[compiler-rt] r314378 - [XRay] [compiler-rt] FDR logging arg1 handler
Martin Pelikan via llvm-commits
llvm-commits at lists.llvm.org
Wed Sep 27 22:29:59 PDT 2017
Author: pelikan
Date: Wed Sep 27 22:29:59 2017
New Revision: 314378
URL: http://llvm.org/viewvc/llvm-project?rev=314378&view=rev
Log:
[XRay] [compiler-rt] FDR logging arg1 handler
Summary:
Write out records about logged function call first arguments. D32840
implements the reading of this in llvm-xray.
Reviewers: dberris
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D32844
Modified:
compiler-rt/trunk/include/xray/xray_log_interface.h
compiler-rt/trunk/lib/xray/xray_fdr_log_records.h
compiler-rt/trunk/lib/xray/xray_fdr_logging.cc
compiler-rt/trunk/lib/xray/xray_fdr_logging.h
compiler-rt/trunk/lib/xray/xray_fdr_logging_impl.h
compiler-rt/trunk/lib/xray/xray_trampoline_x86_64.S
compiler-rt/trunk/test/xray/TestCases/Linux/arg1-logger.cc
compiler-rt/trunk/test/xray/TestCases/Linux/fdr-mode.cc
Modified: compiler-rt/trunk/include/xray/xray_log_interface.h
URL: http://llvm.org/viewvc/llvm-project/compiler-rt/trunk/include/xray/xray_log_interface.h?rev=314378&r1=314377&r2=314378&view=diff
==============================================================================
--- compiler-rt/trunk/include/xray/xray_log_interface.h (original)
+++ compiler-rt/trunk/include/xray/xray_log_interface.h Wed Sep 27 22:29:59 2017
@@ -159,6 +159,9 @@ struct XRayLogImpl {
/// 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
Modified: compiler-rt/trunk/lib/xray/xray_fdr_log_records.h
URL: http://llvm.org/viewvc/llvm-project/compiler-rt/trunk/lib/xray/xray_fdr_log_records.h?rev=314378&r1=314377&r2=314378&view=diff
==============================================================================
--- compiler-rt/trunk/lib/xray/xray_fdr_log_records.h (original)
+++ compiler-rt/trunk/lib/xray/xray_fdr_log_records.h Wed Sep 27 22:29:59 2017
@@ -30,6 +30,7 @@ struct alignas(16) MetadataRecord {
TSCWrap,
WalltimeMarker,
CustomEventMarker,
+ CallArgument,
};
// Use 7 bits to identify this record type.
/* RecordKinds */ uint8_t RecordKind : 7;
Modified: compiler-rt/trunk/lib/xray/xray_fdr_logging.cc
URL: http://llvm.org/viewvc/llvm-project/compiler-rt/trunk/lib/xray/xray_fdr_logging.cc?rev=314378&r1=314377&r2=314378&view=diff
==============================================================================
--- compiler-rt/trunk/lib/xray/xray_fdr_logging.cc (original)
+++ compiler-rt/trunk/lib/xray/xray_fdr_logging.cc Wed Sep 27 22:29:59 2017
@@ -196,9 +196,17 @@ getTimestamp() XRAY_NEVER_INSTRUMENT {
void fdrLoggingHandleArg0(int32_t FuncId,
XRayEntryType Entry) XRAY_NEVER_INSTRUMENT {
auto TSC_CPU = getTimestamp();
- __xray_fdr_internal::processFunctionHook(FuncId, Entry, std::get<0>(TSC_CPU),
- std::get<1>(TSC_CPU), clock_gettime,
- LoggingStatus, *BQ);
+ __xray_fdr_internal::processFunctionHook(
+ FuncId, Entry, std::get<0>(TSC_CPU), std::get<1>(TSC_CPU), 0,
+ clock_gettime, *BQ);
+}
+
+void fdrLoggingHandleArg1(int32_t FuncId, XRayEntryType Entry,
+ uint64_t Arg) XRAY_NEVER_INSTRUMENT {
+ auto TSC_CPU = getTimestamp();
+ __xray_fdr_internal::processFunctionHook(
+ FuncId, Entry, std::get<0>(TSC_CPU), std::get<1>(TSC_CPU), Arg,
+ clock_gettime, *BQ);
}
void fdrLoggingHandleCustomEvent(void *Event,
@@ -280,6 +288,9 @@ XRayLogInitStatus fdrLoggingInit(std::si
return XRayLogInitStatus::XRAY_LOG_UNINITIALIZED;
}
+ // Arg1 handler should go in first to avoid concurrent code accidentally
+ // falling back to arg0 when it should have ran arg1.
