tools/testing/selftests/powerpc/alignment/copy_paste_unaligned_common.c

   1 /*
   2  * Copyright 2016, Chris Smart, IBM Corporation.
   3  *
   4  * This program is free software; you can redistribute it and/or
   5  * modify it under the terms of the GNU General Public License
   6  * as published by the Free Software Foundation; either version
   7  * 2 of the License, or (at your option) any later version.
   8  *
   9  * Common code for copy, copy_first, paste and paste_last unaligned
  10  * tests.
  11  *
  12  */
  13
  14 #include <signal.h>
  15 #include <string.h>
  16 #include <unistd.h>
  17 #include "utils.h"
  18 #include "instructions.h"
  19 #include "copy_paste_unaligned_common.h"
  20
  21 unsigned int expected_instruction;
  22 unsigned int instruction_mask;
  23
  24 char cacheline_buf[128] __cacheline_aligned;
  25
  26 void signal_action_handler(int signal_num, siginfo_t *info, void *ptr)
  27 {
  28         ucontext_t *ctx = ptr;
  29 #if defined(__powerpc64__)
  30         unsigned int *pc = (unsigned int *)ctx->uc_mcontext.gp_regs[PT_NIP];
  31 #else
  32         unsigned int *pc = (unsigned int *)ctx->uc_mcontext.uc_regs->gregs[PT_NIP];
  33 #endif
  34
  35         /*
  36          * Check that the signal was on the correct instruction, using a
  37          * mask because the compiler assigns the register at RB.
  38          */
  39         if ((*pc & instruction_mask) == expected_instruction)
  40                 _exit(0); /* We hit the right instruction */
  41
  42         _exit(1);
  43 }
  44
  45 void setup_signal_handler(void)
  46 {
  47         struct sigaction signal_action;
  48
  49         memset(&signal_action, 0, sizeof(signal_action));
  50         signal_action.sa_sigaction = signal_action_handler;
  51         signal_action.sa_flags = SA_SIGINFO;
  52         sigaction(SIGBUS, &signal_action, NULL);
  53 }