xray_records.h 0000644 00000007545 14751147110 0007435 0 ustar 00 //===-- xray_records.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 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
#include <cstdint>
namespace __xray {
enum FileTypes {
NAIVE_LOG = 0,
FDR_LOG = 1,
};
// FDR mode use of the union field in the XRayFileHeader.
struct alignas(16) FdrAdditionalHeaderData {
uint64_t ThreadBufferSize;
};
static_assert(sizeof(FdrAdditionalHeaderData) == 16,
"FdrAdditionalHeaderData != 16 bytes");
// 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;
union {
char FreeForm[16];
// The current civiltime timestamp, as retrieved from 'clock_gettime'. This
// allows readers of the file to determine when the file was created or
// written down.
struct timespec TS;
struct FdrAdditionalHeaderData FdrData;
};
} __attribute__((packed));
static_assert(sizeof(XRayFileHeader) == 32, "XRayFileHeader != 32 bytes");
enum RecordTypes {
NORMAL = 0,
ARG_PAYLOAD = 1,
};
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 = RecordTypes::NORMAL;
// The CPU where the thread is running. We assume number of CPUs <= 256.
uint8_t CPU = 0;
// The type of the event. One of the following:
// ENTER = 0
// EXIT = 1
// TAIL_EXIT = 2
// ENTER_ARG = 3
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;
// The ID of process that is currently running
uint32_t PId = 0;
// Use some bytes in the end of the record for buffers.
char Buffer[8] = {};
} __attribute__((packed));
static_assert(sizeof(XRayRecord) == 32, "XRayRecord != 32 bytes");
struct alignas(32) XRayArgPayload {
// We use the same 16 bits as a discriminant for the records in the log here
// too, and so that the first 4 bytes are packed properly.
uint16_t RecordType = RecordTypes::ARG_PAYLOAD;
// Add a few bytes to pad.
uint8_t Padding[2] = {};
// The function ID for the record.
int32_t FuncId = 0;
// The thread ID for the currently running thread.
uint32_t TId = 0;
// The ID of process that is currently running
uint32_t PId = 0;
// The argument payload.
uint64_t Arg = 0;
// The rest of this record ought to be left as padding.
uint8_t TailPadding[8] = {};
} __attribute__((packed));
static_assert(sizeof(XRayArgPayload) == 32, "XRayArgPayload != 32 bytes");
} // namespace __xray
#endif // XRAY_XRAY_RECORDS_H
xray_log_interface.h 0000644 00000037167 14751147110 0010600 0 ustar 00 //===-- xray_log_interface.h ----------------------------------------------===//
//
// 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 a part of XRay, a function call tracing system.
//
// APIs for installing a new logging implementation.
//
//===----------------------------------------------------------------------===//
///
/// XRay allows users to implement their own logging handlers and install them
/// to replace the default runtime-controllable implementation that comes with
/// compiler-rt/xray. The "flight data recorder" (FDR) mode implementation uses
/// this API to install itself in an XRay-enabled binary. See
/// compiler-rt/lib/xray_fdr_logging.{h,cc} for details of that implementation.
///
/// The high-level usage pattern for these APIs look like the following:
///
/// // We choose the mode which we'd like to install, and check whether this
/// // has succeeded. Each mode will have their own set of flags they will
/// // support, outside of the global XRay configuration options that are
/// // defined in the XRAY_OPTIONS environment variable.
/// auto select_status = __xray_log_select_mode("xray-fdr");
/// if (select_status != XRayLogRegisterStatus::XRAY_REGISTRATION_OK) {
/// // This failed, we should not proceed with attempting to initialise
/// // the currently selected mode.
/// return;
/// }
///
/// // Once that's done, we can now attempt to configure the implementation.
/// // To do this, we provide the string flags configuration for the mode.
/// auto config_status = __xray_log_init_mode(
/// "xray-fdr", "verbosity=1 some_flag=1 another_flag=2");
/// if (config_status != XRayLogInitStatus::XRAY_LOG_INITIALIZED) {
/// // deal with the error here, if there is one.
/// }
///
/// // When the log implementation has had the chance to initialize, we can
/// // now patch the instrumentation points. Note that we could have patched
/// // the instrumentation points first, but there's no strict ordering to
/// // these operations.
