freebsd-nq/tests/sys/kern/ptrace_test.c
John Baldwin 368b2b1c76 Add a test to verify that a traced process sees its original parent via
getppid() after a debugger process that is not the parent has attached.

Reviewed by:	kib (earlier version)
Differential Revision:	https://reviews.freebsd.org/D3615
2015-09-09 22:42:26 +00:00

974 lines
26 KiB
C

/*-
* Copyright (c) 2015 John Baldwin <jhb@FreeBSD.org>
* 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 <sys/types.h>
#include <sys/ptrace.h>
#include <sys/sysctl.h>
#include <sys/user.h>
#include <sys/wait.h>
#include <errno.h>
#include <signal.h>
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <atf-c.h>
/*
* A variant of ATF_REQUIRE that is suitable for use in child
* processes. This only works if the parent process is tripped up by
* the early exit and fails some requirement itself.
*/
#define CHILD_REQUIRE(exp) do { \
if (!(exp)) \
child_fail_require(__FILE__, __LINE__, \
#exp " not met"); \
} while (0)
static __dead2 void
child_fail_require(const char *file, int line, const char *str)
{
char buf[128];
snprintf(buf, sizeof(buf), "%s:%d: %s\n", file, line, str);
write(2, buf, strlen(buf));
_exit(32);
}
static void
trace_me(void)
{
/* Attach the parent process as a tracer of this process. */
CHILD_REQUIRE(ptrace(PT_TRACE_ME, 0, NULL, 0) != -1);
/* Trigger a stop. */
raise(SIGSTOP);
}
static void
attach_child(pid_t pid)
{
pid_t wpid;
int status;
ATF_REQUIRE(ptrace(PT_ATTACH, pid, NULL, 0) == 0);
wpid = waitpid(pid, &status, 0);
ATF_REQUIRE(wpid == pid);
ATF_REQUIRE(WIFSTOPPED(status));
ATF_REQUIRE(WSTOPSIG(status) == SIGSTOP);
}
static void
wait_for_zombie(pid_t pid)
{
/*
* Wait for a process to exit. This is kind of gross, but
* there is not a better way.
*/
for (;;) {
struct kinfo_proc kp;
size_t len;
int mib[4];
mib[0] = CTL_KERN;
mib[1] = KERN_PROC;
mib[2] = KERN_PROC_PID;
mib[3] = pid;
len = sizeof(kp);
if (sysctl(mib, nitems(mib), &kp, &len, NULL, 0) == -1) {
/* The KERN_PROC_PID sysctl fails for zombies. */
ATF_REQUIRE(errno == ESRCH);
break;
}
usleep(5000);
}
}
/*
* Verify that a parent debugger process "sees" the exit of a debugged
* process exactly once when attached via PT_TRACE_ME.
*/
ATF_TC_WITHOUT_HEAD(ptrace__parent_wait_after_trace_me);
ATF_TC_BODY(ptrace__parent_wait_after_trace_me, tc)
{
pid_t child, wpid;
int status;
ATF_REQUIRE((child = fork()) != -1);
if (child == 0) {
/* Child process. */
trace_me();
exit(1);
}
/* Parent process. */
/* The first wait() should report the stop from SIGSTOP. */
wpid = waitpid(child, &status, 0);
ATF_REQUIRE(wpid == child);
ATF_REQUIRE(WIFSTOPPED(status));
ATF_REQUIRE(WSTOPSIG(status) == SIGSTOP);
/* Continue the child ignoring the SIGSTOP. */
ATF_REQUIRE(ptrace(PT_CONTINUE, child, (caddr_t)1, 0) != -1);
/* The second wait() should report the exit status. */
wpid = waitpid(child, &status, 0);
ATF_REQUIRE(wpid == child);
ATF_REQUIRE(WIFEXITED(status));
ATF_REQUIRE(WEXITSTATUS(status) == 1);
/* The child should no longer exist. */
wpid = waitpid(child, &status, 0);
ATF_REQUIRE(wpid == -1);
ATF_REQUIRE(errno == ECHILD);
}
/*
* Verify that a parent debugger process "sees" the exit of a debugged
* process exactly once when attached via PT_ATTACH.
