1 //===-- sanitizer_linux_libcdep.cc ----------------------------------------===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // This file is shared between AddressSanitizer and ThreadSanitizer
11 // run-time libraries and implements linux-specific functions from
13 //===----------------------------------------------------------------------===//
15 #include "sanitizer_platform.h"
17 #if SANITIZER_FREEBSD || SANITIZER_LINUX
19 #include "sanitizer_allocator_internal.h"
20 #include "sanitizer_atomic.h"
21 #include "sanitizer_common.h"
22 #include "sanitizer_flags.h"
23 #include "sanitizer_freebsd.h"
24 #include "sanitizer_linux.h"
25 #include "sanitizer_placement_new.h"
26 #include "sanitizer_procmaps.h"
27 #include "sanitizer_stacktrace.h"
29 #if SANITIZER_ANDROID || SANITIZER_FREEBSD
30 #include <dlfcn.h> // for dlsym()
36 #include <sys/resource.h>
39 #include <pthread_np.h>
40 #include <osreldate.h>
41 #define pthread_getattr_np pthread_attr_get_np
45 #include <sys/prctl.h>
49 #include <android/api-level.h>
52 #if SANITIZER_ANDROID && __ANDROID_API__ < 21
53 #include <android/log.h>
58 #if !SANITIZER_ANDROID
63 namespace __sanitizer {
65 SANITIZER_WEAK_ATTRIBUTE int
66 real_sigaction(int signum, const void *act, void *oldact);
68 int internal_sigaction(int signum, const void *act, void *oldact) {
71 return real_sigaction(signum, act, oldact);
73 return sigaction(signum, (const struct sigaction *)act,
74 (struct sigaction *)oldact);
77 void GetThreadStackTopAndBottom(bool at_initialization, uptr *stack_top,
81 if (at_initialization) {
82 // This is the main thread. Libpthread may not be initialized yet.
84 CHECK_EQ(getrlimit(RLIMIT_STACK, &rl), 0);
86 // Find the mapping that contains a stack variable.
87 MemoryMappingLayout proc_maps(/*cache_enabled*/true);
88 uptr start, end, offset;
90 while (proc_maps.Next(&start, &end, &offset, nullptr, 0,
91 /* protection */nullptr)) {
96 CHECK((uptr)&rl >= start && (uptr)&rl < end);
98 // Get stacksize from rlimit, but clip it so that it does not overlap
99 // with other mappings.
100 uptr stacksize = rl.rlim_cur;
101 if (stacksize > end - prev_end)
102 stacksize = end - prev_end;
103 // When running with unlimited stack size, we still want to set some limit.
104 // The unlimited stack size is caused by 'ulimit -s unlimited'.
105 // Also, for some reason, GNU make spawns subprocesses with unlimited stack.
106 if (stacksize > kMaxThreadStackSize)
107 stacksize = kMaxThreadStackSize;
109 *stack_bottom = end - stacksize;
113 pthread_attr_init(&attr);
114 CHECK_EQ(pthread_getattr_np(pthread_self(), &attr), 0);
116 void *stackaddr = nullptr;
117 my_pthread_attr_getstack(&attr, &stackaddr, &stacksize);
118 pthread_attr_destroy(&attr);
120 CHECK_LE(stacksize, kMaxThreadStackSize); // Sanity check.
121 *stack_top = (uptr)stackaddr + stacksize;
122 *stack_bottom = (uptr)stackaddr;
126 bool SetEnv(const char *name, const char *value) {
127 void *f = dlsym(RTLD_NEXT, "setenv");
130 typedef int(*setenv_ft)(const char *name, const char *value, int overwrite);
132 CHECK_EQ(sizeof(setenv_f), sizeof(f));
133 internal_memcpy(&setenv_f, &f, sizeof(f));
134 return setenv_f(name, value, 1) == 0;
138 bool SanitizerSetThreadName(const char *name) {
140 return 0 == prctl(PR_SET_NAME, (unsigned long)name, 0, 0, 0); // NOLINT
146 bool SanitizerGetThreadName(char *name, int max_len) {
149 if (prctl(PR_GET_NAME, (unsigned long)buff, 0, 0, 0)) // NOLINT
151 internal_strncpy(name, buff, max_len);
159 #if !SANITIZER_FREEBSD && !SANITIZER_ANDROID && !SANITIZER_GO
160 static uptr g_tls_size;
164 # define DL_INTERNAL_FUNCTION __attribute__((regparm(3), stdcall))
166 # define DL_INTERNAL_FUNCTION
169 #if defined(__mips__) || defined(__powerpc64__)
170 // TlsPreTcbSize includes size of struct pthread_descr and size of tcb
171 // head structure. It lies before the static tls blocks.
