crash.types.task module

class crash.types.task.LinuxTask(task_struct: gdb.Value)

Bases: object

A wrapper class for struct task_struct. There will be typically one of these allocated for every task discovered in the debugging environment.

Parameters:task_struct – The task to wrap. The value must be of type struct task_struct.

task_struct

The task being wrapped. The value is of type struct task_struct.

Type:gdb.Value

active

Whether this task is active

Type:bool

cpu

The CPU number the task was using

Type:int

regs

The registers associated with this task, if active

thread_info

The architecture-specific struct thread_info for this task. The value will be of type struct thread_info.

Type:gdb.Value

thread

The GDB representation of the thread.

Type:gdb.InferiorThread

mem_valid

Whether the memory statistics are currently valid.

Type:bool

rss

The size of the resident memory for this task.

Type:int

total_vm

The total size of the vm space for this task.

Type:int

pgd_addr

The address of the top of the page table tree.

Type:int

Raises:

• ArgumentTypeError – task_struct was not a gdb.Value.
• UnexpectedGDBTypeError – task_struct was not of type struct task_struct.
• InvalidArgumentError – The cpu number was not None or an int.

attach_thread(thread: gdb.InferiorThread) → None

Associate a gdb thread with this task

Parameters:thread – The gdb thread to associate with this task

get_last_cpu() → int

Returns the last cpu this task was scheduled to execute on

Returns:The last cpu this task was scheduled to execute on Return type:int

get_rss() → int

Return the resident set for this task

Returns:The size of the resident memory set for this task Return type:int

get_stack_pointer() → int

Get the stack pointer for this task

Returns:

The address of the stack pointer for this task.

Return type:

int

Raises:

• NotImplementedError – The architecture hasn’t provided
• a stack pointer callback.

get_thread_info() → gdb.Value

Get the thread info for this task

The thread info structure is architecture specific and so this method abstracts its retreival.

Returns:

The struct thread_info associated with this

task. The type of the value is struct thread_info.

Return type:gdb.Value

is_exiting() → bool

Returns whether a task is exiting

Returns:Whether the task is exiting Return type:bool

is_kernel_task() → bool

is_thread_group_leader() → bool

Returns whether a task is a thread group leader

Returns:Whether the task is a thread group leader Return type:bool

is_zombie() → bool

Returns whether a task is in Zombie state

Returns:Whether the task is in zombie state Return type:bool

last_run() → int

The timestamp of when this task was last run

Returns:The timestamp of when this task was last run Return type:int

maybe_dead() → bool

Returns whether this task is dead

Returns:Whether this task is dead Return type:bool

parent_pid() → int

Returns the pid of this task’s parent

Returns:The pid of this task’s parent Return type:int

set_active(cpu: int, regs: Dict[str, int]) → None

Set this task as active in the debugging environment

Parameters:

• cpu – Which CPU this task was using
• regs – The registers associated with this task

Raises:

InvalidArgumentError – The cpu was not a valid integer.

classmethod set_get_stack_pointer(fn: Callable[[gdb.Value], int]) → None

Set the stack pointer callback for this architecture

The callback must accept a gdb.Value of type struct thread and return a int containing the address of the stack pointer.

Parameters:fn – The callback to use. It will be used by all tasks.

set_thread_info(thread_info: gdb.Value) → None

Set the thread info for this task

The thread info structure is architecture specific. This method allows the architecture code to assign its thread info structure to this task.

Parameters:thread_info – The struct thread_info to be associated with this task. The value must be of type struct thread_info.

task_address() → int

Returns the address of the task_struct for this task

Returns:The address of the task_struct Return type:int

task_flags() → int

Returns the flags for this task

Returns:The flags for this task Return type:int

task_name(brackets: bool = False) → str

Returns the comm field of this task

Parameters:brackets – If this task is a kernel thread, surround the name in square brackets Returns:The comm field of this task a python string Return type:str

task_pid() → int

Returns the pid of this task

Returns:The pid of this task Return type:int

task_state() → int

Return the task state flags for this task (possibly broken due to combining flags from ``state`` and ``exit_state``).

Returns:The state flags for this task. Return type:int

update_mem_usage() → None

Update the memory usage for this task

Tasks are created initially without their memory statistics. This method explicitly updates them.

crash.types.task.TF

alias of crash.types.task.TaskStateFlags

class crash.types.task.TaskStateFlags

Bases: object

A class to contain state related to discovering task flag values. Not meant to be instantiated.

The initial values below are overridden once symbols are available to resolve them properly.

EXIT_DEAD = -1

EXIT_ZOMBIE = -1

TASK_DEAD = -1

TASK_FLAG_UNINITIALIZED = -1

TASK_IDLE = -1

TASK_INTERRUPTIBLE = -1

TASK_NEW = -1

TASK_NOLOAD = -1

TASK_PARKED = -1

TASK_RUNNING = 0

TASK_STOPPED = -1

TASK_SWAPPING = -1

TASK_TRACING_STOPPED = -1

TASK_UNINTERRUPTIBLE = -1

TASK_WAKEKILL = -1

TASK_WAKING = -1

classmethod has_flag(flagname: str) → bool

classmethod task_state_flags_callback(symbol: gdb.Symbol) → None

Detect which task flags this kernel uses.

Meant to be used as a SymbolCallback.

Different kernels use different task flags or even different values for the same flags. This method tries to determine the flags for the kernel.

Parameters:symbol – The task_state_array symbol.

crash.types.task.for_each_all_tasks() → Iterator[gdb.Value]

Iterate the task list and yield each task including any associated thread tasks

Yields:gdb.Value – The next task on the list. The value is of type struct task_struct.

crash.types.task.for_each_thread_group_leader() → Iterator[gdb.Value]

Iterate the task list and yield each thread group leader

Yields:gdb.Value – The next task on the list. The value is of type struct task_struct.

crash.types.task.for_each_thread_in_group(task: gdb.Value) → Iterator[gdb.Value]

Iterate a thread group leader’s thread list and yield each struct task_struct

Parameters:task – The task_struct that is the thread group leader. The value must be of type struct task_struct. Yields:gdb.Value – The next task on the list. The value is of type struct task_struct.