mbligh | 2b8cd19 | 2008-11-20 17:27:17 +0000 | [diff] [blame] | 1 | #include <stdio.h> |
| 2 | #include <stdlib.h> |
| 3 | #include <sys/mman.h> |
| 4 | #include <unistd.h> |
| 5 | #include <fcntl.h> |
| 6 | |
| 7 | /* This file includes a simple set of memory allocation calls that |
| 8 | * a user space program can use to allocate/free or move memory mappings. |
| 9 | * The intent of this program is to make it easier to verify if the kernel |
| 10 | * internal mappings are correct. |
| 11 | */ |
| 12 | |
| 13 | #define PAGE_SHIFT 12 |
| 14 | |
| 15 | #define ROUND_PAGES(memsize) ((memsize >> (PAGE_SHIFT)) << PAGE_SHIFT) |
| 16 | |
| 17 | /* approximately half of memsize, page aligned */ |
| 18 | #define HALF_MEM(memsize) ((memsize >> (PAGE_SHIFT))<<(PAGE_SHIFT - 1)) |
| 19 | |
| 20 | inline void waitnext() { |
| 21 | fflush(NULL); |
| 22 | getchar(); |
| 23 | } |
| 24 | |
| 25 | int main(int argc, char *argv[]) { |
| 26 | unsigned int memsize; |
| 27 | char *mem; |
| 28 | int i, numpages, fd; |
| 29 | |
| 30 | if (argc != 2) { |
| 31 | printf("Usage: %s <memory_size>\n", argv[0]); |
| 32 | exit(EXIT_FAILURE); |
| 33 | } |
| 34 | |
| 35 | memsize = strtoul(argv[1], NULL, 10); |
| 36 | |
| 37 | memsize = ROUND_PAGES(memsize); |
| 38 | |
| 39 | /* We should be limited to < 4G so any size other than 0 is ok */ |
| 40 | if (memsize == 0) { |
| 41 | printf("Invalid memsize\n"); |
| 42 | exit(EXIT_FAILURE); |
| 43 | } |
| 44 | |
| 45 | |
| 46 | numpages = memsize >> PAGE_SHIFT; |
| 47 | |
| 48 | mlockall(MCL_FUTURE); |
| 49 | |
| 50 | mem = sbrk(memsize); |
| 51 | |
| 52 | if (mem == (void*) -1) { |
| 53 | perror("Failed to allocate memory using sbrk\n"); |
| 54 | exit(EXIT_FAILURE); |
| 55 | } |
| 56 | |
| 57 | printf("Successfully allocated sbrk memory %d bytes @%p\n", |
| 58 | memsize, mem); |
| 59 | |
| 60 | waitnext(); |
| 61 | |
| 62 | sbrk(-(memsize)); |
| 63 | |
| 64 | mem = mmap(0, memsize, PROT_READ | PROT_WRITE, |
| 65 | MAP_PRIVATE| MAP_ANONYMOUS, |
| 66 | -1, 0); |
| 67 | |
| 68 | if (mem == (void*) -1) { |
| 69 | perror("Failed to allocate anon private memory using mmap\n"); |
| 70 | exit(EXIT_FAILURE); |
| 71 | } |
| 72 | |
| 73 | printf("Successfully allocated anon mmap memory %d bytes @%p\n", |
| 74 | memsize, mem); |
| 75 | |
| 76 | waitnext(); |
| 77 | |
| 78 | if (-1 == mprotect(mem, HALF_MEM(memsize), PROT_READ)) { |
| 79 | perror("Failed to W protect memory using mprotect\n"); |
| 80 | exit(EXIT_FAILURE); |
| 81 | } |
| 82 | |
| 83 | printf("Successfully write protected %d bytes @%p\n", |
| 84 | HALF_MEM(memsize), mem); |
| 85 | |
| 86 | waitnext(); |
| 87 | |
| 88 | if (-1 == mprotect(mem, HALF_MEM(memsize), |
| 89 | PROT_READ | PROT_WRITE)) { |
| 90 | perror("Failed to RW protect memory using mprotect\n"); |
| 91 | exit(EXIT_FAILURE); |
| 92 | } |
| 93 | |
| 94 | printf("Successfully cleared write protected %d bytes @%p\n", |
| 95 | memsize, mem); |
| 96 | waitnext(); |
| 97 | |
| 98 | /* Mark all pages with a specific pattern */ |
| 99 | for (i = 0; i < numpages; i++) { |
| 100 | int *ptr = (int *)(mem + i*4096); |
| 101 | *ptr = i; |
| 102 | } |
| 103 | |
| 104 | mem = mremap(mem , memsize, |
| 105 | memsize + HALF_MEM(memsize), |
| 106 | 1 /* MREMAP_MAYMOVE */); |
| 107 | |
| 108 | if (mem == MAP_FAILED) { |
| 109 | perror("Failed to remap expand anon private memory\n"); |
| 110 | exit(EXIT_FAILURE); |
| 111 | } |
| 112 | |
| 113 | printf("Successfully remapped %d bytes @%p\n", |
| 114 | memsize + HALF_MEM(memsize), mem); |
| 115 | |
| 116 | waitnext(); |
| 117 | |
| 118 | /* Mark all pages with a specific pattern */ |
| 119 | for (i = 0; i < numpages; i++) { |
| 120 | int value = *(int*)(mem + i*4096); |
| 121 | if (value != i) { |
| 122 | printf("remap error expected %d got %d\n", |
| 123 | i, value); |
| 124 | exit(EXIT_FAILURE); |
| 125 | } |
| 126 | } |
| 127 | |
| 128 | if (munmap(mem, memsize + HALF_MEM(memsize))) { |
| 129 | perror("Could not unmap and free memory\n"); |
| 130 | exit(EXIT_FAILURE); |
| 131 | } |
| 132 | |
| 133 | |
| 134 | fd = open("/dev/zero", O_RDONLY); |
| 135 | |
| 136 | mem = mmap(0, memsize, PROT_READ | PROT_WRITE, |
| 137 | MAP_PRIVATE, |
| 138 | fd, 0); |
| 139 | |
| 140 | if (mem == (void*) -1) { |
| 141 | perror("Failed to allocate file backed memory using mmap\n"); |
| 142 | exit(EXIT_FAILURE); |
| 143 | } |
| 144 | |
| 145 | printf("Successfully allocated file backed mmap memory %d bytes @%p\n", |
| 146 | memsize, mem); |
| 147 | waitnext(); |
| 148 | |
| 149 | if (munmap(mem, memsize)) { |
| 150 | perror("Could not unmap and free file backed memory\n"); |
| 151 | exit(EXIT_FAILURE); |
| 152 | } |
| 153 | |
| 154 | exit(EXIT_SUCCESS); |
| 155 | } |