glibc/support/support_test_main.c
Chung-Lin Tang e6fd79f379 elf: Testing infrastructure for ld.so DSO sorting (BZ #17645)
This is the first of a 2-part patch set that fixes slow DSO sorting behavior in
the dynamic loader, as reported in BZ #17645. In order to facilitate such a
large modification to the dynamic loader, this first patch implements a testing
framework for validating shared object sorting behavior, to enable comparison
between old/new sorting algorithms, and any later enhancements.

This testing infrastructure consists of a Python script
scripts/dso-ordering-test.py' which takes in a description language, consisting
of strings that describe a set of link dependency relations between DSOs, and
generates testcase programs and Makefile fragments to automatically test the
described situation, for example:

  a->b->c->d          # four objects linked one after another

  a->[bc]->d;b->c     # a depends on b and c, which both depend on d,
                      # b depends on c (b,c linked to object a in fixed order)

  a->b->c;{+a;%a;-a}  # a, b, c serially dependent, main program uses
                      # dlopen/dlsym/dlclose on object a

  a->b->c;{}!->[abc]  # a, b, c serially dependent; multiple tests generated
                      # to test all permutations of a, b, c ordering linked
                      # to main program

 (Above is just a short description of what the script can do, more
  documentation is in the script comments.)

Two files containing several new tests, elf/dso-sort-tests-[12].def are added,
including test scenarios for BZ #15311 and Redhat issue #1162810 [1].

Due to the nature of dynamic loader tests, where the sorting behavior and test
output occurs before/after main(), generating testcases to use
support/test-driver.c does not suffice to control meaningful timeout for ld.so.
Therefore a new utility program 'support/test-run-command', based on
test-driver.c/support_test_main.c has been added. This does the same testcase
control, but for a program specified through a command-line rather than at the
source code level. This utility is used to run the dynamic loader testcases
generated by dso-ordering-test.py.

[1] https://bugzilla.redhat.com/show_bug.cgi?id=1162810

Signed-off-by: Chung-Lin Tang  <cltang@codesourcery.com>
Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>
2021-10-21 11:23:53 -03:00

