| //===-- sanitizer_stacktrace.h ----------------------------------*- C++ -*-===// |
| // |
| // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. |
| // See https://llvm.org/LICENSE.txt for license information. |
| // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception |
| // |
| //===----------------------------------------------------------------------===// |
| // |
| // This file is shared between AddressSanitizer and ThreadSanitizer |
| // run-time libraries. |
| //===----------------------------------------------------------------------===// |
| #ifndef SANITIZER_STACKTRACE_H |
| #define SANITIZER_STACKTRACE_H |
| |
| #include "sanitizer_common.h" |
| #include "sanitizer_internal_defs.h" |
| #include "sanitizer_platform.h" |
| |
| namespace __sanitizer { |
| |
| struct BufferedStackTrace; |
| |
| static const u32 kStackTraceMax = 256; |
| |
| #if SANITIZER_LINUX && defined(__mips__) |
| # define SANITIZER_CAN_FAST_UNWIND 0 |
| #elif SANITIZER_WINDOWS |
| # define SANITIZER_CAN_FAST_UNWIND 0 |
| #else |
| # define SANITIZER_CAN_FAST_UNWIND 1 |
| #endif |
| |
| // Fast unwind is the only option on Mac for now; we will need to |
| // revisit this macro when slow unwind works on Mac, see |
| // https://github.com/google/sanitizers/issues/137 |
| #if SANITIZER_MAC |
| # define SANITIZER_CAN_SLOW_UNWIND 0 |
| #else |
| # define SANITIZER_CAN_SLOW_UNWIND 1 |
| #endif |
| |
| struct StackTrace { |
| const uptr *trace; |
| u32 size; |
| u32 tag; |
| |
| static const int TAG_UNKNOWN = 0; |
| static const int TAG_ALLOC = 1; |
| static const int TAG_DEALLOC = 2; |
| static const int TAG_CUSTOM = 100; // Tool specific tags start here. |
| |
| StackTrace() : trace(nullptr), size(0), tag(0) {} |
| StackTrace(const uptr *trace, u32 size) : trace(trace), size(size), tag(0) {} |
| StackTrace(const uptr *trace, u32 size, u32 tag) |
| : trace(trace), size(size), tag(tag) {} |
| |
| // Prints a symbolized stacktrace, followed by an empty line. |
| void Print() const; |
| |
| // Prints a symbolized stacktrace to the output string, followed by an empty |
| // line. |
| void PrintTo(InternalScopedString *output) const; |
| |
| // Prints a symbolized stacktrace to the output buffer, followed by an empty |
| // line. Returns the number of symbols that should have been written to buffer |
| // (not including trailing '\0'). Thus, the string is truncated iff return |
| // value is not less than "out_buf_size". |
| uptr PrintTo(char *out_buf, uptr out_buf_size) const; |
| |
| static bool WillUseFastUnwind(bool request_fast_unwind) { |
| if (!SANITIZER_CAN_FAST_UNWIND) |
| return false; |
| if (!SANITIZER_CAN_SLOW_UNWIND) |
| return true; |
| return request_fast_unwind; |
| } |
| |
| static uptr GetCurrentPc(); |
| static inline uptr GetPreviousInstructionPc(uptr pc); |
| static uptr GetNextInstructionPc(uptr pc); |
| }; |
| |
| // Performance-critical, must be in the header. |
| ALWAYS_INLINE |
| uptr StackTrace::GetPreviousInstructionPc(uptr pc) { |
| #if defined(__arm__) |
| // T32 (Thumb) branch instructions might be 16 or 32 bit long, |
| // so we return (pc-2) in that case in order to be safe. |
| // For A32 mode we return (pc-4) because all instructions are 32 bit long. |
| return (pc - 3) & (~1); |
| #elif defined(__powerpc__) || defined(__powerpc64__) || defined(__aarch64__) |
| // PCs are always 4 byte aligned. |
| return pc - 4; |
| #elif defined(__sparc__) || defined(__mips__) |
| return pc - 8; |
| #elif SANITIZER_RISCV64 |
| // RV-64 has variable instruciton length... |
| // C extentions gives us 2-byte instructoins |
| // RV-64 has 4-byte instructions |
| // + RISCV architecture allows instructions up to 8 bytes |
| // It seems difficult to figure out the exact instruction length - |
| // pc - 2 seems like a safe option for the purposes of stack tracing |
| return pc - 2; |
| #else |
| return pc - 1; |
| #endif |
| } |
| |
| // StackTrace that owns the buffer used to store the addresses. |
