Commit | Line | Data |
---|---|---|
2025cf9e | 1 | // SPDX-License-Identifier: GPL-2.0-only |
65cacec1 AL |
2 | /* |
3 | * vdso_restorer.c - tests vDSO-based signal restore | |
4 | * Copyright (c) 2015 Andrew Lutomirski | |
5 | * | |
65cacec1 AL |
6 | * This makes sure that sa_restorer == NULL keeps working on 32-bit |
7 | * configurations. Modern glibc doesn't use it under any circumstances, | |
8 | * so it's easy to overlook breakage. | |
9 | * | |
10 | * 64-bit userspace has never supported sa_restorer == NULL, so this is | |
11 | * 32-bit only. | |
12 | */ | |
13 | ||
14 | #define _GNU_SOURCE | |
15 | ||
16 | #include <err.h> | |
17 | #include <stdio.h> | |
18 | #include <string.h> | |
19 | #include <signal.h> | |
20 | #include <unistd.h> | |
21 | #include <syscall.h> | |
22 | #include <sys/syscall.h> | |
23 | ||
24 | /* Open-code this -- the headers are too messy to easily use them. */ | |
25 | struct real_sigaction { | |
26 | void *handler; | |
27 | unsigned long flags; | |
28 | void *restorer; | |
29 | unsigned int mask[2]; | |
30 | }; | |
31 | ||
32 | static volatile sig_atomic_t handler_called; | |
33 | ||
34 | static void handler_with_siginfo(int sig, siginfo_t *info, void *ctx_void) | |
35 | { | |
36 | handler_called = 1; | |
37 | } | |
38 | ||
39 | static void handler_without_siginfo(int sig) | |
40 | { | |
41 | handler_called = 1; | |
42 | } | |
43 | ||
44 | int main() | |
45 | { | |
46 | int nerrs = 0; | |
47 | struct real_sigaction sa; | |
48 | ||
49 | memset(&sa, 0, sizeof(sa)); | |
50 | sa.handler = handler_with_siginfo; | |
51 | sa.flags = SA_SIGINFO; | |
52 | sa.restorer = NULL; /* request kernel-provided restorer */ | |
53 | ||
54 | if (syscall(SYS_rt_sigaction, SIGUSR1, &sa, NULL, 8) != 0) | |
55 | err(1, "raw rt_sigaction syscall"); | |
56 | ||
57 | raise(SIGUSR1); | |
58 | ||
59 | if (handler_called) { | |
60 | printf("[OK]\tSA_SIGINFO handler returned successfully\n"); | |
61 | } else { | |
62 | printf("[FAIL]\tSA_SIGINFO handler was not called\n"); | |
63 | nerrs++; | |
64 | } | |
65 | ||
66 | sa.flags = 0; | |
67 | sa.handler = handler_without_siginfo; | |
68 | if (syscall(SYS_sigaction, SIGUSR1, &sa, 0) != 0) | |
69 | err(1, "raw sigaction syscall"); | |
70 | handler_called = 0; | |
71 | ||
72 | raise(SIGUSR1); | |
73 | ||
74 | if (handler_called) { | |
75 | printf("[OK]\t!SA_SIGINFO handler returned successfully\n"); | |
76 | } else { | |
77 | printf("[FAIL]\t!SA_SIGINFO handler was not called\n"); | |
78 | nerrs++; | |
79 | } | |
80 | } |