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Diffstat (limited to '')
| -rw-r--r-- | sal/osl/unx/backtraceapi.cxx | 279 |
1 files changed, 279 insertions, 0 deletions
diff --git a/sal/osl/unx/backtraceapi.cxx b/sal/osl/unx/backtraceapi.cxx new file mode 100644 index 000000000..a4cec46ca --- /dev/null +++ b/sal/osl/unx/backtraceapi.cxx @@ -0,0 +1,279 @@ +/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */ +/* + * This file is part of the LibreOffice project. + * + * This Source Code Form is subject to the terms of the Mozilla Public + * License, v. 2.0. If a copy of the MPL was not distributed with this + * file, You can obtain one at http://mozilla.org/MPL/2.0/. + */ + +#include <sal/config.h> + +#include <cassert> +#include <cstdlib> +#include <limits> +#include <memory> +#include <mutex> + +#include <o3tl/runtimetooustring.hxx> +#include <rtl/ustrbuf.hxx> +#include <rtl/ustring.hxx> +#include <sal/types.h> +#include <sal/log.hxx> +#include <sal/backtrace.hxx> + +#include "backtrace.h" +#include <backtraceasstring.hxx> + +OUString osl::detail::backtraceAsString(sal_uInt32 maxDepth) { + std::unique_ptr<sal::BacktraceState> backtrace = sal::backtrace_get( maxDepth ); + return sal::backtrace_to_string( backtrace.get()); +} + +std::unique_ptr<sal::BacktraceState> sal::backtrace_get(sal_uInt32 maxDepth) +{ + assert(maxDepth != 0); + auto const maxInt = static_cast<unsigned int>( + std::numeric_limits<int>::max()); + if (maxDepth > maxInt) { + maxDepth = static_cast<sal_uInt32>(maxInt); + } + auto b1 = new void *[maxDepth]; + int n = backtrace(b1, static_cast<int>(maxDepth)); + return std::unique_ptr<BacktraceState>(new BacktraceState{ b1, n }); +} + +#if OSL_DEBUG_LEVEL > 0 && (defined LINUX || defined MACOSX || defined FREEBSD || defined NETBSD || defined OPENBSD || defined(DRAGONFLY)) +// The backtrace_symbols() function is unreliable, it requires -rdynamic and even then it cannot resolve names +// of many functions, such as those with hidden ELF visibility. Libunwind doesn't resolve names for me either, +// boost::stacktrace doesn't work properly, the best result I've found is addr2line. Using addr2line is relatively +// slow, but I don't find that to be a big problem for printing of backtraces. Feel free to improve if needed +// (e.g. the calls could be grouped by the binary). +#include <dlfcn.h> +#include <unistd.h> +#include <vector> +#include <osl/process.h> +#include <rtl/strbuf.hxx> +#include <osl/mutex.hxx> +#include <o3tl/lru_map.hxx> +#include "file_url.hxx" + +namespace +{ +struct FrameData +{ + const char* file = nullptr; + void* addr; + ptrdiff_t offset; + OString info; + bool handled = false; +}; + +typedef o3tl::lru_map<void*, OString> FrameCache; +std::mutex frameCacheMutex; +FrameCache frameCache( 256 ); + +void process_file_addr2line( const char* file, std::vector<FrameData>& frameData ) +{ + if(access( file, R_OK ) != 0) + return; // cannot read info from the binary file anyway + OUString binary("addr2line"); + OUString dummy; +#if defined __clang__ + // llvm-addr2line is faster than addr2line + if(osl::detail::find_in_PATH("llvm-addr2line", dummy)) + binary = "llvm-addr2line"; +#endif + if(!osl::detail::find_in_PATH(binary, dummy)) + return; // Will not work, avoid warnings from osl process code. + OUString arg1("-Cfe"); + OUString arg2 = OUString::fromUtf8(file); + std::vector<OUString> addrs; + std::vector<rtl_uString*> args; + args.reserve(frameData.size() + 2); + args.push_back( arg1.pData ); + args.push_back( arg2.pData ); + for( FrameData& frame : frameData ) + { + if( frame.file != nullptr && strcmp( file, frame.file ) == 0 ) + { + addrs.push_back("0x" + OUString::number(frame.offset, 16)); + args.push_back(addrs.back().pData); + frame.handled = true; + } + } + + oslProcess aProcess; + oslFileHandle pOut = nullptr; + oslFileHandle pErr = nullptr; + oslSecurity pSecurity = osl_getCurrentSecurity(); + oslProcessError eErr = osl_executeProcess_WithRedirectedIO( + binary.pData, args.data(), args.size(), osl_Process_SEARCHPATH | osl_Process_HIDDEN, pSecurity, nullptr, + nullptr, 0, &aProcess, nullptr, &pOut, &pErr); + osl_freeSecurityHandle(pSecurity); + + if (eErr != osl_Process_E_None) + { + SAL_WARN("sal.osl", binary << " call to resolve " << file << " symbols failed"); + return; + } + + OStringBuffer outputBuffer; + if (pOut) + { + const sal_uInt64 BUF_SIZE = 