sanitizer_linux_libcdep.cc revision 5d2104281930f0c1af3d586d950e2878cd1a16e1
1e46c9386c4f79aa40185f79a19fc5b2a7ef528b3Patrick Scott//===-- sanitizer_linux_libcdep.cc ----------------------------------------===// 2e46c9386c4f79aa40185f79a19fc5b2a7ef528b3Patrick Scott// 3e46c9386c4f79aa40185f79a19fc5b2a7ef528b3Patrick Scott// The LLVM Compiler Infrastructure 4e46c9386c4f79aa40185f79a19fc5b2a7ef528b3Patrick Scott// 5e46c9386c4f79aa40185f79a19fc5b2a7ef528b3Patrick Scott// This file is distributed under the University of Illinois Open Source 6e46c9386c4f79aa40185f79a19fc5b2a7ef528b3Patrick Scott// License. See LICENSE.TXT for details. 7e46c9386c4f79aa40185f79a19fc5b2a7ef528b3Patrick Scott// 8e46c9386c4f79aa40185f79a19fc5b2a7ef528b3Patrick Scott//===----------------------------------------------------------------------===// 9e46c9386c4f79aa40185f79a19fc5b2a7ef528b3Patrick Scott// 10e46c9386c4f79aa40185f79a19fc5b2a7ef528b3Patrick Scott// This file is shared between AddressSanitizer and ThreadSanitizer 11e46c9386c4f79aa40185f79a19fc5b2a7ef528b3Patrick Scott// run-time libraries and implements linux-specific functions from 12e46c9386c4f79aa40185f79a19fc5b2a7ef528b3Patrick Scott// sanitizer_libc.h. 13e46c9386c4f79aa40185f79a19fc5b2a7ef528b3Patrick Scott//===----------------------------------------------------------------------===// 14e46c9386c4f79aa40185f79a19fc5b2a7ef528b3Patrick Scott 15e46c9386c4f79aa40185f79a19fc5b2a7ef528b3Patrick Scott#include "sanitizer_platform.h" 16e46c9386c4f79aa40185f79a19fc5b2a7ef528b3Patrick Scott#if SANITIZER_LINUX 17e46c9386c4f79aa40185f79a19fc5b2a7ef528b3Patrick Scott 18e46c9386c4f79aa40185f79a19fc5b2a7ef528b3Patrick Scott#include "sanitizer_common.h" 19e46c9386c4f79aa40185f79a19fc5b2a7ef528b3Patrick Scott#include "sanitizer_procmaps.h" 20e46c9386c4f79aa40185f79a19fc5b2a7ef528b3Patrick Scott#include "sanitizer_stacktrace.h" 21e46c9386c4f79aa40185f79a19fc5b2a7ef528b3Patrick Scott 22e46c9386c4f79aa40185f79a19fc5b2a7ef528b3Patrick Scott#include <dlfcn.h> 23e46c9386c4f79aa40185f79a19fc5b2a7ef528b3Patrick Scott#include <pthread.h> 24e46c9386c4f79aa40185f79a19fc5b2a7ef528b3Patrick Scott#include <sys/prctl.h> 25e46c9386c4f79aa40185f79a19fc5b2a7ef528b3Patrick Scott#include <sys/resource.h> 26e46c9386c4f79aa40185f79a19fc5b2a7ef528b3Patrick Scott#include <unwind.h> 27e46c9386c4f79aa40185f79a19fc5b2a7ef528b3Patrick Scott 28e46c9386c4f79aa40185f79a19fc5b2a7ef528b3Patrick Scottnamespace __sanitizer { 29e46c9386c4f79aa40185f79a19fc5b2a7ef528b3Patrick Scott 30e46c9386c4f79aa40185f79a19fc5b2a7ef528b3Patrick Scottvoid GetThreadStackTopAndBottom(bool at_initialization, uptr *stack_top, 31e46c9386c4f79aa40185f79a19fc5b2a7ef528b3Patrick Scott uptr *stack_bottom) { 32e46c9386c4f79aa40185f79a19fc5b2a7ef528b3Patrick Scott static const uptr kMaxThreadStackSize = 256 * (1 << 20); // 256M 33e46c9386c4f79aa40185f79a19fc5b2a7ef528b3Patrick Scott CHECK(stack_top); 34e46c9386c4f79aa40185f79a19fc5b2a7ef528b3Patrick Scott CHECK(stack_bottom); 35e46c9386c4f79aa40185f79a19fc5b2a7ef528b3Patrick Scott if (at_initialization) { 36e46c9386c4f79aa40185f79a19fc5b2a7ef528b3Patrick Scott // This is the main thread. Libpthread may not be initialized yet. 37e46c9386c4f79aa40185f79a19fc5b2a7ef528b3Patrick Scott struct rlimit rl; 38e46c9386c4f79aa40185f79a19fc5b2a7ef528b3Patrick Scott CHECK_EQ(getrlimit(RLIMIT_STACK, &rl), 0); 39e46c9386c4f79aa40185f79a19fc5b2a7ef528b3Patrick Scott 40e46c9386c4f79aa40185f79a19fc5b2a7ef528b3Patrick Scott // Find the mapping that contains a stack variable. 41e46c9386c4f79aa40185f79a19fc5b2a7ef528b3Patrick Scott MemoryMappingLayout proc_maps(/*cache_enabled*/true); 42e46c9386c4f79aa40185f79a19fc5b2a7ef528b3Patrick Scott uptr start, end, offset; 43e46c9386c4f79aa40185f79a19fc5b2a7ef528b3Patrick Scott uptr prev_end = 0; 44e46c9386c4f79aa40185f79a19fc5b2a7ef528b3Patrick Scott while (proc_maps.Next(&start, &end, &offset, 0, 0, /* protection */0)) { 45e46c9386c4f79aa40185f79a19fc5b2a7ef528b3Patrick Scott if ((uptr)&rl < end) 46e46c9386c4f79aa40185f79a19fc5b2a7ef528b3Patrick Scott break; 47e46c9386c4f79aa40185f79a19fc5b2a7ef528b3Patrick Scott prev_end = end; 48e46c9386c4f79aa40185f79a19fc5b2a7ef528b3Patrick Scott } 49e46c9386c4f79aa40185f79a19fc5b2a7ef528b3Patrick Scott CHECK((uptr)&rl >= start && (uptr)&rl < end); 50e46c9386c4f79aa40185f79a19fc5b2a7ef528b3Patrick Scott 51e46c9386c4f79aa40185f79a19fc5b2a7ef528b3Patrick Scott // Get stacksize from rlimit, but clip it so that it does not overlap 52e46c9386c4f79aa40185f79a19fc5b2a7ef528b3Patrick Scott // with other mappings. 53e46c9386c4f79aa40185f79a19fc5b2a7ef528b3Patrick Scott uptr stacksize = rl.rlim_cur; 54e46c9386c4f79aa40185f79a19fc5b2a7ef528b3Patrick Scott if (stacksize > end - prev_end) 55e46c9386c4f79aa40185f79a19fc5b2a7ef528b3Patrick Scott stacksize = end - prev_end; 56e46c9386c4f79aa40185f79a19fc5b2a7ef528b3Patrick Scott // When running with unlimited stack size, we still want to set some limit. 57e46c9386c4f79aa40185f79a19fc5b2a7ef528b3Patrick Scott // The unlimited stack size is caused by 'ulimit -s unlimited'. 58e46c9386c4f79aa40185f79a19fc5b2a7ef528b3Patrick Scott // Also, for some reason, GNU make spawns subprocesses with unlimited stack. 