162306a36Sopenharmony_ci// SPDX-License-Identifier: GPL-2.0+ 262306a36Sopenharmony_ci/* 362306a36Sopenharmony_ci * Copyright (c) 2020 Bernd Edlinger <bernd.edlinger@hotmail.de> 462306a36Sopenharmony_ci * All rights reserved. 562306a36Sopenharmony_ci * 662306a36Sopenharmony_ci * Check whether /proc/$pid/mem can be accessed without causing deadlocks 762306a36Sopenharmony_ci * when de_thread is blocked with ->cred_guard_mutex held. 862306a36Sopenharmony_ci */ 962306a36Sopenharmony_ci 1062306a36Sopenharmony_ci#include "../kselftest_harness.h" 1162306a36Sopenharmony_ci#include <stdio.h> 1262306a36Sopenharmony_ci#include <fcntl.h> 1362306a36Sopenharmony_ci#include <pthread.h> 1462306a36Sopenharmony_ci#include <signal.h> 1562306a36Sopenharmony_ci#include <unistd.h> 1662306a36Sopenharmony_ci#include <sys/ptrace.h> 1762306a36Sopenharmony_ci 1862306a36Sopenharmony_cistatic void *thread(void *arg) 1962306a36Sopenharmony_ci{ 2062306a36Sopenharmony_ci ptrace(PTRACE_TRACEME, 0, 0L, 0L); 2162306a36Sopenharmony_ci return NULL; 2262306a36Sopenharmony_ci} 2362306a36Sopenharmony_ci 2462306a36Sopenharmony_ciTEST(vmaccess) 2562306a36Sopenharmony_ci{ 2662306a36Sopenharmony_ci int f, pid = fork(); 2762306a36Sopenharmony_ci char mm[64]; 2862306a36Sopenharmony_ci 2962306a36Sopenharmony_ci if (!pid) { 3062306a36Sopenharmony_ci pthread_t pt; 3162306a36Sopenharmony_ci 3262306a36Sopenharmony_ci pthread_create(&pt, NULL, thread, NULL); 3362306a36Sopenharmony_ci pthread_join(pt, NULL); 3462306a36Sopenharmony_ci execlp("true", "true", NULL); 3562306a36Sopenharmony_ci } 3662306a36Sopenharmony_ci 3762306a36Sopenharmony_ci sleep(1); 3862306a36Sopenharmony_ci sprintf(mm, "/proc/%d/mem", pid); 3962306a36Sopenharmony_ci f = open(mm, O_RDONLY); 4062306a36Sopenharmony_ci ASSERT_GE(f, 0); 4162306a36Sopenharmony_ci close(f); 4262306a36Sopenharmony_ci f = kill(pid, SIGCONT); 4362306a36Sopenharmony_ci ASSERT_EQ(f, 0); 4462306a36Sopenharmony_ci} 4562306a36Sopenharmony_ci 4662306a36Sopenharmony_ciTEST(attach) 4762306a36Sopenharmony_ci{ 4862306a36Sopenharmony_ci int s, k, pid = fork(); 4962306a36Sopenharmony_ci 5062306a36Sopenharmony_ci if (!pid) { 5162306a36Sopenharmony_ci pthread_t pt; 5262306a36Sopenharmony_ci 5362306a36Sopenharmony_ci pthread_create(&pt, NULL, thread, NULL); 5462306a36Sopenharmony_ci pthread_join(pt, NULL); 5562306a36Sopenharmony_ci execlp("sleep", "sleep", "2", NULL); 5662306a36Sopenharmony_ci } 5762306a36Sopenharmony_ci 5862306a36Sopenharmony_ci sleep(1); 5962306a36Sopenharmony_ci k = ptrace(PTRACE_ATTACH, pid, 0L, 0L); 6062306a36Sopenharmony_ci ASSERT_EQ(errno, EAGAIN); 6162306a36Sopenharmony_ci ASSERT_EQ(k, -1); 6262306a36Sopenharmony_ci k = waitpid(-1, &s, WNOHANG); 6362306a36Sopenharmony_ci ASSERT_NE(k, -1); 6462306a36Sopenharmony_ci ASSERT_NE(k, 0); 6562306a36Sopenharmony_ci ASSERT_NE(k, pid); 6662306a36Sopenharmony_ci ASSERT_EQ(WIFEXITED(s), 1); 6762306a36Sopenharmony_ci ASSERT_EQ(WEXITSTATUS(s), 0); 6862306a36Sopenharmony_ci sleep(1); 6962306a36Sopenharmony_ci k = ptrace(PTRACE_ATTACH, pid, 0L, 0L); 7062306a36Sopenharmony_ci ASSERT_EQ(k, 0); 7162306a36Sopenharmony_ci k = waitpid(-1, &s, 0); 7262306a36Sopenharmony_ci ASSERT_EQ(k, pid); 7362306a36Sopenharmony_ci ASSERT_EQ(WIFSTOPPED(s), 1); 7462306a36Sopenharmony_ci ASSERT_EQ(WSTOPSIG(s), SIGSTOP); 7562306a36Sopenharmony_ci k = ptrace(PTRACE_DETACH, pid, 0L, 0L); 7662306a36Sopenharmony_ci ASSERT_EQ(k, 0); 7762306a36Sopenharmony_ci k = waitpid(-1, &s, 0); 7862306a36Sopenharmony_ci ASSERT_EQ(k, pid); 7962306a36Sopenharmony_ci ASSERT_EQ(WIFEXITED(s), 1); 8062306a36Sopenharmony_ci ASSERT_EQ(WEXITSTATUS(s), 0); 8162306a36Sopenharmony_ci k = waitpid(-1, NULL, 0); 8262306a36Sopenharmony_ci ASSERT_EQ(k, -1); 8362306a36Sopenharmony_ci ASSERT_EQ(errno, ECHILD); 8462306a36Sopenharmony_ci} 8562306a36Sopenharmony_ci 8662306a36Sopenharmony_ciTEST_HARNESS_MAIN 87