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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
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