| struct BufferedStackTrace : public StackTrace { |
| uptr trace_buffer[kStackTraceMax]; |
| uptr top_frame_bp; // Optional bp of a top frame. |
| |
| BufferedStackTrace() : StackTrace(trace_buffer, 0), top_frame_bp(0) {} |
| |
| void Init(const uptr *pcs, uptr cnt, uptr extra_top_pc = 0); |
| |
| // Get the stack trace with the given pc and bp. |
| // The pc will be in the position 0 of the resulting stack trace. |
| // The bp may refer to the current frame or to the caller's frame. |
| void Unwind(uptr pc, uptr bp, void *context, bool request_fast, |
| u32 max_depth = kStackTraceMax) { |
| top_frame_bp = (max_depth > 0) ? bp : 0; |
| // Small max_depth optimization |
| if (max_depth <= 1) { |
| if (max_depth == 1) |
| trace_buffer[0] = pc; |
| size = max_depth; |
| return; |
| } |
| UnwindImpl(pc, bp, context, request_fast, max_depth); |
| } |
| |
| void Unwind(u32 max_depth, uptr pc, uptr bp, void *context, uptr stack_top, |
| uptr stack_bottom, bool request_fast_unwind); |
| |
| void Reset() { |
| *static_cast<StackTrace *>(this) = StackTrace(trace_buffer, 0); |
| top_frame_bp = 0; |
| } |
| |
| private: |
| // Every runtime defines its own implementation of this method |
| void UnwindImpl(uptr pc, uptr bp, void *context, bool request_fast, |
| u32 max_depth); |
| |
| // UnwindFast/Slow have platform-specific implementations |
| void UnwindFast(uptr pc, uptr bp, uptr stack_top, uptr stack_bottom, |
| u32 max_depth); |
| void UnwindSlow(uptr pc, u32 max_depth); |
| void UnwindSlow(uptr pc, void *context, u32 max_depth); |
| |
| void PopStackFrames(uptr count); |
| uptr LocatePcInTrace(uptr pc); |
| |
| BufferedStackTrace(const BufferedStackTrace &) = delete; |
| void operator=(const BufferedStackTrace &) = delete; |
| |
| friend class FastUnwindTest; |
| }; |
| |
| #if defined(__s390x__) |
| static const uptr kFrameSize = 160; |
| #elif defined(__s390__) |
| static const uptr kFrameSize = 96; |
| #else |
| static const uptr kFrameSize = 2 * sizeof(uhwptr); |
| #endif |
| |
| // Check if given pointer points into allocated stack area. |
| static inline bool IsValidFrame(uptr frame, uptr stack_top, uptr stack_bottom) { |
| return frame > stack_bottom && frame < stack_top - kFrameSize; |
| } |
| |
| } // namespace __sanitizer |
| |
| // Use this macro if you want to print stack trace with the caller |
| // of the current function in the top frame. |
| #define GET_CALLER_PC_BP \ |
| uptr bp = GET_CURRENT_FRAME(); \ |
| uptr pc = GET_CALLER_PC(); |
| |
| #define GET_CALLER_PC_BP_SP \ |
| GET_CALLER_PC_BP; \ |
| uptr local_stack; \ |
| uptr sp = (uptr)&local_stack |
| |
| // Use this macro if you want to print stack trace with the current |
| // function in the top frame. |
| #define GET_CURRENT_PC_BP \ |
| uptr bp = GET_CURRENT_FRAME(); \ |
| uptr pc = StackTrace::GetCurrentPc() |
| |
| #define GET_CURRENT_PC_BP_SP \ |
| GET_CURRENT_PC_BP; \ |
| uptr local_stack; \ |
| uptr sp = (uptr)&local_stack |
| |
| // GET_CURRENT_PC() is equivalent to StackTrace::GetCurrentPc(). |
| // Optimized x86 version is faster than GetCurrentPc because |
| // it does not involve a function call, instead it reads RIP register. |
| // Reads of RIP by an instruction return RIP pointing to the next |
| // instruction, which is exactly what we want here, thus 0 offset. |
| // It needs to be a macro because otherwise we will get the name |
| // of this function on the top of most stacks. Attribute artificial |
| // does not do what it claims to do, unfortunatley. And attribute |
| // __nodebug__ is clang-only. If we would have an attribute that |
| // would remove this function from debug info, we could simply make |
| // StackTrace::GetCurrentPc() faster. |
| #if defined(__x86_64__) |
| # define GET_CURRENT_PC() \ |
| (__extension__({ \ |
| uptr pc; \ |
| asm("lea 0(%%rip), %0" : "=r"(pc)); \ |
| pc; \ |
| })) |
| #else |
| # define GET_CURRENT_PC() StackTrace::GetCurrentPc() |
| #endif |
| |
| #endif // SANITIZER_STACKTRACE_H |