k, kb, kc, kd, kp, kP, kv (Display Stack Backtrace)
The k* commands display the stack frame of the given thread with related information.
User-Mode, x86 Processor
[~Thread] k[b|p|P|v] [c] [n] [f] [L] [M] [FrameCount]
[~Thread] k[b|p|P|v] [c] [n] [f] [L] [M] = BasePtr [FrameCount]
[~Thread] k[b|p|P|v] [c] [n] [f] [L] [M] = BasePtr StackPtr InstructionPtr
[~Thread] kd [WordCount]
Kernel-Mode, x86 Processor
[Processor] k[b|p|P|v] [c] [n] [f] [L] [M] [FrameCount]
[Processor] k[b|p|P|v] [c] [n] [f] [L] [M] = StackPtr FrameCount
[Processor] k[b|p|P|v] [c] [n] [f] [L] [M] = BasePtr StackPtr InstructionPtr
[Processor] kd [WordCount]
User-Mode, x64 Processor
[~Thread] k[b|p|P|v] [c] [n] [f] [L] [M] [FrameCount]
[~Thread] k[b|p|P|v] [c] [n] [f] [L] [M] = StackPtr FrameCount
[~Thread] k[b|p|P|v] [c] [n] [f] [L] [M] = StackPtr InstructionPtr FrameCount
[~Thread] kd [WordCount]
Kernel-Mode, x64 Processor
[Processor] k[b|p|P|v] [c] [n] [f] [L] [M] [FrameCount]
[Processor] k[b|p|P|v] [c] [n] [f] [L] [M] = StackPtr FrameCount
[Processor] k[b|p|P|v] [c] [n] [f] [L] [M] = StackPtr InstructionPtr FrameCount
[Processor] kd [WordCount]
User-Mode, ARM Processor
[~Thread] k[b|p|P|v] [c] [n] [f] [L] [M] [FrameCount]
[~Thread] k[b|p|P|v] [c] [n] [f] [L] [M] = StackPtr FrameCount
[~Thread] k[b|p|P|v] [c] [n] [f] [L] [M] = StackPtr InstructionPtr FrameCount
[~Thread] kd [WordCount]
Kernel-Mode, ARM Processor
[Processor] k[b|p|P|v] [c] [n] [f] [L] [M] [FrameCount]
[Processor] k[b|p|P|v] [c] [n] [f] [L] [M] = StackPtr FrameCount
[Processor] k[b|p|P|v] [c] [n] [f] [L] [M] = StackPtr InstructionPtr FrameCount
[Processor] kd [WordCount]
Parameters
Thread
Specifies the thread stack to be displayed. If you omit this parameter, the stack of the current thread is displayed. For more information about thread syntax, see Thread syntax. You can specify threads only in user mode.
Processor
Specifies the processor whose stack is to be displayed. For more information about processor syntax, see Multiprocessor Syntax.
b
Displays the first three parameters that are passed to each function in the stack trace.
c
Displays a clean stack trace. Each display line includes only the module name and the function name.
p
Displays all of the parameters for each function that's called in the stack trace. The parameter list includes each parameter's data type, name, and value. The p option is case sensitive. This parameter requires full symbol information.
P
Displays all of the parameters for each function that's called in the stack trace, like the p parameter. However, for P, the function parameters are printed on a second line of the display, instead of on the same line as the rest of the data.
v
Displays frame pointer omission (FPO) information. On x86-based processors, the display also includes calling convention information.
n
Displays frame numbers.
f
Displays the distance between adjacent frames. This distance is the number of bytes that separate the frames on the actual stack.
L
Hides source lines in the display. L is case sensitive.
M
Displays the output using Debugger markup language. Each frame number in the display is a link that you can select to set the local context and display local variables. For information about the local context, see .frame.
FrameCount
Specifies the number of stack frames to display. You should specify this number in hexadecimal format unless you've changed the radix by using the n (set number base) command. Use the .kframes (set stack length) command to display the default and to change the value.
BasePtr
Specifies the base pointer for the stack trace. The BasePtr parameter is available only if there's an equal sign (=) after the command.
StackPtr
Specifies the stack pointer for the stack trace. If you omit StackPtr and InstructionPtr, the command uses the stack pointer that the rsp (or esp) register specifies and the instruction pointer that the rip (or eip) register specifies.
InstructionPtr
Specifies the instruction pointer for the stack trace. If you omit StackPtr and InstructionPtr, the command uses the stack pointer that the rsp (or esp) register specifies and the instruction pointer that the rip (or eip) register specifies.
WordCount
Specifies the number of DWORD_PTR values in the stack to dump.
| Environment | |
|---|---|
| Modes | User mode, kernel mode |
| Targets | Live, crash dump |
| Platforms | All |
Remarks
When you issue the k, kb, kp, kP, or kv commands, a stack trace is displayed in a tabular format. If line loading is enabled, source modules and line numbers are also displayed.
The stack trace includes the base pointer for the stack frame, the return address, and the function names.
If you use the kp or kP commands, the full parameters for each function that's called in the stack trace are displayed. The parameter list includes each parameter's data type, name, and value.
The command might be slow. For example, when MyFunction1 calls MyFunction2, the debugger must have full symbol information for MyFunction1 to display the parameters that are passed in this call. This command doesn't fully display internal Microsoft Windows routines that aren't exposed in public symbols.
If you use the kb or kv commands, the first three parameters that are passed to each function are displayed. If you use the kv command, FPO data is also displayed.
On an x86-based processor, the kv command also displays calling convention information.
When you use the kv command, the FPO information is added at the end of the line in the following format.
| FPO text | Meaning |
|---|---|
| FPO: [non-Fpo] | No FPO data for the frame. |
| FPO: [N1,N2,N3] | N1 is the total number of parameters. N2 is the number of DWORD values for the local variables. N3 is the number of registers that are saved. |
| FPO: [N1,N2] TrapFrame @ Address | N1 is the total number of parameters. N2 is the number of DWORD values for the locals. Address is the address of the trap frame. |
| FPO: TaskGate Segment:0 | Segment is the segment selector for the task gate. |
| FPO: [EBP 0xBase] | Base is the base pointer for the frame. |
The kd command displays the raw stack data. Each DWORD value is displayed on a separate line. Symbol information is displayed for those lines together with associated symbols. This format creates a more detailed list than the other k* commands. The kd command is equivalent to a dds (display memory) command that uses the stack address as its parameter.
If you use the k command at the beginning of a function (before the function prolog has been executed), you receive incorrect results. The debugger uses the frame register to compute the current backtrace, and this register isn't set correctly for a function until its prolog has been executed.
In user mode, the stack trace is based on the stack of the current thread. For more information about threads, see Controlling processes and threads.
In kernel mode, the stack trace is based on the current register context. You can set the register context to match a specific thread, context record, or trap frame.
Additional information
For more information about the Register context and other context settings, see Changing contexts.