1 //===-- sanitizer_posix.cc ------------------------------------------------===//
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 // This file is shared between AddressSanitizer and ThreadSanitizer
10 // run-time libraries and implements POSIX-specific functions from
12 //===----------------------------------------------------------------------===//
14 #include "sanitizer_platform.h"
18 #include "sanitizer_common.h"
19 #include "sanitizer_file.h"
20 #include "sanitizer_flags.h"
21 #include "sanitizer_libc.h"
22 #include "sanitizer_posix.h"
23 #include "sanitizer_procmaps.h"
31 // The MAP_NORESERVE define has been removed in FreeBSD 11.x, and even before
32 // that, it was never implemented. So just define it to zero.
34 #define MAP_NORESERVE 0
37 namespace __sanitizer {
39 // ------------- sanitizer_common.h
40 uptr GetMmapGranularity() {
44 void *MmapOrDie(uptr size, const char *mem_type, bool raw_report) {
45 size = RoundUpTo(size, GetPageSizeCached());
46 uptr res = MmapNamed(nullptr, size, PROT_READ | PROT_WRITE,
47 MAP_PRIVATE | MAP_ANON, mem_type);
49 if (UNLIKELY(internal_iserror(res, &reserrno)))
50 ReportMmapFailureAndDie(size, mem_type, "allocate", reserrno, raw_report);
51 IncreaseTotalMmap(size);
55 void UnmapOrDie(void *addr, uptr size) {
56 if (!addr || !size) return;
57 uptr res = internal_munmap(addr, size);
58 if (UNLIKELY(internal_iserror(res))) {
59 Report("ERROR: %s failed to deallocate 0x%zx (%zd) bytes at address %p\n",
60 SanitizerToolName, size, size, addr);
61 CHECK("unable to unmap" && 0);
63 DecreaseTotalMmap(size);
66 void *MmapOrDieOnFatalError(uptr size, const char *mem_type) {
67 size = RoundUpTo(size, GetPageSizeCached());
68 uptr res = MmapNamed(nullptr, size, PROT_READ | PROT_WRITE,
69 MAP_PRIVATE | MAP_ANON, mem_type);
71 if (UNLIKELY(internal_iserror(res, &reserrno))) {
72 if (reserrno == ENOMEM)
74 ReportMmapFailureAndDie(size, mem_type, "allocate", reserrno);
76 IncreaseTotalMmap(size);
80 // We want to map a chunk of address space aligned to 'alignment'.
81 // We do it by mapping a bit more and then unmapping redundant pieces.
82 // We probably can do it with fewer syscalls in some OS-dependent way.
83 void *MmapAlignedOrDieOnFatalError(uptr size, uptr alignment,
84 const char *mem_type) {
85 CHECK(IsPowerOfTwo(size));
86 CHECK(IsPowerOfTwo(alignment));
87 uptr map_size = size + alignment;
88 uptr map_res = (uptr)MmapOrDieOnFatalError(map_size, mem_type);
89 if (UNLIKELY(!map_res))
91 uptr map_end = map_res + map_size;
93 if (!IsAligned(res, alignment)) {
94 res = (map_res + alignment - 1) & ~(alignment - 1);
95 UnmapOrDie((void*)map_res, res - map_res);
97 uptr end = res + size;
99 UnmapOrDie((void*)end, map_end - end);
103 void *MmapNoReserveOrDie(uptr size, const char *mem_type) {
104 size = RoundUpTo(size, GetPageSizeCached());
105 uptr p = MmapNamed(nullptr, size, PROT_READ | PROT_WRITE,
106 MAP_PRIVATE | MAP_ANON | MAP_NORESERVE, mem_type);
108 if (UNLIKELY(internal_iserror(p, &reserrno)))
109 ReportMmapFailureAndDie(size, mem_type, "allocate noreserve", reserrno);
110 IncreaseTotalMmap(size);
114 static void *MmapFixedImpl(uptr fixed_addr, uptr size, bool tolerate_enomem,
116 size = RoundUpTo(size, GetPageSizeCached());
117 fixed_addr = RoundDownTo(fixed_addr, GetPageSizeCached());
118 uptr p = MmapNamed((void *)fixed_addr, size, PROT_READ | PROT_WRITE,