*/
ATF_TC_WITHOUT_HEAD(ptrace__parent_wait_after_attach);
ATF_TC_BODY(ptrace__parent_wait_after_attach, tc)
{
pid_t child, wpid;
int cpipe[2], status;
char c;
ATF_REQUIRE(pipe(cpipe) == 0);
ATF_REQUIRE((child = fork()) != -1);
if (child == 0) {
/* Child process. */
close(cpipe[0]);
/* Wait for the parent to attach. */
CHILD_REQUIRE(read(cpipe[1], &c, sizeof(c)) == 0);
exit(1);
}
close(cpipe[1]);
/* Parent process. */
/* Attach to the child process. */
attach_child(child);
/* Continue the child ignoring the SIGSTOP. */
ATF_REQUIRE(ptrace(PT_CONTINUE, child, (caddr_t)1, 0) != -1);
/* Signal the child to exit. */
close(cpipe[0]);
/* The second wait() should report the exit status. */
wpid = waitpid(child, &status, 0);
ATF_REQUIRE(wpid == child);
ATF_REQUIRE(WIFEXITED(status));
ATF_REQUIRE(WEXITSTATUS(status) == 1);
/* The child should no longer exist. */
wpid = waitpid(child, &status, 0);
ATF_REQUIRE(wpid == -1);
ATF_REQUIRE(errno == ECHILD);
}
/*
* Verify that a parent process "sees" the exit of a debugged process only
* after the debugger has seen it.
*/
ATF_TC_WITHOUT_HEAD(ptrace__parent_sees_exit_after_child_debugger);
ATF_TC_BODY(ptrace__parent_sees_exit_after_child_debugger, tc)
{
pid_t child, debugger, wpid;
int cpipe[2], dpipe[2], status;
char c;
ATF_REQUIRE(pipe(cpipe) == 0);
ATF_REQUIRE((child = fork()) != -1);
if (child == 0) {
/* Child process. */
close(cpipe[0]);
/* Wait for parent to be ready. */
CHILD_REQUIRE(read(cpipe[1], &c, sizeof(c)) == sizeof(c));
exit(1);
}
close(cpipe[1]);
ATF_REQUIRE(pipe(dpipe) == 0);
ATF_REQUIRE((debugger = fork()) != -1);
if (debugger == 0) {
/* Debugger process. */
close(dpipe[0]);
CHILD_REQUIRE(ptrace(PT_ATTACH, child, NULL, 0) != -1);
wpid = waitpid(child, &status, 0);
CHILD_REQUIRE(wpid == child);
CHILD_REQUIRE(WIFSTOPPED(status));
CHILD_REQUIRE(WSTOPSIG(status) == SIGSTOP);
CHILD_REQUIRE(ptrace(PT_CONTINUE, child, (caddr_t)1, 0) != -1);
/* Signal parent that debugger is attached. */
CHILD_REQUIRE(write(dpipe[1], &c, sizeof(c)) == sizeof(c));
/* Wait for parent's failed wait. */
CHILD_REQUIRE(read(dpipe[1], &c, sizeof(c)) == 0);
wpid = waitpid(child, &status, 0);
CHILD_REQUIRE(wpid == child);
CHILD_REQUIRE(WIFEXITED(status));
CHILD_REQUIRE(WEXITSTATUS(status) == 1);
exit(0);
}
close(dpipe[1]);
/* Parent process. */
/* Wait for the debugger to attach to the child. */
ATF_REQUIRE(read(dpipe[0], &c, sizeof(c)) == sizeof(c));
/* Release the child. */
ATF_REQUIRE(write(cpipe[0], &c, sizeof(c)) == sizeof(c));
ATF_REQUIRE(read(cpipe[0], &c, sizeof(c)) == 0);
close(cpipe[0]);
wait_for_zombie(child);
/*
* This wait should return a pid of 0 to indicate no status to
* report. The parent should see the child as non-exited
* until the debugger sees the exit.
