diff options
| -rw-r--r-- | compiler-rt/include/xray/xray_records.h | 80 | ||||
| -rw-r--r-- | compiler-rt/lib/xray/CMakeLists.txt | 9 | ||||
| -rw-r--r-- | compiler-rt/lib/xray/xray_flags.inc | 4 | ||||
| -rw-r--r-- | compiler-rt/lib/xray/xray_inmemory_log.cc | 227 | ||||
| -rw-r--r-- | compiler-rt/lib/xray/xray_trampoline_x86_64.S (renamed from compiler-rt/lib/xray/xray_trampoline_x86.S) | 0 | ||||
| -rw-r--r-- | compiler-rt/test/lit.common.cfg | 3 | ||||
| -rw-r--r-- | compiler-rt/test/xray/TestCases/Linux/fixedsize-logging.cc | 20 | ||||
| -rw-r--r-- | compiler-rt/test/xray/TestCases/Linux/optional-inmemory-log.cc | 21 |
8 files changed, 359 insertions, 5 deletions
diff --git a/compiler-rt/include/xray/xray_records.h b/compiler-rt/include/xray/xray_records.h new file mode 100644 index 00000000000..34c236b39bd --- /dev/null +++ b/compiler-rt/include/xray/xray_records.h @@ -0,0 +1,80 @@ +//===-- xray_records.h ------------------------------------------*- C++ -*-===// +// +// The LLVM Compiler Infrastructure +// +// This file is distributed under the University of Illinois Open Source +// License. See LICENSE.TXT for details. +// +//===----------------------------------------------------------------------===// +// +// This file is a part of XRay, a dynamic runtime instrumentation system. +// +// This header exposes some record types useful for the XRay in-memory logging +// implementation. +// +//===----------------------------------------------------------------------===// + +#ifndef XRAY_XRAY_RECORDS_H +#define XRAY_XRAY_RECORDS_H + +namespace __xray { + +enum FileTypes { + NAIVE_LOG = 0, +}; + +// This data structure is used to describe the contents of the file. We use this +// for versioning the supported XRay file formats. +struct alignas(32) XRayFileHeader { + uint16_t Version = 0; + + // The type of file we're writing out. See the FileTypes enum for more + // information. This allows different implementations of the XRay logging to + // have different files for different information being stored. + uint16_t Type = 0; + + // What follows are a set of flags that indicate useful things for when + // reading the data in the file. + bool ConstantTSC : 1; + bool NonstopTSC : 1; + + // The frequency by which TSC increases per-second. + alignas(8) uint64_t CycleFrequency = 0; +} __attribute__((packed)); + +static_assert(sizeof(XRayFileHeader) == 32, "XRayFileHeader != 32 bytes"); + +enum RecordTypes { + NORMAL = 0, +}; + +struct alignas(32) XRayRecord { + // This is the type of the record being written. We use 16 bits to allow us to + // treat this as a discriminant, and so that the first 4 bytes get packed + // properly. See RecordTypes for more supported types. + uint16_t RecordType = 0; + + // The CPU where the thread is running. We assume number of CPUs <= 256. + uint8_t CPU = 0; + + // The type of the event. Usually either ENTER = 0 or EXIT = 1. + uint8_t Type = 0; + + // The function ID for the record. + int32_t FuncId = 0; + + // Get the full 8 bytes of the TSC when we get the log record. + uint64_t TSC = 0; + + // The thread ID for the currently running thread. + uint32_t TId = 0; + + // Use some bytes in the end of the record for buffers. + char Buffer[4] = {}; +} __attribute__((packed)); + +static_assert(sizeof(XRayRecord) == 32, "XRayRecord != 32 bytes"); + +} // namespace __xray + +#endif // XRAY_XRAY_RECORDS_H diff --git a/compiler-rt/lib/xray/CMakeLists.txt b/compiler-rt/lib/xray/CMakeLists.txt index 2013bbf1adb..845f856e77c 100644 --- a/compiler-rt/lib/xray/CMakeLists.txt +++ b/compiler-rt/lib/xray/CMakeLists.txt @@ -4,10 +4,11 @@ set(XRAY_SOURCES xray_init.cc xray_interface.cc xray_flags.cc + xray_inmemory_log.cc ) set(x86_64_SOURCES - xray_trampoline_x86.S + xray_trampoline_x86_64.S ${XRAY_SOURCES}) include_directories(..) @@ -18,9 +19,9 @@ set(XRAY_CFLAGS ${SANITIZER_COMMON_CFLAGS}) set(XRAY_COMMON_DEFINITIONS XRAY_HAS_EXCEPTIONS=1) add_compiler_rt_object_libraries(RTXray - ARCHS ${XRAY_SUPPORTED_ARCH} - SOURCES ${XRAY_SOURCES} CFLAGS ${XRAY_CFLAGS} - DEFS ${XRAY_COMMON_DEFINITIONS}) + ARCHS ${XRAY_SUPPORTED_ARCH} + SOURCES ${XRAY_SOURCES} CFLAGS ${XRAY_CFLAGS} + DEFS ${XRAY_COMMON_DEFINITIONS}) add_custom_target(xray) set(XRAY_COMMON_RUNTIME_OBJECT_LIBS diff --git a/compiler-rt/lib/xray/xray_flags.inc b/compiler-rt/lib/xray/xray_flags.inc index bc2f45e9b10..0f6ced8ead0 100644 --- a/compiler-rt/lib/xray/xray_flags.inc +++ b/compiler-rt/lib/xray/xray_flags.inc @@ -16,3 +16,7 @@ XRAY_FLAG(bool, patch_premain, true, "Whether to patch instrumentation points before main.") +XRAY_FLAG(bool, xray_naive_log, true, + "Whether to install the naive log implementation.") +XRAY_FLAG(const char *, xray_logfile_base, "xray-log.", + "Filename base for the xray logfile.") diff --git a/compiler-rt/lib/xray/xray_inmemory_log.cc b/compiler-rt/lib/xray/xray_inmemory_log.cc new file mode 100644 index 00000000000..073ebe7311d --- /dev/null +++ b/compiler-rt/lib/xray/xray_inmemory_log.cc @@ -0,0 +1,227 @@ +//===-- xray_inmemory_log.cc ------------------------------------*- C++ -*-===// +// +// The LLVM Compiler Infrastructure +// +// This file is distributed under the University of Illinois Open Source +// License. See LICENSE.TXT for details. +// +//===----------------------------------------------------------------------===// +// +// This file is a part of XRay, a dynamic runtime instrumentation system. +// +// Implementation of a simple in-memory log of XRay events. This defines a +// logging function that's compatible with the XRay handler interface, and +// routines for exporting data to files. +// +//===----------------------------------------------------------------------===// + +#include <cassert> +#include <fcntl.h> +#include <mutex> +#include <sys/stat.h> +#include <sys/syscall.h> +#include <sys/types.h> +#include <thread> +#include <unistd.h> +#include <x86intrin.h> + +#include "sanitizer_common/sanitizer_libc.h" +#include "xray/xray_records.h" +#include "xray_flags.h" +#include "xray_interface_internal.h" + +// __xray_InMemoryRawLog will use a thread-local aligned buffer capped to a +// certain size (32kb by default) and use it as if it were a circular buffer for +// events. We store simple fixed-sized entries in the log for external analysis. + +extern "C" { +void __xray_InMemoryRawLog(int32_t FuncId, XRayEntryType Type); +} + +namespace __xray { + +std::mutex LogMutex; + +static void retryingWriteAll(int Fd, char *Begin, char *End) { + if (Begin == End) + return; + auto TotalBytes = std::distance(Begin, End); + while (auto Written = write(Fd, Begin, TotalBytes)) { + if (Written < 0) { + if (errno == EINTR) + continue; // Try again. + Report("Failed to write; errno = %d", errno); + return; + } + + // FIXME: Figure out whether/how to assert properly. + assert(static_cast<uint64_t>(Written) <= TotalBytes); + TotalBytes -= Written; + if (TotalBytes == 0) + break; + Begin += Written; + } +} + +static std::pair<ssize_t, bool> retryingReadSome(int Fd, char *Begin, + char *End) { + auto BytesToRead = std::distance(Begin, End); + ssize_t BytesRead; + ssize_t TotalBytesRead = 0; + while (BytesToRead && (BytesRead = read(Fd, Begin, BytesToRead))) { + if (BytesRead == -1) { + if (errno == EINTR) + continue; + Report("Read error; errno = %d", errno); + return std::make_pair(TotalBytesRead, false); + } + + TotalBytesRead += BytesRead; + BytesToRead -= BytesRead; + Begin += BytesRead; + } + return std::make_pair(TotalBytesRead, true); +} + +static bool readValueFromFile(const char *Filename, long long *Value) { + int Fd = open(Filename, O_RDONLY | O_CLOEXEC); + if (Fd == -1) + return false; + static constexpr size_t BufSize = 256; + char Line[BufSize] = {}; + ssize_t BytesRead; + bool Success; + std::tie(BytesRead, Success) = retryingReadSome(Fd, Line, Line + BufSize); + if (!Success) + return false; + close(Fd); + char *End = nullptr; + long long Tmp = internal_simple_strtoll(Line, &End, 10); + bool Result = false; + if (Line[0] != '\0' && (*End == '\n' || *End == '\0')) { + *Value = Tmp; + Result = true; + } + return Result; +} + +class ThreadExitFlusher { + int Fd; + XRayRecord *Start; + size_t &Offset; + +public: + explicit ThreadExitFlusher(int Fd, XRayRecord *Start, size_t &Offset) + : Fd(Fd), Start(Start), Offset(Offset) {} + + ~ThreadExitFlusher() { + std::lock_guard<std::mutex> L(LogMutex); + if (Fd > 0 && Start != nullptr) { + retryingWriteAll(Fd, reinterpret_cast<char *>(Start), + reinterpret_cast<char *>(Start + Offset)); + // Because this thread's exit could be the last one trying to write to the + // file and that we're not able to close out the file properly, we sync + // instead and hope that the pending writes are flushed as the thread + // exits. + fsync(Fd); + } + } +}; + +} // namespace __xray + +using namespace __xray; + +void PrintToStdErr(const char *Buffer) { fprintf(stderr, "%s", Buffer); } + +void __xray_InMemoryRawLog(int32_t FuncId, XRayEntryType Type) { + using Buffer = + std::aligned_storage<sizeof(XRayRecord), alignof(XRayRecord)>::type; + static constexpr size_t BuffLen = 1024; + thread_local static Buffer InMemoryBuffer[BuffLen] = {}; + thread_local static size_t Offset = 0; + static int Fd = [] { + // FIXME: Figure out how to make this less stderr-dependent. + SetPrintfAndReportCallback(PrintToStdErr); + // Open a temporary file once for the log. + static char TmpFilename[256] = {}; + static char TmpWildcardPattern[] = "XXXXXX"; + auto E = internal_strncat(TmpFilename, flags()->xray_logfile_base, + sizeof(TmpFilename) - 10); + if (static_cast<size_t>((E + 6) - TmpFilename) > + (sizeof(TmpFilename) - 1)) { + Report("XRay log file base too long: %s", flags()->xray_logfile_base); + return -1; + } + internal_strncat(TmpFilename, TmpWildcardPattern, + sizeof(TmpWildcardPattern) - 1); + int Fd = mkstemp(TmpFilename); + if (Fd == -1) { + Report("XRay: Failed opening temporary file '%s'; not logging events.", + TmpFilename); + return -1; + } + if (Verbosity()) + fprintf(stderr, "XRay: Log file in '%s'\n", TmpFilename); + + // Get the cycle frequency from SysFS on Linux. + long long CPUFrequency = -1; + if (readValueFromFile("/sys/devices/system/cpu/cpu0/tsc_freq_khz", + &CPUFrequency)) { + CPUFrequency *= 1000; + } else if (readValueFromFile( + "/sys/devices/system/cpu/cpu0/cpufreq/cpuinfo_max_freq", + &CPUFrequency)) { + CPUFrequency *= 1000; + } else { + Report("Unable to determine CPU frequency for TSC accounting."); + } + + // Since we're here, we get to write the header. We set it up so that the + // header will only be written once, at the start, and let the threads + // logging do writes which just append. + XRayFileHeader Header; + Header.Version = 1; + Header.Type = FileTypes::NAIVE_LOG; + Header.CycleFrequency = + CPUFrequency == -1 ? 