+ __xray_set_handler_arg1(fdrLoggingHandleArg1);
// Install the actual handleArg0 handler after initialising the buffers.
__xray_set_handler(fdrLoggingHandleArg0);
__xray_set_customevent_handler(fdrLoggingHandleCustomEvent);
Modified: compiler-rt/trunk/lib/xray/xray_fdr_logging.h
URL: http://llvm.org/viewvc/llvm-project/compiler-rt/trunk/lib/xray/xray_fdr_logging.h?rev=314378&r1=314377&r2=314378&view=diff
==============================================================================
--- compiler-rt/trunk/lib/xray/xray_fdr_logging.h (original)
+++ compiler-rt/trunk/lib/xray/xray_fdr_logging.h Wed Sep 27 22:29:59 2017
@@ -30,6 +30,7 @@ XRayLogInitStatus fdrLoggingInit(size_t
void *Options, size_t OptionsSize);
XRayLogInitStatus fdrLoggingFinalize();
void fdrLoggingHandleArg0(int32_t FuncId, XRayEntryType Entry);
+void fdrLoggingHandleArg1(int32_t FuncId, XRayEntryType Entry, uint64_t Arg1);
XRayLogFlushStatus fdrLoggingFlush();
XRayLogInitStatus fdrLoggingReset();
Modified: compiler-rt/trunk/lib/xray/xray_fdr_logging_impl.h
URL: http://llvm.org/viewvc/llvm-project/compiler-rt/trunk/lib/xray/xray_fdr_logging_impl.h?rev=314378&r1=314377&r2=314378&view=diff
==============================================================================
--- compiler-rt/trunk/lib/xray/xray_fdr_logging_impl.h (original)
+++ compiler-rt/trunk/lib/xray/xray_fdr_logging_impl.h Wed Sep 27 22:29:59 2017
@@ -91,19 +91,6 @@ static void writeEOBMetadata();
/// TSC Wrap records are written when a TSC delta encoding scheme overflows.
static void writeTSCWrapMetadata(uint64_t TSC);
-/// Here's where the meat of the processing happens. The writer captures
-/// function entry, exit and tail exit points with a time and will create
-/// TSCWrap, NewCPUId and Function records as necessary. The writer might
-/// walk backward through its buffer and erase trivial functions to avoid
-/// polluting the log and may use the buffer queue to obtain or release a
-/// buffer.
-static void processFunctionHook(int32_t FuncId, XRayEntryType Entry,
- uint64_t TSC, unsigned char CPU,
- int (*wall_clock_reader)(clockid_t,
- struct timespec *),
- __sanitizer::atomic_sint32_t &LoggingStatus,
- const std::shared_ptr<BufferQueue> &BQ);
-
// Group together thread-local-data in a struct, then hide it behind a function
// call so that it can be initialized on first use instead of as a global.
struct ThreadLocalData {
@@ -331,9 +318,22 @@ inline void writeTSCWrapMetadata(uint64_
writeTSCWrapMetadata(TSC, getThreadLocalData().RecordPtr);
}
-inline void writeFunctionRecord(int FuncId, uint32_t TSCDelta,
- XRayEntryType EntryType,
- char *&MemPtr) XRAY_NEVER_INSTRUMENT {
+// Call Argument metadata records store the arguments to a function in the
+// order of their appearance; holes are not supported by the buffer format.