119 MAP_PRIVATE | MAP_ANON | MAP_FIXED, name);
121 if (UNLIKELY(internal_iserror(p, &reserrno))) {
122 if (tolerate_enomem && reserrno == ENOMEM)
125 internal_snprintf(mem_type, sizeof(mem_type), "memory at address 0x%zx",
127 ReportMmapFailureAndDie(size, mem_type, "allocate", reserrno);
129 IncreaseTotalMmap(size);
133 void *MmapFixedOrDie(uptr fixed_addr, uptr size, const char *name) {
134 return MmapFixedImpl(fixed_addr, size, false /*tolerate_enomem*/, name);
137 void *MmapFixedOrDieOnFatalError(uptr fixed_addr, uptr size, const char *name) {
138 return MmapFixedImpl(fixed_addr, size, true /*tolerate_enomem*/, name);
141 bool MprotectNoAccess(uptr addr, uptr size) {
142 return 0 == internal_mprotect((void*)addr, size, PROT_NONE);
145 bool MprotectReadOnly(uptr addr, uptr size) {
146 return 0 == internal_mprotect((void *)addr, size, PROT_READ);
150 void MprotectMallocZones(void *addr, int prot) {}
153 fd_t OpenFile(const char *filename, FileAccessMode mode, error_t *errno_p) {
154 if (ShouldMockFailureToOpen(filename))
158 case RdOnly: flags = O_RDONLY; break;
159 case WrOnly: flags = O_WRONLY | O_CREAT | O_TRUNC; break;
160 case RdWr: flags = O_RDWR | O_CREAT; break;
162 fd_t res = internal_open(filename, flags, 0660);
163 if (internal_iserror(res, errno_p))
165 return ReserveStandardFds(res);
168 void CloseFile(fd_t fd) {
172 bool ReadFromFile(fd_t fd, void *buff, uptr buff_size, uptr *bytes_read,
174 uptr res = internal_read(fd, buff, buff_size);
175 if (internal_iserror(res, error_p))
182 bool WriteToFile(fd_t fd, const void *buff, uptr buff_size, uptr *bytes_written,
184 uptr res = internal_write(fd, buff, buff_size);
185 if (internal_iserror(res, error_p))
188 *bytes_written = res;
192 void *MapFileToMemory(const char *file_name, uptr *buff_size) {
193 fd_t fd = OpenFile(file_name, RdOnly);
194 CHECK(fd != kInvalidFd);
195 uptr fsize = internal_filesize(fd);
196 CHECK_NE(fsize, (uptr)-1);
198 *buff_size = RoundUpTo(fsize, GetPageSizeCached());
199 uptr map = internal_mmap(nullptr, *buff_size, PROT_READ, MAP_PRIVATE, fd, 0);
200 return internal_iserror(map) ? nullptr : (void *)map;
203 void *MapWritableFileToMemory(void *addr, uptr size, fd_t fd, OFF_T offset) {
204 uptr flags = MAP_SHARED;
205 if (addr) flags |= MAP_FIXED;
206 uptr p = internal_mmap(addr, size, PROT_READ | PROT_WRITE, flags, fd, offset);
208 if (internal_iserror(p, &mmap_errno)) {
209 Printf("could not map writable file (%d, %lld, %zu): %zd, errno: %d\n",
210 fd, (long long)offset, size, p, mmap_errno);
216 static inline bool IntervalsAreSeparate(uptr start1, uptr end1,
217 uptr start2, uptr end2) {
218 CHECK(start1 <= end1);
219 CHECK(start2 <= end2);
220 return (end1 < start2) || (end2 < start1);
223 // FIXME: this is thread-unsafe, but should not cause problems most of the time.
224 // When the shadow is mapped only a single thread usually exists (plus maybe
225 // several worker threads on Mac, which aren't expected to map big chunks of
227 bool MemoryRangeIsAvailable(uptr range_start, uptr range_end) {
228 MemoryMappingLayout proc_maps(/*cache_enabled*/true);
229 if (proc_maps.Error())
230 return true; // and hope for the best
231 MemoryMappedSegment segment;
232 while (proc_maps.Next(&segment)) {
233 if (segment.start == segment.end) continue; // Empty range.
