1//===------------------ sanitizer_unwind_fuchsia.cpp 2//---------------------------===// 3// 4// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. 5// See https://llvm.org/LICENSE.txt for license information. 6// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception 7// 8//===----------------------------------------------------------------------===// 9// 10/// Sanitizer unwind Fuchsia specific functions. 11// 12//===----------------------------------------------------------------------===// 13 14#include "sanitizer_platform.h" 15#if SANITIZER_FUCHSIA 16 17# include <limits.h> 18# include <unwind.h> 19 20# include "sanitizer_common.h" 21# include "sanitizer_stacktrace.h" 22 23namespace __sanitizer { 24 25# if SANITIZER_CAN_SLOW_UNWIND 26struct UnwindTraceArg { 27 BufferedStackTrace *stack; 28 u32 max_depth; 29}; 30 31_Unwind_Reason_Code Unwind_Trace(struct _Unwind_Context *ctx, void *param) { 32 UnwindTraceArg *arg = static_cast<UnwindTraceArg *>(param); 33 CHECK_LT(arg->stack->size, arg->max_depth); 34 uptr pc = _Unwind_GetIP(ctx); 35 if (pc < GetPageSizeCached()) 36 return _URC_NORMAL_STOP; 37 arg->stack->trace_buffer[arg->stack->size++] = pc; 38 return (arg->stack->size == arg->max_depth ? _URC_NORMAL_STOP 39 : _URC_NO_REASON); 40} 41 42void BufferedStackTrace::UnwindSlow(uptr pc, u32 max_depth) { 43 CHECK_GE(max_depth, 2); 44 size = 0; 45 UnwindTraceArg arg = {this, Min(max_depth + 1, kStackTraceMax)}; 46 _Unwind_Backtrace(Unwind_Trace, &arg); 47 CHECK_GT(size, 0); 48 // We need to pop a few frames so that pc is on top. 49 uptr to_pop = LocatePcInTrace(pc); 50 // trace_buffer[0] belongs to the current function so we always pop it, 51 // unless there is only 1 frame in the stack trace (1 frame is always better 52 // than 0!). 53 PopStackFrames(Min(to_pop, static_cast<uptr>(1))); 54 trace_buffer[0] = pc; 55} 56 57void BufferedStackTrace::UnwindSlow(uptr pc, void *context, u32 max_depth) { 58 CHECK(context); 59 CHECK_GE(max_depth, 2); 60 UNREACHABLE("signal context doesn't exist"); 61} 62# endif // SANITIZER_CAN_SLOW_UNWIND 63 64} // namespace __sanitizer 65 66#endif // SANITIZER_FUCHSIA 67