i'm calling the Event Tracing for Windows StartTrace
function:
StartTrace(sessionHandle, KERNEL_LOGGER_NAME, sessionProperties);
It is failing with error code 87 (ERROR_INVALID_PARAMETER
). The MSDN gives some common causes for this error:
- Properties is NULL.
- SessionHandle is NULL.
- The LogFileNameOffset member of Properties is not valid.
- The LoggerNameOffset member of Properties is not valid.
- The LogFileMode member of Properties specifies a combination of flags that is not valid.
- The Wnode.Guid member is SystemTraceControlGuid, but the SessionName parameter is not KERNEL_LOGGER_NAME.
The code i'm calling is:
procedure StartKernelLogging;
var
sessionProperties: PEVENT_TRACE_PROPERTIES;
bufferSize: Int64;
loggerName: AnsiString;
logFilePath: AnsiString;
th: TRACEHANDLE;
hr: Cardinal;
begin
{
Allocate memory for the session properties. The memory must
be large enough to include the log file name and session name,
which get appended to the end of the session properties structure.
}
loggerName := KERNEL_LOGGER_NAME;
logFilePath := 'C:\Users\Ian\foo.etl';
bufferSize := sizeof(EVENT_TRACE_PROPERTIES)
+ Length(loggerName)+1
+ Length(logFilePath)+1;
sessionProperties := AllocMem(bufferSize);
ZeroMemory(sessionProperties, bufferSize);
sessionProperties.Wnode.BufferSize := bufferSize;
sessionProperties.Wnode.Flags := WNODE_FLAG_TRACED_GUID;
sessionProperties.Wnode.ClientContext := 1; //QPC clock resolution
sessionProperties.Wnode.Guid := SystemTraceControlGuid;
sessionProperties.EnableFlags := EVENT_TRACE_FLAG_NETWORK_TCPIP;
sessionProperties.LogFileMode := EVENT_TRACE_FILE_MODE_CIRCULAR;
sessionProperties.MaximumFileSize := 5; // 5 MB
sessionProperties.LoggerNameOffset := sizeof(EVENT_TRACE_PROPERTIES);
sessionProperties.LogFileNameOffset := sizeof(EVENT_TRACE_PROPERTIES) + Length(loggerName)+1;
//Copy LoggerName to the offset address
MoveMemory(Pointer(Cardinal(sessionProperties)+Cardinal(sessionProperties.LoggerNameOffset)), PAnsiChar(loggerName), Length(loggerName)+1);
//Copy LogFilePath to the offset address
MoveMemory(Pointer(Cardinal(sessionProperties)+Cardinal(sessionProperties.LogFileNameOffset)), PAnsiChar(logFilePath), Length(logFilePath)+1);
th := 0;
hr := EventTrace.StartTrace({var}th, PChar(loggerName), sessionProperties);
if (hr <> ERROR_SUCCESS) then
begin
raise EWin32Error.Create(SysErrorMessage(hr));
end;
end;
The language agnostic version of my call:
ADVAPI32.StartTraceA(
TraceHandle: 0x18F56C
InstanceName: 0x44E840
Properties: 0x243BD8);
where TraceHandle
points to a a 64-bit integer:
0018F56C: 00 00 00 00 00 00 00 00
and InstanceName
is a pointer to a null-terminated ansi string:
0044E840: 4E 54 20 4B 65 72 6E 65 NT Kerne
0044E848: 6C 20 4C 6F 67 67 65 72 l Logger
0044E850: 00
and Properties
is a pointer to an EVENT_TRACE_PROPERTIES
structure, which i'll refrain from reproducing a complete hex dump
002A3BD8: 0000009A (154 bytes)
The important values are the two offsets:
properties.LoggerNameOffset = 116 (i.e. $243BB8 + 116 = $243C4C)
properties.LogFileNameOffset = 133 (i.e. $243BD8 + 133 = $243C5D)
which also contain the valid null-terminated ansi strings they are supposed to:
"NT Kernel Logger":
$243C4C 4B20544E 656E7265 NT Kerne
$243C54 6F4C206C 72656767 l Logger
$243C5C xxxxxx00 .
