| From 1234063488134ad1f541f56dd30caa7896905f06 Mon Sep 17 00:00:00 2001 |
| From: Ilya Leoshkevich <iii@linux.ibm.com> |
| Date: Wed, 28 Feb 2024 10:25:18 -1000 |
| Subject: [PATCH 5/5] tests/tcg: Check that shmat() does not break |
| /proc/self/maps |
| |
| 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. |
| |
| Upstream-Status: Submitted [https://www.mail-archive.com/qemu-devel@nongnu.org/msg1026793.html] |
| |
| Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com> |
| Message-Id: <jwyuvao4apydvykmsnvacwshdgy3ixv7qvkh4dbxm3jkwgnttw@k4wpaayou7oq> |
| Signed-off-by: Richard Henderson <richard.henderson@linaro.org> |
| Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org> |
| --- |
| tests/tcg/multiarch/linux/linux-shmat-maps.c | 55 ++++++++++++++++++++ |
| 1 file changed, 55 insertions(+) |
| create mode 100644 tests/tcg/multiarch/linux/linux-shmat-maps.c |
| |
| diff --git a/tests/tcg/multiarch/linux/linux-shmat-maps.c b/tests/tcg/multiarch/linux/linux-shmat-maps.c |
| new file mode 100644 |
| index 000000000..0ccf7a973 |
| --- /dev/null |
| +++ b/tests/tcg/multiarch/linux/linux-shmat-maps.c |
| @@ -0,0 +1,55 @@ |
| +/* |
| + * 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; |
| +} |
| -- |
| 2.34.1 |
| |