kernel-hacking-2024-linux-s.../kernel/debug/debug_core.h
Jason Wessel dcc7871128 kgdb: core changes to support kdb
These are the minimum changes to the kgdb core in order to enable an
API to connect a new front end (kdb) to the debug core.

This patch introduces the dbg_kdb_mode variable controls where the
user level I/O is routed.  It will be routed to the gdbstub (kgdb) or
to the kdb front end which is a simple shell available over the kgdboc
connection.

You can switch back and forth between kdb or the gdb stub mode of
operation dynamically.  From gdb stub mode you can blindly type
"$3#33", or from the kdb mode you can enter "kgdb" to switch to the
gdb stub.

The logic in the debug core depends on kdb to look for the typical gdb
connection sequences and return immediately with KGDB_PASS_EVENT if a
gdb serial command sequence is detected.  That should allow a
reasonably seamless transition between kdb -> gdb without leaving the
kernel exception state.  The two gdb serial queries that kdb is
responsible for detecting are the "?" and "qSupported" packets.

CC: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
Acked-by: Martin Hicks <mort@sgi.com>
2010-05-20 21:04:21 -05:00

79 lines
2.2 KiB
C

/*
* Created by: Jason Wessel <jason.wessel@windriver.com>
*
* Copyright (c) 2009 Wind River Systems, Inc. All Rights Reserved.
*
* This file is licensed under the terms of the GNU General Public
* License version 2. This program is licensed "as is" without any
* warranty of any kind, whether express or implied.
*/
#ifndef _DEBUG_CORE_H_
#define _DEBUG_CORE_H_
/*
* These are the private implementation headers between the kernel
* debugger core and the debugger front end code.
*/
/* kernel debug core data structures */
struct kgdb_state {
int ex_vector;
int signo;
int err_code;
int cpu;
int pass_exception;
unsigned long thr_query;
unsigned long threadid;
long kgdb_usethreadid;
struct pt_regs *linux_regs;
};
/* Exception state values */
#define DCPU_WANT_MASTER 0x1 /* Waiting to become a master kgdb cpu */
#define DCPU_NEXT_MASTER 0x2 /* Transition from one master cpu to another */
#define DCPU_IS_SLAVE 0x4 /* Slave cpu enter exception */
#define DCPU_SSTEP 0x8 /* CPU is single stepping */
struct debuggerinfo_struct {
void *debuggerinfo;
struct task_struct *task;
int exception_state;
int ret_state;
int irq_depth;
};
extern struct debuggerinfo_struct kgdb_info[];
/* kernel debug core break point routines */
extern int dbg_remove_all_break(void);
extern int dbg_set_sw_break(unsigned long addr);
extern int dbg_remove_sw_break(unsigned long addr);
extern int dbg_activate_sw_breakpoints(void);
extern int dbg_deactivate_sw_breakpoints(void);
/* polled character access to i/o module */
extern int dbg_io_get_char(void);
/* stub return value for switching between the gdbstub and kdb */
#define DBG_PASS_EVENT -12345
/* Switch from one cpu to another */
#define DBG_SWITCH_CPU_EVENT -123456
extern int dbg_switch_cpu;
/* gdbstub interface functions */
extern int gdb_serial_stub(struct kgdb_state *ks);
extern void gdbstub_msg_write(const char *s, int len);
/* gdbstub functions used for kdb <-> gdbstub transition */
extern int gdbstub_state(struct kgdb_state *ks, char *cmd);
#ifdef CONFIG_KGDB_KDB
extern int kdb_stub(struct kgdb_state *ks);
#else /* ! CONFIG_KGDB_KDB */
static inline int kdb_stub(struct kgdb_state *ks)
{
return DBG_PASS_EVENT;
}
#endif /* CONFIG_KGDB_KDB */
#endif /* _DEBUG_CORE_H_ */