519 lines
15 KiB
C

/* Main worker function for the test driver.
Copyright (C) 1998-2021 Free Software Foundation, Inc.
This file is part of the GNU C Library.
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
The GNU C Library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with the GNU C Library; if not, see
<https://www.gnu.org/licenses/>. */
#include <support/test-driver.h>
#include <support/check.h>
#include <support/temp_file-internal.h>
#include <support/support.h>
#include <assert.h>
#include <errno.h>
#include <getopt.h>
#include <malloc.h>
#include <signal.h>
#include <stdbool.h>
#include <stdlib.h>
#include <string.h>
#include <sys/param.h>
#include <sys/resource.h>
#include <sys/time.h>
#include <sys/types.h>
#include <sys/wait.h>
#include <time.h>
#include <unistd.h>
#include <xstdio.h>
static const struct option default_options[] =
{
TEST_DEFAULT_OPTIONS
{ NULL, 0, NULL, 0 }
};
/* Show people how to run the program. */
static void
usage (const struct option *options)
{
size_t i;
printf ("Usage: %s [options]\n"
"\n"
"Environment Variables:\n"
" TIMEOUTFACTOR An integer used to scale the timeout\n"
" TMPDIR Where to place temporary files\n"
" TEST_COREDUMPS Do not disable coredumps if set\n"
"\n",
program_invocation_short_name);
printf ("Options:\n");
for (i = 0; options[i].name; ++i)
{
int indent;
indent = printf (" --%s", options[i].name);
if (options[i].has_arg == required_argument)
indent += printf (" <arg>");
printf ("%*s", 25 - indent, "");
switch (options[i].val)
{
case 'v':
printf ("Increase the output verbosity");
break;
case OPT_DIRECT:
printf ("Run the test directly (instead of forking & monitoring)");
break;
case OPT_TESTDIR:
printf ("Override the TMPDIR env var");
break;
}
printf ("\n");
}
}
/* The PID of the test process. */
static pid_t test_pid;
/* The cleanup handler passed to test_main. */
static void (*cleanup_function) (void);
static void
print_timestamp (const char *what, struct timespec tv)
{
struct tm tm;
/* Casts of tv.tv_nsec below are necessary because the type of
tv_nsec is not literally long int on all supported platforms. */
if (gmtime_r (&tv.tv_sec, &tm) == NULL)
printf ("%s: %lld.%09ld\n",
what, (long long int) tv.tv_sec, (long int) tv.tv_nsec);
else
printf ("%s: %04d-%02d-%02dT%02d:%02d:%02d.%09ld\n",
what, 1900 + tm.tm_year, tm.tm_mon + 1, tm.tm_mday,
tm.tm_hour, tm.tm_min, tm.tm_sec, (long int) tv.tv_nsec);
}
/* Timeout handler. We kill the child and exit with an error. */
static void
__attribute__ ((noreturn))
signal_handler (int sig)
{
int killed;
int status;
/* Do this first to avoid further interference from the
subprocess. */
struct timespec now;
clock_gettime (CLOCK_REALTIME, &now);
struct stat64 st;
bool st_available = fstat64 (STDOUT_FILENO, &st) == 0 && st.st_mtime != 0;
assert (test_pid > 1);
/* Kill the whole process group. */
kill (-test_pid, SIGKILL);
/* In case setpgid failed in the child, kill it individually too. */
kill (test_pid, SIGKILL);
/* Wait for it to terminate. */
int i;
for (i = 0; i < 5; ++i)
{
killed = waitpid (test_pid, &status, WNOHANG|WUNTRACED);
if (killed != 0)
break;
/* Delay, give the system time to process the kill. If the
nanosleep() call return prematurely, all the better. We
won't restart it since this probably means the child process
finally died. */
struct timespec ts;
ts.tv_sec = 0;
ts.tv_nsec = 100000000;
nanosleep (&ts, NULL);
}
if (killed != 0 && killed != test_pid)
{
printf ("Failed to kill test process: %m\n");
exit (1);
}
if (cleanup_function != NULL)
cleanup_function ();
if (sig == SIGINT)
{
signal (sig, SIG_DFL);
raise (sig);
}
if (killed == 0 || (WIFSIGNALED (status) && WTERMSIG (status) == SIGKILL))
puts ("Timed out: killed the child process");
else if (WIFSTOPPED (status))
printf ("Timed out: the child process was %s\n",
strsignal (WSTOPSIG (status)));
else if (WIFSIGNALED (status))
printf ("Timed out: the child process got signal %s\n",
strsignal (WTERMSIG (status)));
else
printf ("Timed out: killed the child process but it exited %d\n",
WEXITSTATUS (status));
print_timestamp ("Termination time", now);
if (st_available)
print_timestamp ("Last write to standard output", st.st_mtim);