59e46c9386c4f79aa40185f79a19fc5b2a7ef528b3Patrick Scott if (stacksize > kMaxThreadStackSize) 60e46c9386c4f79aa40185f79a19fc5b2a7ef528b3Patrick Scott stacksize = kMaxThreadStackSize; 61e46c9386c4f79aa40185f79a19fc5b2a7ef528b3Patrick Scott *stack_top = end; 62e46c9386c4f79aa40185f79a19fc5b2a7ef528b3Patrick Scott *stack_bottom = end - stacksize; 63e46c9386c4f79aa40185f79a19fc5b2a7ef528b3Patrick Scott return; 64e46c9386c4f79aa40185f79a19fc5b2a7ef528b3Patrick Scott } 65e46c9386c4f79aa40185f79a19fc5b2a7ef528b3Patrick Scott pthread_attr_t attr; 66e46c9386c4f79aa40185f79a19fc5b2a7ef528b3Patrick Scott CHECK_EQ(pthread_getattr_np(pthread_self(), &attr), 0); 67e46c9386c4f79aa40185f79a19fc5b2a7ef528b3Patrick Scott uptr stacksize = 0; 68e46c9386c4f79aa40185f79a19fc5b2a7ef528b3Patrick Scott void *stackaddr = 0; 69e46c9386c4f79aa40185f79a19fc5b2a7ef528b3Patrick Scott pthread_attr_getstack(&attr, &stackaddr, (size_t*)&stacksize); 70e46c9386c4f79aa40185f79a19fc5b2a7ef528b3Patrick Scott pthread_attr_destroy(&attr); 71e46c9386c4f79aa40185f79a19fc5b2a7ef528b3Patrick Scott 72e46c9386c4f79aa40185f79a19fc5b2a7ef528b3Patrick Scott *stack_top = (uptr)stackaddr + stacksize; 73e46c9386c4f79aa40185f79a19fc5b2a7ef528b3Patrick Scott *stack_bottom = (uptr)stackaddr; 74e46c9386c4f79aa40185f79a19fc5b2a7ef528b3Patrick Scott CHECK(stacksize < kMaxThreadStackSize); // Sanity check. 75e46c9386c4f79aa40185f79a19fc5b2a7ef528b3Patrick Scott} 76e46c9386c4f79aa40185f79a19fc5b2a7ef528b3Patrick Scott 77e46c9386c4f79aa40185f79a19fc5b2a7ef528b3Patrick Scott// Does not compile for Go because dlsym() requires -ldl 78e46c9386c4f79aa40185f79a19fc5b2a7ef528b3Patrick Scott#ifndef SANITIZER_GO 79e46c9386c4f79aa40185f79a19fc5b2a7ef528b3Patrick Scottbool SetEnv(const char *name, const char *value) { 80e46c9386c4f79aa40185f79a19fc5b2a7ef528b3Patrick Scott void *f = dlsym(RTLD_NEXT, "setenv"); 81e46c9386c4f79aa40185f79a19fc5b2a7ef528b3Patrick Scott if (f == 0) 82e46c9386c4f79aa40185f79a19fc5b2a7ef528b3Patrick Scott return false; 83e46c9386c4f79aa40185f79a19fc5b2a7ef528b3Patrick Scott typedef int(*setenv_ft)(const char *name, const char *value, int overwrite); 84e46c9386c4f79aa40185f79a19fc5b2a7ef528b3Patrick Scott setenv_ft setenv_f; 85e46c9386c4f79aa40185f79a19fc5b2a7ef528b3Patrick Scott CHECK_EQ(sizeof(setenv_f), sizeof(f)); 86e46c9386c4f79aa40185f79a19fc5b2a7ef528b3Patrick Scott internal_memcpy(&setenv_f, &f, sizeof(f)); 87e46c9386c4f79aa40185f79a19fc5b2a7ef528b3Patrick Scott return setenv_f(name, value, 1) == 0; 88e46c9386c4f79aa40185f79a19fc5b2a7ef528b3Patrick Scott} 89e46c9386c4f79aa40185f79a19fc5b2a7ef528b3Patrick Scott#endif 90e46c9386c4f79aa40185f79a19fc5b2a7ef528b3Patrick Scott 91e46c9386c4f79aa40185f79a19fc5b2a7ef528b3Patrick Scottbool SanitizerSetThreadName(const char *name) { 92e46c9386c4f79aa40185f79a19fc5b2a7ef528b3Patrick Scott#ifdef PR_SET_NAME 93e46c9386c4f79aa40185f79a19fc5b2a7ef528b3Patrick