samples/bpf/tracex6_user.c')
| -rw-r--r-- | samples/bpf/tracex6_user.c | 222 |
1 files changed, 222 insertions, 0 deletions
diff --git a/samples/bpf/tracex6_user.c b/samples/bpf/tracex6_user.c new file mode 100644 index 000000000..8e83bf2a8 --- /dev/null +++ b/samples/bpf/tracex6_user.c @@ -0,0 +1,222 @@ +// SPDX-License-Identifier: GPL-2.0 +#define _GNU_SOURCE + +#include <assert.h> +#include <fcntl.h> +#include <linux/perf_event.h> +#include <sched.h> +#include <stdio.h> +#include <stdlib.h> +#include <sys/ioctl.h> +#include <sys/time.h> +#include <sys/types.h> +#include <sys/wait.h> +#include <unistd.h> + +#include <bpf/bpf.h> +#include <bpf/libbpf.h> +#include "perf-sys.h" + +#define SAMPLE_PERIOD 0x7fffffffffffffffULL + +/* counters, values, values2 */ +static int map_fd[3]; + +static void check_on_cpu(int cpu, struct perf_event_attr *attr) +{ + struct bpf_perf_event_value value2; + int pmu_fd, error = 0; + cpu_set_t set; + __u64 value; + + /* Move to target CPU */ + CPU_ZERO(&set); + CPU_SET(cpu, &set); + assert(sched_setaffinity(0, sizeof(set), &set) == 0); + /* Open perf event and attach to the perf_event_array */ + pmu_fd = sys_perf_event_open(attr, -1/*pid*/, cpu/*cpu*/, -1/*group_fd*/, 0); + if (pmu_fd < 0) { + fprintf(stderr, "sys_perf_event_open failed on CPU %d\n", cpu); + error = 1; + goto on_exit; + } + assert(bpf_map_update_elem(map_fd[0], &cpu, &pmu_fd, BPF_ANY) == 0); + assert(ioctl(pmu_fd, PERF_EVENT_IOC_ENABLE, 0) == 0); + /* Trigger the kprobe */ + bpf_map_get_next_key(map_fd[1], &cpu, NULL); + /* Check the value */ + if (bpf_map_lookup_elem(map_fd[1], &cpu, &value)) { + fprintf(stderr, "Value missing for CPU %d\n", cpu); + error = 1; + goto on_exit; + } else { + fprintf(stderr, "CPU %d: %llu\n", cpu, value); + } + /* The above bpf_map_lookup_elem should trigger the second kprobe */ + if (bpf_map_lookup_elem(map_fd[2], &cpu, &value2)) { + fprintf(stderr, "Value2 missing for CPU %d\n", cpu); + error = 1; + goto on_exit; + } else { + fprintf(stderr, "CPU %d: counter: %llu, enabled: %llu, running: %llu\n", cpu, + value2.counter, value2.enabled, value2.running); + } + +on_exit: + assert(bpf_map_delete_elem(map_fd[0], &cpu) == 0 || error); + assert(ioctl(pmu_fd, PERF_EVENT_IOC_DISABLE, 0) == 0 || error); + assert(close(pmu_fd) == 0 || error); + assert(bpf_map_delete_elem(map_fd[1], &cpu) == 0 || error); + exit(error); +} + +static void test_perf_event_array(struct perf_event_attr *attr, + const char *name) +{ + int i, status, nr_cpus = sysconf(_SC_NPROCESSORS_CONF); + pid_t pid[nr_cpus]; + int err = 0; + + printf("Test reading %s counters\n", name); + + for (i = 0; i < nr_cpus; i++) { + pid[i] = fork(); + assert(pid[i] >= 0); + if (pid[i] == 0) { + check_on_cpu(i, attr); + exit(1); + } + } + + for (i = 0; i < nr_cpus; i++) { + assert(waitpid(pid[i], &status, 0) == pid[i]); + err |= status; + } + + if (err) + printf("Test: %s FAILED\n", name); +} + +static void test_bpf_perf_event(void) +{ + struct perf_event_attr attr_cycles = { + .freq = 0, + .sample_period = SAMPLE_PERIOD, + .inherit = 0, + .type = PERF_TYPE_HARDWARE, + .read_format = 0, + .sample_type = 0, + .config = PERF_COUNT_HW_CPU_CYCLES, + }; + struct perf_event_attr attr_clock = { + .freq = 0, + .sample_period = SAMPLE_PERIOD, + .inherit = 0, + .type = PERF_TYPE_SOFTWARE, + .read_format = 0, + .sample_type = 0, + .config = PERF_COUNT_SW_CPU_CLOCK, + }; + struct perf_event_attr attr_raw = { + .freq = 0, + .sample_period = SAMPLE_PERIOD, + .inherit = 0, + .type = PERF_TYPE_RAW, + .read_format = 0, + .sample_type = 0, + /* Intel Instruction Retired */ + .config = 0xc0, + }; + struct perf_event_attr attr_l1d_load = { + .freq = 0, + .sample_period = SAMPLE_PERIOD, + .inherit = 0, + .type = PERF_TYPE_HW_CACHE, + .read_format = 0, + .sample_type = 0, + .config = + PERF_COUNT_HW_CACHE_L1D | + (PERF_COUNT_HW_CACHE_OP_READ << 8) | + (PERF_COUNT_HW_CACHE_RESULT_ACCESS << 16), + }; + struct perf_event_attr attr_llc_miss = { + .freq = 0, + .sample_period = SAMPLE_PERIOD, + .inherit = 0, + .type = PERF_TYPE_HW_CACHE, + .read_format = 0, + .sample_type = 0, + .config = + PERF_COUNT_HW_CACHE_LL | + (PERF_COUNT_HW_CACHE_OP_READ << 8) | + (PERF_COUNT_HW_CACHE_RESULT_MISS << 16), + }; + struct perf_event_attr attr_msr_tsc = { + .freq = 0, + .sample_period = 0, + .inherit = 0, + /* From /sys/bus/event_source/devices/msr/ */ + .type = 7, + .read_format = 0, + .sample_type = 0, + .config = 0, + }; + + test_perf_event_array(&attr_cycles, "HARDWARE-cycles"); + test_perf_event_array(&attr_clock, "SOFTWARE-clock"); + test_perf_event_array(&attr_raw, "RAW-instruction-retired"); + test_perf_event_array(&attr_l1d_load, "HW_CACHE-L1D-load"); + + /* below tests may fail in qemu */ + test_perf_event_array(&attr_llc_miss, "HW_CACHE-LLC-miss"); + test_perf_event_array(&attr_msr_tsc, "Dynamic-msr-tsc"); +} + +int main(int argc, char **argv) +{ + struct bpf_link *links[2]; + struct bpf_program *prog; + struct bpf_object *obj; + char filename[256]; + int i = 0; + + snprintf(filename, sizeof(filename), "%s_kern.o", argv[0]); + obj = bpf_object__open_file(filename, NULL); + if (libbpf_get_error(obj)) { + fprintf(stderr, "ERROR: opening BPF object file failed\n"); + return 0; + } + + /* load BPF program */ + if (bpf_object__load(obj)) { + fprintf(stderr, "ERROR: loading BPF object file failed\n"); + goto cleanup; + } + + map_fd[0] = bpf_object__find_map_fd_by_name(obj, "counters"); + map_fd[1] = bpf_object__find_map_fd_by_name(obj, "values"); + map_fd[2] = bpf_object__find_map_fd_by_name(obj, "values2"); + if (map_fd[0] < 0 || map_fd[1] < 0 || map_fd[2] < 0) { + fprintf(stderr, "ERROR: finding a map in obj file failed\n"); + goto cleanup; + } + + bpf_object__for_each_program(prog, obj) { + links[i] = bpf_program__attach(prog); + if (libbpf_get_error(links[i])) { + fprintf(stderr, "ERROR: bpf_program__attach failed\n"); + links[i] = NULL; + goto cleanup; + } + i++; + } + + test_bpf_perf_event(); + +cleanup: + for (i--; i >= 0; i--) + bpf_link__destroy(links[i]); + + bpf_object__close(obj); + return 0; +} |