| // -*- Mode: C++; c-basic-offset: 2; indent-tabs-mode: nil -*- |
| // Copyright (c) 2005, 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: Arun Sharma |
| // |
| // Produce stack trace using libunwind |
| |
| #ifndef BASE_STACKTRACE_LIBINWIND_INL_H_ |
| #define BASE_STACKTRACE_LIBINWIND_INL_H_ |
| // Note: this file is included into stacktrace.cc more than once. |
| // Anything that should only be defined once should be here: |
| |
| // We only need local unwinder. |
| #define UNW_LOCAL_ONLY |
| |
| extern "C" { |
| #include <assert.h> |
| #include <string.h> // for memset() |
| #include <libunwind.h> |
| } |
| #include "gperftools/stacktrace.h" |
| |
| #include "base/basictypes.h" |
| #include "base/logging.h" |
| |
| // Sometimes, we can try to get a stack trace from within a stack |
| // trace, because libunwind can call mmap (maybe indirectly via an |
| // internal mmap based memory allocator), and that mmap gets trapped |
| // and causes a stack-trace request. If were to try to honor that |
| // recursive request, we'd end up with infinite recursion or deadlock. |
| // Luckily, it's safe to ignore those subsequent traces. In such |
| // cases, we return 0 to indicate the situation. |
| static __thread int recursive ATTR_INITIAL_EXEC; |
| |
| #if defined(TCMALLOC_ENABLE_UNWIND_FROM_UCONTEXT) && (defined(__i386__) || defined(__x86_64__)) && defined(__GNU_LIBRARY__) |
| #define BASE_STACKTRACE_UNW_CONTEXT_IS_UCONTEXT 1 |
| #endif |
| |
| #endif // BASE_STACKTRACE_LIBINWIND_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 { |
| void *ip; |
| int n = 0; |
| unw_cursor_t cursor; |
| unw_context_t uc; |
| #if IS_STACK_FRAMES |
| unw_word_t sp = 0, next_sp = 0; |
| #endif |
| |
| if (recursive) { |
| return 0; |
| } |
| ++recursive; |
| |
| #if (IS_WITH_CONTEXT && defined(BASE_STACKTRACE_UNW_CONTEXT_IS_UCONTEXT)) |
| if (ucp) { |
| uc = *(static_cast<unw_context_t *>(const_cast<void *>(ucp))); |
| /* this is a bit weird. profiler.cc calls us with signal's ucontext |
| * yet passing us 2 as skip_count and essentially assuming we won't |
| * use ucontext. */ |
| /* In order to fix that I'm going to assume that if ucp is |
| * non-null we're asked to ignore skip_count in case we're |
| * able to use ucp */ |
| skip_count = 0; |
| } else { |
| unw_getcontext(&uc); |
| skip_count += 2; // Do not include current and parent frame |
| } |
| #else |
| unw_getcontext(&uc); |
| skip_count += 2; // Do not include current and parent frame |
| #endif |
| |
| int ret = unw_init_local(&cursor, &uc); |
| (void)ret; |
| assert(ret >= 0); |
| |
| while (skip_count--) { |
| if (unw_step(&cursor) <= 0) { |
| goto out; |
| } |
| #if IS_STACK_FRAMES |
| if (unw_get_reg(&cursor, UNW_REG_SP, &next_sp)) { |
| goto out; |
| } |
| #endif |
| } |
| |
| while (n < max_depth) { |
| if (unw_get_reg(&cursor, UNW_REG_IP, (unw_word_t *) &ip) < 0) { |
| break; |
| } |
| #if IS_STACK_FRAMES |
| sizes[n] = 0; |
| #endif |
| result[n++] = ip; |
| if (unw_step(&cursor) <= 0) { |
| break; |
| } |
| #if IS_STACK_FRAMES |
| sp = next_sp; |
| if (unw_get_reg(&cursor, UNW_REG_SP, &next_sp) , 0) { |
| break; |
| } |
| sizes[n - 1] = next_sp - sp; |
| #endif |
| } |
| out: |
| --recursive; |
| return n; |
| } |