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_FPU_REGS 18 /* Number of non-volatile FP registers */
33 #define FPR14 14 /* First non-volatile FP register to check in f14-31 subset */
34
35 long tm_signal_self_context_load(pid_t pid, long *gprs, double *fps, vector int *vms, vector int *vss);
36
37 /* Test only non-volatile registers, i.e. 18 fpr registers from f14 to f31 */
38 static double fps[] = {
39 /* First context will be set with these values, i.e. non-speculative */
40 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18,
41 /* Second context will be set with these values, i.e. speculative */
42 -1,-2,-3,-4,-5,-6,-7,-8,-9,-10,-11,-12,-13,-14,-15,-16,-17,-18
43 };
44
45 static sig_atomic_t fail, broken;
46
signal_usr1(int signum,siginfo_t * info,void * uc)47 static void signal_usr1(int signum, siginfo_t *info, void *uc)
48 {
49 int i;
50 ucontext_t *ucp = uc;
51 ucontext_t *tm_ucp = ucp->uc_link;
52
53 for (i = 0; i < NV_FPU_REGS; i++) {
54 /* Check first context. Print all mismatches. */
55 fail = (ucp->uc_mcontext.fp_regs[FPR14 + i] != fps[i]);
56 if (fail) {
57 broken = 1;
58 printf("FPR%d (1st context) == %g instead of %g (expected)\n",
59 FPR14 + i, ucp->uc_mcontext.fp_regs[FPR14 + i], fps[i]);
60 }
61 }
62
63 for (i = 0; i < NV_FPU_REGS; i++) {
64 /* Check second context. Print all mismatches. */
65 fail = (tm_ucp->uc_mcontext.fp_regs[FPR14 + i] != fps[NV_FPU_REGS + i]);
66 if (fail) {
67 broken = 1;
68 printf("FPR%d (2nd context) == %g instead of %g (expected)\n",
69 FPR14 + i, tm_ucp->uc_mcontext.fp_regs[FPR14 + i], fps[NV_FPU_REGS + i]);
70 }
71 }
72 }
73
tm_signal_context_chk_fpu()74 static int tm_signal_context_chk_fpu()
75 {
76 struct sigaction act;
77 int i;
78 long rc;
79 pid_t pid = getpid();
80
81 SKIP_IF(!have_htm());
82
83 act.sa_sigaction = signal_usr1;
84 sigemptyset(&act.sa_mask);
85 act.sa_flags = SA_SIGINFO;
86 if (sigaction(SIGUSR1, &act, NULL) < 0) {
87 perror("sigaction sigusr1");
88 exit(1);
89 }
90
91 i = 0;
92 while (i < MAX_ATTEMPT && !broken) {
93 /*
94 * tm_signal_self_context_load will set both first and second
95 * contexts accordingly to the values passed through non-NULL
96 * array pointers to it, in that case 'fps', and invoke the
97 * signal handler installed for SIGUSR1.
98 */
99 rc = tm_signal_self_context_load(pid, NULL, fps, NULL, NULL);
100 FAIL_IF(rc != pid);
101 i++;
102 }
103
104 return (broken);
105 }
106
main(void)107 int main(void)
108 {
109 return test_harness(tm_signal_context_chk_fpu, "tm_signal_context_chk_fpu");
110 }
111
