1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Copyright 2015, Michael Neuling, IBM Corp.
4 *
5 * Test the kernel's signal return code to ensure that it doesn't
6 * crash when both the transactional and suspend MSR bits are set in
7 * the signal context.
8 *
9 * For this test, we send ourselves a SIGUSR1.  In the SIGUSR1 handler
10 * we modify the signal context to set both MSR TM S and T bits (which
11 * is "reserved" by the PowerISA). When we return from the signal
12 * handler (implicit sigreturn), the kernel should detect reserved MSR
13 * value and send us with a SIGSEGV.
14 */
15
16#include <stdlib.h>
17#include <stdio.h>
18#include <signal.h>
19#include <unistd.h>
20
21#include "utils.h"
22#include "tm.h"
23
24int segv_expected = 0;
25
26void signal_segv(int signum)
27{
28	if (segv_expected && (signum == SIGSEGV))
29		_exit(0);
30	_exit(1);
31}
32
33void signal_usr1(int signum, siginfo_t *info, void *uc)
34{
35	ucontext_t *ucp = uc;
36
37	/* Link tm checkpointed context to normal context */
38	ucp->uc_link = ucp;
39	/* Set all TM bits so that the context is now invalid */
40#ifdef __powerpc64__
41	ucp->uc_mcontext.gp_regs[PT_MSR] |= (7ULL << 32);
42#else
43	ucp->uc_mcontext.uc_regs->gregs[PT_MSR] |= (7ULL);
44#endif
45	/* Should segv on return becuase of invalid context */
46	segv_expected = 1;
47}
48
49int tm_signal_msr_resv()
50{
51	struct sigaction act;
52
53	SKIP_IF(!have_htm());
54
55	act.sa_sigaction = signal_usr1;
56	sigemptyset(&act.sa_mask);
57	act.sa_flags = SA_SIGINFO;
58	if (sigaction(SIGUSR1, &act, NULL) < 0) {
59		perror("sigaction sigusr1");
60		exit(1);
61	}
62	if (signal(SIGSEGV, signal_segv) == SIG_ERR)
63		exit(1);
64
65	raise(SIGUSR1);
66
67	/* We shouldn't get here as we exit in the segv handler */
68	return 1;
69}
70
71int main(void)
72{
73	return test_harness(tm_signal_msr_resv, "tm_signal_msr_resv");
74}
75