xref: /freebsd/contrib/llvm-project/compiler-rt/lib/sanitizer_common/sanitizer_linux.h (revision ec0ea6efa1ad229d75c394c1a9b9cac33af2b1d3)
1 //===-- sanitizer_linux.h ---------------------------------------*- 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 // Linux-specific syscall wrappers and classes.
10 //
11 //===----------------------------------------------------------------------===//
12 #ifndef SANITIZER_LINUX_H
13 #define SANITIZER_LINUX_H
14 
15 #include "sanitizer_platform.h"
16 #if SANITIZER_FREEBSD || SANITIZER_LINUX || SANITIZER_NETBSD ||                \
17     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_posix.h"
23 #include "sanitizer_platform_limits_solaris.h"
24 #include "sanitizer_posix.h"
25 
26 struct link_map;  // Opaque type returned by dlopen().
27 struct utsname;
28 
29 namespace __sanitizer {
30 // Dirent structure for getdents(). Note that this structure is different from
31 // the one in <dirent.h>, which is used by readdir().
32 struct linux_dirent;
33 
34 struct ProcSelfMapsBuff {
35   char *data;
36   uptr mmaped_size;
37   uptr len;
38 };
39 
40 struct MemoryMappingLayoutData {
41   ProcSelfMapsBuff proc_self_maps;
42   const char *current;
43 };
44 
45 void ReadProcMaps(ProcSelfMapsBuff *proc_maps);
46 
47 // Syscall wrappers.
48 uptr internal_getdents(fd_t fd, struct linux_dirent *dirp, unsigned int count);
49 uptr internal_sigaltstack(const void* ss, void* oss);
50 uptr internal_sigprocmask(int how, __sanitizer_sigset_t *set,
51     __sanitizer_sigset_t *oldset);
52 #if SANITIZER_GLIBC
53 uptr internal_clock_gettime(__sanitizer_clockid_t clk_id, void *tp);
54 #endif
55 
56 // Linux-only syscalls.
57 #if SANITIZER_LINUX
58 uptr internal_prctl(int option, uptr arg2, uptr arg3, uptr arg4, uptr arg5);
59 // Used only by sanitizer_stoptheworld. Signal handlers that are actually used
60 // (like the process-wide error reporting SEGV handler) must use
61 // internal_sigaction instead.
62 int internal_sigaction_norestorer(int signum, const void *act, void *oldact);
63 void internal_sigdelset(__sanitizer_sigset_t *set, int signum);
64 #if defined(__x86_64__) || defined(__mips__) || defined(__aarch64__) || \
65     defined(__powerpc64__) || defined(__s390__) || defined(__i386__) || \
66     defined(__arm__) || SANITIZER_RISCV64
67 uptr internal_clone(int (*fn)(void *), void *child_stack, int flags, void *arg,
68                     int *parent_tidptr, void *newtls, int *child_tidptr);
69 #endif
70 int internal_uname(struct utsname *buf);
71 #elif SANITIZER_FREEBSD
72 void internal_sigdelset(__sanitizer_sigset_t *set, int signum);
73 #elif SANITIZER_NETBSD
74 void internal_sigdelset(__sanitizer_sigset_t *set, int signum);
75 uptr internal_clone(int (*fn)(void *), void *child_stack, int flags, void *arg);
76 #endif  // SANITIZER_LINUX
77 
78 // This class reads thread IDs from /proc/<pid>/task using only syscalls.
79 class ThreadLister {
80  public:
81   explicit ThreadLister(pid_t pid);
82   ~ThreadLister();
83   enum Result {
84     Error,
85     Incomplete,
86     Ok,
87   };
88   Result ListThreads(InternalMmapVector<tid_t> *threads);
89 
90  private:
91   bool IsAlive(int tid);
92 
93   pid_t pid_;
94   int descriptor_ = -1;
95   InternalMmapVector<char> buffer_;
96 };
97 
98 // Exposed for testing.
99 uptr ThreadDescriptorSize();
100 uptr ThreadSelf();
101 
102 // Matches a library's file name against a base name (stripping path and version
103 // information).
104 bool LibraryNameIs(const char *full_name, const char *base_name);
105 
106 // Call cb for each region mapped by map.
107 void ForEachMappedRegion(link_map *map, void (*cb)(const void *, uptr));
108 
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);
118 }
119 
120 #if SANITIZER_ANDROID
121 
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
130 // optimized for v1.
131 # define __get_tls() \
132     ({ register void** __v asm("v1"); \
133        __asm__(".set    push\n" \
134                ".set    mips32r2\n" \
135                "rdhwr   %0,$29\n" \
136                ".set    pop\n" : "=r"(__v)); \
137        __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; })
144 #else
145 #error "Unsupported architecture."
146 #endif
147 
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;
152 
153 ALWAYS_INLINE uptr *get_android_tls_ptr() {
154   return reinterpret_cast<uptr *>(&__get_tls()[TLS_SLOT_SANITIZER]);
155 }
156 
157 #endif  // SANITIZER_ANDROID
158 
159 }  // namespace __sanitizer
160 
161 #endif
162 #endif  // SANITIZER_LINUX_H
163