/* Exit with an error. */
exit (1);
}
/* This must be volatile as it will be modified by the debugger. */
static volatile int wait_for_debugger = 0;
/* Run test_function or test_function_argv. */
static int
run_test_function (int argc, char **argv, const struct test_config *config)
{
const char *wfd = getenv("WAIT_FOR_DEBUGGER");
if (wfd != NULL)
wait_for_debugger = atoi (wfd);
if (wait_for_debugger)
{
pid_t mypid;
FILE *gdb_script;
char *gdb_script_name;
int inside_container = 0;
mypid = getpid();
if (mypid < 3)
{
const char *outside_pid = getenv("PID_OUTSIDE_CONTAINER");
if (outside_pid)
{
mypid = atoi (outside_pid);
inside_container = 1;
}
}
gdb_script_name = (char *) xmalloc (strlen (argv[0]) + strlen (".gdb") + 1);
sprintf (gdb_script_name, "%s.gdb", argv[0]);
gdb_script = xfopen (gdb_script_name, "w");
fprintf (stderr, "Waiting for debugger, test process is pid %d\n", mypid);
fprintf (stderr, "gdb -x %s\n", gdb_script_name);
if (inside_container)
fprintf (gdb_script, "set sysroot %s/testroot.root\n", support_objdir_root);
fprintf (gdb_script, "file\n");
fprintf (gdb_script, "file %s\n", argv[0]);
fprintf (gdb_script, "symbol-file %s\n", argv[0]);
fprintf (gdb_script, "exec-file %s\n", argv[0]);
fprintf (gdb_script, "attach %ld\n", (long int) mypid);
fprintf (gdb_script, "set wait_for_debugger = 0\n");
fclose (gdb_script);
free (gdb_script_name);
}
/* Wait for the debugger to set wait_for_debugger to zero. */
while (wait_for_debugger)
usleep (1000);
if (config->run_command_mode)
{
/* In run-command-mode, the child process executes the command line
arguments as a new program. */
char **argv_ = xmalloc (sizeof (char *) * argc);
memcpy (argv_, &argv[1], sizeof (char *) * (argc - 1));
argv_[argc - 1] = NULL;
execv (argv_[0], argv_);
printf ("error: should not return here\n");
exit (1);
}
if (config->test_function != NULL)
return config->test_function ();
else if (config->test_function_argv != NULL)
return config->test_function_argv (argc, argv);
else
{
printf ("error: no test function defined\n");
exit (1);
}
}
static bool test_main_called;
const char *test_dir = NULL;
unsigned int test_verbose = 0;
/* If test failure reporting has been linked in, it may contribute
additional test failures. */
static int
adjust_exit_status (int status)
{
if (support_report_failure != NULL)
return support_report_failure (status);
return status;
}
int
support_test_main (int argc, char **argv, const struct test_config *config)
{
if (test_main_called)
{
printf ("error: test_main called for a second time\n");
exit (1);
}
test_main_called = true;
const struct option *options;
if (config->options != NULL)
options = config->options;
else
options = default_options;
cleanup_function = config->cleanup_function;
int direct = 0; /* Directly call the test function? */
int status;
int opt;
unsigned int timeoutfactor = 1;
pid_t termpid;
/* If we're debugging the test, we need to disable timeouts and use
the initial pid (esp if we're running inside a container). */
if (getenv("WAIT_FOR_DEBUGGER") != NULL)
direct = 1;
if (!config->no_mallopt)
{
/* Make uses of freed and uninitialized memory known. Do not
pull in a definition for mallopt if it has not been defined
already. */
extern __typeof__ (mallopt) mallopt __attribute__ ((weak));
if (mallopt != NULL)
mallopt (M_PERTURB, 42);
}
while ((opt = getopt_long (argc, argv, config->optstring, options, NULL))
!= -1)
switch (opt)
{
case '?':
usage (options);
exit (1);
case 'v':
++test_verbose;
break;
case OPT_DIRECT:
direct = 1;
break;
case OPT_TESTDIR:
test_dir = optarg;
break;
default:
if (config->cmdline_function != NULL)
config->cmdline_function (opt);
}
/* If set, read the test TIMEOUTFACTOR value from the environment.
This value is used to scale the default test timeout values. */
char *envstr_timeoutfactor = getenv ("TIMEOUTFACTOR");
if (envstr_timeoutfactor != NULL)
{
char *envstr_conv = envstr_timeoutfactor;
unsigned long int env_fact;
env_fact = strtoul (envstr_timeoutfactor, &envstr_conv, 0);
if (*envstr_conv == '\0' && envstr_conv != envstr_timeoutfactor)
timeoutfactor = MAX (env_fact, 1);
}
/* Set TMPDIR to specified test directory. */
