// SPDX-License-Identifier: GPL-2.0
#include <inttypes.h>
#include <pthread.h>
#include <stdbool.h>
#include <stdio.h>
#include <stdlib.h>
#include <sys/mount.h>
#include <sys/time.h>
#include <unistd.h>
#include "../../../../../include/linux/kernel.h"
#include "aolib.h"
static char ftrace_path[] = "ksft-ftrace-XXXXXX";
static bool ftrace_mounted;
uint64_t ns_cookie1, ns_cookie2;
struct test_ftracer {
pthread_t tracer_thread;
int error;
char *instance_path;
FILE *trace_pipe;
enum ftracer_op (*process_line)(const char *line);
void (*destructor)(struct test_ftracer *tracer);
bool (*expecting_more)(void);
char **saved_lines;
size_t saved_lines_size;
size_t next_line_ind;
pthread_cond_t met_all_expected;
pthread_mutex_t met_all_expected_lock;
struct test_ftracer *next;
};
static struct test_ftracer *ftracers;
static pthread_mutex_t ftracers_lock = PTHREAD_MUTEX_INITIALIZER;
static int mount_ftrace(void)
{
if (!mkdtemp(ftrace_path))
test_error("Can't create temp dir");
if (mount("tracefs", ftrace_path, "tracefs", 0, "rw"))
return -errno;
ftrace_mounted = true;
return 0;
}
static void unmount_ftrace(void)
{
if (ftrace_mounted && umount(ftrace_path))
test_print("Failed on cleanup: can't unmount tracefs: %m");
if (rmdir(ftrace_path))
test_error("Failed on cleanup: can't remove ftrace dir %s",
ftrace_path);
}
struct opts_list_t {
char *opt_name;
struct opts_list_t *next;
};
static int disable_trace_options(const char *ftrace_path)
{
struct opts_list_t *opts_list = NULL;
char *fopts, *line = NULL;
size_t buf_len = 0;
ssize_t line_len;
int ret = 0;
FILE *opts;
fopts = test_sprintf("%s/%s", ftrace_path, "trace_options");
if (!fopts)
return -ENOMEM;
opts = fopen(fopts, "r+");
if (!opts) {
ret = -errno;
goto out_free;
}
while ((line_len = getline(&line, &buf_len, opts)) != -1) {
struct opts_list_t *tmp;
if (!strncmp(line, "no", 2))
continue;
tmp = malloc(sizeof(*tmp));
if (!tmp) {
ret = -ENOMEM;
goto out_free_opts_list;
}
tmp->next = opts_list;
tmp->opt_name = test_sprintf("no%s", line);
if (!tmp->opt_name) {
ret = -ENOMEM;
free(tmp);
goto out_free_opts_list;
}
opts_list = tmp;
}
while (opts_list) {
struct opts_list_t *tmp = opts_list;
fseek(opts, 0, SEEK_SET);
fwrite(tmp->opt_name, 1, strlen(tmp->opt_name), opts);
opts_list = opts_list->next;
free(tmp->opt_name);
free(tmp);
}
out_free_opts_list:
while (opts_list) {
struct opts_list_t *tmp = opts_list;
opts_list = opts_list->next;
free(tmp->opt_name);
free(tmp);
}
free(line);
fclose(opts);
out_free:
free(fopts);
return ret;
}
static int setup_buffer_size(const char *ftrace_path, size_t sz)
{
char *fbuf_size = test_sprintf("%s/buffer_size_kb", ftrace_path);
int ret;
if (!fbuf_size)
return -1;
ret = test_echo(fbuf_size, 0, "%zu", sz);
free(fbuf_size);
return ret;
}
static int setup_ftrace_instance(struct test_ftracer *tracer, const char *name)
{
char *tmp;
tmp = test_sprintf("%s/instances/ksft-%s-XXXXXX", ftrace_path, name);
if (!tmp)
return -ENOMEM;
tracer->instance_path = mkdtemp(tmp);
if (!tracer->instance_path) {
free(tmp);
return -errno;
}
return 0;
}
static void remove_ftrace_instance(struct test_ftracer *tracer)
{
if (rmdir(tracer->instance_path))
test_print("Failed on cleanup: can't remove ftrace instance %s",
tracer->instance_path);
free(tracer->instance_path);
}
static void tracer_cleanup(void *arg)
{
struct test_ftracer *tracer = arg;
fclose(tracer->trace_pipe);
}
static void tracer_set_error(struct test_ftracer *tracer, int error)
{
if (!tracer->error)
tracer->error = error;
}
const size_t tracer_get_savedlines_nr(struct test_ftracer *tracer)
{
return tracer->next_line_ind;
}
const char **tracer_get_savedlines(struct test_ftracer *tracer)
{
return (const char **)tracer->saved_lines;
}
static void *tracer_thread_func(void *arg)
{
struct test_ftracer *tracer = arg;