"C:\Users\Ian\foo.etl":
$243C5C 5C3A43xx 72657355 .C:\User
$243C64 61495C73 6F665C6E s\Ian\fo
$243C6C 74652E6F xxxx006C o.etc.
Why are my parameters incorrect?
Bonus Reading
- wtf wants to know how to register for realtime monitoring of kernel events
- MSDN sample code (which this is a translation of) of how to connect to the kernel logging session
Update:
The session parameters:
9A 00 00 00 00 00 00 00
00 00 00 00 00 00 00 00
00 00 00 00 00 00 00 00
AD 4A 81 9E 04 32 D2 11
9A 82 00 60 08 A8 69 39
01 00 00 00 00 00 02 00
00 00 00 00 00 00 00 00
00 00 00 00 05 00 00 00
02 00 00 00 00 00 00 00
00 00 01 00 00 00 00 00
00 00 00 00 00 00 00 00
00 00 00 00 00 00 00 00
00 00 00 00 00 00 00 00
00 00 00 00 85 00 00 00
74 00 00 00
Which breaks down to:
000| Wnode.BufferSize: 9A 00 00 00 (154)
004| Wnode.ProviderID: 00 00 00 00
008| Wnode.Version: 00 00 00 00
012| Wnode.Linkage: 00 00 00 00
016| Wnode.Timestamp: 00 00 00 00 00 00 00 00
024| Wnode.Guid: AD 4A 81 9E 04 32 D2 11 9A 82 00 60 08 A8 69 39 (SystemTraceControlGuid)
040| Wnode.ClientContext: 01 00 00 00 (1)
044| Wnode.Flags: 00 00 02 00 (WNODE_FLAG_TRACED_GUID)
048| BufferSize: 00 00 00 00
052| MinimumBuffers: 00 00 00 00
056| MaximumBuffers: 00 00 00 00
060| MaximumFileSize: 05 00 00 00 (5 MB)
064| LogFileMode: 02 00 00 00 (EVENT_TRACE_FILE_MODE_CIRCULAR)
068| FlushTimer: 00 00 00 00
072| EnableFlags: 00 00 01 00 (EVENT_TRACE_FLAG_NETWORK_TCPIP)
076| AgeLimit: 00 00 00 00
080| NumberOfBuffers: 00 00 00 00
084| FreeBuffers: 00 00 00 00
088| EventsLost: 00 00 00 00
092| BuffersWritten: 00 00 00 00
096| LogBuffersLost: 00 00 00 00
100| RealTimeBuffersLost: 00 00 00 00
104| LoggerThreadId: 00 00 00 00
108| LogFileNameOffset: 85 00 00 00 (133)
112| LoggerNameOffset: 74 00 00 00 (116)
116| NT Kernel Logger\0
133| C:\Users\Ian\foo.etl\0
154|
If there's an alignment problem i won't be able to discover it alone.
The structure:
EVENT_TRACE_PROPERTIES = packed record
Wnode : WNODE_HEADER;
// data provided by caller
BufferSize : Longword; // buffer size for logging (kbytes)
MinimumBuffers : Longword; // minimum to preallocate
MaximumBuffers : Longword; // maximum buffers allowed
MaximumFileSize : Longword; // maximum logfile size (in MBytes)
LogFileMode : Longword; // sequential, circular
FlushTimer : Longword; // buffer flush timer, in seconds
EnableFlags :Longword; // trace enable flags
AgeLimit : Longint; // age decay time, in minutes
// data returned to caller
NumberOfBuffers : Longword; // no of buffers in use
FreeBuffers : Longword; // no of buffers free
EventsLost : Longword; // event records lost
BuffersWritten : Longword; // no of buffers written to file
LogBuffersLost : Longword; // no of logfile write failures
RealTimeBuffersLost : Longword; // no of rt delivery failures
LoggerThreadId : HANDLE; // thread id of Logger
LogFileNameOffset : Longword; // Offset to LogFileName
LoggerNameOffset : Longword; // Offset to LoggerName
end;
along with:
WNODE_HEADER = packed record
BufferSize : Longword;
ProviderId : Longword;
Version : Longword;
Linkage : Longword;
TimeStamp : Int64;
Guid : TGUID;
ClientContext : Longword;
Flags : Longword;
end;