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
35long 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 */
38static 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
45static sig_atomic_t fail, broken;
46
47static 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
74static 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	SKIP_IF(htm_is_synthetic());
83
84	act.sa_sigaction = signal_usr1;
85	sigemptyset(&act.sa_mask);
86	act.sa_flags = SA_SIGINFO;
87	if (sigaction(SIGUSR1, &act, NULL) < 0) {
88		perror("sigaction sigusr1");
89		exit(1);
90	}
91
92	i = 0;
93	while (i < MAX_ATTEMPT && !broken) {
94		/*
95		 * tm_signal_self_context_load will set both first and second
96		 * contexts accordingly to the values passed through non-NULL
97		 * array pointers to it, in that case 'fps', and invoke the
98		 * signal handler installed for SIGUSR1.
99		 */
100		rc = tm_signal_self_context_load(pid, NULL, fps, NULL, NULL);
101		FAIL_IF(rc != pid);
102		i++;
103	}
104
105	return (broken);
106}
107
108int main(void)
109{
110	return test_harness(tm_signal_context_chk_fpu, "tm_signal_context_chk_fpu");
111}
112