pthread_cleanup_push(tracer_cleanup, arg);
while (tracer->next_line_ind < tracer->saved_lines_size) {
char **lp = &tracer->saved_lines[tracer->next_line_ind];
enum ftracer_op op;
size_t buf_len = 0;
ssize_t line_len;
line_len = getline(lp, &buf_len, tracer->trace_pipe);
if (line_len == -1)
break;
pthread_setcancelstate(PTHREAD_CANCEL_DISABLE, NULL);
op = tracer->process_line(*lp);
pthread_setcancelstate(PTHREAD_CANCEL_ENABLE, NULL);
if (tracer->expecting_more) {
pthread_mutex_lock(&tracer->met_all_expected_lock);
if (!tracer->expecting_more())
pthread_cond_signal(&tracer->met_all_expected);
pthread_mutex_unlock(&tracer->met_all_expected_lock);
}
if (op == FTRACER_LINE_DISCARD)
continue;
if (op == FTRACER_EXIT)
break;
if (op != FTRACER_LINE_PRESERVE)
test_error("unexpected tracer command %d", op);
tracer->next_line_ind++;
buf_len = 0;
}
test_print("too many lines in ftracer buffer %zu, exiting tracer",
tracer->next_line_ind);
pthread_cleanup_pop(1);
return NULL;
}
static int setup_trace_thread(struct test_ftracer *tracer)
{
int ret = 0;
char *path;
path = test_sprintf("%s/trace_pipe", tracer->instance_path);
if (!path)
return -ENOMEM;
tracer->trace_pipe = fopen(path, "r");
if (!tracer->trace_pipe) {
ret = -errno;
goto out_free;
}
if (pthread_create(&tracer->tracer_thread, NULL,
tracer_thread_func, (void *)tracer)) {
ret = -errno;
fclose(tracer->trace_pipe);
}
out_free:
free(path);
return ret;
}
static void stop_trace_thread(struct test_ftracer *tracer)
{
void *res;
if (pthread_cancel(tracer->tracer_thread)) {
test_print("Can't stop tracer pthread: %m");
tracer_set_error(tracer, -errno);
}
if (pthread_join(tracer->tracer_thread, &res)) {
test_print("Can't join tracer pthread: %m");
tracer_set_error(tracer, -errno);
}
if (res != PTHREAD_CANCELED) {
test_print("Tracer thread wasn't canceled");
tracer_set_error(tracer, -errno);
}
if (tracer->error)
test_fail("tracer errored by %s", strerror(tracer->error));
}
static void final_wait_for_events(struct test_ftracer *tracer,
unsigned timeout_sec)
{
struct timespec timeout;
struct timeval now;
int ret = 0;
if (!tracer->expecting_more)
return;
pthread_mutex_lock(&tracer->met_all_expected_lock);
gettimeofday(&now, NULL);
timeout.tv_sec = now.tv_sec + timeout_sec;
timeout.tv_nsec = now.tv_usec * 1000;
while (tracer->expecting_more() && ret != ETIMEDOUT)
ret = pthread_cond_timedwait(&tracer->met_all_expected,
&tracer->met_all_expected_lock, &timeout);
pthread_mutex_unlock(&tracer->met_all_expected_lock);
}
int setup_trace_event(struct test_ftracer *tracer,
const char *event, const char *filter)
{
char *enable_path, *filter_path, *instance = tracer->instance_path;
int ret;
enable_path = test_sprintf("%s/events/%s/enable", instance, event);
if (!enable_path)
return -ENOMEM;
filter_path = test_sprintf("%s/events/%s/filter", instance, event);
if (!filter_path) {
ret = -ENOMEM;
goto out_free;
}
ret = test_echo(filter_path, 0, "%s", filter);
if (!ret)
ret = test_echo(enable_path, 0, "1");
out_free:
free(filter_path);
free(enable_path);
return ret;
}
struct test_ftracer *create_ftracer(const char *name,
enum ftracer_op (*process_line)(const char *line),
void (*destructor)(struct test_ftracer *tracer),
bool (*expecting_more)(void),
size_t lines_buf_sz, size_t buffer_size_kb)
{
struct test_ftracer *tracer;
int err;
/* XXX: separate __create_ftracer() helper and do here
* if (!kernel_config_has(KCONFIG_FTRACE))
* return NULL;
*/
tracer = malloc(sizeof(*tracer));
if (!tracer) {
test_print("malloc()");
return NULL;
}
memset(tracer, 0, sizeof(*tracer));
err = setup_ftrace_instance(tracer, name);
if (err) {
test_print("setup_ftrace_instance(): %d", err);
goto err_free;
}
err = disable_trace_options(tracer->instance_path);
if (err) {
