tests/tcg/ppc64/signal_save_restore_xer.c

   1 #include <assert.h>
   2 #include <stdint.h>
   3 #include <signal.h>
   4 #include <sys/user.h>
   5
   6 #define XER_SO   (1 << 31)
   7 #define XER_OV   (1 << 30)
   8 #define XER_CA   (1 << 29)
   9 #define XER_OV32 (1 << 19)
  10 #define XER_CA32 (1 << 18)
  11
  12 uint64_t saved;
  13
  14 void sigtrap_handler(int sig, siginfo_t *si, void *ucontext)
  15 {
  16     ucontext_t *uc = ucontext;
  17     uc->uc_mcontext.regs->nip += 4;
  18     saved = uc->uc_mcontext.regs->xer;
  19     uc->uc_mcontext.regs->xer |= XER_OV | XER_OV32;
  20 }
  21
  22 int main(void)
  23 {
  24     uint64_t initial = XER_CA | XER_CA32, restored;
  25     struct sigaction sa = {
  26         .sa_sigaction = sigtrap_handler,
  27         .sa_flags = SA_SIGINFO
  28     };
  29
  30     sigaction(SIGTRAP, &sa, NULL);
  31
  32     asm("mtspr 1, %1\n\t"
  33         "trap\n\t"
  34         "mfspr %0, 1\n\t"
  35         : "=r" (restored)
  36         : "r" (initial));
  37
  38     assert(saved == initial);
  39     assert(restored == (XER_OV | XER_OV32 | XER_CA | XER_CA32));
  40
  41     return 0;
  42 }