1 //===-- sanitizer_linux.h ---------------------------------------*- C++ -*-===//
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
7 //===----------------------------------------------------------------------===//
9 // Linux-specific syscall wrappers and classes.
11 //===----------------------------------------------------------------------===//
12 #ifndef SANITIZER_LINUX_H
13 #define SANITIZER_LINUX_H
15 #include "sanitizer_platform.h"
16 #if SANITIZER_FREEBSD || SANITIZER_LINUX || SANITIZER_NETBSD || \
17 SANITIZER_OPENBSD || SANITIZER_SOLARIS
18 #include "sanitizer_common.h"
19 #include "sanitizer_internal_defs.h"
20 #include "sanitizer_platform_limits_freebsd.h"
21 #include "sanitizer_platform_limits_netbsd.h"
22 #include "sanitizer_platform_limits_openbsd.h"
23 #include "sanitizer_platform_limits_posix.h"
24 #include "sanitizer_platform_limits_solaris.h"
25 #include "sanitizer_posix.h"
27 struct link_map; // Opaque type returned by dlopen().
30 namespace __sanitizer {
31 // Dirent structure for getdents(). Note that this structure is different from
32 // the one in <dirent.h>, which is used by readdir().
35 struct ProcSelfMapsBuff {
41 struct MemoryMappingLayoutData {
42 ProcSelfMapsBuff proc_self_maps;
46 void ReadProcMaps(ProcSelfMapsBuff *proc_maps);
49 uptr internal_getdents(fd_t fd, struct linux_dirent *dirp, unsigned int count);
50 uptr internal_sigaltstack(const void* ss, void* oss);
51 uptr internal_sigprocmask(int how, __sanitizer_sigset_t *set,
52 __sanitizer_sigset_t *oldset);
53 uptr internal_clock_gettime(__sanitizer_clockid_t clk_id, void *tp);
55 // Linux-only syscalls.
57 uptr 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.
61 int internal_sigaction_norestorer(int signum, const void *act, void *oldact);
62 void internal_sigdelset(__sanitizer_sigset_t *set, int signum);
63 #if defined(__x86_64__) || defined(__mips__) || defined(__aarch64__) \
64 || defined(__powerpc64__) || defined(__s390__) || defined(__i386__) \
66 uptr internal_clone(int (*fn)(void *), void *child_stack, int flags, void *arg,
67 int *parent_tidptr, void *newtls, int *child_tidptr);
69 int internal_uname(struct utsname *buf);
70 #elif SANITIZER_FREEBSD
71 void internal_sigdelset(__sanitizer_sigset_t *set, int signum);
72 #elif SANITIZER_NETBSD
73 void internal_sigdelset(__sanitizer_sigset_t *set, int signum);
74 uptr internal_clone(int (*fn)(void *), void *child_stack, int flags, void *arg);
75 #endif // SANITIZER_LINUX
77 // This class reads thread IDs from /proc/<pid>/task using only syscalls.
80 explicit ThreadLister(pid_t pid);
87 Result ListThreads(InternalMmapVector<tid_t> *threads);
90 bool IsAlive(int tid);
94 InternalMmapVector<char> buffer_;
97 // Exposed for testing.
98 uptr ThreadDescriptorSize();
100 uptr ThreadSelfOffset();
102 // Matches a library's file name against a base name (stripping path and version
104 bool LibraryNameIs(const char *full_name, const char *base_name);
106 // Call cb for each region mapped by map.
107 void ForEachMappedRegion(link_map *map, void (*cb)(const void *, uptr));
109 // Releases memory pages entirely within the [beg, end] address range.
110 // The pages no longer count toward RSS; reads are guaranteed to return 0.
111 // Requires (but does not verify!) that pages are MAP_PRIVATE.
112 INLINE void ReleaseMemoryPagesToOSAndZeroFill(uptr beg, uptr end) {
113 // man madvise on Linux promises zero-fill for anonymous private pages.
114 // Testing shows the same behaviour for private (but not anonymous) mappings
115 // of shm_open() files, as long as the underlying file is untouched.
116 CHECK(SANITIZER_LINUX);
117 ReleaseMemoryPagesToOS(beg, end);
120 #if SANITIZER_ANDROID
122 #if defined(__aarch64__)
123 # define __get_tls() \
124 ({ void** __v; __asm__("mrs %0, tpidr_el0" : "=r"(__v)); __v; })
125 #elif defined(__arm__)
126 # define __get_tls() \
127 ({ void** __v; __asm__("mrc p15, 0, %0, c13, c0, 3" : "=r"(__v)); __v; })
128 #elif defined(__mips__)
129 // On mips32r1, this goes via a kernel illegal instruction trap that's
131 # define __get_tls() \
132 ({ register void** __v asm("v1"); \
133 __asm__(".set push\n" \
136 ".set pop\n" : "=r"(__v)); \
138 #elif defined(__i386__)
139 # define __get_tls() \
140 ({ void** __v; __asm__("movl %%gs:0, %0" : "=r"(__v)); __v; })
141 #elif defined(__x86_64__)
142 # define __get_tls() \
143 ({ void** __v; __asm__("mov %%fs:0, %0" : "=r"(__v)); __v; })
145 #error "Unsupported architecture."
148 // The Android Bionic team has allocated a TLS slot for sanitizers starting
149 // with Q, given that Android currently doesn't support ELF TLS. It is used to
150 // store sanitizer thread specific data.
151 static const int TLS_SLOT_SANITIZER = 6;
153 ALWAYS_INLINE uptr *get_android_tls_ptr() {
154 return reinterpret_cast<uptr *>(&__get_tls()[TLS_SLOT_SANITIZER]);
157 #endif // SANITIZER_ANDROID
159 } // namespace __sanitizer
162 #endif // SANITIZER_LINUX_H