/// auto patch_status = __xray_patch();
/// if (patch_status != XRayPatchingStatus::SUCCESS) {
/// // deal with the error here, if it is an error.
/// }
///
/// // If we want to stop the implementation, we can then finalize it (before
/// // optionally flushing the log).
/// auto fin_status = __xray_log_finalize();
/// if (fin_status != XRayLogInitStatus::XRAY_LOG_FINALIZED) {
/// // deal with the error here, if it is an error.
/// }
///
/// // We can optionally wait before flushing the log to give other threads a
/// // chance to see that the implementation is already finalized. Also, at
/// // this point we can optionally unpatch the instrumentation points to
/// // reduce overheads at runtime.
/// auto unpatch_status = __xray_unpatch();
/// if (unpatch_status != XRayPatchingStatus::SUCCESS) {
/// // deal with the error here, if it is an error.
/// }
///
/// // If there are logs or data to be flushed somewhere, we can do so only
/// // after we've finalized the log. Some implementations may not actually
/// // have anything to log (it might keep the data in memory, or periodically
/// // be logging the data anyway).
/// auto flush_status = __xray_log_flushLog();
/// if (flush_status != XRayLogFlushStatus::XRAY_LOG_FLUSHED) {
/// // deal with the error here, if it is an error.
/// }
///
/// // Alternatively, we can go through the buffers ourselves without
/// // relying on the implementations' flushing semantics (if the
/// // implementation supports exporting this data directly).
/// auto MyBufferProcessor = +[](const char* mode, XRayBuffer buffer) {
/// // Check the "mode" to see if it's something we know how to handle...
/// // and/or do something with an XRayBuffer instance.
/// };
/// auto process_status = __xray_log_process_buffers(MyBufferProcessor);
/// if (process_status != XRayLogFlushStatus::XRAY_LOG_FLUSHED) {
/// // deal with the error here, if it is an error.
/// }
///
/// NOTE: Before calling __xray_patch() again, consider re-initializing the
/// implementation first. Some implementations might stay in an "off" state when
/// they are finalized, while some might be in an invalid/unknown state.
///
#ifndef XRAY_XRAY_LOG_INTERFACE_H
#define XRAY_XRAY_LOG_INTERFACE_H
#include "xray/xray_interface.h"
#include <stddef.h>
extern "C" {
/// This enum defines the valid states in which the logging implementation can
/// be at.
enum XRayLogInitStatus {
/// The default state is uninitialized, and in case there were errors in the
/// initialization, the implementation MUST return XRAY_LOG_UNINITIALIZED.
XRAY_LOG_UNINITIALIZED = 0,
/// Some implementations support multi-stage init (or asynchronous init), and
/// may return XRAY_LOG_INITIALIZING to signal callers of the API that
/// there's an ongoing initialization routine running. This allows
/// implementations to support concurrent threads attempting to initialize,
/// while only signalling success in one.
XRAY_LOG_INITIALIZING = 1,
/// When an implementation is done initializing, it MUST return
/// XRAY_LOG_INITIALIZED. When users call `__xray_patch()`, they are
/// guaranteed that the implementation installed with
/// `__xray_set_log_impl(...)` has been initialized.
XRAY_LOG_INITIALIZED = 2,
/// Some implementations might support multi-stage finalization (or
/// asynchronous finalization), and may return XRAY_LOG_FINALIZING to signal
/// callers of the API that there's an ongoing finalization routine running.
/// This allows implementations to support concurrent threads attempting to
/// finalize, while only signalling success/completion in one.
XRAY_LOG_FINALIZING = 3,
/// When an implementation is done finalizing, it MUST return
/// XRAY_LOG_FINALIZED. It is up to the implementation to determine what the
/// semantics of a finalized implementation is. Some implementations might
/// allow re-initialization once the log is finalized, while some might always
/// be on (and that finalization is a no-op).
XRAY_LOG_FINALIZED = 4,
};
/// This enum allows an implementation to signal log flushing operations via
/// `__xray_log_flushLog()`, and the state of flushing the log.
enum XRayLogFlushStatus {
XRAY_LOG_NOT_FLUSHING = 0,
XRAY_LOG_FLUSHING = 1,
XRAY_LOG_FLUSHED = 2,
};
/// This enum indicates the installation state of a logging implementation, when
/// associating a mode to a particular logging implementation through
/// `__xray_log_register_impl(...)` or through `__xray_log_select_mode(...`.
enum XRayLogRegisterStatus {
XRAY_REGISTRATION_OK = 0,
XRAY_DUPLICATE_MODE = 1,
XRAY_MODE_NOT_FOUND = 2,
XRAY_INCOMPLETE_IMPL = 3,
};
/// A valid XRay logging implementation MUST provide all of the function
/// pointers in XRayLogImpl when being installed through `__xray_set_log_impl`.