172 static uptr TlsPreTcbSize() {
173 # if defined(__mips__)
174 const uptr kTcbHead = 16; // sizeof (tcbhead_t)
175 # elif defined(__powerpc64__)
176 const uptr kTcbHead = 88; // sizeof (tcbhead_t)
178 const uptr kTlsAlign = 16;
179 const uptr kTlsPreTcbSize =
180 (ThreadDescriptorSize() + kTcbHead + kTlsAlign - 1) & ~(kTlsAlign - 1);
182 g_tls_size = (g_tls_size + kTlsPreTcbSize + kTlsAlign -1) & ~(kTlsAlign - 1);
183 return kTlsPreTcbSize;
188 #if !SANITIZER_FREEBSD && !SANITIZER_ANDROID && !SANITIZER_GO
189 // all current supported platforms have 16 bytes stack alignment
190 const size_t kStackAlign = 16;
191 typedef void (*get_tls_func)(size_t*, size_t*) DL_INTERNAL_FUNCTION;
192 get_tls_func get_tls;
193 void *get_tls_static_info_ptr = dlsym(RTLD_NEXT, "_dl_get_tls_static_info");
194 CHECK_EQ(sizeof(get_tls), sizeof(get_tls_static_info_ptr));
195 internal_memcpy(&get_tls, &get_tls_static_info_ptr,
196 sizeof(get_tls_static_info_ptr));
197 CHECK_NE(get_tls, 0);
199 size_t tls_align = 0;
200 get_tls(&tls_size, &tls_align);
201 if (tls_align < kStackAlign)
202 tls_align = kStackAlign;
203 g_tls_size = RoundUpTo(tls_size, tls_align);
204 #endif // !SANITIZER_FREEBSD && !SANITIZER_ANDROID && !SANITIZER_GO
207 #if (defined(__x86_64__) || defined(__i386__) || defined(__mips__) \
208 || defined(__aarch64__) || defined(__powerpc64__)) \
209 && SANITIZER_LINUX && !SANITIZER_ANDROID
210 // sizeof(struct pthread) from glibc.
211 static atomic_uintptr_t kThreadDescriptorSize;
213 uptr ThreadDescriptorSize() {
214 uptr val = atomic_load(&kThreadDescriptorSize, memory_order_relaxed);
217 #if defined(__x86_64__) || defined(__i386__)
218 #ifdef _CS_GNU_LIBC_VERSION
220 uptr len = confstr(_CS_GNU_LIBC_VERSION, buf, sizeof(buf));
221 if (len < sizeof(buf) && internal_strncmp(buf, "glibc 2.", 8) == 0) {
223 int minor = internal_simple_strtoll(buf + 8, &end, 10);
224 if (end != buf + 8 && (*end == '\0' || *end == '.')) {
225 /* sizeof(struct pthread) values from various glibc versions. */
227 val = 1728; // Assume only one particular version for x32.
229 val = FIRST_32_SECOND_64(1104, 1696);
231 val = FIRST_32_SECOND_64(1120, 1728);
233 val = FIRST_32_SECOND_64(1136, 1728);
235 val = FIRST_32_SECOND_64(1136, 1712);
236 else if (minor == 10)
237 val = FIRST_32_SECOND_64(1168, 1776);
238 else if (minor <= 12)
239 val = FIRST_32_SECOND_64(1168, 2288);
240 else if (minor == 13)
241 val = FIRST_32_SECOND_64(1168, 2304);
243 val = FIRST_32_SECOND_64(1216, 2304);
246 atomic_store(&kThreadDescriptorSize, val, memory_order_relaxed);
250 #elif defined(__mips__)
251 // TODO(sagarthakur): add more values as per different glibc versions.
252 val = FIRST_32_SECOND_64(1152, 1776);
254 atomic_store(&kThreadDescriptorSize, val, memory_order_relaxed);
256 #elif defined(__aarch64__)
257 // The sizeof (struct pthread) is the same from GLIBC 2.17 to 2.22.
259 atomic_store(&kThreadDescriptorSize, val, memory_order_relaxed);
261 #elif defined(__powerpc64__)
262 val = 1776; // from glibc.ppc64le 2.20-8.fc21
263 atomic_store(&kThreadDescriptorSize, val, memory_order_relaxed);
269 // The offset at which pointer to self is located in the thread descriptor.
