gdb_arch.c File Reference

x86-specific parts of in-kernel GDB stub. More...

Functions
void	gdb_handle_exception_onstack (int vector, uintptr_t *NONNULL COUNT(GDB_X86_64_NUM_REGS) save_area)
	Entry point for an exception; we are now on our own stack. More...
int	gdb_arch_get_register (int regnum, uintptr_t *value)
	Get the value of a single register in the frame. More...
int	gdb_arch_set_register (int regnum, uintptr_t value)
	Set the value of a single register in the frame. More...
void	gdb_resume (void)
	Resume execution. More...
void	gdb_arch_continue (lvaddr_t addr)
	Resume program execution. More...
void	gdb_arch_single_step (lvaddr_t addr)
	Single-step program execution. More...
int	gdb_arch_write_byte (uint8_t *addr, uint8_t val)
	Writes a byte to an arbitrary address in kernel memory. More...
int	gdb_arch_read_byte (uint8_t *addr, uint8_t *val)
	Reads a byte from an arbitrary address in kernel memory. More...

Variables
uintptr_t *	gdb_arch_registers
	GDB register save area / frame. More...
uintptr_t *SNT	gdb_stack_top = &gdb_stack[KERNEL_STACK_SIZE/sizeof(uintptr_t)]
	Pointer to top of GDB stack area.

Detailed Description

x86-specific parts of in-kernel GDB stub.

This file implements x86 architecture support for the kernel-side GDB stubs.

Function Documentation

void gdb_arch_continue

(

lvaddr_t

addr

)

Resume program execution.

Parameters

addr	Address to resume at, or 0 to continue at last address.

int gdb_arch_get_register	(	int	regnum,
		uintptr_t *	value
	)

Get the value of a single register in the frame.

Parameters

regnum	register number (as defined by the #gdb_register_nums enum)
value	pointer to location in which to return current value

Returns

Zero on success, nonzero on failure (invalid regnum).

int gdb_arch_read_byte	(	uint8_t *	addr,
		uint8_t *	val
	)

Reads a byte from an arbitrary address in kernel memory.

Returns

Zero on success, nonzero on error (invalid address)

int gdb_arch_set_register	(	int	regnum,
		uintptr_t	value
	)

Set the value of a single register in the frame.

Parameters

regnum	register number (as defined by the #gdb_register_nums enum)
value	new value

Returns

Zero on success, nonzero on failure (invalid regnum).

void gdb_arch_single_step

(

lvaddr_t

addr

)

Single-step program execution.

Parameters

addr	Address to resume at, or 0 to continue at last address.

int gdb_arch_write_byte	(	uint8_t *	addr,
		uint8_t	val
	)

Writes a byte to an arbitrary address in kernel memory.

Returns

Zero on success, nonzero on error (invalid address)

void gdb_handle_exception_onstack	(	int	vector,
		uintptr_t *NONNULL COUNT(GDB_X86_64_NUM_REGS)	save_area
	)

Entry point for an exception; we are now on our own stack.

This function sets up the GDB-format register save frame, constructs the initial message to the remote GDB and calls into the generic debugger entry point.

void gdb_resume

(

void

)

Resume execution.

Resumes execution with the CPU state stored in the gdb_arch_registers frame.

Variable Documentation

uintptr_t* gdb_arch_registers

GDB register save area / frame.

Stores pointer to current save frame used by GDB. Used to read/modify register contents, and reloaded when program execution resumes.