wayland/tests/test-runner.c
Bryce Harrington 76fe89ed53 tests: Fix FAIL in sanity-test (*timeout*) when Yama LSM enabled
This fixes a regression in the testsuite since c3653f7f, where four of
the timeout tests fail with "Timeouts suppressed" messages.

The timeouts are being suppressed because the testsuite is erroneously
detecting that a debugger is attached.  This detection mechanism
(adopted from libinput) uses ptrace to test if there is a debugger
parent process that can be attached.  Unfortunately, this is an
unreliable test: Kernel security policies exist to restrict the scope of
ptrace to prevent processes from snooping on one another.[1] This
security policy is set as the default on Ubuntu, and potentially other
Linux distributions.[2]

The Yama documentation suggests, "For software that has defined
application-specific relationships between a debugging process and its
inferior (crash handlers, etc), prctl(PR_SET_PTRACER, pid, ...) can be
used.  An inferior can declare which other process (and its descendents)
are allowed to call PTRACE_ATTACH against it."  This prctl call has no
effect if Yama LSM is not loaded.

The child needs to be synchronized to the client to prevent a race
condition where the child might try to operate before the parent has
finished its prctl call.  This synchronization is done via pipes.

This patch can be tested by running sanity-test with
/proc/sys/kernel/yama/ptrace_scope set to 0 or 1; the test must pass for
either value.

1: http://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=2d514487faf188938a4ee4fb3464eeecfbdcf8eb
2: https://wiki.ubuntu.com/SecurityTeam/Roadmap/KernelHardening#ptrace_Protection

Signed-off-by: Bryce Harrington <bryce@osg.samsung.com>
Reviewed-by: Marek Chalupa <mchqwerty@gmail.com>
Reviewed-by: Daniel Stone <daniels@collabora.com>
Reviewed-by: Derek Foreman <derekf@osg.samsung.com>

v4: Allow parent to communicate error state to child to prevent leaving
child in zombie state if parent hits an error.

v5: Check errno instead of rc for error.  Don't waitpid on ppid.
Signed-off-by: Bryce Harrington <bryce@osg.samsung.com>
2015-02-06 14:39:36 -08:00

