libsanitizer/sanitizer_common/sanitizer_signal_interceptors.inc

   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
  18 using 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
  45 INTERCEPTOR(uptr, bsd_signal, int signum, uptr handler) {
  46   if (GetHandleSignalMode(signum) == kHandleSignalExclusive) return 0;
  47   SIGNAL_INTERCEPTOR_SIGNAL_IMPL(bsd_signal, signum, handler);
  48 }
  49 #define INIT_BSD_SIGNAL COMMON_INTERCEPT_FUNCTION(bsd_signal)
  50 #else  // SANITIZER_INTERCEPT_BSD_SIGNAL
  51 #define INIT_BSD_SIGNAL
  52 #endif  // SANITIZER_INTERCEPT_BSD_SIGNAL
  53
  54 #if SANITIZER_INTERCEPT_SIGNAL_AND_SIGACTION
  55 INTERCEPTOR(uptr, signal, int signum, uptr handler) {
  56   if (GetHandleSignalMode(signum) == kHandleSignalExclusive)
  57     return (uptr) nullptr;
  58   SIGNAL_INTERCEPTOR_SIGNAL_IMPL(signal, signum, handler);
  59 }
  60 #define INIT_SIGNAL COMMON_INTERCEPT_FUNCTION(signal)
  61
  62 INTERCEPTOR(int, sigaction_symname, int signum,
  63             const __sanitizer_sigaction *act, __sanitizer_sigaction *oldact) {
  64   if (GetHandleSignalMode(signum) == kHandleSignalExclusive) {
  65     if (!oldact) return 0;
  66     act = nullptr;
  67   }
  68   SIGNAL_INTERCEPTOR_SIGACTION_IMPL(signum, act, oldact);
  69 }
  70 #define INIT_SIGACTION COMMON_INTERCEPT_FUNCTION(sigaction_symname)
  71
  72 namespace __sanitizer {
  73 int real_sigaction(int signum, const void *act, void *oldact) {
  74   return REAL(sigaction_symname)(signum, (const __sanitizer_sigaction *)act,
  75                          (__sanitizer_sigaction *)oldact);
  76 }
  77 }  // namespace __sanitizer
  78 #else  // SANITIZER_INTERCEPT_SIGNAL_AND_SIGACTION
  79 #define INIT_SIGNAL
  80 #define INIT_SIGACTION
  81 // We need to have defined REAL(sigaction) on other systems.
  82 namespace __sanitizer {
  83 struct __sanitizer_sigaction;
  84 }
  85 DEFINE_REAL(int, sigaction, int signum, const __sanitizer_sigaction *act,
  86             __sanitizer_sigaction *oldact)
  87 #endif  // SANITIZER_INTERCEPT_SIGNAL_AND_SIGACTION
  88
  89 static void InitializeSignalInterceptors() {
  90   static bool was_called_once;
  91   CHECK(!was_called_once);
  92   was_called_once = true;
  93
  94   INIT_BSD_SIGNAL;
  95   INIT_SIGNAL;
  96   INIT_SIGACTION;
  97 }