*/
wpid = waitpid(child, &status, WNOHANG);
ATF_REQUIRE(wpid == 0);
/* Signal the debugger to wait for the child. */
close(dpipe[0]);
/* Wait for the debugger. */
wpid = waitpid(debugger, &status, 0);
ATF_REQUIRE(wpid == debugger);
ATF_REQUIRE(WIFEXITED(status));
ATF_REQUIRE(WEXITSTATUS(status) == 0);
/* The child process should now be ready. */
wpid = waitpid(child, &status, WNOHANG);
ATF_REQUIRE(wpid == child);
ATF_REQUIRE(WIFEXITED(status));
ATF_REQUIRE(WEXITSTATUS(status) == 1);
}
/*
* Verify that a parent process "sees" the exit of a debugged process
* only after a non-direct-child debugger has seen it. In particular,
* various wait() calls in the parent must avoid failing with ESRCH by
* checking the parent's orphan list for the debugee.
*/
ATF_TC_WITHOUT_HEAD(ptrace__parent_sees_exit_after_unrelated_debugger);
ATF_TC_BODY(ptrace__parent_sees_exit_after_unrelated_debugger, tc)
{
pid_t child, debugger, fpid, wpid;
int cpipe[2], dpipe[2], status;
char c;
ATF_REQUIRE(pipe(cpipe) == 0);
ATF_REQUIRE((child = fork()) != -1);
if (child == 0) {
/* Child process. */
close(cpipe[0]);
/* Wait for parent to be ready. */
CHILD_REQUIRE(read(cpipe[1], &c, sizeof(c)) == sizeof(c));
exit(1);
}
close(cpipe[1]);
ATF_REQUIRE(pipe(dpipe) == 0);
ATF_REQUIRE((debugger = fork()) != -1);
if (debugger == 0) {
/* Debugger parent. */
/*
* Fork again and drop the debugger parent so that the
* debugger is not a child of the main parent.
*/
CHILD_REQUIRE((fpid = fork()) != -1);
if (fpid != 0)
exit(2);
/* Debugger process. */
close(dpipe[0]);
CHILD_REQUIRE(ptrace(PT_ATTACH, child, NULL, 0) != -1);
wpid = waitpid(child, &status, 0);
CHILD_REQUIRE(wpid == child);
CHILD_REQUIRE(WIFSTOPPED(status));
CHILD_REQUIRE(WSTOPSIG(status) == SIGSTOP);
CHILD_REQUIRE(ptrace(PT_CONTINUE, child, (caddr_t)1, 0) != -1);
/* Signal parent that debugger is attached. */
CHILD_REQUIRE(write(dpipe[1], &c, sizeof(c)) == sizeof(c));
/* Wait for parent's failed wait. */
CHILD_REQUIRE(read(dpipe[1], &c, sizeof(c)) == sizeof(c));
wpid = waitpid(child, &status, 0);
CHILD_REQUIRE(wpid == child);
CHILD_REQUIRE(WIFEXITED(status));
CHILD_REQUIRE(WEXITSTATUS(status) == 1);
exit(0);
}
close(dpipe[1]);
/* Parent process. */
/* Wait for the debugger parent process to exit. */
wpid = waitpid(debugger, &status, 0);
ATF_REQUIRE(wpid == debugger);
ATF_REQUIRE(WIFEXITED(status));
ATF_REQUIRE(WEXITSTATUS(status) == 2);
/* A WNOHANG wait here should see the non-exited child. */
wpid = waitpid(child, &status, WNOHANG);
ATF_REQUIRE(wpid == 0);
/* Wait for the debugger to attach to the child. */
ATF_REQUIRE(read(dpipe[0], &c, sizeof(c)) == sizeof(c));
/* Release the child. */
ATF_REQUIRE(write(cpipe[0], &c, sizeof(c)) == sizeof(c));
ATF_REQUIRE(read(cpipe[0], &c, sizeof(c)) == 0);
close(cpipe[0]);
wait_for_zombie(child);
/*
* This wait should return a pid of 0 to indicate no status to
* report. The parent should see the child as non-exited
* until the debugger sees the exit.
*/
wpid = waitpid(child, &status, WNOHANG);
ATF_REQUIRE(wpid == 0);
/* Signal the debugger to wait for the child. */
ATF_REQUIRE(write(dpipe[0], &c, sizeof(c)) == sizeof(c));
/* Wait for the debugger. */
ATF_REQUIRE(read(dpipe[0], &c, sizeof(c)) == 0);
close(dpipe[0]);
/* The child process should now be ready. */
wpid = waitpid(child, &status, WNOHANG);
ATF_REQUIRE(wpid == child);
ATF_REQUIRE(WIFEXITED(status));
ATF_REQUIRE(WEXITSTATUS(status) == 1);
}
/*
* The parent process should always act the same regardless of how the
* debugger is attached to it.
