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 <string.h>
23 #include <signal.h>
24 #include <unistd.h>
25
26 #include <altivec.h>
27
28 #include "utils.h"
29 #include "tm.h"
30
31 #define MAX_ATTEMPT 500000
32
33 #define NV_VMX_REGS 12 /* Number of non-volatile VMX registers */
34 #define VMX20 20 /* First non-volatile register to check in vr20-31 subset */
35
36 long tm_signal_self_context_load(pid_t pid, long *gprs, double *fps, vector int *vms, vector int *vss);
37
38 static sig_atomic_t fail, broken;
39
40 /* Test only non-volatile registers, i.e. 12 vmx registers from vr20 to vr31 */
41 vector int vms[] = {
42 /* First context will be set with these values, i.e. non-speculative */
43 /* VMX20 , VMX21 , ... */
44 { 1, 2, 3, 4},{ 5, 6, 7, 8},{ 9,10,11,12},
45 {13,14,15,16},{17,18,19,20},{21,22,23,24},
46 {25,26,27,28},{29,30,31,32},{33,34,35,36},
47 {37,38,39,40},{41,42,43,44},{45,46,47,48},
48 /* Second context will be set with these values, i.e. speculative */
49 /* VMX20 , VMX21 , ... */
50 { -1, -2, -3, -4},{ -5, -6, -7, -8},{ -9,-10,-11,-12},
51 {-13,-14,-15,-16},{-17,-18,-19,-20},{-21,-22,-23,-24},
52 {-25,-26,-27,-28},{-29,-30,-31,-32},{-33,-34,-35,-36},
53 {-37,-38,-39,-40},{-41,-42,-43,-44},{-45,-46,-47,-48}
54 };
55
56 static void signal_usr1(int signum, siginfo_t *info, void *uc)
57 {
58 int i, j;
59 ucontext_t *ucp = uc;
60 ucontext_t *tm_ucp = ucp->uc_link;
61
62 for (i = 0; i < NV_VMX_REGS; i++) {
63 /* Check first context. Print all mismatches. */
64 fail = memcmp(ucp->uc_mcontext.v_regs->vrregs[VMX20 + i],
65 &vms[i], sizeof(vector int));
66 if (fail) {
67 broken = 1;
68 printf("VMX%d (1st context) == 0x", VMX20 + i);
69 /* Print actual value in first context. */
70 for (j = 0; j < 4; j++)
71 printf("%08x", ucp->uc_mcontext.v_regs->vrregs[VMX20 + i][j]);
72 printf(" instead of 0x");
73 /* Print expected value. */
74 for (j = 0; j < 4; j++)
75 printf("%08x", vms[i][j]);
76 printf(" (expected)\n");
77 }
78 }
79
80 for (i = 0; i < NV_VMX_REGS; i++) {
81 /* Check second context. Print all mismatches. */
82 fail = memcmp(tm_ucp->uc_mcontext.v_regs->vrregs[VMX20 + i],
83 &vms[NV_VMX_REGS + i], sizeof (vector int));
84 if (fail) {
85 broken = 1;
86 printf("VMX%d (2nd context) == 0x", NV_VMX_REGS + i);
87 /* Print actual value in second context. */
88 for (j = 0; j < 4; j++)
89 printf("%08x", tm_ucp->uc_mcontext.v_regs->vrregs[VMX20 + i][j]);
90 printf(" instead of 0x");
91 /* Print expected value. */
92 for (j = 0; j < 4; j++)
93 printf("%08x", vms[NV_VMX_REGS + i][j]);
94 printf(" (expected)\n");
95 }
96 }
97 }
98
99 static int tm_signal_context_chk()
100 {
101 struct sigaction act;
102 int i;
103 long rc;
104 pid_t pid = getpid();
105
106 SKIP_IF(!have_htm());
107
108 act.sa_sigaction = signal_usr1;
109 sigemptyset(&act.sa_mask);
110 act.sa_flags = SA_SIGINFO;
111 if (sigaction(SIGUSR1, &act, NULL) < 0) {
112 perror("sigaction sigusr1");
113 exit(1);
114 }
115
116 i = 0;
117 while (i < MAX_ATTEMPT && !broken) {
118 /*
119 * tm_signal_self_context_load will set both first and second
120 * contexts accordingly to the values passed through non-NULL
121 * array pointers to it, in that case 'vms', and invoke the
122 * signal handler installed for SIGUSR1.
123 */
124 rc = tm_signal_self_context_load(pid, NULL, NULL, vms, NULL);
125 FAIL_IF(rc != pid);
126 i++;
127 }
128
129 return (broken);
130 }
131
132 int main(void)
133 {
134 return test_harness(tm_signal_context_chk, "tm_signal_context_chk_vmx");
135 }