1//===-- sanitizer_signal_interceptors.inc -----------------------*- C++ -*-===//
2//
3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4// See https://llvm.org/LICENSE.txt for license information.
5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6//
7//===----------------------------------------------------------------------===//
8//
9// Signal interceptors for sanitizers.
10//
11//===----------------------------------------------------------------------===//
12
13#include "interception/interception.h"
14#include "sanitizer_common.h"
15#include "sanitizer_internal_defs.h"
16#include "sanitizer_platform_interceptors.h"
17
18using namespace __sanitizer;
19
20#if SANITIZER_NETBSD
21#define sigaction_symname __sigaction14
22#else
23#define sigaction_symname sigaction
24#endif
25
26#ifndef SIGNAL_INTERCEPTOR_SIGNAL_IMPL
27#define SIGNAL_INTERCEPTOR_SIGNAL_IMPL(func, signum, handler) \
28 { return REAL(func)(signum, handler); }
29#endif
30
31#ifndef SIGNAL_INTERCEPTOR_SIGACTION_IMPL
32# define SIGNAL_INTERCEPTOR_SIGACTION_IMPL(signum, act, oldact) \
33 { \
34 if (!REAL(sigaction_symname)) { \
35 Printf( \
36 "Warning: REAL(sigaction_symname) == nullptr. This may happen " \
37 "if you link with ubsan statically. Sigaction will not work.\n"); \
38 return -1; \
39 } \
40 return REAL(sigaction_symname)(signum, act, oldact); \
41 }
42#endif
43
44#if SANITIZER_INTERCEPT_BSD_SIGNAL
45INTERCEPTOR(uptr, bsd_signal, int signum, uptr handler) {
46 SIGNAL_INTERCEPTOR_ENTER();
47 if (GetHandleSignalMode(signum) == kHandleSignalExclusive) return 0;
48 SIGNAL_INTERCEPTOR_SIGNAL_IMPL(bsd_signal, signum, handler);
49}
50#define INIT_BSD_SIGNAL COMMON_INTERCEPT_FUNCTION(bsd_signal)
51#else // SANITIZER_INTERCEPT_BSD_SIGNAL
52#define INIT_BSD_SIGNAL
53#endif // SANITIZER_INTERCEPT_BSD_SIGNAL
54
55#if SANITIZER_INTERCEPT_SIGNAL_AND_SIGACTION
56INTERCEPTOR(uptr, signal, int signum, uptr handler) {
57 SIGNAL_INTERCEPTOR_ENTER();
58 if (GetHandleSignalMode(signum) == kHandleSignalExclusive)
59 return (uptr) nullptr;
60 SIGNAL_INTERCEPTOR_SIGNAL_IMPL(signal, signum, handler);
61}
62#define INIT_SIGNAL COMMON_INTERCEPT_FUNCTION(signal)
63
64INTERCEPTOR(int, sigaction_symname, int signum,
65 const __sanitizer_sigaction *act, __sanitizer_sigaction *oldact) {
66 SIGNAL_INTERCEPTOR_ENTER();
67 if (GetHandleSignalMode(signum) == kHandleSignalExclusive) {
68 if (!oldact) return 0;
69 act = nullptr;
70 }
71 SIGNAL_INTERCEPTOR_SIGACTION_IMPL(signum, act, oldact);
72}
73#define INIT_SIGACTION COMMON_INTERCEPT_FUNCTION(sigaction_symname)
74
75namespace __sanitizer {
76int real_sigaction(int signum, const void *act, void *oldact) {
77 return REAL(sigaction_symname)(signum, (const __sanitizer_sigaction *)act,
78 (__sanitizer_sigaction *)oldact);
79}
80} // namespace __sanitizer
81#else // SANITIZER_INTERCEPT_SIGNAL_AND_SIGACTION
82#define INIT_SIGNAL
83#define INIT_SIGACTION
84// We need to have defined REAL(sigaction) on other systems.
85namespace __sanitizer {
86struct __sanitizer_sigaction;
87}
88DEFINE_REAL(int, sigaction, int signum, const __sanitizer_sigaction *act,
89 __sanitizer_sigaction *oldact)
90#endif // SANITIZER_INTERCEPT_SIGNAL_AND_SIGACTION
91
92static void InitializeSignalInterceptors() {
93 static bool was_called_once;
94 CHECK(!was_called_once);
95 was_called_once = true;
96
97 INIT_BSD_SIGNAL;
98 INIT_SIGNAL;
99 INIT_SIGACTION;
100}
101