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"
16 #if SANITIZER_FREEBSD || SANITIZER_LINUX
18 #include "sanitizer_atomic.h"
19 #include "sanitizer_common.h"
20 #include "sanitizer_flags.h"
21 #include "sanitizer_freebsd.h"
22 #include "sanitizer_linux.h"
23 #include "sanitizer_placement_new.h"
24 #include "sanitizer_procmaps.h"
25 #include "sanitizer_stacktrace.h"
27 #if SANITIZER_ANDROID || SANITIZER_FREEBSD
28 #include <dlfcn.h> // for dlsym()
34 #include <sys/resource.h>
37 #include <pthread_np.h>
38 #include <osreldate.h>
39 #define pthread_getattr_np pthread_attr_get_np
43 #include <sys/prctl.h>
47 #include <android/api-level.h>
50 #if !SANITIZER_ANDROID
55 namespace __sanitizer {
57 // This function is defined elsewhere if we intercepted pthread_attr_getstack.
59 SANITIZER_WEAK_ATTRIBUTE int
60 real_pthread_attr_getstack(void *attr, void **addr, size_t *size);
63 static int my_pthread_attr_getstack(void *attr, void **addr, size_t *size) {
65 if (&real_pthread_attr_getstack)
66 return real_pthread_attr_getstack((pthread_attr_t *)attr, addr, size);
68 return pthread_attr_getstack((pthread_attr_t *)attr, addr, size);
71 SANITIZER_WEAK_ATTRIBUTE int
72 real_sigaction(int signum, const void *act, void *oldact);
74 int internal_sigaction(int signum, const void *act, void *oldact) {
77 return real_sigaction(signum, act, oldact);
79 return sigaction(signum, (const struct sigaction *)act,
80 (struct sigaction *)oldact);
83 void GetThreadStackTopAndBottom(bool at_initialization, uptr *stack_top,
87 if (at_initialization) {
88 // This is the main thread. Libpthread may not be initialized yet.
90 CHECK_EQ(getrlimit(RLIMIT_STACK, &rl), 0);
92 // Find the mapping that contains a stack variable.
93 MemoryMappingLayout proc_maps(/*cache_enabled*/true);
94 uptr start, end, offset;
96 while (proc_maps.Next(&start, &end, &offset, 0, 0, /* protection */0)) {
101 CHECK((uptr)&rl >= start && (uptr)&rl < end);
103 // Get stacksize from rlimit, but clip it so that it does not overlap
104 // with other mappings.
105 uptr stacksize = rl.rlim_cur;
106 if (stacksize > end - prev_end)
107 stacksize = end - prev_end;
108 // When running with unlimited stack size, we still want to set some limit.
109 // The unlimited stack size is caused by 'ulimit -s unlimited'.
110 // Also, for some reason, GNU make spawns subprocesses with unlimited stack.
111 if (stacksize > kMaxThreadStackSize)
112 stacksize = kMaxThreadStackSize;
114 *stack_bottom = end - stacksize;
118 pthread_attr_init(&attr);
119 CHECK_EQ(pthread_getattr_np(pthread_self(), &attr), 0);
122 my_pthread_attr_getstack(&attr, &stackaddr, (size_t*)&stacksize);
123 pthread_attr_destroy(&attr);
125 CHECK_LE(stacksize, kMaxThreadStackSize); // Sanity check.
126 *stack_top = (uptr)stackaddr + stacksize;
127 *stack_bottom = (uptr)stackaddr;
131 bool SetEnv(const char *name, const char *value) {
132 void *f = dlsym(RTLD_NEXT, "setenv");
135 typedef int(*setenv_ft)(const char *name, const char *value, int overwrite);
137 CHECK_EQ(sizeof(setenv_f), sizeof(f));
138 internal_memcpy(&setenv_f, &f, sizeof(f));
139 return setenv_f(name, value, 1) == 0;
143 bool SanitizerSetThreadName(const char *name) {
145 return 0 == prctl(PR_SET_NAME, (unsigned long)name, 0, 0, 0); // NOLINT
151 bool SanitizerGetThreadName(char *name, int max_len) {
154 if (prctl(PR_GET_NAME, (unsigned long)buff, 0, 0, 0)) // NOLINT
156 internal_strncpy(name, buff, max_len);
164 #if !SANITIZER_FREEBSD
165 static uptr g_tls_size;
169 # define DL_INTERNAL_FUNCTION __attribute__((regparm(3), stdcall))
171 # define DL_INTERNAL_FUNCTION
174 #if defined(__mips__)
175 // TlsPreTcbSize includes size of struct pthread_descr and size of tcb
176 // head structure. It lies before the static tls blocks.