*/
static __dead2 void
follow_fork_parent(void)
{
pid_t fpid, wpid;
int status;
CHILD_REQUIRE((fpid = fork()) != -1);
if (fpid == 0)
/* Child */
exit(2);
wpid = waitpid(fpid, &status, 0);
CHILD_REQUIRE(wpid == fpid);
CHILD_REQUIRE(WIFEXITED(status));
CHILD_REQUIRE(WEXITSTATUS(status) == 2);
exit(1);
}
/*
* Helper routine for follow fork tests. This waits for two stops
* that report both "sides" of a fork. It returns the pid of the new
* child process.
*/
static pid_t
handle_fork_events(pid_t parent)
{
struct ptrace_lwpinfo pl;
bool fork_reported[2];
pid_t child, wpid;
int i, status;
fork_reported[0] = false;
fork_reported[1] = false;
child = -1;
/*
* Each process should report a fork event. The parent should
* report a PL_FLAG_FORKED event, and the child should report
* a PL_FLAG_CHILD event.
*/
for (i = 0; i < 2; i++) {
wpid = wait(&status);
ATF_REQUIRE(wpid > 0);
ATF_REQUIRE(WIFSTOPPED(status));
ATF_REQUIRE(ptrace(PT_LWPINFO, wpid, (caddr_t)&pl,
sizeof(pl)) != -1);
ATF_REQUIRE((pl.pl_flags & (PL_FLAG_FORKED | PL_FLAG_CHILD)) !=
0);
ATF_REQUIRE((pl.pl_flags & (PL_FLAG_FORKED | PL_FLAG_CHILD)) !=
(PL_FLAG_FORKED | PL_FLAG_CHILD));
if (pl.pl_flags & PL_FLAG_CHILD) {
ATF_REQUIRE(wpid != parent);
ATF_REQUIRE(WSTOPSIG(status) == SIGSTOP);
ATF_REQUIRE(!fork_reported[1]);
if (child == -1)
child = wpid;
else
ATF_REQUIRE(child == wpid);
fork_reported[1] = true;
} else {
ATF_REQUIRE(wpid == parent);
ATF_REQUIRE(WSTOPSIG(status) == SIGTRAP);
ATF_REQUIRE(!fork_reported[0]);
if (child == -1)
child = pl.pl_child_pid;
else
ATF_REQUIRE(child == pl.pl_child_pid);
fork_reported[0] = true;
}
}
return (child);
}
/*
* Verify that a new child process is stopped after a followed fork and
* that the traced parent sees the exit of the child after the debugger
* when both processes remain attached to the debugger.
*/
ATF_TC_WITHOUT_HEAD(ptrace__follow_fork_both_attached);
ATF_TC_BODY(ptrace__follow_fork_both_attached, tc)
{
pid_t children[2], fpid, wpid;
int status;
ATF_REQUIRE((fpid = fork()) != -1);
if (fpid == 0) {
trace_me();
follow_fork_parent();
}
/* Parent process. */
children[0] = fpid;
/* The first wait() should report the stop from SIGSTOP. */
wpid = waitpid(children[0], &status, 0);
ATF_REQUIRE(wpid == children[0]);
ATF_REQUIRE(WIFSTOPPED(status));
ATF_REQUIRE(WSTOPSIG(status) == SIGSTOP);
ATF_REQUIRE(ptrace(PT_FOLLOW_FORK, children[0], NULL, 1) != -1);
/* Continue the child ignoring the SIGSTOP. */
ATF_REQUIRE(ptrace(PT_CONTINUE, children[0], (caddr_t)1, 0) != -1);
children[1] = handle_fork_events(children[0]);
ATF_REQUIRE(children[1] > 0);
ATF_REQUIRE(ptrace(PT_CONTINUE, children[0], (caddr_t)1, 0) != -1);
ATF_REQUIRE(ptrace(PT_CONTINUE, children[1], (caddr_t)1, 0) != -1);
/*
* The child can't exit until the grandchild reports status, so the
* grandchild should report its exit first to the debugger.
