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#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] "a" (dst),
[src] "a" (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;
}
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