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 
15 unsigned int expected_instruction = PPC_INST_COPY_FIRST;
16 unsigned int instruction_mask = 0xfc2007fe;
17 
18 void 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 
37 void 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 
47 char cacheline_buf[128] __cacheline_aligned;
48 
49 int 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 
64 int main(int argc, char *argv[])
65 {
66 	return test_harness(test_copy_first_unaligned, "test_copy_first_unaligned");
67 }
68