1 /*
2 * Copyright (C) 2013 The Android Open Source Project
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * * Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * * Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in
12 * the documentation and/or other materials provided with the
13 * distribution.
14 *
15 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
16 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
17 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
18 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
19 * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
20 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
21 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
22 * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
23 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
24 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
25 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26 * SUCH DAMAGE.
27 */
28
29 #include <signal.h>
30
31 extern "C" void __restore_rt(void);
32 extern "C" void __restore(void);
33
34 #if defined(__LP64__)
35
36 extern "C" int __rt_sigaction(int, const struct __kernel_sigaction*, struct __kernel_sigaction*, size_t);
37
sigaction(int signal,const struct sigaction * bionic_new_action,struct sigaction * bionic_old_action)38 int sigaction(int signal, const struct sigaction* bionic_new_action, struct sigaction* bionic_old_action) {
39 __kernel_sigaction kernel_new_action;
40 if (bionic_new_action != NULL) {
41 kernel_new_action.sa_flags = bionic_new_action->sa_flags;
42 kernel_new_action.sa_handler = bionic_new_action->sa_handler;
43 kernel_new_action.sa_mask = bionic_new_action->sa_mask;
44 #if defined(SA_RESTORER)
45 kernel_new_action.sa_restorer = bionic_new_action->sa_restorer;
46 #if defined(__aarch64__)
47 // arm64 has sa_restorer, but unwinding works best if you just let the
48 // kernel supply the default restorer from [vdso]. gdb doesn't care, but
49 // libgcc needs the nop that the kernel includes before the actual code.
50 // (We could add that ourselves, but why bother?)
51 #else
52 if (!(kernel_new_action.sa_flags & SA_RESTORER)) {
53 kernel_new_action.sa_flags |= SA_RESTORER;
54 kernel_new_action.sa_restorer = &__restore_rt;
55 }
56 #endif
57 #endif
58 }
59
60 __kernel_sigaction kernel_old_action;
61 int result = __rt_sigaction(signal,
62 (bionic_new_action != NULL) ? &kernel_new_action : NULL,
63 (bionic_old_action != NULL) ? &kernel_old_action : NULL,
64 sizeof(sigset_t));
65
66 if (bionic_old_action != NULL) {
67 bionic_old_action->sa_flags = kernel_old_action.sa_flags;
68 bionic_old_action->sa_handler = kernel_old_action.sa_handler;
69 bionic_old_action->sa_mask = kernel_old_action.sa_mask;
70 #if defined(SA_RESTORER)
71 bionic_old_action->sa_restorer = kernel_old_action.sa_restorer;
72 #endif
73 }
74
75 return result;
76 }
77
78 #else
79
80 extern "C" int __sigaction(int, const struct sigaction*, struct sigaction*);
81
sigaction(int signal,const struct sigaction * bionic_new_action,struct sigaction * bionic_old_action)82 int sigaction(int signal, const struct sigaction* bionic_new_action, struct sigaction* bionic_old_action) {
83 // The 32-bit ABI is broken. struct sigaction includes a too-small sigset_t,
84 // so we have to use sigaction(2) rather than rt_sigaction(2).
85 struct sigaction kernel_new_action;
86 if (bionic_new_action != NULL) {
87 kernel_new_action.sa_flags = bionic_new_action->sa_flags;
88 kernel_new_action.sa_handler = bionic_new_action->sa_handler;
89 kernel_new_action.sa_mask = bionic_new_action->sa_mask;
90 #if defined(SA_RESTORER)
91 kernel_new_action.sa_restorer = bionic_new_action->sa_restorer;
92
93 if (!(kernel_new_action.sa_flags & SA_RESTORER)) {
94 kernel_new_action.sa_flags |= SA_RESTORER;
95 kernel_new_action.sa_restorer = (kernel_new_action.sa_flags & SA_SIGINFO) ? &__restore_rt : &__restore;
96 }
97 #endif
98 }
99 return __sigaction(signal, (bionic_new_action != NULL) ? &kernel_new_action : NULL, bionic_old_action);
100 }
101
102 #endif
103