/// To be precise, ALL the functions pointers MUST NOT be nullptr.
struct XRayLogImpl {
/// The log initialization routine provided by the implementation, always
/// provided with the following parameters:
///
/// - buffer size (unused)
/// - maximum number of buffers (unused)
/// - a pointer to an argument struct that the implementation MUST handle
/// - the size of the argument struct
///
/// See XRayLogInitStatus for details on what the implementation MUST return
/// when called.
///
/// If the implementation needs to install handlers aside from the 0-argument
/// function call handler, it MUST do so in this initialization handler.
///
/// See xray_interface.h for available handler installation routines.
XRayLogInitStatus (*log_init)(size_t, size_t, void *, size_t);
/// The log finalization routine provided by the implementation.
///
/// See XRayLogInitStatus for details on what the implementation MUST return
/// when called.
XRayLogInitStatus (*log_finalize)();
/// The 0-argument function call handler. XRay logging implementations MUST
/// always have a handler for function entry and exit events. In case the
/// implementation wants to support arg1 (or other future extensions to XRay
/// logging) those MUST be installed by the installed 'log_init' handler.
///
/// Because we didn't want to change the ABI of this struct, the arg1 handler
/// may be silently overwritten during initialization as well.
void (*handle_arg0)(int32_t, XRayEntryType);
/// The log implementation provided routine for when __xray_log_flushLog() is
/// called.
///
/// See XRayLogFlushStatus for details on what the implementation MUST return
/// when called.
XRayLogFlushStatus (*flush_log)();
};
/// DEPRECATED: Use the mode registration workflow instead with
/// __xray_log_register_mode(...) and __xray_log_select_mode(...). See the
/// documentation for those function.
///
/// This function installs a new logging implementation that XRay will use. In
/// case there are any nullptr members in Impl, XRay will *uninstall any
/// existing implementations*. It does NOT patch the instrumentation points.
///
/// NOTE: This function does NOT attempt to finalize the currently installed
/// implementation. Use with caution.
///
/// It is guaranteed safe to call this function in the following states:
///
/// - When the implementation is UNINITIALIZED.
/// - When the implementation is FINALIZED.
/// - When there is no current implementation installed.
///
/// It is logging implementation defined what happens when this function is
/// called while in any other states.
void __xray_set_log_impl(XRayLogImpl Impl);
/// This function registers a logging implementation against a "mode"
/// identifier. This allows multiple modes to be registered, and chosen at
/// runtime using the same mode identifier through
/// `__xray_log_select_mode(...)`.
///
/// We treat the Mode identifier as a null-terminated byte string, as the
/// identifier used when retrieving the log impl.
///
/// Returns:
/// - XRAY_REGISTRATION_OK on success.
/// - XRAY_DUPLICATE_MODE when an implementation is already associated with
/// the provided Mode; does not update the already-registered
/// implementation.
XRayLogRegisterStatus __xray_log_register_mode(const char *Mode,
XRayLogImpl Impl);
/// This function selects the implementation associated with Mode that has been
/// registered through __xray_log_register_mode(...) and installs that
/// implementation (as if through calling __xray_set_log_impl(...)). The same
/// caveats apply to __xray_log_select_mode(...) as with
/// __xray_log_set_log_impl(...).
///
/// Returns:
/// - XRAY_REGISTRATION_OK on success.
/// - XRAY_MODE_NOT_FOUND if there is no implementation associated with Mode;
/// does not update the currently installed implementation.
XRayLogRegisterStatus __xray_log_select_mode(const char *Mode);
/// Returns an identifier for the currently selected XRay mode chosen through
/// the __xray_log_select_mode(...) function call. Returns nullptr if there is
/// no currently installed mode.
const char *__xray_log_get_current_mode();
/// This function removes the currently installed implementation. It will also
/// uninstall any handlers that have been previously installed. It does NOT
/// unpatch the instrumentation points.