234 CHECK_NE(0, segment.end);
235 if (!IntervalsAreSeparate(segment.start, segment.end - 1, range_start,
242 void DumpProcessMap() {
243 MemoryMappingLayout proc_maps(/*cache_enabled*/true);
244 const sptr kBufSize = 4095;
245 char *filename = (char*)MmapOrDie(kBufSize, __func__);
246 MemoryMappedSegment segment(filename, kBufSize);
247 Report("Process memory map follows:\n");
248 while (proc_maps.Next(&segment)) {
249 Printf("\t%p-%p\t%s\n", (void *)segment.start, (void *)segment.end,
252 Report("End of process memory map.\n");
253 UnmapOrDie(filename, kBufSize);
256 const char *GetPwd() {
257 return GetEnv("PWD");
260 bool IsPathSeparator(const char c) {
264 bool IsAbsolutePath(const char *path) {
265 return path != nullptr && IsPathSeparator(path[0]);
268 void ReportFile::Write(const char *buffer, uptr length) {
271 internal_write(fd, buffer, length);
274 bool GetCodeRangeForFile(const char *module, uptr *start, uptr *end) {
275 MemoryMappingLayout proc_maps(/*cache_enabled*/false);
276 InternalScopedString buff(kMaxPathLength);
277 MemoryMappedSegment segment(buff.data(), kMaxPathLength);
278 while (proc_maps.Next(&segment)) {
279 if (segment.IsExecutable() &&
280 internal_strcmp(module, segment.filename) == 0) {
281 *start = segment.start;
289 uptr SignalContext::GetAddress() const {
290 auto si = static_cast<const siginfo_t *>(siginfo);
291 return (uptr)si->si_addr;
294 bool SignalContext::IsMemoryAccess() const {
295 auto si = static_cast<const siginfo_t *>(siginfo);
296 return si->si_signo == SIGSEGV;
299 int SignalContext::GetType() const {
300 return static_cast<const siginfo_t *>(siginfo)->si_signo;
303 const char *SignalContext::Describe() const {
316 return "UNKNOWN SIGNAL";
319 fd_t ReserveStandardFds(fd_t fd) {
324 internal_memset(used, 0, sizeof(used));
327 fd = internal_dup(fd);
329 for (int i = 0; i <= 2; ++i)
335 bool ShouldMockFailureToOpen(const char *path) {
336 return common_flags()->test_only_emulate_no_memorymap &&
337 internal_strncmp(path, "/proc/", 6) == 0;
340 #if SANITIZER_LINUX && !SANITIZER_ANDROID && !SANITIZER_GO
341 int GetNamedMappingFd(const char *name, uptr size, int *flags) {
342 if (!common_flags()->decorate_proc_maps || !name)
345 CHECK(internal_strlen(name) < sizeof(shmname) - 10);
346 internal_snprintf(shmname, sizeof(shmname), "/dev/shm/%zu [%s]",
347 internal_getpid(), name);
348 int fd = ReserveStandardFds(
349 internal_open(shmname, O_RDWR | O_CREAT | O_TRUNC | O_CLOEXEC, S_IRWXU));
351 int res = internal_ftruncate(fd, size);
353 res = internal_unlink(shmname);
355 *flags &= ~(MAP_ANON | MAP_ANONYMOUS);
359 int GetNamedMappingFd(const char *name, uptr size, int *flags) {
364 #if SANITIZER_ANDROID
365 #define PR_SET_VMA 0x53564d41
366 #define PR_SET_VMA_ANON_NAME 0
367 void DecorateMapping(uptr addr, uptr size, const char *name) {
368 if (!common_flags()->decorate_proc_maps || !name)
370 internal_prctl(PR_SET_VMA, PR_SET_VMA_ANON_NAME, addr, size, (uptr)name);
373 void DecorateMapping(uptr addr, uptr size, const char *name) {
377 uptr MmapNamed(void *addr, uptr length, int prot, int flags, const char *name) {
378 int fd = GetNamedMappingFd(name, length, &flags);
379 uptr res = internal_mmap(addr, length, prot, flags, fd, 0);
380 if (!internal_iserror(res))
381 DecorateMapping(res, length, name);
386 } // namespace __sanitizer
388 #endif // SANITIZER_POSIX