tests/tcg/multiarch/sigbus.c

   1 #define _GNU_SOURCE 1
   2
   3 #include <assert.h>
   4 #include <stdlib.h>
   5 #include <signal.h>
   6 #include <endian.h>
   7
   8
   9 unsigned long long x = 0x8877665544332211ull;
  10 void * volatile p = (void *)&x + 1;
  11
  12 void sigbus(int sig, siginfo_t *info, void *uc)
  13 {
  14     assert(sig == SIGBUS);
  15     assert(info->si_signo == SIGBUS);
  16 #ifdef BUS_ADRALN
  17     assert(info->si_code == BUS_ADRALN);
  18 #endif
  19     assert(info->si_addr == p);
  20     exit(EXIT_SUCCESS);
  21 }
  22
  23 int main()
  24 {
  25     struct sigaction sa = {
  26         .sa_sigaction = sigbus,
  27         .sa_flags = SA_SIGINFO
  28     };
  29     int allow_fail = 0;
  30     int tmp;
  31
  32     tmp = sigaction(SIGBUS, &sa, NULL);
  33     assert(tmp == 0);
  34
  35     /*
  36      * Select an operation that's likely to enforce alignment.
  37      * On many guests that support unaligned accesses by default,
  38      * this is often an atomic operation.
  39      */
  40 #if defined(__aarch64__)
  41     asm volatile("ldxr %w0,[%1]" : "=r"(tmp) : "r"(p) : "memory");
  42 #elif defined(__alpha__)
  43     asm volatile("ldl_l %0,0(%1)" : "=r"(tmp) : "r"(p) : "memory");
  44 #elif defined(__arm__)
  45     asm volatile("ldrex %0,[%1]" : "=r"(tmp) : "r"(p) : "memory");
  46 #elif defined(__powerpc__)
  47     asm volatile("lwarx %0,0,%1" : "=r"(tmp) : "r"(p) : "memory");
  48 #elif defined(__riscv_atomic)
  49     asm volatile("lr.w %0,(%1)" : "=r"(tmp) : "r"(p) : "memory");
  50 #else
  51     /* No insn known to fault unaligned -- try for a straight load. */
  52     allow_fail = 1;
  53     tmp = *(volatile int *)p;
  54 #endif
  55
  56     assert(allow_fail);
  57
  58     /*
  59      * We didn't see a signal.
  60      * We might as well validate the unaligned load worked.
  61      */
  62     if (BYTE_ORDER == LITTLE_ENDIAN) {
  63         assert(tmp == 0x55443322);
  64     } else {
  65         assert(tmp == 0x77665544);
  66     }
  67     return EXIT_SUCCESS;
  68 }