LXR linux/tools/testing/selftests/powerpc/alignment/copy_paste_unaligned

   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
  21unsigned int expected_instruction;
  22unsigned int instruction_mask;
  23
  24char cacheline_buf[128] __cacheline_aligned;
  25
  26void 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
  45void 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}
  54