270 const uptr kThreadSelfOffset = FIRST_32_SECOND_64(8, 16);
272 uptr ThreadSelfOffset() {
273 return kThreadSelfOffset;
278 # if defined(__i386__)
279 asm("mov %%gs:%c1,%0" : "=r"(descr_addr) : "i"(kThreadSelfOffset));
280 # elif defined(__x86_64__)
281 asm("mov %%fs:%c1,%0" : "=r"(descr_addr) : "i"(kThreadSelfOffset));
282 # elif defined(__mips__)
283 // MIPS uses TLS variant I. The thread pointer (in hardware register $29)
284 // points to the end of the TCB + 0x7000. The pthread_descr structure is
285 // immediately in front of the TCB. TlsPreTcbSize() includes the size of the
286 // TCB and the size of pthread_descr.
287 const uptr kTlsTcbOffset = 0x7000;
289 asm volatile(".set push;\
292 .set pop" : "=r" (thread_pointer));
293 descr_addr = thread_pointer - kTlsTcbOffset - TlsPreTcbSize();
294 # elif defined(__aarch64__)
295 descr_addr = reinterpret_cast<uptr>(__builtin_thread_pointer());
296 # elif defined(__powerpc64__)
297 // PPC64LE uses TLS variant I. The thread pointer (in GPR 13)
298 // points to the end of the TCB + 0x7000. The pthread_descr structure is
299 // immediately in front of the TCB. TlsPreTcbSize() includes the size of the
300 // TCB and the size of pthread_descr.
301 const uptr kTlsTcbOffset = 0x7000;
303 asm("addi %0,13,%1" : "=r"(thread_pointer) : "I"(-kTlsTcbOffset));
304 descr_addr = thread_pointer - TlsPreTcbSize();
306 # error "unsupported CPU arch"
310 #endif // (x86_64 || i386 || MIPS) && SANITIZER_LINUX
312 #if SANITIZER_FREEBSD
313 static void **ThreadSelfSegbase() {
315 # if defined(__i386__)
316 // sysarch(I386_GET_GSBASE, segbase);
317 __asm __volatile("mov %%gs:0, %0" : "=r" (segbase));
318 # elif defined(__x86_64__)
319 // sysarch(AMD64_GET_FSBASE, segbase);
320 __asm __volatile("movq %%fs:0, %0" : "=r" (segbase));
322 # error "unsupported CPU arch for FreeBSD platform"
328 return (uptr)ThreadSelfSegbase()[2];
330 #endif // SANITIZER_FREEBSD
333 static void GetTls(uptr *addr, uptr *size) {
334 #if SANITIZER_LINUX && !SANITIZER_ANDROID
335 # if defined(__x86_64__) || defined(__i386__)
336 *addr = ThreadSelf();
337 *size = GetTlsSize();
339 *addr += ThreadDescriptorSize();
340 # elif defined(__mips__) || defined(__aarch64__) || defined(__powerpc64__)
341 *addr = ThreadSelf();
342 *size = GetTlsSize();
347 #elif SANITIZER_FREEBSD
348 void** segbase = ThreadSelfSegbase();
353 // tls_size = round(tls_static_space, tcbalign);
355 // dtv[2] = segbase - tls_static_space;
356 void **dtv = (void**) segbase[1];
357 *addr = (uptr) dtv[2];
358 *size = (*addr == 0) ? 0 : ((uptr) segbase[0] - (uptr) dtv[2]);
360 #elif SANITIZER_ANDROID
371 #if SANITIZER_FREEBSD || SANITIZER_ANDROID
373 GetTls(&addr, &size);
381 void GetThreadStackAndTls(bool main, uptr *stk_addr, uptr *stk_size,
382 uptr *tls_addr, uptr *tls_size) {
384 // Stub implementation for Go.
385 *stk_addr = *stk_size = *tls_addr = *tls_size = 0;
387 GetTls(tls_addr, tls_size);
389 uptr stack_top, stack_bottom;
390 GetThreadStackTopAndBottom(main, &stack_top, &stack_bottom);
391 *stk_addr = stack_bottom;
392 *stk_size = stack_top - stack_bottom;
395 // If stack and tls intersect, make them non-intersecting.
396 if (*tls_addr > *stk_addr && *tls_addr < *stk_addr + *stk_size) {
397 CHECK_GT(*tls_addr + *tls_size, *stk_addr);
398 CHECK_LE(*tls_addr + *tls_size, *stk_addr + *stk_size);
399 *stk_size -= *tls_size;
400 *tls_addr = *stk_addr + *stk_size;
406 # if !SANITIZER_FREEBSD
407 typedef ElfW(Phdr) Elf_Phdr;
408 # elif SANITIZER_WORDSIZE == 32 && __FreeBSD_version <= 902001 // v9.2
409 # define Elf_Phdr XElf32_Phdr
410 # define dl_phdr_info xdl_phdr_info
411 # define dl_iterate_phdr(c, b) xdl_iterate_phdr((c), (b))
414 struct DlIteratePhdrData {
415 LoadedModule *modules;
419 string_predicate_t filter;
422 static int dl_iterate_phdr_cb(dl_phdr_info *info, size_t size, void *arg) {
423 DlIteratePhdrData *data = (DlIteratePhdrData*)arg;
424 if (data->current_n == data->max_n)
426 InternalScopedString module_name(kMaxPathLength);
429 // First module is the binary itself.