+static inline void writeCallArgumentMetadata(uint64_t A) XRAY_NEVER_INSTRUMENT {
+ auto &TLD = getThreadLocalData();
+ MetadataRecord CallArg;
+ CallArg.Type = uint8_t(RecordType::Metadata);
+ CallArg.RecordKind = uint8_t(MetadataRecord::RecordKinds::CallArgument);
+
+ std::memcpy(CallArg.Data, &A, sizeof(A));
+ std::memcpy(TLD.RecordPtr, &CallArg, sizeof(MetadataRecord));
+ TLD.RecordPtr += sizeof(MetadataRecord);
+}
+
+static inline void writeFunctionRecord(int FuncId, uint32_t TSCDelta,
+ XRayEntryType EntryType,
+ char *&MemPtr) XRAY_NEVER_INSTRUMENT {
std::aligned_storage<sizeof(FunctionRecord), alignof(FunctionRecord)>::type
AlignedFuncRecordBuffer;
auto &FuncRecord =
@@ -560,6 +560,41 @@ inline bool isLogInitializedAndReady(
return true;
} // namespace __xray_fdr_internal
+// Compute the TSC difference between the time of measurement and the previous
+// event. There are a few interesting situations we need to account for:
+//
+// - The thread has migrated to a different CPU. If this is the case, then
+// we write down the following records:
+//
+// 1. A 'NewCPUId' Metadata record.
+// 2. A FunctionRecord with a 0 for the TSCDelta field.
+//
+// - The TSC delta is greater than the 32 bits we can store in a
+// FunctionRecord. In this case we write down the following records:
+//
+// 1. A 'TSCWrap' Metadata record.
+// 2. A FunctionRecord with a 0 for the TSCDelta field.
+//
+// - The TSC delta is representable within the 32 bits we can store in a
+// FunctionRecord. In this case we write down just a FunctionRecord with
+// the correct TSC delta.
+inline uint32_t writeCurrentCPUTSC(ThreadLocalData &TLD, uint64_t TSC, uint8_t CPU) {
+ if (CPU != TLD.CurrentCPU) {
+ // We've moved to a new CPU.
+ writeNewCPUIdMetadata(CPU, TSC);
+ return 0;
+ }
+ // If the delta is greater than the range for a uint32_t, then we write out
+ // the TSC wrap metadata entry with the full TSC, and the TSC for the
+ // function record be 0.
+ uint64_t Delta = TSC - TLD.LastTSC;
+ if (Delta <= std::numeric_limits<uint32_t>::max())
+ return Delta;
+
+ writeTSCWrapMetadata(TSC);
+ return 0;
+}
+
inline void endBufferIfFull() XRAY_NEVER_INSTRUMENT {
auto &TLD = getThreadLocalData();
auto BufferStart = static_cast<char *>(TLD.Buffer.Buffer);
@@ -573,10 +608,15 @@ inline void endBufferIfFull() XRAY_NEVER
thread_local volatile bool Running = false;
+/// Here's where the meat of the processing happens. The writer captures
+/// function entry, exit and tail exit points with a time and will create
+/// TSCWrap, NewCPUId and Function records as necessary. The writer might
+/// walk backward through its buffer and erase trivial functions to avoid
+/// polluting the log and may use the buffer queue to obtain or release a
+/// buffer.
inline void processFunctionHook(
int32_t FuncId, XRayEntryType Entry, uint64_t TSC, unsigned char CPU,
- int (*wall_clock_reader)(clockid_t, struct timespec *),
- __sanitizer::atomic_sint32_t &LoggingStatus,
+ uint64_t Arg1, int (*wall_clock_reader)(clockid_t, struct timespec *),
const std::shared_ptr<BufferQueue> &BQ) XRAY_NEVER_INSTRUMENT {
// Prevent signal handler recursion, so in case we're already in a log writing
// mode and the signal handler comes in (and is also instrumented) then we
@@ -609,10 +649,10 @@ inline void processFunctionHook(
// - The least number of bytes we will ever write is 8
// (sizeof(FunctionRecord)) only if the delta between the previous entry
// and this entry is within 32 bits.
- // - The most number of bytes we will ever write is 8 + 16 = 24. This is
- // computed by:
+ // - The most number of bytes we will ever write is 8 + 16 + 16 = 40.
+ // This is computed by:
//
- // sizeof(FunctionRecord) + sizeof(MetadataRecord)
+ // MaxSize = sizeof(FunctionRecord) + 2 * sizeof(MetadataRecord)
//
// These arise in the following cases:
//
@@ -626,6 +666,7 @@ inline void processFunctionHook(
// FunctionRecord.
// 3. When we learn about a new CPU ID, we need to write down a "new cpu
// id" MetadataRecord before writing out the actual FunctionRecord.
+ // 4. The second MetadataRecord is the optional function call argument.
//
// - An End-of-Buffer (EOB) MetadataRecord is 16 bytes.
