| 1 | #include <stdint.h> |
| 2 | #include <stdlib.h> |
| 3 | #include <stdio.h> |
| 4 | #include <string.h> |
| 5 | #include <sys/mman.h> |
| 6 | #include <signal.h> |
| 7 | #include <setjmp.h> |
| 8 | |
| 9 | jmp_buf jmp_env; |
| 10 | |
| 11 | static void handle_sigsegv(int sig) |
| 12 | { |
| 13 | siglongjmp(jmp_env, 1); |
| 14 | } |
| 15 | |
| 16 | #define ALLOC_SIZE (2 * 4096) |
| 17 | |
| 18 | static inline void mvc_256(const char *dst, const char *src) |
| 19 | { |
| 20 | asm volatile ( |
| 21 | " mvc 0(256,%[dst]),0(%[src])\n" |
| 22 | : |
| 23 | : [dst] "a" (dst), |
| 24 | [src] "a" (src) |
| 25 | : "memory"); |
| 26 | } |
| 27 | |
| 28 | int main(void) |
| 29 | { |
| 30 | char *src, *dst; |
| 31 | int i; |
| 32 | |
| 33 | /* register the SIGSEGV handler */ |
| 34 | if (signal(SIGSEGV, handle_sigsegv) == SIG_ERR) { |
| 35 | fprintf(stderr, "SIGSEGV not registered\n"); |
| 36 | return 1; |
| 37 | } |
| 38 | |
| 39 | /* prepare the buffers - two consecutive pages */ |
| 40 | src = valloc(ALLOC_SIZE); |
| 41 | dst = valloc(ALLOC_SIZE); |
| 42 | memset(src, 0xff, ALLOC_SIZE); |
| 43 | memset(dst, 0x0, ALLOC_SIZE); |
| 44 | |
| 45 | /* protect the second pages */ |
| 46 | if (mprotect(src + 4096, 4096, PROT_NONE) || |
| 47 | mprotect(dst + 4096, 4096, PROT_NONE)) { |
| 48 | fprintf(stderr, "mprotect failed\n"); |
| 49 | return 1; |
| 50 | } |
| 51 | |
| 52 | /* fault on second destination page */ |
| 53 | if (sigsetjmp(jmp_env, 1) == 0) { |
| 54 | mvc_256(dst + 4096 - 128, src); |
| 55 | fprintf(stderr, "fault not triggered\n"); |
| 56 | return 1; |
| 57 | } |
| 58 | |
| 59 | /* fault on second source page */ |
| 60 | if (sigsetjmp(jmp_env, 1) == 0) { |
| 61 | mvc_256(dst, src + 4096 - 128); |
| 62 | fprintf(stderr, "fault not triggered\n"); |
| 63 | return 1; |
| 64 | } |
| 65 | |
| 66 | /* fault on second source and second destination page */ |
| 67 | if (sigsetjmp(jmp_env, 1) == 0) { |
| 68 | mvc_256(dst + 4096 - 128, src + 4096 - 128); |
| 69 | fprintf(stderr, "fault not triggered\n"); |
| 70 | return 1; |
| 71 | } |
| 72 | |
| 73 | /* restore permissions */ |
| 74 | if (mprotect(src + 4096, 4096, PROT_READ | PROT_WRITE) || |
| 75 | mprotect(dst + 4096, 4096, PROT_READ | PROT_WRITE)) { |
| 76 | fprintf(stderr, "mprotect failed\n"); |
| 77 | return 1; |
| 78 | } |
| 79 | |
| 80 | /* no data must be touched during the faults */ |
| 81 | for (i = 0; i < ALLOC_SIZE; i++) { |
| 82 | if (src[i] != 0xff || dst[i]) { |
| 83 | fprintf(stderr, "data modified during a fault\n"); |
| 84 | return 1; |
| 85 | } |
| 86 | } |
| 87 | |
| 88 | /* test if MVC works now correctly across page boundaries */ |
| 89 | mvc_256(dst + 4096 - 128, src + 4096 - 128); |
| 90 | for (i = 0; i < ALLOC_SIZE; i++) { |
| 91 | if (src[i] != 0xff) { |
| 92 | fprintf(stderr, "src modified\n"); |
| 93 | return 1; |
| 94 | } |
| 95 | if (i < 4096 - 128 || i >= 4096 + 128) { |
| 96 | if (dst[i]) { |
| 97 | fprintf(stderr, "wrong dst modified\n"); |
| 98 | return 1; |
| 99 | } |
| 100 | } else { |
| 101 | if (dst[i] != 0xff) { |
| 102 | fprintf(stderr, "wrong data moved\n"); |
| 103 | return 1; |
| 104 | } |
| 105 | } |
| 106 | } |
| 107 | |
| 108 | return 0; |
| 109 | } |