177 static uptr TlsPreTcbSize() {
178 const uptr kTcbHead = 16;
179 const uptr kTlsAlign = 16;
180 const uptr kTlsPreTcbSize =
181 (ThreadDescriptorSize() + kTcbHead + kTlsAlign - 1) & ~(kTlsAlign - 1);
183 g_tls_size = (g_tls_size + kTlsPreTcbSize + kTlsAlign -1) & ~(kTlsAlign - 1);
184 return kTlsPreTcbSize;
189 #if !SANITIZER_FREEBSD && !SANITIZER_ANDROID && !SANITIZER_GO
190 typedef void (*get_tls_func)(size_t*, size_t*) DL_INTERNAL_FUNCTION;
191 get_tls_func get_tls;
192 void *get_tls_static_info_ptr = dlsym(RTLD_NEXT, "_dl_get_tls_static_info");
193 CHECK_EQ(sizeof(get_tls), sizeof(get_tls_static_info_ptr));
194 internal_memcpy(&get_tls, &get_tls_static_info_ptr,
195 sizeof(get_tls_static_info_ptr));
196 CHECK_NE(get_tls, 0);
198 size_t tls_align = 0;
199 get_tls(&tls_size, &tls_align);
200 g_tls_size = tls_size;
201 #endif // !SANITIZER_FREEBSD && !SANITIZER_ANDROID
204 #if (defined(__x86_64__) || defined(__i386__) || defined(__mips__)) \
206 // sizeof(struct thread) from glibc.
207 static atomic_uintptr_t kThreadDescriptorSize;
209 uptr ThreadDescriptorSize() {
210 uptr val = atomic_load(&kThreadDescriptorSize, memory_order_relaxed);
213 #if defined(__x86_64__) || defined(__i386__)
214 #ifdef _CS_GNU_LIBC_VERSION
216 uptr len = confstr(_CS_GNU_LIBC_VERSION, buf, sizeof(buf));
217 if (len < sizeof(buf) && internal_strncmp(buf, "glibc 2.", 8) == 0) {
219 int minor = internal_simple_strtoll(buf + 8, &end, 10);
220 if (end != buf + 8 && (*end == '\0' || *end == '.')) {
221 /* sizeof(struct thread) values from various glibc versions. */
223 val = 1728; // Assume only one particular version for x32.
225 val = FIRST_32_SECOND_64(1104, 1696);
227 val = FIRST_32_SECOND_64(1120, 1728);
229 val = FIRST_32_SECOND_64(1136, 1728);
231 val = FIRST_32_SECOND_64(1136, 1712);
232 else if (minor == 10)
233 val = FIRST_32_SECOND_64(1168, 1776);
234 else if (minor <= 12)
235 val = FIRST_32_SECOND_64(1168, 2288);
236 else if (minor == 13)
237 val = FIRST_32_SECOND_64(1168, 2304);
239 val = FIRST_32_SECOND_64(1216, 2304);
242 atomic_store(&kThreadDescriptorSize, val, memory_order_relaxed);
246 #elif defined(__mips__)
247 // TODO(sagarthakur): add more values as per different glibc versions.
248 val = FIRST_32_SECOND_64(1152, 1776);
250 atomic_store(&kThreadDescriptorSize, val, memory_order_relaxed);
256 // The offset at which pointer to self is located in the thread descriptor.
257 const uptr kThreadSelfOffset = FIRST_32_SECOND_64(8, 16);
259 uptr ThreadSelfOffset() {
260 return kThreadSelfOffset;
265 # if defined(__i386__)
266 asm("mov %%gs:%c1,%0" : "=r"(descr_addr) : "i"(kThreadSelfOffset));
267 # elif defined(__x86_64__)
268 asm("mov %%fs:%c1,%0" : "=r"(descr_addr) : "i"(kThreadSelfOffset));
269 # elif defined(__mips__)
270 // MIPS uses TLS variant I. The thread pointer (in hardware register $29)
271 // points to the end of the TCB + 0x7000. The pthread_descr structure is
272 // immediately in front of the TCB. TlsPreTcbSize() includes the size of the
273 // TCB and the size of pthread_descr.
