support for toggling EnableFlags after the singleton kernel session has started

This commit is contained in:
Marcos Slomp
2025-12-16 13:34:50 -08:00
parent eeacbac8bc
commit dacb3dbae6
2 changed files with 78 additions and 36 deletions

View File

@@ -191,33 +191,21 @@ bool SysTraceStart( int64_t& samplingPeriod )
if ( !etw::CheckAdminPrivilege() )
return false;
ULONGLONG EnableFlags = 0;
#ifndef TRACY_NO_CONTEXT_SWITCH
EnableFlags |= EVENT_TRACE_FLAG_CSWITCH;
EnableFlags |= EVENT_TRACE_FLAG_DISPATCHER;
EnableFlags |= EVENT_TRACE_FLAG_THREAD;
#endif
#ifndef TRACY_NO_SAMPLING
DWORD access = etw::ElevatePrivilege( SE_SYSTEM_PROFILE_NAME );
if( access != ERROR_SUCCESS )
return access;
EnableFlags |= etw::IsOS64Bit() ? EVENT_TRACE_FLAG_PROFILE : 0;
#endif
session_kernel = etw::StartSingletonKernelLoggerSession( EnableFlags );
session_kernel = etw::StartSingletonKernelLoggerSession();
if ( session_kernel.handle == 0 )
return false;
#ifndef TRACY_NO_CONTEXT_SWITCH
if ( etw::EnableStackWalk( session_kernel, etw::ThreadGuid, etw::CSwitch::Opcode ) != ERROR_SUCCESS )
if ( etw::EnableProcessAndThreadMonitoring( session_kernel ) != ERROR_SUCCESS )
return etw::StopSession( session_kernel ), false;
if ( etw::EnableContextSwitchMonitoring( session_kernel ) != ERROR_SUCCESS )
return etw::StopSession( session_kernel ), false;
#endif
#ifndef TRACY_NO_SAMPLING
if ( etw::EnableStackWalk( session_kernel, etw::PerfInfoGuid, etw::SampledProfile::Opcode ) != ERROR_SUCCESS )
return etw::StopSession( session_kernel ), false;
int microseconds = GetSamplingInterval() / 10;
if ( etw::SetCPUProfilingInterval( microseconds ) != ERROR_SUCCESS )
if ( etw::EnableCPUProfiling( session_kernel, microseconds ) != ERROR_SUCCESS )
return etw::StopSession( session_kernel ), false;
samplingPeriod = GetSamplingPeriod();
#endif

