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/*
* Test that shmat() does not break /proc/self/maps.
*
* SPDX-License-Identifier: GPL-2.0-or-later
*/
#include <assert.h>
#include <fcntl.h>
#include <stdlib.h>
#include <sys/ipc.h>
#include <sys/shm.h>
#include <unistd.h>
int main(void)
{
char buf[128];
int err, fd;
int shmid;
ssize_t n;
void *p;
shmid = shmget(IPC_PRIVATE, 1, IPC_CREAT | 0600);
assert(shmid != -1);
/*
* The original bug required a non-NULL address, which skipped the
* mmap_find_vma step, which could result in a host mapping smaller
* than the target mapping. Choose an address at random.
*/
p = shmat(shmid, (void *)0x800000, SHM_RND);
if (p == (void *)-1) {
/*
* Because we are now running the testcase for all guests for which
* we have a cross-compiler, the above random address might conflict
* with the guest executable in some way. Rather than stopping,
* continue with a system supplied address, which should never fail.
*/
p = shmat(shmid, NULL, 0);
assert(p != (void *)-1);
}
fd = open("/proc/self/maps", O_RDONLY);
assert(fd != -1);
do {
n = read(fd, buf, sizeof(buf));
assert(n >= 0);
} while (n != 0);
close(fd);
err = shmdt(p);
assert(err == 0);
err = shmctl(shmid, IPC_RMID, NULL);
assert(err == 0);
return EXIT_SUCCESS;
}
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