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

   1// SPDX-License-Identifier: GPL-2.0-or-later
   2/*
   3 * Copyright 2016, Chris Smart, IBM Corporation.
   4 *
   5 * Calls to copy_first which are not 128-byte aligned should be
   6 * caught and sent a SIGBUS.
   7 */
   8
   9#include <signal.h>
  10#include <string.h>
  11#include <unistd.h>
  12#include "utils.h"
  13#include "instructions.h"
  14
  15unsigned int expected_instruction = PPC_INST_COPY_FIRST;
  16unsigned int instruction_mask = 0xfc2007fe;
  17
  18void signal_action_handler(int signal_num, siginfo_t *info, void *ptr)
  19{
  20        ucontext_t *ctx = ptr;
  21#ifdef __powerpc64__
  22        unsigned int *pc = (unsigned int *)ctx->uc_mcontext.gp_regs[PT_NIP];
  23#else
  24        unsigned int *pc = (unsigned int *)ctx->uc_mcontext.uc_regs->gregs[PT_NIP];
  25#endif
  26
  27        /*
  28         * Check that the signal was on the correct instruction, using a
  29         * mask because the compiler assigns the register at RB.
  30         */
  31        if ((*pc & instruction_mask) == expected_instruction)
  32                _exit(0); /* We hit the right instruction */
  33
  34        _exit(1);
  35}
  36
  37void setup_signal_handler(void)
  38{
  39        struct sigaction signal_action;
  40
  41        memset(&signal_action, 0, sizeof(signal_action));
  42        signal_action.sa_sigaction = signal_action_handler;
  43        signal_action.sa_flags = SA_SIGINFO;
  44        sigaction(SIGBUS, &signal_action, NULL);
  45}
  46
  47char cacheline_buf[128] __cacheline_aligned;
  48
  49int test_copy_first_unaligned(void)
  50{
  51        /* Only run this test on a P9 or later */
  52        SKIP_IF(!have_hwcap2(PPC_FEATURE2_ARCH_3_00));
  53
  54        /* Register our signal handler with SIGBUS */
  55        setup_signal_handler();
  56
  57        /* +1 makes buf unaligned */
  58        copy_first(cacheline_buf+1);
  59
  60        /* We should not get here */
  61        return 1;
  62}
  63
  64int main(int argc, char *argv[])
  65{
  66        return test_harness(test_copy_first_unaligned, "test_copy_first_unaligned");
  67}
  68