| //===-- sanitizer_linux_libcdep.cc ----------------------------------------===// |
| // |
| // The LLVM Compiler Infrastructure |
| // |
| // This file is distributed under the University of Illinois Open Source |
| // License. See LICENSE.TXT for details. |
| // |
| //===----------------------------------------------------------------------===// |
| // |
| // This file is shared between AddressSanitizer and ThreadSanitizer |
| // run-time libraries and implements linux-specific functions from |
| // sanitizer_libc.h. |
| //===----------------------------------------------------------------------===// |
| |
| #include "sanitizer_platform.h" |
| #if SANITIZER_LINUX |
| |
| #include "sanitizer_common.h" |
| #include "sanitizer_procmaps.h" |
| #include "sanitizer_stacktrace.h" |
| |
| #include <dlfcn.h> |
| #include <pthread.h> |
| #include <sys/prctl.h> |
| #include <sys/resource.h> |
| #include <unwind.h> |
| |
| namespace __sanitizer { |
| |
| void GetThreadStackTopAndBottom(bool at_initialization, uptr *stack_top, |
| uptr *stack_bottom) { |
| static const uptr kMaxThreadStackSize = 256 * (1 << 20); // 256M |
| CHECK(stack_top); |
| CHECK(stack_bottom); |
| if (at_initialization) { |
| // This is the main thread. Libpthread may not be initialized yet. |
| struct rlimit rl; |
| CHECK_EQ(getrlimit(RLIMIT_STACK, &rl), 0); |
| |
| // Find the mapping that contains a stack variable. |
| MemoryMappingLayout proc_maps(/*cache_enabled*/true); |
| uptr start, end, offset; |
| uptr prev_end = 0; |
| while (proc_maps.Next(&start, &end, &offset, 0, 0, /* protection */0)) { |
| if ((uptr)&rl < end) |
| break; |
| prev_end = end; |
| } |
| CHECK((uptr)&rl >= start && (uptr)&rl < end); |
| |
| // Get stacksize from rlimit, but clip it so that it does not overlap |
| // with other mappings. |
| uptr stacksize = rl.rlim_cur; |
| if (stacksize > end - prev_end) |
| stacksize = end - prev_end; |
| // When running with unlimited stack size, we still want to set some limit. |
| // The unlimited stack size is caused by 'ulimit -s unlimited'. |
| // Also, for some reason, GNU make spawns subprocesses with unlimited stack. |
| if (stacksize > kMaxThreadStackSize) |
| stacksize = kMaxThreadStackSize; |
| *stack_top = end; |
| *stack_bottom = end - stacksize; |
| return; |
| } |
| pthread_attr_t attr; |
| pthread_attr_init(&attr); |
| CHECK_EQ(pthread_getattr_np(pthread_self(), &attr), 0); |
| uptr stacksize = 0; |
| void *stackaddr = 0; |
| pthread_attr_getstack(&attr, &stackaddr, (size_t*)&stacksize); |
| pthread_attr_destroy(&attr); |
| |
| *stack_top = (uptr)stackaddr + stacksize; |
| *stack_bottom = (uptr)stackaddr; |
| CHECK(stacksize < kMaxThreadStackSize); // Sanity check. |
| } |
| |
| // Does not compile for Go because dlsym() requires -ldl |
| #ifndef SANITIZER_GO |
| bool SetEnv(const char *name, const char *value) { |
| void *f = dlsym(RTLD_NEXT, "setenv"); |
| if (f == 0) |
| return false; |
| typedef int(*setenv_ft)(const char *name, const char *value, int overwrite); |
| setenv_ft setenv_f; |
| CHECK_EQ(sizeof(setenv_f), sizeof(f)); |
| internal_memcpy(&setenv_f, &f, sizeof(f)); |
| return setenv_f(name, value, 1) == 0; |