//
@@ -634,53 +675,18 @@ inline void processFunctionHook(
// MetadataRecord. If we don't have enough space after writing as much as 24
// bytes in the end of the buffer, we need to write out the EOB, get a new
// Buffer, set it up properly before doing any further writing.
- //
- if (!prepareBuffer(wall_clock_reader, FunctionRecSize + MetadataRecSize)) {
+ size_t MaxSize = FunctionRecSize + 2 * MetadataRecSize;
+ if (!prepareBuffer(wall_clock_reader, MaxSize)) {
TLD.LocalBQ = nullptr;
return;
}
- // By this point, we are now ready to write at most 24 bytes (one metadata
- // record and one function record).
- assert((TLD.RecordPtr + (MetadataRecSize + FunctionRecSize)) -
- static_cast<char *>(TLD.Buffer.Buffer) >=
+ // By this point, we are now ready to write up to 40 bytes (explained above).
+ assert((TLD.RecordPtr + MaxSize) - static_cast<char *>(TLD.Buffer.Buffer) >=
static_cast<ptrdiff_t>(MetadataRecSize) &&
"Misconfigured BufferQueue provided; Buffer size not large enough.");
- // Here we compute the TSC Delta. There are a few interesting situations we
- // need to account for:
- //
- // - The thread has migrated to a different CPU. If this is the case, then
- // we write down the following records:
- //
- // 1. A 'NewCPUId' Metadata record.
- // 2. A FunctionRecord with a 0 for the TSCDelta field.
- //
- // - The TSC delta is greater than the 32 bits we can store in a
- // FunctionRecord. In this case we write down the following records:
- //
- // 1. A 'TSCWrap' Metadata record.
- // 2. A FunctionRecord with a 0 for the TSCDelta field.
- //
- // - The TSC delta is representable within the 32 bits we can store in a
- // FunctionRecord. In this case we write down just a FunctionRecord with
- // the correct TSC delta.
- //
- uint32_t RecordTSCDelta = 0;
- if (CPU != TLD.CurrentCPU) {
- // We've moved to a new CPU.
- writeNewCPUIdMetadata(CPU, TSC);
- } else {
- // If the delta is greater than the range for a uint32_t, then we write out
- // the TSC wrap metadata entry with the full TSC, and the TSC for the
- // function record be 0.
- auto Delta = TSC - TLD.LastTSC;
- if (Delta > (1ULL << 32) - 1)
- writeTSCWrapMetadata(TSC);
- else
- RecordTSCDelta = Delta;
- }
-
+ auto RecordTSCDelta = writeCurrentCPUTSC(TLD, TSC, CPU);
TLD.LastTSC = TSC;
TLD.CurrentCPU = CPU;
switch (Entry) {
@@ -711,6 +717,8 @@ inline void processFunctionHook(
}
writeFunctionRecord(FuncId, RecordTSCDelta, Entry, TLD.RecordPtr);
+ if (Entry == XRayEntryType::LOG_ARGS_ENTRY)
+ writeCallArgumentMetadata(Arg1);
// If we've exhausted the buffer by this time, we then release the buffer to
// make sure that other threads may start using this buffer.