430 ReadBinaryNameCached(module_name.data(), module_name.size());
431 } else if (info->dlpi_name) {
432 module_name.append("%s", info->dlpi_name);
434 if (module_name[0] == '\0')
436 if (data->filter && !data->filter(module_name.data()))
438 LoadedModule *cur_module = &data->modules[data->current_n];
439 cur_module->set(module_name.data(), info->dlpi_addr);
441 for (int i = 0; i < info->dlpi_phnum; i++) {
442 const Elf_Phdr *phdr = &info->dlpi_phdr[i];
443 if (phdr->p_type == PT_LOAD) {
444 uptr cur_beg = info->dlpi_addr + phdr->p_vaddr;
445 uptr cur_end = cur_beg + phdr->p_memsz;
446 bool executable = phdr->p_flags & PF_X;
447 cur_module->addAddressRange(cur_beg, cur_end, executable);
453 #if SANITIZER_ANDROID && __ANDROID_API__ < 21
454 extern "C" __attribute__((weak)) int dl_iterate_phdr(
455 int (*)(struct dl_phdr_info *, size_t, void *), void *);
458 uptr GetListOfModules(LoadedModule *modules, uptr max_modules,
459 string_predicate_t filter) {
460 #if SANITIZER_ANDROID && __ANDROID_API__ <= 22
461 u32 api_level = AndroidGetApiLevel();
462 // Fall back to /proc/maps if dl_iterate_phdr is unavailable or broken.
463 // The runtime check allows the same library to work with
464 // both K and L (and future) Android releases.
465 if (api_level <= ANDROID_LOLLIPOP_MR1) { // L or earlier
466 MemoryMappingLayout memory_mapping(false);
467 return memory_mapping.DumpListOfModules(modules, max_modules, filter);
471 DlIteratePhdrData data = {modules, 0, true, max_modules, filter};
472 dl_iterate_phdr(dl_iterate_phdr_cb, &data);
473 return data.current_n;
476 // getrusage does not give us the current RSS, only the max RSS.
477 // Still, this is better than nothing if /proc/self/statm is not available
478 // for some reason, e.g. due to a sandbox.
479 static uptr GetRSSFromGetrusage() {
481 if (getrusage(RUSAGE_SELF, &usage)) // Failed, probably due to a sandbox.
483 return usage.ru_maxrss << 10; // ru_maxrss is in Kb.
487 if (!common_flags()->can_use_proc_maps_statm)
488 return GetRSSFromGetrusage();
489 fd_t fd = OpenFile("/proc/self/statm", RdOnly);
490 if (fd == kInvalidFd)
491 return GetRSSFromGetrusage();
493 uptr len = internal_read(fd, buf, sizeof(buf) - 1);
498 // The format of the file is:
499 // 1084 89 69 11 0 79 0
500 // We need the second number which is RSS in pages.
502 // Skip the first number.
503 while (*pos >= '0' && *pos <= '9')
506 while (!(*pos >= '0' && *pos <= '9') && *pos != 0)
510 while (*pos >= '0' && *pos <= '9')
511 rss = rss * 10 + *pos++ - '0';
512 return rss * GetPageSizeCached();
515 // 64-bit Android targets don't provide the deprecated __android_log_write.
516 // Starting with the L release, syslog() works and is preferable to
517 // __android_log_write.
520 #if SANITIZER_ANDROID
521 static atomic_uint8_t android_log_initialized;
523 void AndroidLogInit() {
524 atomic_store(&android_log_initialized, 1, memory_order_release);
527 static bool ShouldLogAfterPrintf() {
528 return atomic_load(&android_log_initialized, memory_order_acquire);
531 void AndroidLogInit() {}
533 static bool ShouldLogAfterPrintf() { return true; }
534 #endif // SANITIZER_ANDROID
536 void WriteOneLineToSyslog(const char *s) {
537 #if SANITIZER_ANDROID &&__ANDROID_API__ < 21
538 __android_log_write(ANDROID_LOG_INFO, NULL, s);
540 syslog(LOG_INFO, "%s", s);
544 void LogMessageOnPrintf(const char *str) {
545 if (common_flags()->log_to_syslog && ShouldLogAfterPrintf())
549 #endif // SANITIZER_LINUX
551 } // namespace __sanitizer
553 #endif // SANITIZER_FREEBSD || SANITIZER_LINUX