///
/// NOTE: This function does NOT attempt to finalize the currently installed
/// implementation. Use with caution.
///
/// It is guaranteed safe to call this function in the following states:
///
/// - When the implementation is UNINITIALIZED.
/// - When the implementation is FINALIZED.
/// - When there is no current implementation installed.
///
/// It is logging implementation defined what happens when this function is
/// called while in any other states.
void __xray_remove_log_impl();
/// DEPRECATED: Use __xray_log_init_mode() instead, and provide all the options
/// in string form.
/// Invokes the installed implementation initialization routine. See
/// XRayLogInitStatus for what the return values mean.
XRayLogInitStatus __xray_log_init(size_t BufferSize, size_t MaxBuffers,
void *Args, size_t ArgsSize);
/// Invokes the installed initialization routine, which *must* support the
/// string based form.
///
/// NOTE: When this API is used, we still invoke the installed initialization
/// routine, but we will call it with the following convention to signal that we
/// are using the string form:
///
/// - BufferSize = 0
/// - MaxBuffers = 0
/// - ArgsSize = 0
/// - Args will be the pointer to the character buffer representing the
/// configuration.
///
/// FIXME: Updating the XRayLogImpl struct is an ABI breaking change. When we
/// are ready to make a breaking change, we should clean this up appropriately.
XRayLogInitStatus __xray_log_init_mode(const char *Mode, const char *Config);
/// Like __xray_log_init_mode(...) this version allows for providing
/// configurations that might have non-null-terminated strings. This will
/// operate similarly to __xray_log_init_mode, with the exception that
/// |ArgsSize| will be what |ConfigSize| is.
XRayLogInitStatus __xray_log_init_mode_bin(const char *Mode, const char *Config,
size_t ConfigSize);
/// Invokes the installed implementation finalization routine. See
/// XRayLogInitStatus for what the return values mean.
XRayLogInitStatus __xray_log_finalize();
/// Invokes the install implementation log flushing routine. See
/// XRayLogFlushStatus for what the return values mean.
XRayLogFlushStatus __xray_log_flushLog();
/// An XRayBuffer represents a section of memory which can be treated by log
/// processing functions as bytes stored in the logging implementation's
/// buffers.
struct XRayBuffer {
const void *Data;
size_t Size;
};
/// Registers an iterator function which takes an XRayBuffer argument, then
/// returns another XRayBuffer function representing the next buffer. When the
/// Iterator function returns an empty XRayBuffer (Data = nullptr, Size = 0),
/// this signifies the end of the buffers.
///
/// The first invocation of this Iterator function will always take an empty
/// XRayBuffer (Data = nullptr, Size = 0).
void __xray_log_set_buffer_iterator(XRayBuffer (*Iterator)(XRayBuffer));
/// Removes the currently registered buffer iterator function.
void __xray_log_remove_buffer_iterator();
/// Invokes the provided handler to process data maintained by the logging
/// handler. This API will be provided raw access to the data available in
/// memory from the logging implementation. The callback function must:
///
/// 1) Not modify the data, to avoid running into undefined behaviour.
///
/// 2) Either know the data layout, or treat the data as raw bytes for later
/// interpretation.
///
/// This API is best used in place of the `__xray_log_flushLog()` implementation
/// above to enable the caller to provide an alternative means of extracting the
/// data from the XRay implementation.
///
/// Implementations MUST then provide:
///
/// 1) A function that will return an XRayBuffer. Functions that return an
/// "empty" XRayBuffer signifies that there are no more buffers to be
/// processed. This function should be registered through the
/// `__xray_log_set_buffer_iterator(...)` function.
///
/// 2) Its own means of converting data it holds in memory into an XRayBuffer
/// structure.
///
/// See XRayLogFlushStatus for what the return values mean.
///
XRayLogFlushStatus __xray_log_process_buffers(void (*Processor)(const char *,
XRayBuffer));
} // extern "C"
#endif // XRAY_XRAY_LOG_INTERFACE_H
xray_interface.h 0000644 00000012151 14751147110 0007721 0 ustar 00 //===- xray_interface.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 a part of XRay, a dynamic runtime instrumentation system.
//
// APIs for controlling XRay functionality explicitly.