Scott return 0 == prctl(PR_SET_NAME, (unsigned long)name, 0, 0, 0); // NOLINT 94e46c9386c4f79aa40185f79a19fc5b2a7ef528b3Patrick Scott#else 95e46c9386c4f79aa40185f79a19fc5b2a7ef528b3Patrick Scott return false; 96e46c9386c4f79aa40185f79a19fc5b2a7ef528b3Patrick Scott#endif 97e46c9386c4f79aa40185f79a19fc5b2a7ef528b3Patrick Scott} 98e46c9386c4f79aa40185f79a19fc5b2a7ef528b3Patrick Scott 99e46c9386c4f79aa40185f79a19fc5b2a7ef528b3Patrick Scottbool SanitizerGetThreadName(char *name, int max_len) { 100e46c9386c4f79aa40185f79a19fc5b2a7ef528b3Patrick Scott#ifdef PR_GET_NAME 101e46c9386c4f79aa40185f79a19fc5b2a7ef528b3Patrick Scott char buff[17]; 102e46c9386c4f79aa40185f79a19fc5b2a7ef528b3Patrick Scott if (prctl(PR_GET_NAME, (unsigned long)buff, 0, 0, 0)) // NOLINT 103e46c9386c4f79aa40185f79a19fc5b2a7ef528b3Patrick Scott return false; 104e46c9386c4f79aa40185f79a19fc5b2a7ef528b3Patrick Scott internal_strncpy(name, buff, max_len); 105e46c9386c4f79aa40185f79a19fc5b2a7ef528b3Patrick Scott name[max_len] = 0; 106e46c9386c4f79aa40185f79a19fc5b2a7ef528b3Patrick Scott return true; 107e46c9386c4f79aa40185f79a19fc5b2a7ef528b3Patrick Scott#else 108e46c9386c4f79aa40185f79a19fc5b2a7ef528b3Patrick Scott return false; 109e46c9386c4f79aa40185f79a19fc5b2a7ef528b3Patrick Scott#endif 110e46c9386c4f79aa40185f79a19fc5b2a7ef528b3Patrick Scott} 111e46c9386c4f79aa40185f79a19fc5b2a7ef528b3Patrick Scott 112e46c9386c4f79aa40185f79a19fc5b2a7ef528b3Patrick Scott#ifndef SANITIZER_GO 113e46c9386c4f79aa40185f79a19fc5b2a7ef528b3Patrick Scott//------------------------- SlowUnwindStack ----------------------------------- 114e46c9386c4f79aa40185f79a19fc5b2a7ef528b3Patrick Scott#ifdef __arm__ 115e46c9386c4f79aa40185f79a19fc5b2a7ef528b3Patrick Scott#define UNWIND_STOP _URC_END_OF_STACK 116e46c9386c4f79aa40185f79a19fc5b2a7ef528b3Patrick Scott#define UNWIND_CONTINUE _URC_NO_REASON 117e46c9386c4f79aa40185f79a19fc5b2a7ef528b3Patrick Scott#else 118e46c9386c4f79aa40185f79a19fc5b2a7ef528b3Patrick Scott#define UNWIND_STOP _URC_NORMAL_STOP 119e46c9386c4f79aa40185f79a19fc5b2a7ef528b3Patrick Scott#define UNWIND_CONTINUE _URC_NO_REASON 120e46c9386c4f79aa40185f79a19fc5b2a7ef528b3Patrick Scott#endif 121e46c9386c4f79aa40185f79a19fc5b2a7ef528b3Patrick Scott 122e46c9386c4f79aa40185f79a19fc5b2a7ef528b3Patrick Scottuptr Unwind_GetIP(struct _Unwind_Context *ctx) { 123e46c9386c4f79aa40185f79a19fc5b2a7ef528b3Patrick Scott#ifdef __arm__ 124e46c9386c4f79aa40185f79a19fc5b2a7ef528b3Patrick Scott uptr val; 125e46c9386c4f79aa40185f79a19fc5b2a7ef528b3Patrick Scott _Unwind_VRS_Result res = _Unwind_VRS_Get(ctx, _UVRSC_CORE, 126e46c9386c4f79aa40185f79a19fc5b2a7ef528b3Patrick Scott 15 /* r15 = PC */, _UVRSD_UINT32, &val); 