Modified: compiler-rt/trunk/lib/xray/xray_trampoline_x86_64.S
URL: http://llvm.org/viewvc/llvm-project/compiler-rt/trunk/lib/xray/xray_trampoline_x86_64.S?rev=314378&r1=314377&r2=314378&view=diff
==============================================================================
--- compiler-rt/trunk/lib/xray/xray_trampoline_x86_64.S (original)
+++ compiler-rt/trunk/lib/xray/xray_trampoline_x86_64.S Wed Sep 27 22:29:59 2017
@@ -173,11 +173,11 @@ __xray_ArgLoggerEntry:
.Larg1entryLog:
- // First argument will become the third
+ // First argument will become the third
movq %rdi, %rdx
- // XRayEntryType::ENTRY into the second
- xorq %rsi, %rsi
+ // XRayEntryType::LOG_ARGS_ENTRY into the second
+ mov $0x3, %esi
// 32-bit function ID becomes the first
movl %r10d, %edi
Modified: compiler-rt/trunk/test/xray/TestCases/Linux/arg1-logger.cc
URL: http://llvm.org/viewvc/llvm-project/compiler-rt/trunk/test/xray/TestCases/Linux/arg1-logger.cc?rev=314378&r1=314377&r2=314378&view=diff
==============================================================================
--- compiler-rt/trunk/test/xray/TestCases/Linux/arg1-logger.cc (original)
+++ compiler-rt/trunk/test/xray/TestCases/Linux/arg1-logger.cc Wed Sep 27 22:29:59 2017
@@ -29,7 +29,7 @@ int main() {
__xray_set_handler_arg1(arg1logger);
foo(nullptr);
- // CHECK: Arg1: 0, XRayEntryType 0
+ // CHECK: Arg1: 0, XRayEntryType 3
__xray_remove_handler_arg1();
foo((void *) 0xBADC0DE);
@@ -37,7 +37,7 @@ int main() {
__xray_set_handler_arg1(arg1logger);
foo((void *) 0xDEADBEEFCAFE);
- // CHECK-NEXT: Arg1: deadbeefcafe, XRayEntryType 0
+ // CHECK-NEXT: Arg1: deadbeefcafe, XRayEntryType 3
foo((void *) -1);
- // CHECK-NEXT: Arg1: ffffffffffffffff, XRayEntryType 0
+ // CHECK-NEXT: Arg1: ffffffffffffffff, XRayEntryType 3
}
Modified: compiler-rt/trunk/test/xray/TestCases/Linux/fdr-mode.cc
URL: http://llvm.org/viewvc/llvm-project/compiler-rt/trunk/test/xray/TestCases/Linux/fdr-mode.cc?rev=314378&r1=314377&r2=314378&view=diff
==============================================================================
--- compiler-rt/trunk/test/xray/TestCases/Linux/fdr-mode.cc (original)
+++ compiler-rt/trunk/test/xray/TestCases/Linux/fdr-mode.cc Wed Sep 27 22:29:59 2017
@@ -30,6 +30,9 @@ thread_local uint64_t var = 0;
[[clang::xray_always_instrument]] void __attribute__((noinline)) fA() { fB(); }
+[[clang::xray_always_instrument, clang::xray_log_args(1)]]
+void __attribute__((noinline)) fArg(int) { }
+
int main(int argc, char *argv[]) {
using namespace __xray;
FDRLoggingOptions Options;
@@ -52,6 +55,7 @@ int main(int argc, char *argv[]) {
fC();
fB();
fA();
+ fArg(1);
});
other_thread.join();
std::cout << "Joined" << std::endl;
@@ -85,8 +89,15 @@ int main(int argc, char *argv[]) {
// TRACE-DAG: - { type: 0, func-id: [[FIDB]], function: {{.*fB.*}}, cpu: {{.*}}, thread: [[THREAD2:[0-9]+]], kind: function-enter, tsc: {{[0-9]+}} }
// TRACE: - { type: 0, func-id: [[FIDB]], function: {{.*fB.*}}, cpu: {{.*}}, thread: [[THREAD2]], kind: function-{{exit|tail-exit}}, tsc: {{[0-9]+}} }
+// TRACE-DAG: - { type: 0, func-id: [[FIDARG:[0-9]+]], function: 'fArg(int)', args: [ 1 ], cpu: {{.*}}, thread: [[THREAD2]], kind: function-enter-arg, tsc: {{[0-9]+}} }
+// TRACE-DAG: - { type: 0, func-id: [[FIDARG]], function: 'fArg(int)', cpu: {{.*}}, thread: [[THREAD2]], kind: function-exit, tsc: {{[0-9]+}} }
+
// Assert that when unwriting is enabled with a high threshold time, all the function records are erased. A CPU switch could erroneously fail this test, but
// is unlikely given the test program.
-// UNWRITE: header
+// Even with a high threshold, arg1 logging is never unwritten.
+// UNWRITE: header:
+// UNWRITE: records:
+// UNWRITE-NEXT: - { type: 0, func-id: [[FIDARG:[0-9]+]], function: 'fArg(int)', args: [ 1 ], cpu: {{.*}}, thread: [[THREAD2:[0-9]+]], kind: function-enter-arg, tsc: {{[0-9]+}} }
+// UNWRITE-NEXT: - { type: 0, func-id: [[FIDARG]], function: 'fArg(int)', cpu: {{.*}}, thread: [[THREAD2]], kind: function-exit, tsc: {{[0-9]+}} }
// UNWRITE-NOT: function-enter
// UNWRITE-NOT: function-{{exit|tail-exit}}
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