*/
wpid = wait(&status);
ATF_REQUIRE(wpid == children[1]);
ATF_REQUIRE(WIFEXITED(status));
ATF_REQUIRE(WEXITSTATUS(status) == 2);
wpid = wait(&status);
ATF_REQUIRE(wpid == children[0]);
ATF_REQUIRE(WIFEXITED(status));
ATF_REQUIRE(WEXITSTATUS(status) == 1);
wpid = wait(&status);
ATF_REQUIRE(wpid == -1);
ATF_REQUIRE(errno == ECHILD);
}
/*
* Verify that a new child process is stopped after a followed fork
* and that the traced parent sees the exit of the child when the new
* child process is detached after it reports its fork.
*/
ATF_TC_WITHOUT_HEAD(ptrace__follow_fork_child_detached);
ATF_TC_BODY(ptrace__follow_fork_child_detached, tc)
{
pid_t children[2], fpid, wpid;
int status;
ATF_REQUIRE((fpid = fork()) != -1);
if (fpid == 0) {
trace_me();
follow_fork_parent();
}
/* Parent process. */
children[0] = fpid;
/* The first wait() should report the stop from SIGSTOP. */
wpid = waitpid(children[0], &status, 0);
ATF_REQUIRE(wpid == children[0]);
ATF_REQUIRE(WIFSTOPPED(status));
ATF_REQUIRE(WSTOPSIG(status) == SIGSTOP);
ATF_REQUIRE(ptrace(PT_FOLLOW_FORK, children[0], NULL, 1) != -1);
/* Continue the child ignoring the SIGSTOP. */
ATF_REQUIRE(ptrace(PT_CONTINUE, children[0], (caddr_t)1, 0) != -1);
children[1] = handle_fork_events(children[0]);
ATF_REQUIRE(children[1] > 0);
ATF_REQUIRE(ptrace(PT_CONTINUE, children[0], (caddr_t)1, 0) != -1);
ATF_REQUIRE(ptrace(PT_DETACH, children[1], (caddr_t)1, 0) != -1);
/*
* Should not see any status from the grandchild now, only the
* child.
*/
wpid = wait(&status);
ATF_REQUIRE(wpid == children[0]);
ATF_REQUIRE(WIFEXITED(status));
ATF_REQUIRE(WEXITSTATUS(status) == 1);
wpid = wait(&status);
ATF_REQUIRE(wpid == -1);
ATF_REQUIRE(errno == ECHILD);
}
/*
* Verify that a new child process is stopped after a followed fork
* and that the traced parent sees the exit of the child when the
* traced parent is detached after the fork.
*/
ATF_TC_WITHOUT_HEAD(ptrace__follow_fork_parent_detached);
ATF_TC_BODY(ptrace__follow_fork_parent_detached, tc)
{
pid_t children[2], fpid, wpid;
int status;
ATF_REQUIRE((fpid = fork()) != -1);
if (fpid == 0) {
trace_me();
follow_fork_parent();
}
/* Parent process. */
children[0] = fpid;
/* The first wait() should report the stop from SIGSTOP. */
wpid = waitpid(children[0], &status, 0);
ATF_REQUIRE(wpid == children[0]);
ATF_REQUIRE(WIFSTOPPED(status));
ATF_REQUIRE(WSTOPSIG(status) == SIGSTOP);
ATF_REQUIRE(ptrace(PT_FOLLOW_FORK, children[0], NULL, 1) != -1);
/* Continue the child ignoring the SIGSTOP. */
ATF_REQUIRE(ptrace(PT_CONTINUE, children[0], (caddr_t)1, 0) != -1);
children[1] = handle_fork_events(children[0]);
ATF_REQUIRE(children[1] > 0);
ATF_REQUIRE(ptrace(PT_DETACH, children[0], (caddr_t)1, 0) != -1);
ATF_REQUIRE(ptrace(PT_CONTINUE, children[1], (caddr_t)1, 0) != -1);
/*
* The child can't exit until the grandchild reports status, so the
* grandchild should report its exit first to the debugger.
*
* Even though the child process is detached, it is still a
* child of the debugger, so it will still report it's exit
* after the grandchild.
