1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3 * Copyright 2016, Cyril Bur, IBM Corp.
4 *
5 * Test the kernel's signal frame code.
6 *
7 * The kernel sets up two sets of ucontexts if the signal was to be
8 * delivered while the thread was in a transaction (referred too as
9 * first and second contexts).
10 * Expected behaviour is that the checkpointed state is in the user
11 * context passed to the signal handler (first context). The speculated
12 * state can be accessed with the uc_link pointer (second context).
13 *
14 * The rationale for this is that if TM unaware code (which linked
15 * against TM libs) installs a signal handler it will not know of the
16 * speculative nature of the 'live' registers and may infer the wrong
17 * thing.
18 */
19
20 #include <stdlib.h>
21 #include <stdio.h>
22 #include <signal.h>
23 #include <unistd.h>
24
25 #include <altivec.h>
26
27 #include "utils.h"
28 #include "tm.h"
29
30 #define MAX_ATTEMPT 500000
31
32 #define NV_GPR_REGS 18 /* Number of non-volatile GPR registers */
33 #define R14 14 /* First non-volatile register to check in r14-r31 subset */
34
35 long tm_signal_self_context_load(pid_t pid, long *gprs, double *fps, vector int *vms, vector int *vss);
36
37 static sig_atomic_t fail, broken;
38
39 /* Test only non-volatile general purpose registers, i.e. r14-r31 */
40 static long gprs[] = {
41 /* First context will be set with these values, i.e. non-speculative */
42 /* R14, R15, ... */
43 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18,
44 /* Second context will be set with these values, i.e. speculative */
45 /* R14, R15, ... */
46 -1,-2,-3,-4,-5,-6,-7,-8,-9,-10,-11,-12,-13,-14,-15,-16,-17,-18
47 };
48
signal_usr1(int signum,siginfo_t * info,void * uc)49 static void signal_usr1(int signum, siginfo_t *info, void *uc)
50 {
51 int i;
52 ucontext_t *ucp = uc;
53 ucontext_t *tm_ucp = ucp->uc_link;
54
55 /* Check first context. Print all mismatches. */
56 for (i = 0; i < NV_GPR_REGS; i++) {
57 fail = (ucp->uc_mcontext.gp_regs[R14 + i] != gprs[i]);
58 if (fail) {
59 broken = 1;
60 printf("GPR%d (1st context) == %lu instead of %lu (expected)\n",
61 R14 + i, ucp->uc_mcontext.gp_regs[R14 + i], gprs[i]);
62 }
63 }
64
65 /* Check second context. Print all mismatches. */
66 for (i = 0; i < NV_GPR_REGS; i++) {
67 fail = (tm_ucp->uc_mcontext.gp_regs[R14 + i] != gprs[NV_GPR_REGS + i]);
68 if (fail) {
69 broken = 1;
70 printf("GPR%d (2nd context) == %lu instead of %lu (expected)\n",
71 R14 + i, tm_ucp->uc_mcontext.gp_regs[R14 + i], gprs[NV_GPR_REGS + i]);
72 }
73 }
74 }
75
tm_signal_context_chk_gpr()76 static int tm_signal_context_chk_gpr()
77 {
78 struct sigaction act;
79 int i;
80 long rc;
81 pid_t pid = getpid();
82
83 SKIP_IF(!have_htm());
84
85 act.sa_sigaction = signal_usr1;
86 sigemptyset(&act.sa_mask);
87 act.sa_flags = SA_SIGINFO;
88 if (sigaction(SIGUSR1, &act, NULL) < 0) {
89 perror("sigaction sigusr1");
90 exit(1);
91 }
92
93 i = 0;
94 while (i < MAX_ATTEMPT && !broken) {
95 /*
96 * tm_signal_self_context_load will set both first and second
97 * contexts accordingly to the values passed through non-NULL
98 * array pointers to it, in that case 'gprs', and invoke the
99 * signal handler installed for SIGUSR1.
100 */
101 rc = tm_signal_self_context_load(pid, gprs, NULL, NULL, NULL);
102 FAIL_IF(rc != pid);
103 i++;
104 }
105
106 return broken;
107 }
108
main(void)109 int main(void)
110 {
111 return test_harness(tm_signal_context_chk_gpr, "tm_signal_context_chk_gpr");
112 }
113