127e46c9386c4f79aa40185f79a19fc5b2a7ef528b3Patrick Scott CHECK(res == _UVRSR_OK && "_Unwind_VRS_Get failed"); 128e46c9386c4f79aa40185f79a19fc5b2a7ef528b3Patrick Scott // Clear the Thumb bit. 129e46c9386c4f79aa40185f79a19fc5b2a7ef528b3Patrick Scott return val & ~(uptr)1; 130#else 131 return _Unwind_GetIP(ctx); 132#endif 133} 134 135_Unwind_Reason_Code Unwind_Trace(struct _Unwind_Context *ctx, void *param) { 136 StackTrace *b = (StackTrace*)param; 137 CHECK(b->size < b->max_size); 138 uptr pc = Unwind_GetIP(ctx); 139 b->trace[b->size++] = pc; 140 if (b->size == b->max_size) return UNWIND_STOP; 141 return UNWIND_CONTINUE; 142} 143 144static bool MatchPc(uptr cur_pc, uptr trace_pc) { 145 return cur_pc - trace_pc <= 64 || trace_pc - cur_pc <= 64; 146} 147 148void StackTrace::SlowUnwindStack(uptr pc, uptr max_depth) { 149 this->size = 0; 150 this->max_size = max_depth; 151 if (max_depth > 1) { 152 _Unwind_Backtrace(Unwind_Trace, this); 153 // We need to pop a few frames so that pc is on top. 154 // trace[0] belongs to the current function so we always pop it. 155 int to_pop = 1; 156 /**/ if (size > 1 && MatchPc(pc, trace[1])) to_pop = 1; 157 else if (size > 2 && MatchPc(pc, trace[2])) to_pop = 2; 158 else if (size > 3 && MatchPc(pc, trace[3])) to_pop = 3; 159 else if (size > 4 && MatchPc(pc, trace[4])) to_pop = 4; 160 else if (size > 5 && MatchPc(pc, trace[5])) to_pop = 5; 161 this->PopStackFrames(to_pop); 162 } 163 this->trace[0] = pc; 164} 165 166#endif // !SANITIZER_GO 167 168static uptr g_tls_size; 169 170#ifdef __i386__ 171# define DL_INTERNAL_FUNCTION __attribute__((regparm(3), stdcall)) 172#else 173# define DL_INTERNAL_FUNCTION 174#endif 175 176void InitTlsSize() { 177#if !defined(SANITIZER_GO) && !SANITIZER_ANDROID 178 typedef void (*get_tls_func)(size_t*, size_t*) DL_INTERNAL_FUNCTION; 179 get_tls_func get_tls; 180 void *get_tls_static_info_ptr = dlsym(RTLD_NEXT, "_dl_get_tls_static_info"); 181 CHECK_EQ(sizeof(get_tls), sizeof(get_tls_static_info_ptr)); 182 internal_memcpy(&get_tls, &get_tls_static_info_ptr, 183 sizeof(get_tls_static_info_ptr)); 184 CHECK_NE(get_tls, 0); 185 size_t tls_size = 0; 186 size_t tls_align = 0; 187 get_tls(&tls_size, &tls_align); 188 g_tls_size = tls_size; 189#endif 190} 191 192uptr GetTlsSize() { 193 return g_tls_size; 194} 195 196#if defined(__x86_64__) || defined(__i386__) 197// sizeof(struct thread) from glibc. 198// There has been a report of this being different on glibc 2.11. We don't know 199// when this change happened, so 2.12 is a conservative estimate. 