linux/tools/perf/tests/bpf.c

360 lines
7.3 KiB
C

#include <errno.h>
#include <stdio.h>
#include <sys/epoll.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <util/util.h>
#include <util/bpf-loader.h>
#include <util/evlist.h>
#include <linux/bpf.h>
#include <linux/filter.h>
#include <linux/kernel.h>
#include <api/fs/fs.h>
#include <bpf/bpf.h>
#include "tests.h"
#include "llvm.h"
#include "debug.h"
#define NR_ITERS 111
#define PERF_TEST_BPF_PATH "/sys/fs/bpf/perf_test"
#ifdef HAVE_LIBBPF_SUPPORT
static int epoll_wait_loop(void)
{
int i;
/* Should fail NR_ITERS times */
for (i = 0; i < NR_ITERS; i++)
epoll_wait(-(i + 1), NULL, 0, 0);
return 0;
}
#ifdef HAVE_BPF_PROLOGUE
static int llseek_loop(void)
{
int fds[2], i;
fds[0] = open("/dev/null", O_RDONLY);
fds[1] = open("/dev/null", O_RDWR);
if (fds[0] < 0 || fds[1] < 0)
return -1;
for (i = 0; i < NR_ITERS; i++) {
lseek(fds[i % 2], i, (i / 2) % 2 ? SEEK_CUR : SEEK_SET);
lseek(fds[(i + 1) % 2], i, (i / 2) % 2 ? SEEK_CUR : SEEK_SET);
}
close(fds[0]);
close(fds[1]);
return 0;
}
#endif
static struct {
enum test_llvm__testcase prog_id;
const char *desc;
const char *name;
const char *msg_compile_fail;
const char *msg_load_fail;
int (*target_func)(void);
int expect_result;
bool pin;
} bpf_testcase_table[] = {
{
LLVM_TESTCASE_BASE,
"Basic BPF filtering",
"[basic_bpf_test]",
"fix 'perf test LLVM' first",
"load bpf object failed",
&epoll_wait_loop,
(NR_ITERS + 1) / 2,
false,
},
{
LLVM_TESTCASE_BASE,
"BPF pinning",
"[bpf_pinning]",
"fix kbuild first",
"check your vmlinux setting?",
&epoll_wait_loop,
(NR_ITERS + 1) / 2,
true,
},
#ifdef HAVE_BPF_PROLOGUE
{
LLVM_TESTCASE_BPF_PROLOGUE,
"BPF prologue generation",
"[bpf_prologue_test]",
"fix kbuild first",
"check your vmlinux setting?",
&llseek_loop,
(NR_ITERS + 1) / 4,
false,
},
#endif
{
LLVM_TESTCASE_BPF_RELOCATION,
"BPF relocation checker",
"[bpf_relocation_test]",
"fix 'perf test LLVM' first",
"libbpf error when dealing with relocation",
NULL,
0,
false,
},
};
static int do_test(struct bpf_object *obj, int (*func)(void),
int expect)
{
struct record_opts opts = {
.target = {
.uid = UINT_MAX,
.uses_mmap = true,
},
.freq = 0,
.mmap_pages = 256,
.default_interval = 1,
};
char pid[16];
char sbuf[STRERR_BUFSIZE];
struct perf_evlist *evlist;
int i, ret = TEST_FAIL, err = 0, count = 0;
struct parse_events_evlist parse_evlist;
struct parse_events_error parse_error;
bzero(&parse_error, sizeof(parse_error));
bzero(&parse_evlist, sizeof(parse_evlist));
parse_evlist.error = &parse_error;
INIT_LIST_HEAD(&parse_evlist.list);
err = parse_events_load_bpf_obj(&parse_evlist, &parse_evlist.list, obj, NULL);
if (err || list_empty(&parse_evlist.list)) {
pr_debug("Failed to add events selected by BPF\n");
return TEST_FAIL;
}
snprintf(pid, sizeof(pid), "%d", getpid());
pid[sizeof(pid) - 1] = '\0';
opts.target.tid = opts.target.pid = pid;
/* Instead of perf_evlist__new_default, don't add default events */
evlist = perf_evlist__new();
if (!evlist) {
pr_debug("Not enough memory to create evlist\n");
return TEST_FAIL;
}
err = perf_evlist__create_maps(evlist, &opts.target);
if (err < 0) {
pr_debug("Not enough memory to create thread/cpu maps\n");
goto out_delete_evlist;
}
perf_evlist__splice_list_tail(evlist, &parse_evlist.list);
evlist->nr_groups = parse_evlist.nr_groups;
perf_evlist__config(evlist, &opts, NULL);
err = perf_evlist__open(evlist);
if (err < 0) {
pr_debug("perf_evlist__open: %s\n",
str_error_r(errno, sbuf, sizeof(sbuf)));
goto out_delete_evlist;
}
