| // -*- Mode: C++; c-basic-offset: 2; indent-tabs-mode: nil -*- |
| // Copyright (c) 2011, Google Inc. |
| // All rights reserved. |
| // |
| // Redistribution and use in source and binary forms, with or without |
| // modification, are permitted provided that the following conditions are |
| // met: |
| // |
| // * Redistributions of source code must retain the above copyright |
| // notice, this list of conditions and the following disclaimer. |
| // * Redistributions in binary form must reproduce the above |
| // copyright notice, this list of conditions and the following disclaimer |
| // in the documentation and/or other materials provided with the |
| // distribution. |
| // * Neither the name of Google Inc. nor the names of its |
| // contributors may be used to endorse or promote products derived from |
| // this software without specific prior written permission. |
| // |
| // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS |
| // "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT |
| // LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR |
| // A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT |
| // OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, |
| // SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT |
| // LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, |
| // DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY |
| // THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT |
| // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE |
| // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
| |
| // --- |
| // Author: Doug Kwan |
| // This is inspired by Craig Silverstein's PowerPC stacktrace code. |
| // |
| |
| #ifndef BASE_STACKTRACE_ARM_INL_H_ |
| #define BASE_STACKTRACE_ARM_INL_H_ |
| // Note: this file is included into stacktrace.cc more than once. |
| // Anything that should only be defined once should be here: |
| |
| #include <stdint.h> // for uintptr_t |
| |
| #include "base/basictypes.h" |
| #include <gperftools/stacktrace.h> |
| |
| // WARNING: |
| // This only works if all your code is in either ARM or THUMB mode. With |
| // interworking, the frame pointer of the caller can either be in r11 (ARM |
| // mode) or r7 (THUMB mode). A callee only saves the frame pointer of its |
| // mode in a fixed location on its stack frame. If the caller is a different |
| // mode, there is no easy way to find the frame pointer. It can either be |
| // still in the designated register or saved on stack along with other callee |
| // saved registers. |
| |
| // Given a pointer to a stack frame, locate and return the calling |
| // stackframe, or return nullptr if no stackframe can be found. Perform sanity |
| // checks (the strictness of which is controlled by the boolean parameter |
| // "STRICT_UNWINDING") to reduce the chance that a bad pointer is returned. |
| template<bool STRICT_UNWINDING> |
| static void **NextStackFrame(void **old_sp) { |
| void **new_sp = (void**) old_sp[-1]; |
| |
| // Check that the transition from frame pointer old_sp to frame |
| // pointer new_sp isn't clearly bogus |
| if (STRICT_UNWINDING) { |
| // With the stack growing downwards, older stack frame must be |
| // at a greater address that the current one. |
| if (new_sp <= old_sp) return nullptr; |
| // Assume stack frames larger than 100,000 bytes are bogus. |
| if ((uintptr_t)new_sp - (uintptr_t)old_sp > 100000) return nullptr; |
| } else { |
| // In the non-strict mode, allow discontiguous stack frames. |
| // (alternate-signal-stacks for example). |
| if (new_sp == old_sp) return nullptr; |
| // And allow frames upto about 1MB. |
| if ((new_sp > old_sp) |
| && ((uintptr_t)new_sp - (uintptr_t)old_sp > 1000000)) return nullptr; |
| } |
| if ((uintptr_t)new_sp & (sizeof(void *) - 1)) return nullptr; |
| return new_sp; |
| } |
| |
| // This ensures that GetStackTrace stes up the Link Register properly. |
| #ifdef __GNUC__ |
| void StacktraceArmDummyFunction() __attribute__((noinline)); |
| void StacktraceArmDummyFunction() { __asm__ volatile(""); } |
| #else |
| # error StacktraceArmDummyFunction() needs to be ported to this platform. |
| #endif |
| #endif // BASE_STACKTRACE_ARM_INL_H_ |
| |
| // Note: this part of the file is included several times. |
| // Do not put globals below. |
| |
| // The following 4 functions are generated from the code below: |
| // GetStack{Trace,Frames}() |
| // GetStack{Trace,Frames}WithContext() |
| // |
| // These functions take the following args: |
| // void** result: the stack-trace, as an array |
| // int* sizes: the size of each stack frame, as an array |
| // (GetStackFrames* only) |
| // int max_depth: the size of the result (and sizes) array(s) |
| // int skip_count: how many stack pointers to skip before storing in result |
| // void* ucp: a ucontext_t* (GetStack{Trace,Frames}WithContext only) |
| static int GET_STACK_TRACE_OR_FRAMES { |
| #ifdef __GNUC__ |
| void **sp = reinterpret_cast<void**>(__builtin_frame_address(0)); |
| #else |
| # error reading stack point not yet supported on this platform. |
| #endif |
| |
| // On ARM, the return address is stored in the link register (r14). |
| // This is not saved on the stack frame of a leaf function. To |
| // simplify code that reads return addresses, we call a dummy |
| // function so that the return address of this function is also |
| // stored in the stack frame. This works at least for gcc. |
| StacktraceArmDummyFunction(); |
| |
| skip_count++; // skip parent frame due to indirection in stacktrace.cc |
| |
| int n = 0; |
| while (sp && n < max_depth) { |
| // The GetStackFrames routine is called when we are in some |
| // informational context (the failure signal handler for example). |
| // Use the non-strict unwinding rules to produce a stack trace |
| // that is as complete as possible (even if it contains a few bogus |
| // entries in some rare cases). |
| void **next_sp = NextStackFrame<IS_STACK_FRAMES == 0>(sp); |
| |
| if (skip_count > 0) { |
| skip_count--; |
| } else { |
| result[n] = *sp; |
| |
| #if IS_STACK_FRAMES |
| if (next_sp > sp) { |
| sizes[n] = (uintptr_t)next_sp - (uintptr_t)sp; |
| } else { |
| // A frame-size of 0 is used to indicate unknown frame size. |
| sizes[n] = 0; |
| } |
| #endif |
| n++; |
| } |
| sp = next_sp; |
| } |
| return n; |
| } |