274 const uptr kTlsTcbOffset = 0x7000;
276 asm volatile(".set push;\
279 .set pop" : "=r" (thread_pointer));
280 descr_addr = thread_pointer - kTlsTcbOffset - TlsPreTcbSize();
282 # error "unsupported CPU arch"
286 #endif // (x86_64 || i386 || MIPS) && SANITIZER_LINUX
288 #if SANITIZER_FREEBSD
289 static void **ThreadSelfSegbase() {
291 # if defined(__i386__)
292 // sysarch(I386_GET_GSBASE, segbase);
293 __asm __volatile("mov %%gs:0, %0" : "=r" (segbase));
294 # elif defined(__x86_64__)
295 // sysarch(AMD64_GET_FSBASE, segbase);
296 __asm __volatile("movq %%fs:0, %0" : "=r" (segbase));
298 # error "unsupported CPU arch for FreeBSD platform"
304 return (uptr)ThreadSelfSegbase()[2];
306 #endif // SANITIZER_FREEBSD
309 static void GetTls(uptr *addr, uptr *size) {
311 # if defined(__x86_64__) || defined(__i386__)
312 *addr = ThreadSelf();
313 *size = GetTlsSize();
315 *addr += ThreadDescriptorSize();
316 # elif defined(__mips__)
317 *addr = ThreadSelf();
318 *size = GetTlsSize();
323 #elif SANITIZER_FREEBSD
324 void** segbase = ThreadSelfSegbase();
329 // tls_size = round(tls_static_space, tcbalign);
331 // dtv[2] = segbase - tls_static_space;
332 void **dtv = (void**) segbase[1];
333 *addr = (uptr) dtv[2];
334 *size = (*addr == 0) ? 0 : ((uptr) segbase[0] - (uptr) dtv[2]);
344 #if SANITIZER_FREEBSD
346 GetTls(&addr, &size);
354 void GetThreadStackAndTls(bool main, uptr *stk_addr, uptr *stk_size,
355 uptr *tls_addr, uptr *tls_size) {
357 // Stub implementation for Go.
358 *stk_addr = *stk_size = *tls_addr = *tls_size = 0;
360 GetTls(tls_addr, tls_size);
362 uptr stack_top, stack_bottom;
363 GetThreadStackTopAndBottom(main, &stack_top, &stack_bottom);
364 *stk_addr = stack_bottom;
365 *stk_size = stack_top - stack_bottom;
368 // If stack and tls intersect, make them non-intersecting.
369 if (*tls_addr > *stk_addr && *tls_addr < *stk_addr + *stk_size) {
370 CHECK_GT(*tls_addr + *tls_size, *stk_addr);
371 CHECK_LE(*tls_addr + *tls_size, *stk_addr + *stk_size);
372 *stk_size -= *tls_size;
373 *tls_addr = *stk_addr + *stk_size;
379 void AdjustStackSize(void *attr_) {
380 pthread_attr_t *attr = (pthread_attr_t *)attr_;
382 size_t stacksize = 0;
383 my_pthread_attr_getstack(attr, (void**)&stackaddr, &stacksize);
384 // GLibC will return (0 - stacksize) as the stack address in the case when
385 // stacksize is set, but stackaddr is not.
386 bool stack_set = (stackaddr != 0) && (stackaddr + stacksize != 0);
387 // We place a lot of tool data into TLS, account for that.