//===----------------------------------------------------------------------===//
#ifndef XRAY_XRAY_INTERFACE_H
#define XRAY_XRAY_INTERFACE_H
#include <cstddef>
#include <cstdint>
extern "C" {
/// Synchronize this with AsmPrinter::SledKind in LLVM.
enum XRayEntryType {
ENTRY = 0,
EXIT = 1,
TAIL = 2,
LOG_ARGS_ENTRY = 3,
CUSTOM_EVENT = 4,
TYPED_EVENT = 5,
};
/// Provide a function to invoke for when instrumentation points are hit. This
/// is a user-visible control surface that overrides the default implementation.
/// The function provided should take the following arguments:
///
/// - function id: an identifier that indicates the id of a function; this id
/// is generated by xray; the mapping between the function id
/// and the actual function pointer is available through
/// __xray_table.
/// - entry type: identifies what kind of instrumentation point was
/// encountered (function entry, function exit, etc.). See the
/// enum XRayEntryType for more details.
///
/// The user handler must handle correctly spurious calls after this handler is
/// removed or replaced with another handler, because it would be too costly for
/// XRay runtime to avoid spurious calls.
/// To prevent circular calling, the handler function itself and all its
/// direct&indirect callees must not be instrumented with XRay, which can be
/// achieved by marking them all with: __attribute__((xray_never_instrument))
///
/// Returns 1 on success, 0 on error.
extern int __xray_set_handler(void (*entry)(int32_t, XRayEntryType));
/// This removes whatever the currently provided handler is. Returns 1 on
/// success, 0 on error.
extern int __xray_remove_handler();
/// Use XRay to log the first argument of each (instrumented) function call.
/// When this function exits, all threads will have observed the effect and
/// start logging their subsequent affected function calls (if patched).
///
/// Returns 1 on success, 0 on error.
extern int __xray_set_handler_arg1(void (*entry)(int32_t, XRayEntryType,
uint64_t));
/// Disables the XRay handler used to log first arguments of function calls.
/// Returns 1 on success, 0 on error.
extern int __xray_remove_handler_arg1();
/// Provide a function to invoke when XRay encounters a custom event.
extern int __xray_set_customevent_handler(void (*entry)(void *, std::size_t));
/// This removes whatever the currently provided custom event handler is.
/// Returns 1 on success, 0 on error.
extern int __xray_remove_customevent_handler();
/// Set a handler for xray typed event logging. The first parameter is a type
/// identifier, the second is a payload, and the third is the payload size.
extern int __xray_set_typedevent_handler(void (*entry)(uint16_t, const void *,
std::size_t));
/// Removes the currently set typed event handler.
/// Returns 1 on success, 0 on error.
extern int __xray_remove_typedevent_handler();
extern uint16_t __xray_register_event_type(const char *event_type);
enum XRayPatchingStatus {
NOT_INITIALIZED = 0,
SUCCESS = 1,
ONGOING = 2,
FAILED = 3,
};
/// This tells XRay to patch the instrumentation points. See XRayPatchingStatus
/// for possible result values.
extern XRayPatchingStatus __xray_patch();
/// Reverses the effect of __xray_patch(). See XRayPatchingStatus for possible
/// result values.
extern XRayPatchingStatus __xray_unpatch();
/// This patches a specific function id. See XRayPatchingStatus for possible
/// result values.
extern XRayPatchingStatus __xray_patch_function(int32_t FuncId);
/// This unpatches a specific function id. See XRayPatchingStatus for possible
/// result values.
extern XRayPatchingStatus __xray_unpatch_function(int32_t FuncId);
/// This function returns the address of the function provided a valid function
/// id. We return 0 if we encounter any error, even if 0 may be a valid function
/// address.
extern uintptr_t __xray_function_address(int32_t FuncId);
/// This function returns the maximum valid function id. Returns 0 if we
/// encounter errors (when there are no instrumented functions, etc.).
extern size_t __xray_max_function_id();
/// Initialize the required XRay data structures. This is useful in cases where
/// users want to control precisely when the XRay instrumentation data
/// structures are initialized, for example when the XRay library is built with
/// the XRAY_NO_PREINIT preprocessor definition.
///
/// Calling __xray_init() more than once is safe across multiple threads.
extern void __xray_init();
} // end extern "C"
#endif // XRAY_XRAY_INTERFACE_H