xref: /freebsd/contrib/llvm-project/compiler-rt/lib/interception/interception_aix.cpp (revision 770cf0a5f02dc8983a89c6568d741fbc25baa999)
1 //===-- interception_aix.cpp ------------------------------------*- 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 // This file is a part of AddressSanitizer, an address sanity checker.
10 //
11 // AIX-specific interception methods.
12 //===----------------------------------------------------------------------===//
13 
14 #include "interception.h"
15 #include "sanitizer_common/sanitizer_common.h"
16 
17 #if SANITIZER_AIX
18 
19 #  include <dlfcn.h>  // for dlsym()
20 
21 namespace __interception {
22 
23 static void *GetFuncAddr(const char *name, uptr wrapper_addr) {
24   // AIX dlsym can only defect the functions that are exported, so
25   // on AIX, we can not intercept some basic functions like memcpy.
26   // FIXME: if we are going to ship dynamic asan library, we may need to search
27   // all the loaded modules with RTLD_DEFAULT if RTLD_NEXT failed.
28   void *addr = dlsym(RTLD_NEXT, name);
29 
30   // In case `name' is not loaded, dlsym ends up finding the actual wrapper.
31   // We don't want to intercept the wrapper and have it point to itself.
32   if ((uptr)addr == wrapper_addr)
33     addr = nullptr;
34   return addr;
35 }
36 
37 bool InterceptFunction(const char *name, uptr *ptr_to_real, uptr func,
38                        uptr wrapper) {
39   void *addr = GetFuncAddr(name, wrapper);
40   *ptr_to_real = (uptr)addr;
41   return addr && (func == wrapper);
42 }
43 
44 }  // namespace __interception
45 #endif  // SANITIZER_AIX
46