diff options
Diffstat (limited to 'tools/testing/selftests/vm/map_fixed_noreplace.c')
| -rw-r--r-- | tools/testing/selftests/vm/map_fixed_noreplace.c | 206 |
1 files changed, 206 insertions, 0 deletions
diff --git a/tools/testing/selftests/vm/map_fixed_noreplace.c b/tools/testing/selftests/vm/map_fixed_noreplace.c new file mode 100644 index 0000000..d91bde5 --- /dev/null +++ b/tools/testing/selftests/vm/map_fixed_noreplace.c @@ -0,0 +1,206 @@ +// SPDX-License-Identifier: GPL-2.0 + +/* + * Test that MAP_FIXED_NOREPLACE works. + * + * Copyright 2018, Jann Horn <jannh@google.com> + * Copyright 2018, Michael Ellerman, IBM Corporation. + */ + +#include <sys/mman.h> +#include <errno.h> +#include <stdio.h> +#include <stdlib.h> +#include <unistd.h> + +#ifndef MAP_FIXED_NOREPLACE +#define MAP_FIXED_NOREPLACE 0x100000 +#endif + +#define BASE_ADDRESS (256ul * 1024 * 1024) + + +static void dump_maps(void) +{ + char cmd[32]; + + snprintf(cmd, sizeof(cmd), "cat /proc/%d/maps", getpid()); + system(cmd); +} + +int main(void) +{ + unsigned long flags, addr, size, page_size; + char *p; + + page_size = sysconf(_SC_PAGE_SIZE); + + flags = MAP_PRIVATE | MAP_ANONYMOUS | MAP_FIXED_NOREPLACE; + + // Check we can map all the areas we need below + errno = 0; + addr = BASE_ADDRESS; + size = 5 * page_size; + p = mmap((void *)addr, size, PROT_NONE, flags, -1, 0); + + printf("mmap() @ 0x%lx-0x%lx p=%p result=%m\n", addr, addr + size, p); + + if (p == MAP_FAILED) { + dump_maps(); + printf("Error: couldn't map the space we need for the test\n"); + return 1; + } + + errno = 0; + if (munmap((void *)addr, 5 * page_size) != 0) { + dump_maps(); + printf("Error: munmap failed!?\n"); + return 1; + } + printf("unmap() successful\n"); + + errno = 0; + addr = BASE_ADDRESS + page_size; + size = 3 * page_size; + p = mmap((void *)addr, size, PROT_NONE, flags, -1, 0); + printf("mmap() @ 0x%lx-0x%lx p=%p result=%m\n", addr, addr + size, p); + + if (p == MAP_FAILED) { + dump_maps(); + printf("Error: first mmap() failed unexpectedly\n"); + return 1; + } + + /* + * Exact same mapping again: + * base | free | new + * +1 | mapped | new + * +2 | mapped | new + * +3 | mapped | new + * +4 | free | new + */ + errno = 0; + addr = BASE_ADDRESS; + size = 5 * page_size; + p = mmap((void *)addr, size, PROT_NONE, flags, -1, 0); + printf("mmap() @ 0x%lx-0x%lx p=%p result=%m\n", addr, addr + size, p); + + if (p != MAP_FAILED) { + dump_maps(); + printf("Error:1: mmap() succeeded when it shouldn't have\n"); + return 1; + } + + /* + * Second mapping contained within first: + * + * base | free | + * +1 | mapped | + * +2 | mapped | new + * +3 | mapped | + * +4 | free | + */ + errno = 0; + addr = BASE_ADDRESS + (2 * page_size); + size = page_size; + p = mmap((void *)addr, size, PROT_NONE, flags, -1, 0); + printf("mmap() @ 0x%lx-0x%lx p=%p result=%m\n", addr, addr + size, p); + + if (p != MAP_FAILED) { + dump_maps(); + printf("Error:2: mmap() succeeded when it shouldn't have\n"); + return 1; + } + + /* + * Overlap end of existing mapping: + * base | free | + * +1 | mapped | + * +2 | mapped | + * +3 | mapped | new + * +4 | free | new + */ + errno = 0; + addr = BASE_ADDRESS + (3 * page_size); + size = 2 * page_size; + p = mmap((void *)addr, size, PROT_NONE, flags, -1, 0); + printf("mmap() @ 0x%lx-0x%lx p=%p result=%m\n", addr, addr + size, p); + + if (p != MAP_FAILED) { + dump_maps(); + printf("Error:3: mmap() succeeded when it shouldn't have\n"); + return 1; + } + + /* + * Overlap start of existing mapping: + * base | free | new + * +1 | mapped | new + * +2 | mapped | + * +3 | mapped | + * +4 | free | + */ + errno = 0; + addr = BASE_ADDRESS; + size = 2 * page_size; + p = mmap((void *)addr, size, PROT_NONE, flags, -1, 0); + printf("mmap() @ 0x%lx-0x%lx p=%p result=%m\n", addr, addr + size, p); + + if (p != MAP_FAILED) { + dump_maps(); + printf("Error:4: mmap() succeeded when it shouldn't have\n"); + return 1; + } + + /* + * Adjacent to start of existing mapping: + * base | free | new + * +1 | mapped | + * +2 | mapped | + * +3 | mapped | + * +4 | free | + */ + errno = 0; + addr = BASE_ADDRESS; + size = page_size; + p = mmap((void *)addr, size, PROT_NONE, flags, -1, 0); + printf("mmap() @ 0x%lx-0x%lx p=%p result=%m\n", addr, addr + size, p); + + if (p == MAP_FAILED) { + dump_maps(); + printf("Error:5: mmap() failed when it shouldn't have\n"); + return 1; + } + + /* + * Adjacent to end of existing mapping: + * base | free | + * +1 | mapped | + * +2 | mapped | + * +3 | mapped | + * +4 | free | new + */ + errno = 0; + addr = BASE_ADDRESS + (4 * page_size); + size = page_size; + p = mmap((void *)addr, size, PROT_NONE, flags, -1, 0); + printf("mmap() @ 0x%lx-0x%lx p=%p result=%m\n", addr, addr + size, p); + + if (p == MAP_FAILED) { + dump_maps(); + printf("Error:6: mmap() failed when it shouldn't have\n"); + return 1; + } + + addr = BASE_ADDRESS; + size = 5 * page_size; + if (munmap((void *)addr, size) != 0) { + dump_maps(); + printf("Error: munmap failed!?\n"); + return 1; + } + printf("unmap() successful\n"); + + printf("OK\n"); + return 0; +} |