*/
wpid = wait(&status);
ATF_REQUIRE(wpid == children[1]);
ATF_REQUIRE(WIFEXITED(status));
ATF_REQUIRE(WEXITSTATUS(status) == 2);
wpid = wait(&status);
ATF_REQUIRE(wpid == children[0]);
ATF_REQUIRE(WIFEXITED(status));
ATF_REQUIRE(WEXITSTATUS(status) == 1);
wpid = wait(&status);
ATF_REQUIRE(wpid == -1);
ATF_REQUIRE(errno == ECHILD);
}
static void
attach_fork_parent(int cpipe[2])
{
pid_t fpid;
close(cpipe[0]);
/* Double-fork to disassociate from the debugger. */
CHILD_REQUIRE((fpid = fork()) != -1);
if (fpid != 0)
exit(3);
/* Send the pid of the disassociated child to the debugger. */
fpid = getpid();
CHILD_REQUIRE(write(cpipe[1], &fpid, sizeof(fpid)) == sizeof(fpid));
/* Wait for the debugger to attach. */
CHILD_REQUIRE(read(cpipe[1], &fpid, sizeof(fpid)) == 0);
}
/*
* Verify that a new child process is stopped after a followed fork and
* that the traced parent sees the exit of the child after the debugger
* when both processes remain attached to the debugger. In this test
* the parent that forks is not a direct child of the debugger.
*/
ATF_TC_WITHOUT_HEAD(ptrace__follow_fork_both_attached_unrelated_debugger);
ATF_TC_BODY(ptrace__follow_fork_both_attached_unrelated_debugger, tc)
{
pid_t children[2], fpid, wpid;
int cpipe[2], status;
ATF_REQUIRE(pipe(cpipe) == 0);
ATF_REQUIRE((fpid = fork()) != -1);
if (fpid == 0) {
attach_fork_parent(cpipe);
follow_fork_parent();
}
/* Parent process. */
close(cpipe[1]);
/* Wait for the direct child to exit. */
wpid = waitpid(fpid, &status, 0);
ATF_REQUIRE(wpid == fpid);
ATF_REQUIRE(WIFEXITED(status));
ATF_REQUIRE(WEXITSTATUS(status) == 3);
/* Read the pid of the fork parent. */
ATF_REQUIRE(read(cpipe[0], &children[0], sizeof(children[0])) ==
sizeof(children[0]));
/* Attach to the fork parent. */
attach_child(children[0]);
ATF_REQUIRE(ptrace(PT_FOLLOW_FORK, children[0], NULL, 1) != -1);
/* Continue the fork parent ignoring the SIGSTOP. */
ATF_REQUIRE(ptrace(PT_CONTINUE, children[0], (caddr_t)1, 0) != -1);
/* Signal the fork parent to continue. */
close(cpipe[0]);
children[1] = handle_fork_events(children[0]);
ATF_REQUIRE(children[1] > 0);
ATF_REQUIRE(ptrace(PT_CONTINUE, children[0], (caddr_t)1, 0) != -1);
ATF_REQUIRE(ptrace(PT_CONTINUE, children[1], (caddr_t)1, 0) != -1);
/*
* The fork parent can't exit until the child reports status,
* so the child should report its exit first to the debugger.
*/
wpid = wait(&status);
ATF_REQUIRE(wpid == children[1]);
ATF_REQUIRE(WIFEXITED(status));
ATF_REQUIRE(WEXITSTATUS(status) == 2);
wpid = wait(&status);
ATF_REQUIRE(wpid == children[0]);
ATF_REQUIRE(WIFEXITED(status));
ATF_REQUIRE(WEXITSTATUS(status) == 1);
wpid = wait(&status);
ATF_REQUIRE(wpid == -1);
ATF_REQUIRE(errno == ECHILD);
}
/*
* Verify that a new child process is stopped after a followed fork
* and that the traced parent sees the exit of the child when the new
* child process is detached after it reports its fork. In this test
* the parent that forks is not a direct child of the debugger.
