Difference between revisions of "Process Manager services"

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When the kernel signals a process handle, it uses svcResetSignal on the process handle and then it uses svcGetProcessInfo to read out the ProcessState.
 
When the kernel signals a process handle, it uses svcResetSignal on the process handle and then it uses svcGetProcessInfo to read out the ProcessState.
  
If the process moved state non-3 -> 3 it clears bit4 in process flags.
+
If the process moved state non-3 -> 3 it clears 4 in process flags.
  
 
If process flags has mask 8 set:
 
If process flags has mask 8 set:

Revision as of 01:04, 19 July 2017

Process Tracker thread

PM has a separate thread that is waiting for synchronization on process handles.

State changes

When the kernel signals a process handle, it uses svcResetSignal on the process handle and then it uses svcGetProcessInfo to read out the ProcessState.

If the process moved state non-3 -> 3 it clears 4 in process flags.

If process flags has mask 8 set:

  • If new state is 2, it clears 0x20 and sets 0x10 in process flags, and signals the ProcessEventWaiter handle.
  • If new state is 4, it clears 0x20 and sets 0x10 in process flags, and signals the ProcessEventWaiter handle.
  • If new state is 7, it sets 0x30 in process flags, and signals the ProcessEventWaiter handle.

If process flags has mask 1 set:

  • If new state is 6, it signals the ProcessEventWaiter handle.

If mask 1 is not set, it immediately does what is otherwise done by the #FinalizeDeadProcess command.

Process launch

This thread can also be triggered by the pm:shell #LaunchProcess cmd.

It uses ldr:pm GetProgramInfo with the supplied title-id.

If ((*(u8*) (info_output+2)) & 3) is == 1, it goes through the process list and errors if any has bit 0x40 set. Thus only one process can have bit 0x40 set at a time.

It calls ldr:pm RegisterTitle, then ldr:pm CreateProcess, then fsp-pr RegisterTitle, then sm:m RegisterTitle.

The second input argument for ldr:pm CreateProcess is (launch_flags >> 2) & 3.

If launch_flags has mask 1 set, it sets mask 1 in process flags.

If launch_flags flags has mask 0x10 set, it sets mask 8 in process flags.

If ((*(u8*) (info_output+2)) & 3) is == 1, it sets 0x40 in the process flags, and signals the event returned by #EnableDebug. svcStartProcess is not called in this case, it has to be done manually by the #StartProcess command.

Finally it does svcStartProcess on the process handle that was returned by ldr:pm CreateProcess, and sets process state to 2.

If the title-id matches the title-id given in #EnableDebugForTitleId, then svcStartProcess is not called. Instead process remains in suspended state, and has to be done manually by the #StartProcess command.

Thus at the point of launch, the pid is already registered in ldr, fs, sm, and pm.

pm:bm

Cmd Name
0 GetMaintenanceMode
1 EnableMaintenanceMode

pm:dmnt

Cmd Name
0 #GetZero
1 #GetProcessesWithFlag4
2 #StartProcess
3 GetProcessTitleIdByPid
4 #EnableDebugForTitleId
5 GetCrashingProcessPid
6 #EnableDebug

GetZero

Always returns u32 0.

GetProcessesWithFlag4

Returns an array of pids of all processes that have mask 4 set in process flags.

StartProcess

Takes a pid. Process state must be 0 or 1. Then it uses svcStartProcess(process_handle, u8, u8, u32) with args coming from ldr:pm GetProgramInfo.

After that, it sets process state to 2.

EnableDebugForTitleId

Takes a title-id of the program to debug. Sets this to a global field. Next time it gets launched it will be handled differently.

Returns an event handle that is signaled when the requested title is launched.

EnableDebug

Does *not* take a specific title-id as input.

Returns an event handle that is triggered for debug titles.

pm:info

Cmd Name
0 GetProcessTitleIdByPid

pm:shell

Cmd Name
0 #LaunchProcess
1 TerminateProcessByPid
2 TerminateProcessByTitleID
3 GetProcessEventWaiter
4 GetProcessEventType (0=CONTINUE, 1=CRASHING, 2,3,5)
5 #FinalizeDeadProcess
6 #ClearProcessNotificationFlag
7 #NotifyBootFinished
8 #GetCrashingProcessPid

LaunchProcess

Takes a title-id and launch_flags. See #Process launch.

FinalizeDeadProcess

Takes a pid as input. If the process with pid has the state "dead", it unregisters the pid in fsp:pr, sm:m, and ldr:pm.

Then it removes the process from PMs internal linked-list of active processes.

ClearProcessNotificationFlag

Takes a pid as input. Clears 0x10 from process flags.

NotifyBootFinished

Launches a process with hardcoded boot2 title-id.

GetCrashingProcessPid

Loops through the internal linked-list of processes, looks for mask 0x40 set in process flags. Returns pid of first such entry.