test_print("disable_trace_options(): %d", err);
goto err_remove;
}
err = setup_buffer_size(tracer->instance_path, buffer_size_kb);
if (err) {
test_print("disable_trace_options(): %d", err);
goto err_remove;
}
tracer->saved_lines = calloc(lines_buf_sz, sizeof(tracer->saved_lines[0]));
if (!tracer->saved_lines) {
test_print("calloc()");
goto err_remove;
}
tracer->saved_lines_size = lines_buf_sz;
tracer->process_line = process_line;
tracer->destructor = destructor;
tracer->expecting_more = expecting_more;
err = pthread_cond_init(&tracer->met_all_expected, NULL);
if (err) {
test_print("pthread_cond_init(): %d", err);
goto err_free_lines;
}
err = pthread_mutex_init(&tracer->met_all_expected_lock, NULL);
if (err) {
test_print("pthread_mutex_init(): %d", err);
goto err_cond_destroy;
}
err = setup_trace_thread(tracer);
if (err) {
test_print("setup_trace_thread(): %d", err);
goto err_mutex_destroy;
}
pthread_mutex_lock(&ftracers_lock);
tracer->next = ftracers;
ftracers = tracer;
pthread_mutex_unlock(&ftracers_lock);
return tracer;
err_mutex_destroy:
pthread_mutex_destroy(&tracer->met_all_expected_lock);
err_cond_destroy:
pthread_cond_destroy(&tracer->met_all_expected);
err_free_lines:
free(tracer->saved_lines);
err_remove:
remove_ftrace_instance(tracer);
err_free:
free(tracer);
return NULL;
}
static void __destroy_ftracer(struct test_ftracer *tracer)
{
size_t i;
final_wait_for_events(tracer, TEST_TIMEOUT_SEC);
stop_trace_thread(tracer);
remove_ftrace_instance(tracer);
if (tracer->destructor)
tracer->destructor(tracer);
for (i = 0; i < tracer->saved_lines_size; i++)
free(tracer->saved_lines[i]);
pthread_cond_destroy(&tracer->met_all_expected);
pthread_mutex_destroy(&tracer->met_all_expected_lock);
free(tracer);
}
void destroy_ftracer(struct test_ftracer *tracer)
{
pthread_mutex_lock(&ftracers_lock);
if (tracer == ftracers) {
ftracers = tracer->next;
} else {
struct test_ftracer *f = ftracers;
while (f->next != tracer) {
if (!f->next)
test_error("tracers list corruption or double free %p", tracer);
f = f->next;
}
f->next = tracer->next;
}
tracer->next = NULL;
pthread_mutex_unlock(&ftracers_lock);
__destroy_ftracer(tracer);
}
static void destroy_all_ftracers(void)
{
struct test_ftracer *f;
pthread_mutex_lock(&ftracers_lock);
f = ftracers;
ftracers = NULL;
pthread_mutex_unlock(&ftracers_lock);
while (f) {
struct test_ftracer *n = f->next;
f->next = NULL;
__destroy_ftracer(f);
f = n;
}
}
static void test_unset_tracing(void)
{
destroy_all_ftracers();
unmount_ftrace();
}
int test_setup_tracing(void)
{
/*
* Just a basic protection - this should be called only once from
* lib/kconfig. Not thread safe, which is fine as it's early, before
* threads are created.
*/
static int already_set;
int err;
if (already_set)
return -1;
/* Needs net-namespace cookies for filters */
if (ns_cookie1 == ns_cookie2) {
test_print("net-namespace cookies: %" PRIu64 " == %" PRIu64 ", can't set up tracing",
ns_cookie1, ns_cookie2);
return -1;
}
already_set = 1;
test_add_destructor(test_unset_tracing);
err = mount_ftrace();
if (err) {
test_print("failed to mount_ftrace(): %d", err);
return err;
}
return setup_aolib_ftracer();
}
static int get_ns_cookie(int nsfd, uint64_t *out)
{
int old_ns = switch_save_ns(nsfd);
socklen_t size = sizeof(*out);
int sk;
sk = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP);
if (sk < 0) {
test_print("socket(): %m");
return -errno;
}
if (getsockopt(sk, SOL_SOCKET, SO_NETNS_COOKIE, out, &size)) {
test_print("getsockopt(SO_NETNS_COOKIE): %m");
close(sk);
return -errno;
}
close(sk);
switch_close_ns(old_ns);
return 0;
}
void test_init_ftrace(int nsfd1, int nsfd2)
{
get_ns_cookie(nsfd1, &ns_cookie1);
get_ns_cookie(nsfd2, &ns_cookie2);
/* Populate kernel config state */
kernel_config_has(KCONFIG_FTRACE);
}
Codebase Browser
linux