| } |
| #endif |
| |
| bool SanitizerSetThreadName(const char *name) { |
| #ifdef PR_SET_NAME |
| return 0 == prctl(PR_SET_NAME, (unsigned long)name, 0, 0, 0); // NOLINT |
| #else |
| return false; |
| #endif |
| } |
| |
| bool SanitizerGetThreadName(char *name, int max_len) { |
| #ifdef PR_GET_NAME |
| char buff[17]; |
| if (prctl(PR_GET_NAME, (unsigned long)buff, 0, 0, 0)) // NOLINT |
| return false; |
| internal_strncpy(name, buff, max_len); |
| name[max_len] = 0; |
| return true; |
| #else |
| return false; |
| #endif |
| } |
| |
| #ifndef SANITIZER_GO |
| //------------------------- SlowUnwindStack ----------------------------------- |
| #ifdef __arm__ |
| #define UNWIND_STOP _URC_END_OF_STACK |
| #define UNWIND_CONTINUE _URC_NO_REASON |
| #else |
| #define UNWIND_STOP _URC_NORMAL_STOP |
| #define UNWIND_CONTINUE _URC_NO_REASON |
| #endif |
| |
| uptr Unwind_GetIP(struct _Unwind_Context *ctx) { |
| #ifdef __arm__ |
| uptr val; |
| _Unwind_VRS_Result res = _Unwind_VRS_Get(ctx, _UVRSC_CORE, |
| 15 /* r15 = PC */, _UVRSD_UINT32, &val); |
| CHECK(res == _UVRSR_OK && "_Unwind_VRS_Get failed"); |
| // Clear the Thumb bit. |
| return val & ~(uptr)1; |
| #else |
| return _Unwind_GetIP(ctx); |
| #endif |
| } |
| |
| _Unwind_Reason_Code Unwind_Trace(struct _Unwind_Context *ctx, void *param) { |
| StackTrace *b = (StackTrace*)param; |
| CHECK(b->size < b->max_size); |
| uptr pc = Unwind_GetIP(ctx); |
| b->trace[b->size++] = pc; |
| if (b->size == b->max_size) return UNWIND_STOP; |
| return UNWIND_CONTINUE; |
| } |
| |
| static bool MatchPc(uptr cur_pc, uptr trace_pc) { |
| return cur_pc - trace_pc <= 64 || trace_pc - cur_pc <= 64; |
| } |
| |
| void StackTrace::SlowUnwindStack(uptr pc, uptr max_depth) { |
| this->size = 0; |
| this->max_size = max_depth; |
| if (max_depth > 1) { |
| _Unwind_Backtrace(Unwind_Trace, this); |
| // We need to pop a few frames so that pc is on top. |
| // trace[0] belongs to the current function so we always pop it. |
| int to_pop = 1; |
| /**/ if (size > 1 && MatchPc(pc, trace[1])) to_pop = 1; |
| else if (size > 2 && MatchPc(pc, trace[2])) to_pop = 2; |
| else if (size > 3 && MatchPc(pc, trace[3])) to_pop = 3; |
| else if (size > 4 && MatchPc(pc, trace[4])) to_pop = 4; |
| else if (size > 5 && MatchPc(pc, trace[5])) to_pop = 5; |
| this->PopStackFrames(to_pop); |
| } |
| this->trace[0] = pc; |
| } |
| |
| #endif // !SANITIZER_GO |
| |
| static uptr g_tls_size; |
| |
| #ifdef __i386__ |
| # define DL_INTERNAL_FUNCTION __attribute__((regparm(3), stdcall)) |
| #else |
| # define DL_INTERNAL_FUNCTION |
| #endif |
| |
| void InitTlsSize() { |
| #if !defined(SANITIZER_GO) && !SANITIZER_ANDROID |
| typedef void (*get_tls_func)(size_t*, size_t*) DL_INTERNAL_FUNCTION; |
| get_tls_func get_tls; |
| void *get_tls_static_info_ptr = dlsym(RTLD_NEXT, "_dl_get_tls_static_info"); |
| CHECK_EQ(sizeof(get_tls), sizeof(get_tls_static_info_ptr)); |
| internal_memcpy(&get_tls, &get_tls_static_info_ptr, |
| sizeof(get_tls_static_info_ptr)); |
| CHECK_NE(get_tls, 0); |
| size_t tls_size = 0; |
| size_t tls_align = 0; |
| get_tls(&tls_size, &tls_align); |
| g_tls_size = tls_size; |
| #endif |
| } |
| |