View File

@@ -317,7 +317,7 @@ static ULONG EnableStackWalk( Session& session, GUID EventGuid, UCHAR Opcode )
static ULONG SetCPUProfilingInterval(int microseconds)
{
if( !IsOS64Bit() )
return 0 /* ERROR_SUCCESS */; // TODO: return error instead?
return 0 /* ERROR_SUCCESS */; // TODO: fabricate SetLastError(ERROR_NOT_SUPPORTED) instead?
TRACE_PROFILE_INTERVAL interval = {};
interval.Source = 0; // 0: ProfileTime (from enum KPROFILE_SOURCE in wdm.h)
interval.Interval = ( microseconds * 1000 ) / 100; // in 100's of nanoseconds
@@ -326,7 +326,7 @@ static ULONG SetCPUProfilingInterval(int microseconds)
return ETWError( status );
}
static Session StartSingletonKernelLoggerSession( ULONGLONG EnableFlags )
static Session StartSingletonKernelLoggerSession( ULONGLONG EnableFlags = 0 )
{
Session session = {};
@@ -421,29 +421,70 @@ static Session StartUserSession( const CHAR* name )
return session;
}
bool IsSingletonKernelLoggerSession( Session& session )
{
bool check = true;
check &= ( session.handle == 0xFFFF );
check &= ( strncmp( session.name, KERNEL_LOGGER_NAMEA, sizeof( session.name ) ) == 0 );
return check;
}
static ULONG UpdateSessionEnableFlags( Session& session, ULONGLONG EnableFlags )
{
// Use a copy of the session properties, because ControlTrace(UPDATE) will modify
// LogFileNameOffset and "pad" the rest with zeros, overwriting the session.handle!
Session temp = session;
temp.properties.EnableFlags = EnableFlags;
ULONG status = ControlTraceA( temp.handle, temp.name, &temp.properties, EVENT_TRACE_CONTROL_UPDATE );
if (status != ERROR_SUCCESS)
return ETWError(status);
session.properties.EnableFlags = EnableFlags;
return status;
}
static ULONG EnableProcessAndThreadMonitoring( Session& session )
{
if ( IsSingletonKernelLoggerSession(session) )
{
ULONGLONG EnableFlags = session.properties.EnableFlags;
EnableFlags |= EVENT_TRACE_FLAG_THREAD;
ULONG status = UpdateSessionEnableFlags( session, EnableFlags );
return status;
}
ULONGLONG MatchAnyKeyword = SYSTEM_PROCESS_KW_THREAD; // ThreadStart and ThreadDCStart events
ULONG status = EnableProvider( session, SystemProcessProviderGuid,
EVENT_CONTROL_CODE_ENABLE_PROVIDER, TRACE_LEVEL_INFORMATION, MatchAnyKeyword );
if( status != ERROR_SUCCESS )
return status;
return status;
}
static ULONG EnableCPUProfiling( Session& session, int microseconds = 125 /* 8KHz = 125us */ )
{
if ( !IsOS64Bit() )
return 0 /* ERROR_SUCCESS */; // TODO: fabricate SetLastError(ERROR_NOT_SUPPORTED) instead?
// CPU Profiling requires special privileges on top of admin privileges
DWORD access = ElevatePrivilege( SE_SYSTEM_PROFILE_NAME );
if( access != ERROR_SUCCESS )
return access;
CheckProviderSessions( SystemProfileProviderGuid, 0 );
ULONG status = EnableProvider( session, SystemProfileProviderGuid );
if( status != ERROR_SUCCESS )
return status;
if ( IsSingletonKernelLoggerSession( session ) )
{
ULONGLONG EnableFlags = session.properties.EnableFlags;
EnableFlags |= EVENT_TRACE_FLAG_PROFILE;
ULONG status = UpdateSessionEnableFlags( session, EnableFlags );
if ( status != ERROR_SUCCESS )
return status;
}
else
{
CheckProviderSessions( SystemProfileProviderGuid, 0 );
ULONG status = EnableProvider( session, SystemProfileProviderGuid );
if( status != ERROR_SUCCESS )
return status;
}
status = SetCPUProfilingInterval(microseconds);
ULONG status = SetCPUProfilingInterval(microseconds);
if( status != ERROR_SUCCESS )
return status;
@@ -453,15 +494,28 @@ static ULONG EnableCPUProfiling( Session& session, int microseconds = 125 /* 8KH
static ULONG EnableContextSwitchMonitoring( Session& session )
{
ULONGLONG MatchAnyKeyword = 0;
MatchAnyKeyword |= SYSTEM_SCHEDULER_KW_CONTEXT_SWITCH; // CSwitch events
MatchAnyKeyword |= SYSTEM_SCHEDULER_KW_DISPATCHER; // ReadyThread events
CheckProviderSessions( SystemSchedulerProviderGuid, MatchAnyKeyword );
ULONG status = EnableProvider( session, SystemSchedulerProviderGuid,
EVENT_CONTROL_CODE_ENABLE_PROVIDER, TRACE_LEVEL_INFORMATION, MatchAnyKeyword );
if( status != ERROR_SUCCESS )
return status;
status = EnableStackWalk( session, ThreadGuid, CSwitch::Opcode );
if ( IsSingletonKernelLoggerSession( session ) )
{
ULONGLONG EnableFlags = session.properties.EnableFlags;
EnableFlags |= EVENT_TRACE_FLAG_CSWITCH;
EnableFlags |= EVENT_TRACE_FLAG_DISPATCHER;
ULONG status = UpdateSessionEnableFlags( session, EnableFlags );
if ( status != ERROR_SUCCESS )
return status;
}
else
{
ULONGLONG MatchAnyKeyword = 0;
MatchAnyKeyword |= SYSTEM_SCHEDULER_KW_CONTEXT_SWITCH; // CSwitch events
MatchAnyKeyword |= SYSTEM_SCHEDULER_KW_DISPATCHER; // ReadyThread events
CheckProviderSessions( SystemSchedulerProviderGuid, MatchAnyKeyword );
ULONG status = EnableProvider( session, SystemSchedulerProviderGuid,
EVENT_CONTROL_CODE_ENABLE_PROVIDER, TRACE_LEVEL_INFORMATION, MatchAnyKeyword );
if( status != ERROR_SUCCESS )
return status;
}
ULONG status = EnableStackWalk( session, ThreadGuid, CSwitch::Opcode );
return status;
}