388 const uptr minstacksize = GetTlsSize() + 128*1024;
389 if (stacksize < minstacksize) {
391 if (stacksize != 0) {
392 VPrintf(1, "Sanitizer: increasing stacksize %zu->%zu\n", stacksize,
394 pthread_attr_setstacksize(attr, minstacksize);
397 Printf("Sanitizer: pre-allocated stack size is insufficient: "
398 "%zu < %zu\n", stacksize, minstacksize);
399 Printf("Sanitizer: pthread_create is likely to fail.\n");
404 # if !SANITIZER_FREEBSD
405 typedef ElfW(Phdr) Elf_Phdr;
406 # elif SANITIZER_WORDSIZE == 32 && __FreeBSD_version <= 902001 // v9.2
407 # define Elf_Phdr XElf32_Phdr
408 # define dl_phdr_info xdl_phdr_info
409 # define dl_iterate_phdr(c, b) xdl_iterate_phdr((c), (b))
412 struct DlIteratePhdrData {
413 LoadedModule *modules;
417 string_predicate_t filter;
420 static int dl_iterate_phdr_cb(dl_phdr_info *info, size_t size, void *arg) {
421 DlIteratePhdrData *data = (DlIteratePhdrData*)arg;
422 if (data->current_n == data->max_n)
424 InternalScopedString module_name(kMaxPathLength);
427 // First module is the binary itself.
428 ReadBinaryNameCached(module_name.data(), module_name.size());
429 } else if (info->dlpi_name) {
430 module_name.append("%s", info->dlpi_name);
432 if (module_name[0] == '\0')
434 if (data->filter && !data->filter(module_name.data()))
436 LoadedModule *cur_module = &data->modules[data->current_n];
437 cur_module->set(module_name.data(), info->dlpi_addr);
439 for (int i = 0; i < info->dlpi_phnum; i++) {
440 const Elf_Phdr *phdr = &info->dlpi_phdr[i];
441 if (phdr->p_type == PT_LOAD) {
442 uptr cur_beg = info->dlpi_addr + phdr->p_vaddr;
443 uptr cur_end = cur_beg + phdr->p_memsz;
444 bool executable = phdr->p_flags & PF_X;
445 cur_module->addAddressRange(cur_beg, cur_end, executable);
451 #if SANITIZER_ANDROID && __ANDROID_API__ < 21
452 extern "C" __attribute__((weak)) int dl_iterate_phdr(
453 int (*)(struct dl_phdr_info *, size_t, void *), void *);
456 uptr GetListOfModules(LoadedModule *modules, uptr max_modules,
457 string_predicate_t filter) {
458 #if SANITIZER_ANDROID && __ANDROID_API__ < 21
459 u32 api_level = AndroidGetApiLevel();
460 // Fall back to /proc/maps if dl_iterate_phdr is unavailable or broken.
461 // The runtime check allows the same library to work with
462 // both K and L (and future) Android releases.
463 if (api_level <= ANDROID_LOLLIPOP_MR1) { // L or earlier
464 MemoryMappingLayout memory_mapping(false);
465 return memory_mapping.DumpListOfModules(modules, max_modules, filter);
469 DlIteratePhdrData data = {modules, 0, true, max_modules, filter};
470 dl_iterate_phdr(dl_iterate_phdr_cb, &data);
471 return data.current_n;
474 // getrusage does not give us the current RSS, only the max RSS.
475 // Still, this is better than nothing if /proc/self/statm is not available
476 // for some reason, e.g. due to a sandbox.
477 static uptr GetRSSFromGetrusage() {
479 if (getrusage(RUSAGE_SELF, &usage)) // Failed, probably due to a sandbox.
481 return usage.ru_maxrss << 10; // ru_maxrss is in Kb.
485 if (!common_flags()->can_use_proc_maps_statm)
486 return GetRSSFromGetrusage();
487 fd_t fd = OpenFile("/proc/self/statm", RdOnly);
488 if (fd == kInvalidFd)
489 return GetRSSFromGetrusage();
491 uptr len = internal_read(fd, buf, sizeof(buf) - 1);
496 // The format of the file is:
497 // 1084 89 69 11 0 79 0
498 // We need the second number which is RSS in pages.
500 // Skip the first number.
501 while (*pos >= '0' && *pos <= '9')
504 while (!(*pos >= '0' && *pos <= '9') && *pos != 0)
508 while (*pos >= '0' && *pos <= '9')
509 rss = rss * 10 + *pos++ - '0';
510 return rss * GetPageSizeCached();
513 } // namespace __sanitizer
515 #endif // SANITIZER_FREEBSD || SANITIZER_LINUX