freebsd-skq/tests/sys/kern/pdeathsig.c
Konstantin Belousov de567a4bef sys.kern.pdeathsig.signal_delivered_ptrace: fix startup.
Inform D that C executed procctl(PROC_PDEATHSIG_CTL).  Otherwise D
might allow B to exit before C is set up to receive a signal on the
parent exit.  In this case, C waits forever for the signal and test
hangs.

PR:	237657
Reported and tested by:	lwhsu
Sponsored by:	The FreeBSD Foundation
MFC after:	1 week
2019-08-19 09:33:09 +00:00

348 lines
8.1 KiB
C

/*-
* Copyright (c) 2018 Thomas Munro
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include <assert.h>
#include <atf-c.h>
#include <errno.h>
#include <signal.h>
#include <stdio.h>
#include <stdlib.h>
#include <time.h>
#include <unistd.h>
#include <sys/procctl.h>
#include <sys/ptrace.h>
#include <sys/signal.h>
#include <sys/types.h>
static void
dummy_signal_handler(int signum)
{
}
ATF_TC_WITHOUT_HEAD(arg_validation);
ATF_TC_BODY(arg_validation, tc)
{
int signum;
int rc;
/* bad signal */
signum = 8888;
rc = procctl(P_PID, 0, PROC_PDEATHSIG_CTL, &signum);
ATF_CHECK_EQ(-1, rc);
ATF_CHECK_EQ(EINVAL, errno);
/* bad id type */
signum = SIGINFO;
rc = procctl(8888, 0, PROC_PDEATHSIG_CTL, &signum);
ATF_CHECK_EQ(-1, rc);
ATF_CHECK_EQ(EINVAL, errno);
/* bad id (pid that doesn't match mine or zero) */
signum = SIGINFO;
rc = procctl(P_PID, (((getpid() + 1) % 10) + 100),
PROC_PDEATHSIG_CTL, &signum);
ATF_CHECK_EQ(-1, rc);
ATF_CHECK_EQ(EINVAL, errno);
/* null pointer */
signum = SIGINFO;
rc = procctl(P_PID, 0, PROC_PDEATHSIG_CTL, NULL);
ATF_CHECK_EQ(-1, rc);
ATF_CHECK_EQ(EFAULT, errno);
/* good (pid == 0) */
signum = SIGINFO;
rc = procctl(P_PID, 0, PROC_PDEATHSIG_CTL, &signum);
ATF_CHECK_EQ(0, rc);
/* good (pid == my pid) */
signum = SIGINFO;
rc = procctl(P_PID, getpid(), PROC_PDEATHSIG_CTL, &signum);
ATF_CHECK_EQ(0, rc);
/* check that we can read the signal number back */
signum = 0xdeadbeef;
rc = procctl(P_PID, 0, PROC_PDEATHSIG_STATUS, &signum);
ATF_CHECK_EQ(0, rc);
ATF_CHECK_EQ(SIGINFO, signum);
}
ATF_TC_WITHOUT_HEAD(fork_no_inherit);
ATF_TC_BODY(fork_no_inherit, tc)
{
int status;
int signum;
int rc;
/* request a signal on parent death in the parent */
signum = SIGINFO;
rc = procctl(P_PID, 0, PROC_PDEATHSIG_CTL, &signum);
rc = fork();
ATF_REQUIRE(rc != -1);
if (rc == 0) {
/* check that we didn't inherit the setting */
signum = 0xdeadbeef;
rc = procctl(P_PID, 0, PROC_PDEATHSIG_STATUS, &signum);
assert(rc == 0);
assert(signum == 0);
_exit(0);
}
/* wait for the child to exit successfully */
waitpid(rc, &status, 0);
ATF_CHECK_EQ(0, status);
}
ATF_TC_WITHOUT_HEAD(exec_inherit);
ATF_TC_BODY(exec_inherit, tc)
{
int status;
int rc;
rc = fork();
ATF_REQUIRE(rc != -1);
if (rc == 0) {
char exec_path[1024];
int signum;
/* compute the path of the helper executable */
snprintf(exec_path, sizeof(exec_path), "%s/pdeathsig_helper",
atf_tc_get_config_var(tc, "srcdir"));
/* request a signal on parent death and register a handler */
signum = SIGINFO;
rc = procctl(P_PID, 0, PROC_PDEATHSIG_CTL, &signum);
assert(rc == 0);
/* execute helper program: it asserts that it has the setting */
rc = execl(exec_path, exec_path, NULL);
assert(rc == 0);
_exit(0);
}
/* wait for the child to exit successfully */
waitpid(rc, &status, 0);
ATF_CHECK_EQ(0, status);
}
ATF_TC_WITHOUT_HEAD(signal_delivered);
ATF_TC_BODY(signal_delivered, tc)
{
sigset_t sigset;
int signum;
int rc;
int pipe_ca[2];
int pipe_cb[2];
char buffer;
rc = pipe(pipe_ca);
ATF_REQUIRE(rc == 0);
rc = pipe(pipe_cb);
ATF_REQUIRE(rc == 0);
rc = fork();
