1 //===-- sanitizer_linux.h ---------------------------------------*- C++ -*-===//
2 //
3 // This file is distributed under the University of Illinois Open Source
4 // License. See LICENSE.TXT for details.
5 //
6 //===----------------------------------------------------------------------===//
7 //
8 // Linux-specific syscall wrappers and classes.
9 //
10 //===----------------------------------------------------------------------===//
11 #ifndef SANITIZER_LINUX_H
12 #define SANITIZER_LINUX_H
13
14 #include "sanitizer_platform.h"
15 #if SANITIZER_FREEBSD || SANITIZER_LINUX || SANITIZER_NETBSD
16 #include "sanitizer_common.h"
17 #include "sanitizer_internal_defs.h"
18 #include "sanitizer_platform_limits_netbsd.h"
19 #include "sanitizer_platform_limits_posix.h"
20 #include "sanitizer_posix.h"
21
22 struct link_map; // Opaque type returned by dlopen().
23
24 namespace __sanitizer {
25 // Dirent structure for getdents(). Note that this structure is different from
26 // the one in <dirent.h>, which is used by readdir().
27 struct linux_dirent;
28
29 struct ProcSelfMapsBuff {
30 char *data;
31 uptr mmaped_size;
32 uptr len;
33 };
34
35 struct MemoryMappingLayoutData {
36 ProcSelfMapsBuff proc_self_maps;
37 const char *current;
38 };
39
40 void ReadProcMaps(ProcSelfMapsBuff *proc_maps);
41
42 // Syscall wrappers.
43 uptr internal_getdents(fd_t fd, struct linux_dirent *dirp, unsigned int count);
44 uptr internal_sigaltstack(const void* ss, void* oss);
45 uptr internal_sigprocmask(int how, __sanitizer_sigset_t *set,
46 __sanitizer_sigset_t *oldset);
47
48 // Linux-only syscalls.
49 #if SANITIZER_LINUX
50 uptr internal_prctl(int option, uptr arg2, uptr arg3, uptr arg4, uptr arg5);
51 // Used only by sanitizer_stoptheworld. Signal handlers that are actually used
52 // (like the process-wide error reporting SEGV handler) must use
53 // internal_sigaction instead.
54 int internal_sigaction_norestorer(int signum, const void *act, void *oldact);
55 #if (defined(__x86_64__) || SANITIZER_MIPS64) && !SANITIZER_GO
56 // Uses a raw system call to avoid interceptors.
57 int internal_sigaction_syscall(int signum, const void *act, void *oldact);
58 #endif
59 void internal_sigdelset(__sanitizer_sigset_t *set, int signum);
60 #if defined(__x86_64__) || defined(__mips__) || defined(__aarch64__) \
61 || defined(__powerpc64__) || defined(__s390__) || defined(__i386__) \
62 || defined(__arm__)
63 uptr internal_clone(int (*fn)(void *), void *child_stack, int flags, void *arg,
64 int *parent_tidptr, void *newtls, int *child_tidptr);
65 #endif
66 #endif // SANITIZER_LINUX
67
68 // This class reads thread IDs from /proc/<pid>/task using only syscalls.
69 class ThreadLister {
70 public:
71 explicit ThreadLister(int pid);
72 ~ThreadLister();
73 // GetNextTID returns -1 if the list of threads is exhausted, or if there has
74 // been an error.
75 int GetNextTID();
76 void Reset();
77 bool error();
78
79 private:
80 bool GetDirectoryEntries();
81
82 int pid_;
83 int descriptor_;
84 InternalScopedBuffer<char> buffer_;
85 bool error_;
86 struct linux_dirent* entry_;
87 int bytes_read_;
88 };
89
90 // Exposed for testing.
91 uptr ThreadDescriptorSize();
92 uptr ThreadSelf();
93 uptr ThreadSelfOffset();
94
95 // Matches a library's file name against a base name (stripping path and version
96 // information).
97 bool LibraryNameIs(const char *full_name, const char *base_name);
98
99 // Call cb for each region mapped by map.
100 void ForEachMappedRegion(link_map *map, void (*cb)(const void *, uptr));
101
102 #if SANITIZER_ANDROID
103
104 #if defined(__aarch64__)
105 # define __get_tls() \
106 ({ void** __v; __asm__("mrs %0, tpidr_el0" : "=r"(__v)); __v; })
107 #elif defined(__arm__)
108 # define __get_tls() \
109 ({ void** __v; __asm__("mrc p15, 0, %0, c13, c0, 3" : "=r"(__v)); __v; })
110 #elif defined(__mips__)
111 // On mips32r1, this goes via a kernel illegal instruction trap that's
112 // optimized for v1.
113 # define __get_tls() \
114 ({ register void** __v asm("v1"); \
115 __asm__(".set push\n" \
116 ".set mips32r2\n" \
117 "rdhwr %0,$29\n" \
118 ".set pop\n" : "=r"(__v)); \
119 __v; })
120 #elif defined(__i386__)
121 # define __get_tls() \
122 ({ void** __v; __asm__("movl %%gs:0, %0" : "=r"(__v)); __v; })
123 #elif defined(__x86_64__)
124 # define __get_tls() \
125 ({ void** __v; __asm__("mov %%fs:0, %0" : "=r"(__v)); __v; })
126 #else
127 #error "Unsupported architecture."
128 #endif
129
130 // The Android Bionic team has allocated a TLS slot for TSan starting with N,
131 // given that Android currently doesn't support ELF TLS. It is used to store
132 // Sanitizers thread specific data.
133 static const int TLS_SLOT_TSAN = 8;
134
get_android_tls_ptr()135 ALWAYS_INLINE uptr *get_android_tls_ptr() {
136 return reinterpret_cast<uptr *>(&__get_tls()[TLS_SLOT_TSAN]);
137 }
138
139 #endif // SANITIZER_ANDROID
140
141 } // namespace __sanitizer
142
143 #endif // SANITIZER_FREEBSD || SANITIZER_LINUX || SANITIZER_NETBSD
144 #endif // SANITIZER_LINUX_H
145