200#if __GLIBC_PREREQ(2, 12) 201const uptr kThreadDescriptorSize = FIRST_32_SECOND_64(1216, 2304); 202#else 203const uptr kThreadDescriptorSize = FIRST_32_SECOND_64(1168, 2304); 204#endif 205 206uptr ThreadDescriptorSize() { 207 return kThreadDescriptorSize; 208} 209 210// The offset at which pointer to self is located in the thread descriptor. 211const uptr kThreadSelfOffset = FIRST_32_SECOND_64(8, 16); 212 213uptr ThreadSelfOffset() { 214 return kThreadSelfOffset; 215} 216 217uptr ThreadSelf() { 218 uptr descr_addr; 219#ifdef __i386__ 220 asm("mov %%gs:%c1,%0" : "=r"(descr_addr) : "i"(kThreadSelfOffset)); 221#else 222 asm("mov %%fs:%c1,%0" : "=r"(descr_addr) : "i"(kThreadSelfOffset)); 223#endif 224 return descr_addr; 225} 226#endif // defined(__x86_64__) || defined(__i386__) 227 228void GetThreadStackAndTls(bool main, uptr *stk_addr, uptr *stk_size, 229 uptr *tls_addr, uptr *tls_size) { 230#ifndef SANITIZER_GO 231#if defined(__x86_64__) || defined(__i386__) 232 *tls_addr = ThreadSelf(); 233 *tls_size = GetTlsSize(); 234 *tls_addr -= *tls_size; 235 *tls_addr += kThreadDescriptorSize; 236#else 237 *tls_addr = 0; 238 *tls_size = 0; 239#endif 240 241 uptr stack_top, stack_bottom; 242 GetThreadStackTopAndBottom(main, &stack_top, &stack_bottom); 243 *stk_addr = stack_bottom; 244 *stk_size = stack_top - stack_bottom; 245 246 if (!main) { 247 // If stack and tls intersect, make them non-intersecting. 248 if (*tls_addr > *stk_addr && *tls_addr < *stk_addr + *stk_size) { 249 CHECK_GT(*tls_addr + *tls_size, *stk_addr); 250 CHECK_LE(*tls_addr + *tls_size, *stk_addr + *stk_size); 251 *stk_size -= *tls_size; 252 *tls_addr = *stk_addr + *stk_size; 253 } 254 } 255#else // SANITIZER_GO 256 *stk_addr = 0; 257 *stk_size = 0; 258 *tls_addr = 0; 259 *tls_size = 0; 260#endif // SANITIZER_GO 261} 262 263void AdjustStackSizeLinux(void *attr_, int verbosity) { 264 pthread_attr_t *attr = (pthread_attr_t *)attr_; 265 uptr stackaddr = 0; 266 size_t stacksize = 0; 267 pthread_attr_getstack(attr, (void**)&stackaddr, &stacksize); 268 // GLibC will return (0 - stacksize) as the stack address in the case when 269 // stacksize is set, but stackaddr is not. 270 bool stack_set = (stackaddr != 0) && (stackaddr + stacksize != 0); 271 // We place a lot of tool data into TLS, account for that. 272 const uptr minstacksize = GetTlsSize() + 128*1024; 273 if (stacksize < minstacksize) { 274 if (!stack_set) { 275 if (verbosity && stacksize != 0) 276 Printf("Sanitizer: increasing stacksize %zu->%zu\n", stacksize, 277 minstacksize); 278 pthread_attr_setstacksize(attr, minstacksize); 279 } else { 280 Printf("Sanitizer: pre-allocated stack size is insufficient: " 281 "%zu < %zu\n", stacksize, minstacksize); 282 Printf("Sanitizer: pthread_create is likely to fail.\n"); 283 } 284 } 285} 286 287} // namespace __sanitizer 288 289#endif // SANITIZER_LINUX 290