0 : static_cast<uint64_t>(CPUFrequency); + + // FIXME: Actually check whether we have 'constant_tsc' and 'nonstop_tsc' + // before setting the values in the header. + Header.ConstantTSC = 1; + Header.NonstopTSC = 1; + retryingWriteAll(Fd, reinterpret_cast<char *>(&Header), + reinterpret_cast<char *>(&Header) + sizeof(Header)); + return Fd; + }(); + if (Fd == -1) + return; + thread_local __xray::ThreadExitFlusher Flusher( + Fd, reinterpret_cast<__xray::XRayRecord *>(InMemoryBuffer), Offset); + thread_local pid_t TId = syscall(SYS_gettid); + + // First we get the useful data, and stuff it into the already aligned buffer + // through a pointer offset. + auto &R = reinterpret_cast<__xray::XRayRecord *>(InMemoryBuffer)[Offset]; + unsigned CPU; + R.RecordType = RecordTypes::NORMAL; + R.TSC = __rdtscp(&CPU); + R.CPU = CPU; + R.TId = TId; + R.Type = Type; + R.FuncId = FuncId; + ++Offset; + if (Offset == BuffLen) { + std::lock_guard<std::mutex> L(LogMutex); + auto RecordBuffer = reinterpret_cast<__xray::XRayRecord *>(InMemoryBuffer); + retryingWriteAll(Fd, reinterpret_cast<char *>(RecordBuffer), + reinterpret_cast<char *>(RecordBuffer + Offset)); + Offset = 0; + } +} + +static auto Unused = [] { + if (flags()->xray_naive_log) + __xray_set_handler(__xray_InMemoryRawLog); + return true; +}(); diff --git a/compiler-rt/lib/xray/xray_trampoline_x86.S b/compiler-rt/lib/xray/xray_trampoline_x86_64.S index 858039624c0..858039624c0 100644 --- a/compiler-rt/lib/xray/xray_trampoline_x86.S +++ b/compiler-rt/lib/xray/xray_trampoline_x86_64.S diff --git a/compiler-rt/test/lit.common.cfg b/compiler-rt/test/lit.common.cfg index f19fde2f89e..8d4d0faccce 100644 --- a/compiler-rt/test/lit.common.cfg +++ b/compiler-rt/test/lit.common.cfg @@ -52,7 +52,8 @@ possibly_dangerous_env_vars = ['ASAN_OPTIONS', 'DFSAN_OPTIONS', 'LSAN_OPTIONS', 'LIBCLANG_LOGGING', 'LIBCLANG_BGPRIO_INDEX', 'LIBCLANG_BGPRIO_EDIT', 'LIBCLANG_NOTHREADS', 'LIBCLANG_RESOURCE_USAGE', - 'LIBCLANG_CODE_COMPLETION_LOGGING'] + 'LIBCLANG_CODE_COMPLETION_LOGGING', + 'XRAY_OPTIONS'] # Clang/Win32 may refer to %INCLUDE%. vsvarsall.bat sets it. if platform.system() != 'Windows': possibly_dangerous_env_vars.append('INCLUDE') diff --git a/compiler-rt/test/xray/TestCases/Linux/fixedsize-logging.cc b/compiler-rt/test/xray/TestCases/Linux/fixedsize-logging.cc new file mode 100644 index 00000000000..90e766876c5 --- /dev/null +++ b/compiler-rt/test/xray/TestCases/Linux/fixedsize-logging.cc @@ -0,0 +1,20 @@ +// Check to make sure that we have a log file with a fixed-size. + +// RUN: %clangxx_xray -std=c++11 %s -o %t +// RUN: XRAY_OPTIONS="verbosity=1 xray_logfile_base=fixedsize-logging-" %run %t 2>&1 | FileCheck %s +// +// After all that, clean up the output xray log. +// +// RUN: rm fixedsize-logging-* + +#include <cstdio> + +[[clang::xray_always_instrument]] void foo() { + printf("foo() is always instrumented!"); +} + +int main() { + // CHECK: XRay: Log file in 'fixedsize-logging-{{.*}}' + foo(); + // CHECK: foo() is always instrumented! +} diff --git a/compiler-rt/test/xray/TestCases/Linux/optional-inmemory-log.cc b/compiler-rt/test/xray/TestCases/Linux/optional-inmemory-log.cc new file mode 100644 index 00000000000..ef2c43f3be7 --- /dev/null +++ b/compiler-rt/test/xray/TestCases/Linux/optional-inmemory-log.cc @@ -0,0 +1,21 @@ +// Make sure that we don't get the inmemory logging implementation enabled when +// we turn it off via options. + +// RUN: %clangxx_xray -std=c++11 %s -o %t +// RUN: XRAY_OPTIONS="verbosity=1 xray_naive_log=false xray_logfile_base=optional-inmemory-log.xray-" %run %t 2>&1 | FileCheck %s +// +// Make sure we clean out the logs in case there was a bug. +// +// RUN: rm -f optional-inmemory-log.xray-* + +#include <cstdio> + +[[clang::xray_always_instrument]] void foo() { + printf("foo() is always instrumented!"); +} + +int main() { + // CHECK-NOT: XRay: Log file in 'optional-inmemory-log.xray-{{.*}}' + foo(); + // CHECK: foo() is always instrumented! +} |
