Peter Collingbourne | 088ea2b | 2013-05-20 15:57:44 +0000 | [diff] [blame] | 1 | //===-- sanitizer_linux_libcdep.cc ----------------------------------------===// |
| 2 | // |
| 3 | // The LLVM Compiler Infrastructure |
| 4 | // |
| 5 | // This file is distributed under the University of Illinois Open Source |
| 6 | // License. See LICENSE.TXT for details. |
| 7 | // |
| 8 | //===----------------------------------------------------------------------===// |
| 9 | // |
| 10 | // This file is shared between AddressSanitizer and ThreadSanitizer |
| 11 | // run-time libraries and implements linux-specific functions from |
| 12 | // sanitizer_libc.h. |
| 13 | //===----------------------------------------------------------------------===// |
| 14 | |
| 15 | #include "sanitizer_platform.h" |
| 16 | #if SANITIZER_LINUX |
| 17 | |
| 18 | #include "sanitizer_common.h" |
| 19 | #include "sanitizer_procmaps.h" |
| 20 | #include "sanitizer_stacktrace.h" |
| 21 | |
Peter Collingbourne | 088ea2b | 2013-05-20 15:57:44 +0000 | [diff] [blame] | 22 | #include <dlfcn.h> |
| 23 | #include <pthread.h> |
| 24 | #include <sys/prctl.h> |
| 25 | #include <sys/resource.h> |
| 26 | #include <unwind.h> |
| 27 | |
Peter Collingbourne | 088ea2b | 2013-05-20 15:57:44 +0000 | [diff] [blame] | 28 | namespace __sanitizer { |
| 29 | |
| 30 | void GetThreadStackTopAndBottom(bool at_initialization, uptr *stack_top, |
| 31 | uptr *stack_bottom) { |
| 32 | static const uptr kMaxThreadStackSize = 256 * (1 << 20); // 256M |
| 33 | CHECK(stack_top); |
| 34 | CHECK(stack_bottom); |
| 35 | if (at_initialization) { |
| 36 | // This is the main thread. Libpthread may not be initialized yet. |
| 37 | struct rlimit rl; |
| 38 | CHECK_EQ(getrlimit(RLIMIT_STACK, &rl), 0); |
| 39 | |
| 40 | // Find the mapping that contains a stack variable. |
| 41 | MemoryMappingLayout proc_maps(/*cache_enabled*/true); |
| 42 | uptr start, end, offset; |
| 43 | uptr prev_end = 0; |
| 44 | while (proc_maps.Next(&start, &end, &offset, 0, 0, /* protection */0)) { |
| 45 | if ((uptr)&rl < end) |
| 46 | break; |
| 47 | prev_end = end; |
| 48 | } |
| 49 | CHECK((uptr)&rl >= start && (uptr)&rl < end); |
| 50 | |
| 51 | // Get stacksize from rlimit, but clip it so that it does not overlap |
| 52 | // with other mappings. |
| 53 | uptr stacksize = rl.rlim_cur; |
| 54 | if (stacksize > end - prev_end) |
| 55 | stacksize = end - prev_end; |
| 56 | // When running with unlimited stack size, we still want to set some limit. |
| 57 | // The unlimited stack size is caused by 'ulimit -s unlimited'. |
| 58 | // Also, for some reason, GNU make spawns subprocesses with unlimited stack. |
| 59 | if (stacksize > kMaxThreadStackSize) |
| 60 | stacksize = kMaxThreadStackSize; |
| 61 | *stack_top = end; |
| 62 | *stack_bottom = end - stacksize; |
| 63 | return; |
| 64 | } |
| 65 | pthread_attr_t attr; |
| 66 | CHECK_EQ(pthread_getattr_np(pthread_self(), &attr), 0); |
| 67 | uptr stacksize = 0; |
| 68 | void *stackaddr = 0; |
| 69 | pthread_attr_getstack(&attr, &stackaddr, (size_t*)&stacksize); |
| 70 | pthread_attr_destroy(&attr); |
| 71 | |
| 72 | *stack_top = (uptr)stackaddr + stacksize; |
| 73 | *stack_bottom = (uptr)stackaddr; |
| 74 | CHECK(stacksize < kMaxThreadStackSize); // Sanity check. |
| 75 | } |
| 76 | |
| 77 | // Does not compile for Go because dlsym() requires -ldl |
| 78 | #ifndef SANITIZER_GO |
| 79 | bool SetEnv(const char *name, const char *value) { |
| 80 | void *f = dlsym(RTLD_NEXT, "setenv"); |
| 81 | if (f == 0) |
| 82 | return false; |
| 83 | typedef int(*setenv_ft)(const char *name, const char *value, int overwrite); |
| 84 | setenv_ft setenv_f; |
| 85 | CHECK_EQ(sizeof(setenv_f), sizeof(f)); |
| 86 | internal_memcpy(&setenv_f, &f, sizeof(f)); |
| 87 | return setenv_f(name, value, 1) == 0; |
| 88 | } |
| 89 | #endif |
| 90 | |
| 91 | bool SanitizerSetThreadName(const char *name) { |
| 92 | #ifdef PR_SET_NAME |
| 93 | return 0 == prctl(PR_SET_NAME, (unsigned long)name, 0, 0, 0); // NOLINT |
