04dadd22ae
Add a regression test for a recently fixed issue, where shmat()
desynced the guest and the host view of the address space and caused
open("/proc/self/maps") to SEGV.
Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>
Message-Id: <jwyuvao4apydvykmsnvacwshdgy3ixv7qvkh4dbxm3jkwgnttw@k4wpaayou7oq>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
56 lines
1.4 KiB
C
56 lines
1.4 KiB
C
/*
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* Test that shmat() does not break /proc/self/maps.
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*
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* SPDX-License-Identifier: GPL-2.0-or-later
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*/
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#include <assert.h>
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#include <fcntl.h>
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#include <stdlib.h>
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#include <sys/ipc.h>
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#include <sys/shm.h>
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#include <unistd.h>
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int main(void)
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{
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char buf[128];
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int err, fd;
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int shmid;
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ssize_t n;
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void *p;
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shmid = shmget(IPC_PRIVATE, 1, IPC_CREAT | 0600);
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assert(shmid != -1);
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/*
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* The original bug required a non-NULL address, which skipped the
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* mmap_find_vma step, which could result in a host mapping smaller
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* than the target mapping. Choose an address at random.
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*/
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p = shmat(shmid, (void *)0x800000, SHM_RND);
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if (p == (void *)-1) {
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/*
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* Because we are now running the testcase for all guests for which
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* we have a cross-compiler, the above random address might conflict
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* with the guest executable in some way. Rather than stopping,
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* continue with a system supplied address, which should never fail.
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*/
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p = shmat(shmid, NULL, 0);
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assert(p != (void *)-1);
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}
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fd = open("/proc/self/maps", O_RDONLY);
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assert(fd != -1);
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do {
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n = read(fd, buf, sizeof(buf));
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assert(n >= 0);
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} while (n != 0);
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close(fd);
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err = shmdt(p);
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assert(err == 0);
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err = shmctl(shmid, IPC_RMID, NULL);
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assert(err == 0);
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return EXIT_SUCCESS;
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}
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