tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
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 * Calls to copy_first which are not 128-byte aligned should be
10 * caught and sent a SIGBUS.
11 *
12 */
13
14#include <signal.h>
15#include <string.h>
16#include <unistd.h>
17#include "utils.h"
18#include "instructions.h"
19
20unsigned int expected_instruction = PPC_INST_COPY_FIRST;
21unsigned int instruction_mask = 0xfc2007fe;
22
23void signal_action_handler(int signal_num, siginfo_t *info, void *ptr)
24{
25 ucontext_t *ctx = ptr;
26#ifdef __powerpc64__
27 unsigned int *pc = (unsigned int *)ctx->uc_mcontext.gp_regs[PT_NIP];
28#else
29 unsigned int *pc = (unsigned int *)ctx->uc_mcontext.uc_regs->gregs[PT_NIP];
30#endif
31
32 /*
33 * Check that the signal was on the correct instruction, using a
34 * mask because the compiler assigns the register at RB.
35 */
36 if ((*pc & instruction_mask) == expected_instruction)
37 _exit(0); /* We hit the right instruction */
38
39 _exit(1);
40}
41
42void setup_signal_handler(void)
43{
44 struct sigaction signal_action;
45
46 memset(&signal_action, 0, sizeof(signal_action));
47 signal_action.sa_sigaction = signal_action_handler;
48 signal_action.sa_flags = SA_SIGINFO;
49 sigaction(SIGBUS, &signal_action, NULL);
50}
51
52char cacheline_buf[128] __cacheline_aligned;
53
54int test_copy_first_unaligned(void)
55{
56 /* Only run this test on a P9 or later */
57 SKIP_IF(!have_hwcap2(PPC_FEATURE2_ARCH_3_00));
58
59 /* Register our signal handler with SIGBUS */
60 setup_signal_handler();
61
62 /* +1 makes buf unaligned */
63 copy_first(cacheline_buf+1);
64
65 /* We should not get here */
66 return 1;
67}
68
69int main(int argc, char *argv[])
70{
71 return test_harness(test_copy_first_unaligned, "test_copy_first_unaligned");
72}