*/
ATF_TC_WITHOUT_HEAD(ptrace__follow_fork_child_detached_unrelated_debugger);
ATF_TC_BODY(ptrace__follow_fork_child_detached_unrelated_debugger, tc)
{
pid_t children[2], fpid, wpid;
int cpipe[2], status;
ATF_REQUIRE(pipe(cpipe) == 0);
ATF_REQUIRE((fpid = fork()) != -1);
if (fpid == 0) {
attach_fork_parent(cpipe);
follow_fork_parent();
}
/* Parent process. */
close(cpipe[1]);
/* Wait for the direct child to exit. */
wpid = waitpid(fpid, &status, 0);
ATF_REQUIRE(wpid == fpid);
ATF_REQUIRE(WIFEXITED(status));
ATF_REQUIRE(WEXITSTATUS(status) == 3);
/* Read the pid of the fork parent. */
ATF_REQUIRE(read(cpipe[0], &children[0], sizeof(children[0])) ==
sizeof(children[0]));
/* Attach to the fork parent. */
attach_child(children[0]);
ATF_REQUIRE(ptrace(PT_FOLLOW_FORK, children[0], NULL, 1) != -1);
/* Continue the fork parent ignoring the SIGSTOP. */
ATF_REQUIRE(ptrace(PT_CONTINUE, children[0], (caddr_t)1, 0) != -1);
/* Signal the fork parent to continue. */
close(cpipe[0]);
children[1] = handle_fork_events(children[0]);
ATF_REQUIRE(children[1] > 0);
ATF_REQUIRE(ptrace(PT_CONTINUE, children[0], (caddr_t)1, 0) != -1);
ATF_REQUIRE(ptrace(PT_DETACH, children[1], (caddr_t)1, 0) != -1);
/*
* Should not see any status from the child now, only the fork
* parent.
*/
wpid = wait(&status);
ATF_REQUIRE(wpid == children[0]);
ATF_REQUIRE(WIFEXITED(status));
ATF_REQUIRE(WEXITSTATUS(status) == 1);
wpid = wait(&status);
ATF_REQUIRE(wpid == -1);
ATF_REQUIRE(errno == ECHILD);
}
/*
* Verify that a new child process is stopped after a followed fork
* and that the traced parent sees the exit of the child when the
* traced parent is detached after the fork. In this test the parent
* that forks is not a direct child of the debugger.
*/
ATF_TC_WITHOUT_HEAD(ptrace__follow_fork_parent_detached_unrelated_debugger);
ATF_TC_BODY(ptrace__follow_fork_parent_detached_unrelated_debugger, tc)
{
pid_t children[2], fpid, wpid;
int cpipe[2], status;
ATF_REQUIRE(pipe(cpipe) == 0);
ATF_REQUIRE((fpid = fork()) != -1);
if (fpid == 0) {
attach_fork_parent(cpipe);
follow_fork_parent();
}
/* Parent process. */
close(cpipe[1]);
/* Wait for the direct child to exit. */
wpid = waitpid(fpid, &status, 0);
ATF_REQUIRE(wpid == fpid);
ATF_REQUIRE(WIFEXITED(status));
ATF_REQUIRE(WEXITSTATUS(status) == 3);
/* Read the pid of the fork parent. */
ATF_REQUIRE(read(cpipe[0], &children[0], sizeof(children[0])) ==
sizeof(children[0]));
/* Attach to the fork parent. */
attach_child(children[0]);
ATF_REQUIRE(ptrace(PT_FOLLOW_FORK, children[0], NULL, 1) != -1);
/* Continue the fork parent ignoring the SIGSTOP. */
ATF_REQUIRE(ptrace(PT_CONTINUE, children[0], (caddr_t)1, 0) != -1);
/* Signal the fork parent to continue. */
close(cpipe[0]);
children[1] = handle_fork_events(children[0]);
ATF_REQUIRE(children[1] > 0);
ATF_REQUIRE(ptrace(PT_DETACH, children[0], (caddr_t)1, 0) != -1);
ATF_REQUIRE(ptrace(PT_CONTINUE, children[1], (caddr_t)1, 0) != -1);
/*
* Should not see any status from the fork parent now, only
* the child.
*/
wpid = wait(&status);
ATF_REQUIRE(wpid == children[1]);
ATF_REQUIRE(WIFEXITED(status));
ATF_REQUIRE(WEXITSTATUS(status) == 2);
wpid = wait(&status);
ATF_REQUIRE(wpid == -1);
ATF_REQUIRE(errno == ECHILD);
}
/*
* Verify that a child process does not see an unrelated debugger as its
* parent but sees its original parent process.
