87 lines
1.7 KiB
C
87 lines
1.7 KiB
C
// 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
|