xref: /openbmc/qemu/tests/tcg/s390x/mie3-mvcrl.c (revision 764a6ee9)
1 #include <stdbool.h>
2 #include <stdint.h>
3 #include <stdlib.h>
4 #include <string.h>
5 
6 static void mvcrl(const char *dst, const char *src, size_t len)
7 {
8     register long r0 asm("r0") = len;
9 
10     asm volatile (
11         ".insn sse, 0xE50A00000000, 0(%[dst]), 0(%[src])"
12         : : [dst] "d" (dst), [src] "d" (src), "r" (r0)
13         : "memory");
14 }
15 
16 static bool test(void)
17 {
18     const char *alpha = "abcdefghijklmnop";
19 
20     /* array missing 'i' */
21     char tstr[17] = "abcdefghjklmnop\0";
22 
23     /* mvcrl reference use: 'open a hole in an array' */
24     mvcrl(tstr + 9, tstr + 8, 8);
25 
26     /* place missing 'i' */
27     tstr[8] = 'i';
28 
29     return strncmp(alpha, tstr, 16ul) == 0;
30 }
31 
32 static bool test_bad_r0(void)
33 {
34     char src[256] = { 0 };
35 
36     /*
37      * PoP says: Bits 32-55 of general register 0 should contain zeros;
38      * otherwise, the program may not operate compatibly in the future.
39      *
40      * Try it anyway in order to check whether this would crash QEMU itself.
41      */
42     mvcrl(src, src, (size_t)-1);
43 
44     return true;
45 }
46 
47 int main(void)
48 {
49     bool ok = true;
50 
51     ok &= test();
52     ok &= test_bad_r0();
53 
54     return ok ? EXIT_SUCCESS : EXIT_FAILURE;
55 }
56