1//===-- sanitizer_linux.h ---------------------------------------*- C++ -*-===//
2//
3//                     The LLVM Compiler Infrastructure
4//
5// This file is distributed under the University of Illinois Open Source
6// License. See LICENSE.TXT for details.
7//
8//===----------------------------------------------------------------------===//
9//
10// Linux-specific syscall wrappers and classes.
11//
12//===----------------------------------------------------------------------===//
13#ifndef SANITIZER_LINUX_H
14#define SANITIZER_LINUX_H
15
16#include "sanitizer_platform.h"
17#if SANITIZER_FREEBSD || SANITIZER_LINUX || SANITIZER_NETBSD ||                \
18    SANITIZER_OPENBSD || SANITIZER_SOLARIS
19#include "sanitizer_common.h"
20#include "sanitizer_internal_defs.h"
21#include "sanitizer_platform_limits_freebsd.h"
22#include "sanitizer_platform_limits_netbsd.h"
23#include "sanitizer_platform_limits_openbsd.h"
24#include "sanitizer_platform_limits_posix.h"
25#include "sanitizer_platform_limits_solaris.h"
26#include "sanitizer_posix.h"
27
28struct link_map;  // Opaque type returned by dlopen().
29
30namespace __sanitizer {
31// Dirent structure for getdents(). Note that this structure is different from
32// the one in <dirent.h>, which is used by readdir().
33struct linux_dirent;
34
35struct ProcSelfMapsBuff {
36  char *data;
37  uptr mmaped_size;
38  uptr len;
39};
40
41struct MemoryMappingLayoutData {
42  ProcSelfMapsBuff proc_self_maps;
43  const char *current;
44};
45
46void ReadProcMaps(ProcSelfMapsBuff *proc_maps);
47
48// Syscall wrappers.
49uptr internal_getdents(fd_t fd, struct linux_dirent *dirp, unsigned int count);
50uptr internal_sigaltstack(const void* ss, void* oss);
51uptr internal_sigprocmask(int how, __sanitizer_sigset_t *set,
52    __sanitizer_sigset_t *oldset);
53uptr internal_clock_gettime(__sanitizer_clockid_t clk_id, void *tp);
54
55// Linux-only syscalls.
56#if SANITIZER_LINUX
57uptr internal_prctl(int option, uptr arg2, uptr arg3, uptr arg4, uptr arg5);
58// Used only by sanitizer_stoptheworld. Signal handlers that are actually used
59// (like the process-wide error reporting SEGV handler) must use
60// internal_sigaction instead.
61int internal_sigaction_norestorer(int signum, const void *act, void *oldact);
62#if (defined(__x86_64__) || SANITIZER_MIPS64) && !SANITIZER_GO
63// Uses a raw system call to avoid interceptors.
64int internal_sigaction_syscall(int signum, const void *act, void *oldact);
65#endif
66void internal_sigdelset(__sanitizer_sigset_t *set, int signum);
67#if defined(__x86_64__) || defined(__mips__) || defined(__aarch64__) \
68  || defined(__powerpc64__) || defined(__s390__) || defined(__i386__) \
69  || defined(__arm__)
70uptr internal_clone(int (*fn)(void *), void *child_stack, int flags, void *arg,
71                    int *parent_tidptr, void *newtls, int *child_tidptr);
72#endif
73#elif SANITIZER_FREEBSD
74void internal_sigdelset(__sanitizer_sigset_t *set, int signum);
75#endif  // SANITIZER_LINUX
76
77// This class reads thread IDs from /proc/<pid>/task using only syscalls.
78class ThreadLister {
79 public:
80  explicit ThreadLister(pid_t pid);
81  ~ThreadLister();
82  enum Result {
83    Error,
84    Incomplete,
85    Ok,
86  };
87  Result ListThreads(InternalMmapVector<tid_t> *threads);
88
89 private:
90  bool IsAlive(int tid);
91
92  pid_t pid_;
93  int descriptor_ = -1;
94  InternalMmapVector<char> buffer_;
95};
96
97// Exposed for testing.
98uptr ThreadDescriptorSize();
99uptr ThreadSelf();
100uptr ThreadSelfOffset();
101
102// Matches a library's file name against a base name (stripping path and version
103// information).
104bool LibraryNameIs(const char *full_name, const char *base_name);
105
106// Call cb for each region mapped by map.
107void ForEachMappedRegion(link_map *map, void (*cb)(const void *, uptr));
108
109#if SANITIZER_ANDROID
110
111#if defined(__aarch64__)
112# define __get_tls() \
113    ({ void** __v; __asm__("mrs %0, tpidr_el0" : "=r"(__v)); __v; })
114#elif defined(__arm__)
115# define __get_tls() \
116    ({ void** __v; __asm__("mrc p15, 0, %0, c13, c0, 3" : "=r"(__v)); __v; })
117#elif defined(__mips__)
118// On mips32r1, this goes via a kernel illegal instruction trap that's
119// optimized for v1.
120# define __get_tls() \
121    ({ register void** __v asm("v1"); \
122       __asm__(".set    push\n" \
123               ".set    mips32r2\n" \
124               "rdhwr   %0,$29\n" \
125               ".set    pop\n" : "=r"(__v)); \
126       __v; })
127#elif defined(__i386__)
128# define __get_tls() \
129    ({ void** __v; __asm__("movl %%gs:0, %0" : "=r"(__v)); __v; })
130#elif defined(__x86_64__)
131# define __get_tls() \
132    ({ void** __v; __asm__("mov %%fs:0, %0" : "=r"(__v)); __v; })
133#else
134#error "Unsupported architecture."
135#endif
136
137// The Android Bionic team has allocated a TLS slot for sanitizers starting
138// with Q, given that Android currently doesn't support ELF TLS. It is used to
139// store sanitizer thread specific data.
140static const int TLS_SLOT_SANITIZER = 6;
141
142ALWAYS_INLINE uptr *get_android_tls_ptr() {
143  return reinterpret_cast<uptr *>(&__get_tls()[TLS_SLOT_SANITIZER]);
144}
145
146#endif  // SANITIZER_ANDROID
147
148}  // namespace __sanitizer
149
150#endif
151#endif  // SANITIZER_LINUX_H
152