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| // SPDX-License-Identifier: GPL-2.0+
| /*
| * Copyright (c) 2020 Bernd Edlinger <bernd.edlinger@hotmail.de>
| * All rights reserved.
| *
| * Check whether /proc/$pid/mem can be accessed without causing deadlocks
| * when de_thread is blocked with ->cred_guard_mutex held.
| */
|
| #include "../kselftest_harness.h"
| #include <stdio.h>
| #include <fcntl.h>
| #include <pthread.h>
| #include <signal.h>
| #include <unistd.h>
| #include <sys/ptrace.h>
|
| static void *thread(void *arg)
| {
| ptrace(PTRACE_TRACEME, 0, 0L, 0L);
| return NULL;
| }
|
| TEST(vmaccess)
| {
| int f, pid = fork();
| char mm[64];
|
| if (!pid) {
| pthread_t pt;
|
| pthread_create(&pt, NULL, thread, NULL);
| pthread_join(pt, NULL);
| execlp("true", "true", NULL);
| }
|
| sleep(1);
| sprintf(mm, "/proc/%d/mem", pid);
| f = open(mm, O_RDONLY);
| ASSERT_GE(f, 0);
| close(f);
| f = kill(pid, SIGCONT);
| ASSERT_EQ(f, 0);
| }
|
| TEST(attach)
| {
| int s, k, pid = fork();
|
| if (!pid) {
| pthread_t pt;
|
| pthread_create(&pt, NULL, thread, NULL);
| pthread_join(pt, NULL);
| execlp("sleep", "sleep", "2", NULL);
| }
|
| sleep(1);
| k = ptrace(PTRACE_ATTACH, pid, 0L, 0L);
| ASSERT_EQ(errno, EAGAIN);
| ASSERT_EQ(k, -1);
| k = waitpid(-1, &s, WNOHANG);
| ASSERT_NE(k, -1);
| ASSERT_NE(k, 0);
| ASSERT_NE(k, pid);
| ASSERT_EQ(WIFEXITED(s), 1);
| ASSERT_EQ(WEXITSTATUS(s), 0);
| sleep(1);
| k = ptrace(PTRACE_ATTACH, pid, 0L, 0L);
| ASSERT_EQ(k, 0);
| k = waitpid(-1, &s, 0);
| ASSERT_EQ(k, pid);
| ASSERT_EQ(WIFSTOPPED(s), 1);
| ASSERT_EQ(WSTOPSIG(s), SIGSTOP);
| k = ptrace(PTRACE_DETACH, pid, 0L, 0L);
| ASSERT_EQ(k, 0);
| k = waitpid(-1, &s, 0);
| ASSERT_EQ(k, pid);
| ASSERT_EQ(WIFEXITED(s), 1);
| ASSERT_EQ(WEXITSTATUS(s), 0);
| k = waitpid(-1, NULL, 0);
| ASSERT_EQ(k, -1);
| ASSERT_EQ(errno, ECHILD);
| }
|
| TEST_HARNESS_MAIN
|
|