err = perf_evlist__mmap(evlist, opts.mmap_pages, false);
if (err < 0) {
pr_debug("perf_evlist__mmap: %s\n",
str_error_r(errno, sbuf, sizeof(sbuf)));
goto out_delete_evlist;
}
perf_evlist__enable(evlist);
(*func)();
perf_evlist__disable(evlist);
for (i = 0; i < evlist->nr_mmaps; i++) {
union perf_event *event;
while ((event = perf_evlist__mmap_read(evlist, i)) != NULL) {
const u32 type = event->header.type;
if (type == PERF_RECORD_SAMPLE)
count ++;
}
}
if (count != expect) {
pr_debug("BPF filter result incorrect\n");
goto out_delete_evlist;
}
ret = TEST_OK;
out_delete_evlist:
perf_evlist__delete(evlist);
return ret;
}
static struct bpf_object *
prepare_bpf(void *obj_buf, size_t obj_buf_sz, const char *name)
{
struct bpf_object *obj;
obj = bpf__prepare_load_buffer(obj_buf, obj_buf_sz, name);
if (IS_ERR(obj)) {
pr_debug("Compile BPF program failed.\n");
return NULL;
}
return obj;
}
static int __test__bpf(int idx)
{
int ret;
void *obj_buf;
size_t obj_buf_sz;
struct bpf_object *obj;
ret = test_llvm__fetch_bpf_obj(&obj_buf, &obj_buf_sz,
bpf_testcase_table[idx].prog_id,
true, NULL);
if (ret != TEST_OK || !obj_buf || !obj_buf_sz) {
pr_debug("Unable to get BPF object, %s\n",
bpf_testcase_table[idx].msg_compile_fail);
if (idx == 0)
return TEST_SKIP;
else
return TEST_FAIL;
}
obj = prepare_bpf(obj_buf, obj_buf_sz,
bpf_testcase_table[idx].name);
if ((!!bpf_testcase_table[idx].target_func) != (!!obj)) {
if (!obj)
pr_debug("Fail to load BPF object: %s\n",
bpf_testcase_table[idx].msg_load_fail);
else
pr_debug("Success unexpectedly: %s\n",
bpf_testcase_table[idx].msg_load_fail);
ret = TEST_FAIL;
goto out;
}
if (obj) {
ret = do_test(obj,
bpf_testcase_table[idx].target_func,
bpf_testcase_table[idx].expect_result);
if (ret != TEST_OK)
goto out;
if (bpf_testcase_table[idx].pin) {
int err;
if (!bpf_fs__mount()) {
pr_debug("BPF filesystem not mounted\n");
ret = TEST_FAIL;
goto out;
}
err = mkdir(PERF_TEST_BPF_PATH, 0777);
if (err && errno != EEXIST) {
pr_debug("Failed to make perf_test dir: %s\n",
strerror(errno));
ret = TEST_FAIL;
goto out;
}
if (bpf_object__pin(obj, PERF_TEST_BPF_PATH))
ret = TEST_FAIL;
if (rm_rf(PERF_TEST_BPF_PATH))
ret = TEST_FAIL;
}
}
out:
bpf__clear();
return ret;
}
int test__bpf_subtest_get_nr(void)
{
return (int)ARRAY_SIZE(bpf_testcase_table);
}
const char *test__bpf_subtest_get_desc(int i)
{
if (i < 0 || i >= (int)ARRAY_SIZE(bpf_testcase_table))
return NULL;
return bpf_testcase_table[i].desc;
}
static int check_env(void)
{
int err;
unsigned int kver_int;
char license[] = "GPL";
struct bpf_insn insns[] = {
BPF_MOV64_IMM(BPF_REG_0, 1),
BPF_EXIT_INSN(),
};
err = fetch_kernel_version(&kver_int, NULL, 0);
if (err) {
pr_debug("Unable to get kernel version\n");
return err;
}
err = bpf_load_program(BPF_PROG_TYPE_KPROBE, insns,
sizeof(insns) / sizeof(insns[0]),
license, kver_int, NULL, 0);
if (err < 0) {
pr_err("Missing basic BPF support, skip this test: %s\n",
strerror(errno));
return err;
}
close(err);
return 0;
}
int test__bpf(int i)
{
int err;
if (i < 0 || i >= (int)ARRAY_SIZE(bpf_testcase_table))
return TEST_FAIL;
if (geteuid() != 0) {
pr_debug("Only root can run BPF test\n");
return TEST_SKIP;
}
if (check_env())
return TEST_SKIP;
err = __test__bpf(i);
return err;
}
#else
int test__bpf_subtest_get_nr(void)
{
return 0;
}
const char *test__bpf_subtest_get_desc(int i __maybe_unused)
{
return NULL;
}
int test__bpf(int i __maybe_unused)
{
pr_debug("Skip BPF test because BPF support is not compiled\n");
return TEST_SKIP;
}
#endif