1024; + char buffer[BUF_SIZE]; + while (true) + { + sal_uInt64 bytesRead = 0; + while(osl_readFile(pErr, buffer, BUF_SIZE, &bytesRead) == osl_File_E_None + && bytesRead != 0) + ; // discard possible stderr output + oslFileError err = osl_readFile(pOut, buffer, BUF_SIZE, &bytesRead); + if(bytesRead == 0 && err == osl_File_E_None) + break; + outputBuffer.append(buffer, bytesRead); + if (err != osl_File_E_None && err != osl_File_E_AGAIN) + break; + } + osl_closeFile(pOut); + } + if(pErr) + osl_closeFile(pErr); + eErr = osl_joinProcess(aProcess); + osl_freeProcessHandle(aProcess); + + OString output = outputBuffer.makeStringAndClear(); + std::vector<OString> lines; + sal_Int32 outputPos = 0; + while(outputPos < output.getLength()) + { + sal_Int32 end1 = output.indexOf('\n', outputPos); + if(end1 < 0) + break; + sal_Int32 end2 = output.indexOf('\n', end1 + 1); + if(end2 < 0) + end2 = output.getLength(); + lines.push_back(output.copy( outputPos, end1 - outputPos )); + lines.push_back(output.copy( end1 + 1, end2 - end1 - 1 )); + outputPos = end2 + 1; + } + if(lines.size() != addrs.size() * 2) + { + SAL_WARN("sal.osl", "failed to parse " << binary << " call output to resolve " << file << " symbols "); + return; // addr2line problem? + } + size_t linesPos = 0; + for( FrameData& frame : frameData ) + { + if( frame.file != nullptr && strcmp( file, frame.file ) == 0 ) + { + // There should be two lines, first function name and second source file information. + // If each of them starts with ??, it is invalid/unknown. + OString function = lines[linesPos]; + OString source = lines[linesPos+1]; + linesPos += 2; + if(function.isEmpty() || function.startsWith("??")) + { + // Cache that the address cannot be resolved. + std::lock_guard guard(frameCacheMutex); + frameCache.insert( { frame.addr, "" } ); + } + else + { + if( source.startsWith("??")) + frame.info = function + " in " + file; + else + frame.info = function + " at " + source; + std::lock_guard guard(frameCacheMutex); + frameCache.insert( { frame.addr, frame.info } ); + } + } + } +} + +} // namespace + +OUString sal::backtrace_to_string(BacktraceState* backtraceState) +{ + // Collect frames for each binary and process each binary in one addr2line + // call for better performance. + std::vector< FrameData > frameData; + frameData.resize(backtraceState->nDepth); + for (int i = 0; i != backtraceState->nDepth; ++i) + { + Dl_info dli; + void* addr = backtraceState->buffer[i]; + std::unique_lock guard(frameCacheMutex); + auto it = frameCache.find(addr); + bool found = it != frameCache.end(); + guard.unlock(); + if( found ) + { + frameData[ i ].info = it->second; + frameData[ i ].handled = true; + } + else if (dladdr(addr, &dli) != 0) + { + if (dli.dli_fname && dli.dli_fbase) + { + frameData[ i ].file = dli.dli_fname; + frameData[ i ].addr = addr; + frameData[ i ].offset = reinterpret_cast<ptrdiff_t>(addr) - reinterpret_cast<ptrdiff_t>(dli.dli_fbase); + } + } + } + for (int i = 0; i != backtraceState->nDepth; ++i) + { + if(frameData[ i ].file != nullptr && !frameData[ i ].handled) + process_file_addr2line( frameData[ i ].file, frameData ); + } + OUStringBuffer b3; + std::unique_ptr<char*, decltype(free)*> b2{ nullptr, free }; + bool fallbackInitDone = false; + for (int i = 0; i != backtraceState->nDepth; ++i) + { + if (i != 0) + b3.append("\n"); + b3.append( "#" + OUString::number( i ) + " " ); + if(!frameData[i].info.isEmpty()) + b3.append(o3tl::runtimeToOUString(frameData[i].info.getStr())); + else + { + if(!fallbackInitDone) + { + b2 = std::unique_ptr<char*, decltype(free)*> + {backtrace_symbols(backtraceState->buffer, backtraceState->nDepth), free}; + fallbackInitDone = true; + } + if(b2) + b3.append(o3tl::runtimeToOUString(b2.get()[i])); + else + b3.append("??"); + } + } + return b3.makeStringAndClear(); +} + +#else + +OUString sal::backtrace_to_string(BacktraceState* backtraceState) +{ + std::unique_ptr<char*, decltype(free)*> b2{backtrace_symbols(backtraceState->buffer, backtraceState->nDepth), free}; + if (!b2) { + return OUString(); + } + OUStringBuffer b3; + for (int i = 0; i != backtraceState->nDepth; ++i) { + if (i != 0) { + b3.append("\n"); + } + b3.append( "#" + OUString::number( i ) + " " ); + b3.append(o3tl::runtimeToOUString(b2.get()[i])); + } + return b3.makeStringAndClear(); +} + +#endif + +/* vim:set shiftwidth=4 softtabstop=4 expandtab: */ |