if (test_dir != NULL)
{
setenv ("TMPDIR", test_dir, 1);
if (chdir (test_dir) < 0)
{
printf ("chdir: %m\n");
exit (1);
}
}
else
{
test_dir = getenv ("TMPDIR");
if (test_dir == NULL || test_dir[0] == '\0')
test_dir = "/tmp";
}
if (support_set_test_dir != NULL)
support_set_test_dir (test_dir);
int timeout = config->timeout;
if (timeout == 0)
timeout = DEFAULT_TIMEOUT;
/* Make sure we see all message, even those on stdout. */
if (!config->no_setvbuf)
setvbuf (stdout, NULL, _IONBF, 0);
/* Make sure temporary files are deleted. */
if (support_delete_temp_files != NULL)
atexit (support_delete_temp_files);
/* Correct for the possible parameters. */
argv[optind - 1] = argv[0];
argv += optind - 1;
argc -= optind - 1;
/* Call the initializing function, if one is available. */
if (config->prepare_function != NULL)
config->prepare_function (argc, argv);
const char *envstr_direct = getenv ("TEST_DIRECT");
if (envstr_direct != NULL)
{
FILE *f = fopen (envstr_direct, "w");
if (f == NULL)
{
printf ("cannot open TEST_DIRECT output file '%s': %m\n",
envstr_direct);
exit (1);
}
fprintf (f, "timeout=%u\ntimeoutfactor=%u\n",
config->timeout, timeoutfactor);
if (config->expected_status != 0)
fprintf (f, "exit=%u\n", config->expected_status);
if (config->expected_signal != 0)
fprintf (f, "signal=%s\n", strsignal (config->expected_signal));
if (support_print_temp_files != NULL)
support_print_temp_files (f);
fclose (f);
direct = 1;
}
bool disable_coredumps;
{
const char *coredumps = getenv ("TEST_COREDUMPS");
disable_coredumps = coredumps == NULL || coredumps[0] == '\0';
}
/* If we are not expected to fork run the function immediately. */
if (direct)
return adjust_exit_status (run_test_function (argc, argv, config));
/* Set up the test environment:
- prevent core dumps
- set up the timer
- fork and execute the function. */
test_pid = fork ();
if (test_pid == 0)
{
/* This is the child. */
if (disable_coredumps)
{
/* Try to avoid dumping core. This is necessary because we
run the test from the source tree, and the coredumps
would end up there (and not in the build tree). */
struct rlimit core_limit;
core_limit.rlim_cur = 0;
core_limit.rlim_max = 0;
setrlimit (RLIMIT_CORE, &core_limit);
}
/* We put the test process in its own pgrp so that if it bogusly
generates any job control signals, they won't hit the whole build. */
if (setpgid (0, 0) != 0)
printf ("Failed to set the process group ID: %m\n");
/* Execute the test function and exit with the return value. */
exit (run_test_function (argc, argv, config));
}
else if (test_pid < 0)
{
printf ("Cannot fork test program: %m\n");
exit (1);
}
/* Set timeout. */
signal (SIGALRM, signal_handler);
alarm (timeout * timeoutfactor);
/* Make sure we clean up if the wrapper gets interrupted. */
signal (SIGINT, signal_handler);
/* Wait for the regular termination. */
termpid = TEMP_FAILURE_RETRY (waitpid (test_pid, &status, 0));
if (termpid == -1)
{
printf ("Waiting for test program failed: %m\n");
exit (1);
}
if (termpid != test_pid)
{
printf ("Oops, wrong test program terminated: expected %ld, got %ld\n",
(long int) test_pid, (long int) termpid);
exit (1);
}
/* Process terminated normaly without timeout etc. */
if (WIFEXITED (status))
{
if (config->expected_status == 0)
{
if (config->expected_signal == 0)
/* Exit with the return value of the test. */
return adjust_exit_status (WEXITSTATUS (status));
else
{
printf ("Expected signal '%s' from child, got none\n",
strsignal (config->expected_signal));
exit (1);
}
}
else
{
/* Non-zero exit status is expected */
if (WEXITSTATUS (status) != config->expected_status)
{
printf ("Expected status %d, got %d\n",
config->expected_status, WEXITSTATUS (status));
exit (1);
}
}
return adjust_exit_status (0);
}
/* Process was killed by timer or other signal. */
else
{
if (config->expected_signal == 0)
{
printf ("Didn't expect signal from child: got `%s'\n",
strsignal (WTERMSIG (status)));
exit (1);
}
else if (WTERMSIG (status) != config->expected_signal)
{
printf ("Incorrect signal from child: got `%s', need `%s'\n",
strsignal (WTERMSIG (status)),
strsignal (config->expected_signal));
exit (1);
}
return adjust_exit_status (0);
}
}