446 lines
9.8 KiB
C

/*
* Copyright © 2012 Intel Corporation
*
* Permission to use, copy, modify, distribute, and sell this software and its
* documentation for any purpose is hereby granted without fee, provided that
* the above copyright notice appear in all copies and that both that copyright
* notice and this permission notice appear in supporting documentation, and
* that the name of the copyright holders not be used in advertising or
* publicity pertaining to distribution of the software without specific,
* written prior permission. The copyright holders make no representations
* about the suitability of this software for any purpose. It is provided "as
* is" without express or implied warranty.
*
* THE COPYRIGHT HOLDERS DISCLAIM ALL WARRANTIES WITH REGARD TO THIS SOFTWARE,
* INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO
* EVENT SHALL THE COPYRIGHT HOLDERS BE LIABLE FOR ANY SPECIAL, INDIRECT OR
* CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE,
* DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER
* TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE
* OF THIS SOFTWARE.
*/
#define _GNU_SOURCE
#include <unistd.h>
#include <stdio.h>
#include <stdlib.h>
#include <sys/types.h>
#include <sys/wait.h>
#include <sys/stat.h>
#include <string.h>
#include <assert.h>
#include <dlfcn.h>
#include <errno.h>
#include <limits.h>
#include <sys/ptrace.h>
#include <sys/prctl.h>
#ifndef PR_SET_PTRACER
# define PR_SET_PTRACER 0x59616d61
#endif
#include "test-runner.h"
static int num_alloc;
static void* (*sys_malloc)(size_t);
static void (*sys_free)(void*);
static void* (*sys_realloc)(void*, size_t);
static void* (*sys_calloc)(size_t, size_t);
/* when set to 1, check if tests are not leaking memory and opened files.
* It is turned on by default. It can be turned off by
* WAYLAND_TEST_NO_LEAK_CHECK environment variable. */
int leak_check_enabled;
/* when this var is set to 0, every call to test_set_timeout() is
* suppressed - handy when debugging the test. Can be set by
* WAYLAND_TEST_NO_TIMEOUTS environment variable. */
static int timeouts_enabled = 1;
/* set to one if the output goes to the terminal */
static int is_atty = 0;
extern const struct test __start_test_section, __stop_test_section;
__attribute__ ((visibility("default"))) void *
malloc(size_t size)
{
num_alloc++;
return sys_malloc(size);
}
__attribute__ ((visibility("default"))) void
free(void* mem)
{
if (mem != NULL)
num_alloc--;
sys_free(mem);
}
__attribute__ ((visibility("default"))) void *
realloc(void* mem, size_t size)
{
if (mem == NULL)
num_alloc++;
return sys_realloc(mem, size);
}
__attribute__ ((visibility("default"))) void *
calloc(size_t nmemb, size_t size)
{
if (sys_calloc == NULL)
return NULL;
num_alloc++;
return sys_calloc(nmemb, size);
}
static const struct test *
find_test(const char *name)
{
const struct test *t;
for (t = &__start_test_section; t < &__stop_test_section; t++)
if (strcmp(t->name, name) == 0)
return t;
return NULL;
}
static void
usage(const char *name, int status)
{
const struct test *t;
fprintf(stderr, "Usage: %s [TEST]\n\n"
"With no arguments, run all test. Specify test case to run\n"
"only that test without forking. Available tests:\n\n",
name);
for (t = &__start_test_section; t < &__stop_test_section; t++)
fprintf(stderr, " %s\n", t->name);
fprintf(stderr, "\n");
exit(status);
}
void
test_set_timeout(unsigned int to)
{
int re;
if (!timeouts_enabled) {
fprintf(stderr, "Timeouts suppressed.\n");
return;
}
re = alarm(to);
fprintf(stderr, "Timeout was %sset", re ? "re-" : "");
if (to != 0)
fprintf(stderr, " to %d second%s from now.\n",
to, to > 1 ? "s" : "");
else
fprintf(stderr, " off.\n");
}
static void
sigalrm_handler(int signum)
{
fprintf(stderr, "Test timed out.\n");
abort();
}
int
get_current_alloc_num(void)
{
return num_alloc;
}
void
check_leaks(int supposed_alloc, int supposed_fds)
{
int num_fds;
if (leak_check_enabled) {
if (supposed_alloc != num_alloc) {
fprintf(stderr, "Memory leak detected in test. "
"Allocated %d blocks, unfreed %d\n", num_alloc,
num_alloc - supposed_alloc);
abort();
}
num_fds = count_open_fds();
if (supposed_fds != num_fds) {
fprintf(stderr, "fd leak detected in test. "
"Opened %d files, unclosed %d\n", num_fds,
num_fds - supposed_fds);
abort();
}
} else {
fprintf(stderr, "Leak checks disabled\n");
}
}
static void
run_test(const struct test *t)
{
int cur_alloc, cur_fds;
struct sigaction sa;
if (timeouts_enabled) {
sa.sa_handler = sigalrm_handler;
sa.sa_flags = 0;
sigemptyset(&sa.sa_mask);
assert(sigaction(SIGALRM, &sa, NULL) == 0);
}
cur_alloc = get_current_alloc_num();
cur_fds = count_open_fds();
t->run();
/* turn off timeout (if any) after test completition */
if (timeouts_enabled)
alarm(0);
check_leaks(cur_alloc, cur_fds);