| uptr GetTlsSize() { |
| return g_tls_size; |
| } |
| |
| #if defined(__x86_64__) || defined(__i386__) |
| // sizeof(struct thread) from glibc. |
| // There has been a report of this being different on glibc 2.11. We don't know |
| // when this change happened, so 2.12 is a conservative estimate. |
| #if __GLIBC_PREREQ(2, 12) |
| const uptr kThreadDescriptorSize = FIRST_32_SECOND_64(1216, 2304); |
| #else |
| const uptr kThreadDescriptorSize = FIRST_32_SECOND_64(1168, 2304); |
| #endif |
| |
| uptr ThreadDescriptorSize() { |
| return kThreadDescriptorSize; |
| } |
| |
| // The offset at which pointer to self is located in the thread descriptor. |
| const uptr kThreadSelfOffset = FIRST_32_SECOND_64(8, 16); |
| |
| uptr ThreadSelfOffset() { |
| return kThreadSelfOffset; |
| } |
| |
| uptr ThreadSelf() { |
| uptr descr_addr; |
| #ifdef __i386__ |
| asm("mov %%gs:%c1,%0" : "=r"(descr_addr) : "i"(kThreadSelfOffset)); |
| #else |
| asm("mov %%fs:%c1,%0" : "=r"(descr_addr) : "i"(kThreadSelfOffset)); |
| #endif |
| return descr_addr; |
| } |
| #endif // defined(__x86_64__) || defined(__i386__) |
| |
| void GetThreadStackAndTls(bool main, uptr *stk_addr, uptr *stk_size, |
| uptr *tls_addr, uptr *tls_size) { |
| #ifndef SANITIZER_GO |
| #if defined(__x86_64__) || defined(__i386__) |
| *tls_addr = ThreadSelf(); |
| *tls_size = GetTlsSize(); |
| *tls_addr -= *tls_size; |
| *tls_addr += kThreadDescriptorSize; |
| #else |
| *tls_addr = 0; |
| *tls_size = 0; |
| #endif |
| |
| uptr stack_top, stack_bottom; |
| GetThreadStackTopAndBottom(main, &stack_top, &stack_bottom); |
| *stk_addr = stack_bottom; |
| *stk_size = stack_top - stack_bottom; |
| |
| if (!main) { |
| // If stack and tls intersect, make them non-intersecting. |
| if (*tls_addr > *stk_addr && *tls_addr < *stk_addr + *stk_size) { |
| CHECK_GT(*tls_addr + *tls_size, *stk_addr); |
| CHECK_LE(*tls_addr + *tls_size, *stk_addr + *stk_size); |
| *stk_size -= *tls_size; |
| *tls_addr = *stk_addr + *stk_size; |
| } |
| } |
| #else // SANITIZER_GO |
| *stk_addr = 0; |
| *stk_size = 0; |
| *tls_addr = 0; |
| *tls_size = 0; |
| #endif // SANITIZER_GO |
| } |
| |
| void AdjustStackSizeLinux(void *attr_, int verbosity) { |
| pthread_attr_t *attr = (pthread_attr_t *)attr_; |
| uptr stackaddr = 0; |
| size_t stacksize = 0; |
| pthread_attr_getstack(attr, (void**)&stackaddr, &stacksize); |
| // GLibC will return (0 - stacksize) as the stack address in the case when |
| // stacksize is set, but stackaddr is not. |
| bool stack_set = (stackaddr != 0) && (stackaddr + stacksize != 0); |
| // We place a lot of tool data into TLS, account for that. |
| const uptr minstacksize = GetTlsSize() + 128*1024; |
| if (stacksize < minstacksize) { |
| if (!stack_set) { |
| if (verbosity && stacksize != 0) |
| Printf("Sanitizer: increasing stacksize %zu->%zu\n", stacksize, |
| minstacksize); |
| pthread_attr_setstacksize(attr, minstacksize); |
| } else { |
| Printf("Sanitizer: pre-allocated stack size is insufficient: " |
| "%zu < %zu\n", stacksize, minstacksize); |
| Printf("Sanitizer: pthread_create is likely to fail.\n"); |
| } |
| } |
| } |
| |
| } // namespace __sanitizer |
| |
| #endif // SANITIZER_LINUX |