| #include <stdint.h> |
| #include <stdlib.h> |
| #include <stdio.h> |
| #include <string.h> |
| #include <sys/mman.h> |
| #include <signal.h> |
| #include <setjmp.h> |
| |
| jmp_buf jmp_env; |
| |
| static void handle_sigsegv(int sig) |
| { |
| siglongjmp(jmp_env, 1); |
| } |
| |
| #define ALLOC_SIZE (2 * 4096) |
| |
| static inline void mvc_256(const char *dst, const char *src) |
| { |
| asm volatile ( |
| " mvc 0(256,%[dst]),0(%[src])\n" |
| : |
| : [dst] "d" (dst), |
| [src] "d" (src) |
| : "memory"); |
| } |
| |
| int main(void) |
| { |
| char *src, *dst; |
| int i; |
| |
| /* register the SIGSEGV handler */ |
| if (signal(SIGSEGV, handle_sigsegv) == SIG_ERR) { |
| fprintf(stderr, "SIGSEGV not registered\n"); |
| return 1; |
| } |
| |
| /* prepare the buffers - two consecutive pages */ |
| src = valloc(ALLOC_SIZE); |
| dst = valloc(ALLOC_SIZE); |
| memset(src, 0xff, ALLOC_SIZE); |
| memset(dst, 0x0, ALLOC_SIZE); |
| |
| /* protect the second pages */ |
| if (mprotect(src + 4096, 4096, PROT_NONE) || |
| mprotect(dst + 4096, 4096, PROT_NONE)) { |
| fprintf(stderr, "mprotect failed\n"); |
| return 1; |
| } |
| |
| /* fault on second destination page */ |
| if (sigsetjmp(jmp_env, 1) == 0) { |
| mvc_256(dst + 4096 - 128, src); |
| fprintf(stderr, "fault not triggered\n"); |
| return 1; |
| } |
| |
| /* fault on second source page */ |
| if (sigsetjmp(jmp_env, 1) == 0) { |
| mvc_256(dst, src + 4096 - 128); |
| fprintf(stderr, "fault not triggered\n"); |
| return 1; |
| } |
| |
| /* fault on second source and second destination page */ |
| if (sigsetjmp(jmp_env, 1) == 0) { |
| mvc_256(dst + 4096 - 128, src + 4096 - 128); |
| fprintf(stderr, "fault not triggered\n"); |
| return 1; |
| } |
| |
| /* restore permissions */ |
| if (mprotect(src + 4096, 4096, PROT_READ | PROT_WRITE) || |
| mprotect(dst + 4096, 4096, PROT_READ | PROT_WRITE)) { |
| fprintf(stderr, "mprotect failed\n"); |
| return 1; |
| } |
| |
| /* no data must be touched during the faults */ |
| for (i = 0; i < ALLOC_SIZE; i++) { |
| if (src[i] != 0xff || dst[i]) { |
| fprintf(stderr, "data modified during a fault\n"); |
| return 1; |
| } |
| } |
| |
| /* test if MVC works now correctly accross page boundaries */ |
| mvc_256(dst + 4096 - 128, src + 4096 - 128); |
| for (i = 0; i < ALLOC_SIZE; i++) { |
| if (src[i] != 0xff) { |
| fprintf(stderr, "src modified\n"); |
| return 1; |
| } |
| if (i < 4096 - 128 || i >= 4096 + 128) { |
| if (dst[i]) { |
| fprintf(stderr, "wrong dst modified\n"); |
| return 1; |
| } |
| } else { |
| if (dst[i] != 0xff) { |
| fprintf(stderr, "wrong data moved\n"); |
| return 1; |
| } |
| } |
| } |
| |
| return 0; |
| } |