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// SPDX-License-Identifier: GPL-2.0
/*
* User Events ABI Test Program
*
* Copyright (c) 2022 Beau Belgrave <beaub@linux.microsoft.com>
*/
#define _GNU_SOURCE
#include <sched.h>
#include <errno.h>
#include <linux/user_events.h>
#include <stdio.h>
#include <stdlib.h>
#include <fcntl.h>
#include <sys/ioctl.h>
#include <sys/stat.h>
#include <unistd.h>
#include <asm/unistd.h>
#include "../kselftest_harness.h"
#include "user_events_selftests.h"
const char *data_file = "/sys/kernel/tracing/user_events_data";
const char *enable_file = "/sys/kernel/tracing/events/user_events/__abi_event/enable";
static int change_event(bool enable)
{
int fd = open(enable_file, O_RDWR);
int ret;
if (fd < 0)
return -1;
if (enable)
ret = write(fd, "1", 1);
else
ret = write(fd, "0", 1);
close(fd);
if (ret == 1)
ret = 0;
else
ret = -1;
return ret;
}
static int reg_enable(long *enable, int size, int bit)
{
struct user_reg reg = {0};
int fd = open(data_file, O_RDWR);
int ret;
if (fd < 0)
return -1;
reg.size = sizeof(reg);
reg.name_args = (__u64)"__abi_event";
reg.enable_bit = bit;
reg.enable_addr = (__u64)enable;
reg.enable_size = size;
ret = ioctl(fd, DIAG_IOCSREG, ®);
close(fd);
return ret;
}
static int reg_disable(long *enable, int bit)
{
struct user_unreg reg = {0};
int fd = open(data_file, O_RDWR);
int ret;
if (fd < 0)
return -1;
reg.size = sizeof(reg);
reg.disable_bit = bit;
reg.disable_addr = (__u64)enable;
ret = ioctl(fd, DIAG_IOCSUNREG, ®);
close(fd);
return ret;
}
FIXTURE(user) {
long check;
};
FIXTURE_SETUP(user) {
USER_EVENT_FIXTURE_SETUP(return);
change_event(false);
self->check = 0;
}
FIXTURE_TEARDOWN(user) {
}
TEST_F(user, enablement) {
/* Changes should be reflected immediately */
ASSERT_EQ(0, self->check);
ASSERT_EQ(0, reg_enable(&self->check, sizeof(int), 0));
ASSERT_EQ(0, change_event(true));
ASSERT_EQ(1, self->check);
ASSERT_EQ(0, change_event(false));
ASSERT_EQ(0, self->check);
/* Ensure kernel clears bit after disable */
ASSERT_EQ(0, change_event(true));
ASSERT_EQ(1, self->check);
ASSERT_EQ(0, reg_disable(&self->check, 0));
ASSERT_EQ(0, self->check);
/* Ensure doesn't change after unreg */
ASSERT_EQ(0, change_event(true));
ASSERT_EQ(0, self->check);
ASSERT_EQ(0, change_event(false));
}
TEST_F(user, bit_sizes) {
/* Allow 0-31 bits for 32-bit */
ASSERT_EQ(0, reg_enable(&self->check, sizeof(int), 0));
ASSERT_EQ(0, reg_enable(&self->check, sizeof(int), 31));
ASSERT_NE(0, reg_enable(&self->check, sizeof(int), 32));
ASSERT_EQ(0, reg_disable(&self->check, 0));
ASSERT_EQ(0, reg_disable(&self->check, 31));
#if BITS_PER_LONG == 8
/* Allow 0-64 bits for 64-bit */
ASSERT_EQ(0, reg_enable(&self->check, sizeof(long), 63));
ASSERT_NE(0, reg_enable(&self->check, sizeof(long), 64));
ASSERT_EQ(0, reg_disable(&self->check, 63));
#endif
/* Disallowed sizes (everything beside 4 and 8) */
ASSERT_NE(0, reg_enable(&self->check, 1, 0));
ASSERT_NE(0, reg_enable(&self->check, 2, 0));
ASSERT_NE(0, reg_enable(&self->check, 3, 0));
ASSERT_NE(0, reg_enable(&self->check, 5, 0));
ASSERT_NE(0, reg_enable(&self->check, 6, 0));
ASSERT_NE(0, reg_enable(&self->check, 7, 0));
ASSERT_NE(0, reg_enable(&self->check, 9, 0));
ASSERT_NE(0, reg_enable(&self->check, 128, 0));
}
TEST_F(user, forks) {
int i;
/* Ensure COW pages get updated after fork */
ASSERT_EQ(0, reg_enable(&self->check, sizeof(int), 0));
ASSERT_EQ(0, self->check);
if (fork() == 0) {
/* Force COW */
self->check = 0;
/* Up to 1 sec for enablement */
for (i = 0; i < 10; ++i) {
usleep(100000);
if (self->check)
exit(0);
}
exit(1);
}
/* Allow generous time for COW, then enable */
usleep(100000);
ASSERT_EQ(0, change_event(true));
ASSERT_NE(-1, wait(&i));
ASSERT_EQ(0, WEXITSTATUS(i));
/* Ensure child doesn't disable parent */
if (fork() == 0)
exit(reg_disable(&self->check, 0));
ASSERT_NE(-1, wait(&i));
ASSERT_EQ(0, WEXITSTATUS(i));
ASSERT_EQ(1, self->check);
ASSERT_EQ(0, change_event(false));
ASSERT_EQ(0, self->check);
}
/* Waits up to 1 sec for enablement */
static int clone_check(void *check)
{
int i;
for (i = 0; i < 10; ++i) {
usleep(100000);
if (*(long *)check)
return 0;
}
return 1;
}
TEST_F(user, clones) {
int i, stack_size = 4096;
void *stack = mmap(NULL, stack_size, PROT_READ | PROT_WRITE,
MAP_PRIVATE | MAP_ANONYMOUS | MAP_STACK,
-1, 0);
ASSERT_NE(MAP_FAILED, stack);
ASSERT_EQ(0, reg_enable(&self->check, sizeof(int), 0));
ASSERT_EQ(0, self->check);
/* Shared VM should see enablements */
ASSERT_NE(-1, clone(&clone_check, stack + stack_size,
CLONE_VM | SIGCHLD, &self->check));
ASSERT_EQ(0, change_event(true));
ASSERT_NE(-1, wait(&i));
ASSERT_EQ(0, WEXITSTATUS(i));
munmap(stack, stack_size);
ASSERT_EQ(0, change_event(false));
}
int main(int argc, char **argv)
{
return test_harness_run(argc, argv);
}
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