| 94 | #else |
| 95 | return false; |
| 96 | #endif |
| 97 | } |
| 98 | |
| 99 | bool SanitizerGetThreadName(char *name, int max_len) { |
| 100 | #ifdef PR_GET_NAME |
| 101 | char buff[17]; |
| 102 | if (prctl(PR_GET_NAME, (unsigned long)buff, 0, 0, 0)) // NOLINT |
| 103 | return false; |
| 104 | internal_strncpy(name, buff, max_len); |
| 105 | name[max_len] = 0; |
| 106 | return true; |
| 107 | #else |
| 108 | return false; |
| 109 | #endif |
| 110 | } |
| 111 | |
| 112 | #ifndef SANITIZER_GO |
| 113 | //------------------------- SlowUnwindStack ----------------------------------- |
| 114 | #ifdef __arm__ |
| 115 | #define UNWIND_STOP _URC_END_OF_STACK |
| 116 | #define UNWIND_CONTINUE _URC_NO_REASON |
| 117 | #else |
| 118 | #define UNWIND_STOP _URC_NORMAL_STOP |
| 119 | #define UNWIND_CONTINUE _URC_NO_REASON |
| 120 | #endif |
| 121 | |
| 122 | uptr Unwind_GetIP(struct _Unwind_Context *ctx) { |
| 123 | #ifdef __arm__ |
| 124 | uptr val; |
| 125 | _Unwind_VRS_Result res = _Unwind_VRS_Get(ctx, _UVRSC_CORE, |
| 126 | 15 /* r15 = PC */, _UVRSD_UINT32, &val); |
| 127 | CHECK(res == _UVRSR_OK && "_Unwind_VRS_Get failed"); |
| 128 | // Clear the Thumb bit. |
| 129 | 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 | |
| 144 | static bool MatchPc(uptr cur_pc, uptr trace_pc) { |
| 145 | return cur_pc - trace_pc <= 64 || trace_pc - cur_pc <= 64; |
| 146 | } |
| 147 | |
| 148 | void 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 | |
| 168 | static 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 | |
| 176 | void 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 | |
| 192 | uptr GetTlsSize() { |
| 193 | return g_tls_size; |
| 194 | } |
| 195 | |
Alexey Samsonov | 816bdb7 | 2013-05-30 09:16:04 +0000 | [diff] [blame] | 196 | #if defined(__x86_64__) || defined(__i386__) |
Peter Collingbourne | 088ea2b | 2013-05-20 15:57:44 +0000 | [diff] [blame] | 197 | // sizeof(struct thread) from glibc. |
Sergey Matveev | d4a0415 | 2013-06-03 10:20:23 +0000 | [diff] [blame] | 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 __GNUC_PREREQ(2, 12) |
Sergey Matveev | 4c08644 | 2013-05-29 13:07:42 +0000 | [diff] [blame] | 201 | const uptr kThreadDescriptorSize = FIRST_32_SECOND_64(1216, 2304); |
Sergey Matveev | d4a0415 | 2013-06-03 10:20:23 +0000 | [diff] [blame] | 202 | #else |
| 203 | const uptr kThreadDescriptorSize = FIRST_32_SECOND_64(1168, 2304); |
| 204 | #endif |
Peter Collingbourne | 088ea2b | 2013-05-20 15:57:44 +0000 | [diff] [blame] | 205 | |
| 206 | uptr ThreadDescriptorSize() { |
| 207 | return kThreadDescriptorSize; |
| 208 | } |
Sergey Matveev | 4c08644 | 2013-05-29 13:07:42 +0000 | [diff] [blame] | 209 | |
| 210 | // The offset at which pointer to self is located in the thread descriptor. |
| 211 | const uptr kThreadSelfOffset = FIRST_32_SECOND_64(8, 16); |
| 212 | |
| 213 | uptr ThreadSelfOffset() { |
| 214 | return kThreadSelfOffset; |
| 215 | } |
| 216 | |
| 217 | uptr 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)); |
Peter Collingbourne | 088ea2b | 2013-05-20 15:57:44 +0000 | [diff] [blame] | 223 | #endif |
Sergey Matveev | 4c08644 | 2013-05-29 13:07:42 +0000 | [diff] [blame] | 224 | return descr_addr; |
| 225 | } |
Alexey Samsonov | 816bdb7 | 2013-05-30 09:16:04 +0000 | [diff] [blame] | 226 | #endif // defined(__x86_64__) || defined(__i386__) |
Peter Collingbourne | 088ea2b | 2013-05-20 15:57:44 +0000 | [diff] [blame] | 227 | |
| 228 | void GetThreadStackAndTls(bool main, uptr *stk_addr, uptr *stk_size, |
| 229 | uptr *tls_addr, uptr *tls_size) { |
| 230 | #ifndef SANITIZER_GO |
Alexey Samsonov | 816bdb7 | 2013-05-30 09:16:04 +0000 | [diff] [blame] | 231 | #if defined(__x86_64__) || defined(__i386__) |
Sergey Matveev | 4c08644 | 2013-05-29 13:07:42 +0000 | [diff] [blame] | 232 | *tls_addr = ThreadSelf(); |
Peter Collingbourne | 088ea2b | 2013-05-20 15:57:44 +0000 | [diff] [blame] | 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 | |
| 263 | void 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 |