ATF_REQUIRE(rc != -1);
if (rc == 0) {
rc = fork();
assert(rc >= 0);
if (rc == 0) {
/* process C */
signum = SIGINFO;
/* block signals so we can handle them synchronously */
rc = sigfillset(&sigset);
assert(rc == 0);
rc = sigprocmask(SIG_SETMASK, &sigset, NULL);
assert(rc == 0);
/* register a dummy handler or the kernel will not queue it */
signal(signum, dummy_signal_handler);
/* request a signal on death of our parent B */
rc = procctl(P_PID, 0, PROC_PDEATHSIG_CTL, &signum);
assert(rc == 0);
/* tell B that we're ready for it to exit now */
rc = write(pipe_cb[1], ".", 1);
assert(rc == 1);
/* wait for B to die and signal us... */
signum = 0xdeadbeef;
rc = sigwait(&sigset, &signum);
assert(rc == 0);
assert(signum == SIGINFO);
/* tell A the test passed */
rc = write(pipe_ca[1], ".", 1);
assert(rc == 1);
_exit(0);
}
/* process B */
/* wait for C to tell us it is ready for us to exit */
rc = read(pipe_cb[0], &buffer, 1);
assert(rc == 1);
/* now we exit so that C gets a signal */
_exit(0);
}
/* process A */
/* wait for C to tell us the test passed */
rc = read(pipe_ca[0], &buffer, 1);
ATF_CHECK_EQ(1, rc);
}
ATF_TC_WITHOUT_HEAD(signal_delivered_ptrace);
ATF_TC_BODY(signal_delivered_ptrace, tc)
{
sigset_t sigset;
int signum;
int rc;
int pipe_ca[2];
int pipe_db[2];
int pipe_cd[2];
char buffer;
int status;
rc = pipe(pipe_ca);
ATF_REQUIRE(rc == 0);
rc = pipe(pipe_db);
ATF_REQUIRE(rc == 0);
rc = pipe(pipe_cd);
assert(rc == 0);
rc = fork();
ATF_REQUIRE(rc != -1);
if (rc == 0) {
pid_t c_pid;
/* process B */
rc = fork();
assert(rc >= 0);
if (rc == 0) {
/* process C */
signum = SIGINFO;
/* block signals so we can handle them synchronously */
rc = sigfillset(&sigset);
assert(rc == 0);
rc = sigprocmask(SIG_SETMASK, &sigset, NULL);
assert(rc == 0);
/* register a dummy handler or the kernel will not queue it */
signal(signum, dummy_signal_handler);
/* request a signal on parent death and register a handler */
rc = procctl(P_PID, 0, PROC_PDEATHSIG_CTL, &signum);
assert(rc == 0);
rc = write(pipe_cd[1], "x", 1);
assert(rc == 1);
/* wait for B to die and signal us... */
signum = 0xdeadbeef;
rc = sigwait(&sigset, &signum);
assert(rc == 0);
assert(signum == SIGINFO);
/* tell A the test passed */
rc = write(pipe_ca[1], ".", 1);
assert(rc == 1);
_exit(0);
}
c_pid = rc;
/* fork another process to ptrace C */
rc = fork();
assert(rc >= 0);
if (rc == 0) {
/* process D */
rc = ptrace(PT_ATTACH, c_pid, 0, 0);
assert(rc == 0);
waitpid(c_pid, &status, 0);
assert(WIFSTOPPED(status));
assert(WSTOPSIG(status) == SIGSTOP);
rc = ptrace(PT_CONTINUE, c_pid, (caddr_t) 1, 0);
assert(rc == 0);
rc = read(pipe_cd[0], &buffer, 1);
assert(rc == 1);
/* tell B that we're ready for it to exit now */
rc = write(pipe_db[1], ".", 1);
assert(rc == 1);
waitpid(c_pid, &status, 0);
assert(WIFSTOPPED(status));
assert(WSTOPSIG(status) == SIGINFO);
rc = ptrace(PT_CONTINUE, c_pid, (caddr_t) 1,
WSTOPSIG(status));
assert(rc == 0);
waitpid(c_pid, &status, 0);
if (!WIFEXITED(status))
ptrace(PT_DETACH, c_pid, 0, 0);
_exit(0);
}
/* wait for D to tell us it is ready for us to exit */
rc = read(pipe_db[0], &buffer, 1);
assert(rc == 1);
/* now we exit so that C gets a signal */
_exit(0);
}
/* process A */
/* wait for C to tell us the test passed */
rc = read(pipe_ca[0], &buffer, 1);
ATF_CHECK_EQ(1, rc);
}
ATF_TP_ADD_TCS(tp)
{
ATF_TP_ADD_TC(tp, arg_validation);
ATF_TP_ADD_TC(tp, fork_no_inherit);
ATF_TP_ADD_TC(tp, exec_inherit);
ATF_TP_ADD_TC(tp, signal_delivered);
ATF_TP_ADD_TC(tp, signal_delivered_ptrace);
return (atf_no_error());
}