1 /*
2 * This file and its contents are supplied under the terms of the
3 * Common Development and Distribution License ("CDDL"), version 1.0.
4 * You may only use this file in accordance with the terms of version
5 * 1.0 of the CDDL.
6 *
7 * A full copy of the text of the CDDL should have accompanied this
8 * source. A copy of the CDDL is also available via the Internet at
9 * http://www.illumos.org/license/CDDL.
10 */
11
12 /*
13 * Copyright 2023 Oxide Comptuer Company
14 */
15
16 /*
17 * Verify that the FPU contents are correctly restored after taking a signal. We
18 * do this by going through and setting up a signal handler for SIGINFO and then
19 * we do the following as tightly as possible: overwriting the FPU contents and
20 * then calling thr_kill(). As part of the regression for #15254, we also
21 * purposefully go off CPU in the signal handler to try to wreak havoc.
22 */
23
24 #include <err.h>
25 #include <stdlib.h>
26 #include <ucontext.h>
27 #include <limits.h>
28 #include <signal.h>
29 #include <thread.h>
30 #include <string.h>
31 #include <time.h>
32 #include <unistd.h>
33
34 #include "xsave_util.h"
35
36 static xsu_fpu_t init_vals, signal_vals, found;
37 static volatile int exit_status = EXIT_SUCCESS;
38 static volatile int took_sig = 0;
39 static uint32_t sr_hwsup;
40
41 static void
signal_restore_siginfo(int sig,siginfo_t * sip,void * ucp)42 signal_restore_siginfo(int sig, siginfo_t *sip, void *ucp)
43 {
44 struct timespec ts;
45 took_sig = 1;
46
47 ts.tv_sec = 0;
48 ts.tv_nsec = 10 * MILLISEC;
49
50 /*
51 * yield doesn't guarantee that we go off CPU, but try a few anyways.
52 * There's a slight chance that nanosleep will modify the FPU state, but
53 * we can hope we're lucky and that the libc function won't.
54 */
55 xsu_setfpu(&signal_vals, sr_hwsup);
56 yield();
57 yield();
58 (void) nanosleep(&ts, NULL);
59 xsu_getfpu(&found, sr_hwsup);
60
61 if (xsu_same(&signal_vals, &found, sr_hwsup)) {
62 (void) printf("TEST PASSED: FPU contents didn't change in "
63 "signal handler\n");
64 } else {
65 warnx("TEST FAILED: FPU contents changed in signal handler!");
66 exit_status = EXIT_FAILURE;
67 }
68
69 }
70
71 int
main(void)72 main(void)
73 {
74 int ret;
75 thread_t self = thr_self();
76 uint32_t start = arc4random();
77 uint32_t hwsup = xsu_hwsupport();
78 struct sigaction sa;
79
80 sr_hwsup = hwsup;
81 sa.sa_sigaction = signal_restore_siginfo;
82 sa.sa_flags = SA_RESETHAND;
83
84 if (sigaction(SIGINFO, &sa, NULL) != 0) {
85 errx(EXIT_FAILURE, "TEST FAILED: failed to set up signal "
86 "handler");
87 }
88
89 (void) printf("filling starting at 0x%x\n", start);
90 xsu_fill(&init_vals, hwsup, start);
91 xsu_fill(&signal_vals, hwsup, start + INT_MAX);
92
93 (void) memset(&sa, 0, sizeof (struct sigaction));
94
95 xsu_setfpu(&init_vals, hwsup);
96 ret = thr_kill(self, SIGINFO);
97 xsu_getfpu(&found, hwsup);
98
99 if (ret != 0) {
100 errc(EXIT_FAILURE, ret, "TEST FAILED: failed to deliver "
101 "signal");
102 }
103
104 if (took_sig == 0) {
105 errx(EXIT_FAILURE, "TEST FAILED: signal handler did not run");
106 }
107
108 (void) printf("TEST PASSED: SIGINFO successfully delivered\n");
109
110 if (xsu_same(&init_vals, &found, hwsup)) {
111 (void) printf("TEST PASSED: FPU contents successfully "
112 "restored\n");
113 } else {
114 warnx("TEST FAILED: FPU contents were not restored!");
115 exit_status = EXIT_FAILURE;
116 }
117
118 return (exit_status);
119 }
120