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
24 int segv_expected = 0;
25
26 void signal_segv(int signum)
27 {
28 if (segv_expected && (signum == SIGSEGV))
29 _exit(0);
30 _exit(1);
31 }
32
33 void 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
49 int 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
71 int main(void)
72 {
73 return test_harness(tm_signal_msr_resv, "tm_signal_msr_resv");
74 }
75
Linux® is a registered trademark of Linus Torvalds in the United States and other countries.
TOMOYO® is a registered trademark of NTT DATA CORPORATION.