1 /*
2  * Copyright 2016, Cyril Bur, IBM Corp.
3  *
4  * This program is free software; you can redistribute it and/or
5  * modify it under the terms of the GNU General Public License
6  * as published by the Free Software Foundation; either version
7  * 2 of the License, or (at your option) any later version.
8  *
9  *
10  * Test the kernel's signal frame code.
11  *
12  * The kernel sets up two sets of ucontexts if the signal was to be
13  * delivered while the thread was in a transaction.
14  * Expected behaviour is that the checkpointed state is in the user
15  * context passed to the signal handler. The speculated state can be
16  * accessed with the uc_link pointer.
17  *
18  * The rationale for this is that if TM unaware code (which linked
19  * against TM libs) installs a signal handler it will not know of the
20  * speculative nature of the 'live' registers and may infer the wrong
21  * thing.
22  */
23 
24 #include <stdlib.h>
25 #include <stdio.h>
26 #include <string.h>
27 #include <signal.h>
28 #include <unistd.h>
29 
30 #include <altivec.h>
31 
32 #include "utils.h"
33 #include "tm.h"
34 
35 #define MAX_ATTEMPT 500000
36 
37 #define NV_VSX_REGS 12
38 
39 long tm_signal_self_context_load(pid_t pid, long *gprs, double *fps, vector int *vms, vector int *vss);
40 
41 static sig_atomic_t fail;
42 
43 vector int vss[] = {
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 	{-1, -2, -3, -4 },{-5, -6, -7, -8 },{-9, -10,-11,-12},
49 	{-13,-14,-15,-16},{-17,-18,-19,-20},{-21,-22,-23,-24},
50 	{-25,-26,-27,-28},{-29,-30,-31,-32},{-33,-34,-35,-36},
51 	{-37,-38,-39,-40},{-41,-42,-43,-44},{-45,-46,-47,-48}
52 };
53 
54 static void signal_usr1(int signum, siginfo_t *info, void *uc)
55 {
56 	int i;
57 	uint8_t vsc[sizeof(vector int)];
58 	uint8_t vst[sizeof(vector int)];
59 	ucontext_t *ucp = uc;
60 	ucontext_t *tm_ucp = ucp->uc_link;
61 
62 	/*
63 	 * The other half of the VSX regs will be after v_regs.
64 	 *
65 	 * In short, vmx_reserve array holds everything. v_regs is a 16
66 	 * byte aligned pointer at the start of vmx_reserve (vmx_reserve
67 	 * may or may not be 16 aligned) where the v_regs structure exists.
68 	 * (half of) The VSX regsters are directly after v_regs so the
69 	 * easiest way to find them below.
70 	 */
71 	long *vsx_ptr = (long *)(ucp->uc_mcontext.v_regs + 1);
72 	long *tm_vsx_ptr = (long *)(tm_ucp->uc_mcontext.v_regs + 1);
73 	for (i = 0; i < NV_VSX_REGS && !fail; i++) {
74 		memcpy(vsc, &ucp->uc_mcontext.fp_regs[i + 20], 8);
75 		memcpy(vsc + 8, &vsx_ptr[20 + i], 8);
76 		fail = memcmp(vsc, &vss[i], sizeof(vector int));
77 		memcpy(vst, &tm_ucp->uc_mcontext.fp_regs[i + 20], 8);
78 		memcpy(vst + 8, &tm_vsx_ptr[20 + i], 8);
79 		fail |= memcmp(vst, &vss[i + NV_VSX_REGS], sizeof(vector int));
80 
81 		if (fail) {
82 			int j;
83 
84 			fprintf(stderr, "Failed on %d vsx 0x", i);
85 			for (j = 0; j < 16; j++)
86 				fprintf(stderr, "%02x", vsc[j]);
87 			fprintf(stderr, " vs 0x");
88 			for (j = 0; j < 16; j++)
89 				fprintf(stderr, "%02x", vst[j]);
90 			fprintf(stderr, "\n");
91 		}
92 	}
93 }
94 
95 static int tm_signal_context_chk()
96 {
97 	struct sigaction act;
98 	int i;
99 	long rc;
100 	pid_t pid = getpid();
101 
102 	SKIP_IF(!have_htm());
103 
104 	act.sa_sigaction = signal_usr1;
105 	sigemptyset(&act.sa_mask);
106 	act.sa_flags = SA_SIGINFO;
107 	if (sigaction(SIGUSR1, &act, NULL) < 0) {
108 		perror("sigaction sigusr1");
109 		exit(1);
110 	}
111 
112 	i = 0;
113 	while (i < MAX_ATTEMPT && !fail) {
114 		rc = tm_signal_self_context_load(pid, NULL, NULL, NULL, vss);
115 		FAIL_IF(rc != pid);
116 		i++;
117 	}
118 
119 	return fail;
120 }
121 
122 int main(void)
123 {
124 	return test_harness(tm_signal_context_chk, "tm_signal_context_chk_vsx");
125 }
126