exit(EXIT_SUCCESS);
}
#ifndef PATH_MAX
#define PATH_MAX 256
#endif
static void
set_xdg_runtime_dir(void)
{
char xdg_runtime_dir[PATH_MAX];
const char *xrd_env;
xrd_env = getenv("XDG_RUNTIME_DIR");
/* if XDG_RUNTIME_DIR is not set in environ, fallback to /tmp */
assert((snprintf(xdg_runtime_dir, PATH_MAX, "%s/wayland-tests",
xrd_env ? xrd_env : "/tmp") < PATH_MAX)
&& "test error: XDG_RUNTIME_DIR too long");
if (mkdir(xdg_runtime_dir, 0700) == -1)
if (errno != EEXIST) {
perror("Creating XDG_RUNTIME_DIR");
abort();
}
if (setenv("XDG_RUNTIME_DIR", xdg_runtime_dir, 1) == -1) {
perror("Setting XDG_RUNTIME_DIR");
abort();
}
}
static void
rmdir_xdg_runtime_dir(void)
{
const char *xrd_env = getenv("XDG_RUNTIME_DIR");
assert(xrd_env && "No XDG_RUNTIME_DIR set");
/* rmdir may fail if some test didn't do clean up */
if (rmdir(xrd_env) == -1)
perror("Cleaning XDG_RUNTIME_DIR");
}
#define RED "\033[31m"
#define GREEN "\033[32m"
static void
stderr_set_color(const char *color)
{
/* use colors only when the output is connected to
* the terminal */
if (is_atty)
fprintf(stderr, "%s", color);
}
static void
stderr_reset_color(void)
{
if (is_atty)
fprintf(stderr, "\033[0m");
}
/* this function is taken from libinput/test/litest.c
* (rev 028513a0a723e97941c39)
*
* Returns: 1 if a debugger is confirmed present; 0 if no debugger is
* present or if it can't be determined.
*/
static int
is_debugger_attached(void)
{
int status;
int rc;
pid_t pid;
int pipefd[2];
if (pipe(pipefd) == -1) {
perror("pipe");
return 0;
}
pid = fork();
if (pid == -1) {
perror("fork");
close(pipefd[0]);
close(pipefd[1]);
return 0;
} else if (pid == 0) {
char buf;
pid_t ppid = getppid();
/* Wait until parent is ready */
close(pipefd[1]); /* Close unused write end */
read(pipefd[0], &buf, 1);
close(pipefd[0]);
if (buf == '-')
_exit(1);
if (ptrace(PTRACE_ATTACH, ppid, NULL, NULL) != 0)
_exit(1);
if (!waitpid(-1, NULL, 0))
_exit(1);
ptrace(PTRACE_CONT, NULL, NULL);
ptrace(PTRACE_DETACH, ppid, NULL, NULL);
_exit(0);
} else {
close(pipefd[0]);
/* Enable child to ptrace the parent process */
rc = prctl(PR_SET_PTRACER, pid);
if (rc != 0 && errno != EINVAL) {
/* An error prevents us from telling if a debugger is attached.
* Instead of propagating the error, assume no debugger present.
* But note the error to the log as a clue for troubleshooting.
* Then flag the error state to the client by sending '-'.
*/
perror("prctl");
write(pipefd[1], "-", 1);
} else {
/* Signal to client that parent is ready by passing '+' */
write(pipefd[1], "+", 1);
}
close(pipefd[1]);
waitpid(pid, &status, 0);
rc = WEXITSTATUS(status);
}
return rc;
}
int main(int argc, char *argv[])
{
const struct test *t;
pid_t pid;
int total, pass;
siginfo_t info;
/* Load system malloc, free, and realloc */
sys_calloc = dlsym(RTLD_NEXT, "calloc");
sys_realloc = dlsym(RTLD_NEXT, "realloc");
sys_malloc = dlsym(RTLD_NEXT, "malloc");
sys_free = dlsym(RTLD_NEXT, "free");
if (isatty(fileno(stderr)))
is_atty = 1;
if (is_debugger_attached()) {
leak_check_enabled = 0;
timeouts_enabled = 0;
} else {
leak_check_enabled = !getenv("WAYLAND_TEST_NO_LEAK_CHECK");
timeouts_enabled = !getenv("WAYLAND_TEST_NO_TIMEOUTS");
}
if (argc == 2 && strcmp(argv[1], "--help") == 0)
usage(argv[0], EXIT_SUCCESS);
if (argc == 2) {
t = find_test(argv[1]);
if (t == NULL) {
fprintf(stderr, "unknown test: \"%s\"\n", argv[1]);
usage(argv[0], EXIT_FAILURE);
}
set_xdg_runtime_dir();
/* run_test calls exit() */
assert(atexit(rmdir_xdg_runtime_dir) == 0);
run_test(t);
}
/* set our own XDG_RUNTIME_DIR */
set_xdg_runtime_dir();
pass = 0;
for (t = &__start_test_section; t < &__stop_test_section; t++) {
int success = 0;
pid = fork();
assert(pid >= 0);
if (pid == 0)
run_test(t); /* never returns */
if (waitid(P_PID, pid, &info, WEXITED)) {
stderr_set_color(RED);
fprintf(stderr, "waitid failed: %m\n");
stderr_reset_color();
abort();
}
switch (info.si_code) {
case CLD_EXITED:
if (info.si_status == EXIT_SUCCESS)
success = !t->must_fail;
else
success = t->must_fail;
stderr_set_color(success ? GREEN : RED);
fprintf(stderr, "test \"%s\":\texit status %d",
t->name, info.si_status);
break;
case CLD_KILLED:
case CLD_DUMPED:
if (t->must_fail)
success = 1;
stderr_set_color(success ? GREEN : RED);
fprintf(stderr, "test \"%s\":\tsignal %d",
t->name, info.si_status);
break;
}
if (success) {
pass++;
fprintf(stderr, ", pass.\n");
} else
fprintf(stderr, ", fail.\n");
stderr_reset_color();
/* print separator line */
fprintf(stderr, "----------------------------------------\n");
}
total = &__stop_test_section - &__start_test_section;
fprintf(stderr, "%d tests, %d pass, %d fail\n",
total, pass, total - pass);
/* cleaning */
rmdir_xdg_runtime_dir();
return pass == total ? EXIT_SUCCESS : EXIT_FAILURE;
}