*/
ATF_TC_WITHOUT_HEAD(ptrace__getppid);
ATF_TC_BODY(ptrace__getppid, tc)
{
pid_t child, debugger, ppid, wpid;
int cpipe[2], dpipe[2], status;
char c;
ATF_REQUIRE(pipe(cpipe) == 0);
ATF_REQUIRE((child = fork()) != -1);
if (child == 0) {
/* Child process. */
close(cpipe[0]);
/* Wait for parent to be ready. */
CHILD_REQUIRE(read(cpipe[1], &c, sizeof(c)) == sizeof(c));
/* Report the parent PID to the parent. */
ppid = getppid();
CHILD_REQUIRE(write(cpipe[1], &ppid, sizeof(ppid)) ==
sizeof(ppid));
_exit(1);
}
close(cpipe[1]);
ATF_REQUIRE(pipe(dpipe) == 0);
ATF_REQUIRE((debugger = fork()) != -1);
if (debugger == 0) {
/* Debugger process. */
close(dpipe[0]);
CHILD_REQUIRE(ptrace(PT_ATTACH, child, NULL, 0) != -1);
wpid = waitpid(child, &status, 0);
CHILD_REQUIRE(wpid == child);
CHILD_REQUIRE(WIFSTOPPED(status));
CHILD_REQUIRE(WSTOPSIG(status) == SIGSTOP);
CHILD_REQUIRE(ptrace(PT_CONTINUE, child, (caddr_t)1, 0) != -1);
/* Signal parent that debugger is attached. */
CHILD_REQUIRE(write(dpipe[1], &c, sizeof(c)) == sizeof(c));
/* Wait for traced child to exit. */
wpid = waitpid(child, &status, 0);
CHILD_REQUIRE(wpid == child);
CHILD_REQUIRE(WIFEXITED(status));
CHILD_REQUIRE(WEXITSTATUS(status) == 1);
_exit(0);
}
close(dpipe[1]);
/* Parent process. */
/* Wait for the debugger to attach to the child. */
ATF_REQUIRE(read(dpipe[0], &c, sizeof(c)) == sizeof(c));
/* Release the child. */
ATF_REQUIRE(write(cpipe[0], &c, sizeof(c)) == sizeof(c));
/* Read the parent PID from the child. */
ATF_REQUIRE(read(cpipe[0], &ppid, sizeof(ppid)) == sizeof(ppid));
close(cpipe[0]);
ATF_REQUIRE(ppid == getpid());
/* Wait for the debugger. */
wpid = waitpid(debugger, &status, 0);
ATF_REQUIRE(wpid == debugger);
ATF_REQUIRE(WIFEXITED(status));
ATF_REQUIRE(WEXITSTATUS(status) == 0);
/* The child process should now be ready. */
wpid = waitpid(child, &status, WNOHANG);
ATF_REQUIRE(wpid == child);
ATF_REQUIRE(WIFEXITED(status));
ATF_REQUIRE(WEXITSTATUS(status) == 1);
}
ATF_TP_ADD_TCS(tp)
{
ATF_TP_ADD_TC(tp, ptrace__parent_wait_after_trace_me);
ATF_TP_ADD_TC(tp, ptrace__parent_wait_after_attach);
ATF_TP_ADD_TC(tp, ptrace__parent_sees_exit_after_child_debugger);
ATF_TP_ADD_TC(tp, ptrace__parent_sees_exit_after_unrelated_debugger);
ATF_TP_ADD_TC(tp, ptrace__follow_fork_both_attached);
ATF_TP_ADD_TC(tp, ptrace__follow_fork_child_detached);
ATF_TP_ADD_TC(tp, ptrace__follow_fork_parent_detached);
ATF_TP_ADD_TC(tp, ptrace__follow_fork_both_attached_unrelated_debugger);
ATF_TP_ADD_TC(tp,
ptrace__follow_fork_child_detached_unrelated_debugger);
ATF_TP_ADD_TC(tp,
ptrace__follow_fork_parent_detached_unrelated_debugger);
ATF_TP_ADD_TC(tp, ptrace__getppid);
return (atf_no_error());
}