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linux/kernel/debug/debug_core.h
Mike Travis 8daaa5f826 kdb: Add support for external NMI handler to call KGDB/KDB
This patch adds a kgdb_nmicallin() interface that can be used by
external NMI handlers to call the KGDB/KDB handler.  The primary
need for this is for those types of NMI interrupts where all the
CPUs have already received the NMI signal.  Therefore no
send_IPI(NMI) is required, and in fact it will cause a 2nd
unhandled NMI to occur. This generates the "Dazed and Confuzed"
messages.

Since all the CPUs are getting the NMI at roughly the same time,
it's not guaranteed that the first CPU that hits the NMI handler
will manage to enter KGDB and set the dbg_master_lock before the
slaves start entering. The new argument "send_ready" was added
for KGDB to signal the NMI handler to release the slave CPUs for
entry into KGDB.

Signed-off-by: Mike Travis <travis@sgi.com>
Acked-by: Jason Wessel <jason.wessel@windriver.com>
Reviewed-by: Dimitri Sivanich <sivanich@sgi.com>
Reviewed-by: Hedi Berriche <hedi@sgi.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Arnaldo Carvalho de Melo <acme@ghostprotocols.net>
Link: http://lkml.kernel.org/r/20131002151417.928886849@asylum.americas.sgi.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-10-03 18:47:54 +02:00

88 lines
2.5 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;
atomic_t *send_ready;
};
/* 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;
int enter_kgdb;
};
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);
extern int dbg_kdb_mode;
#ifdef CONFIG_KGDB_KDB
extern int kdb_stub(struct kgdb_state *ks);
extern int kdb_parse(const char *cmdstr);
extern int kdb_common_init_state(struct kgdb_state *ks);
extern int kdb_common_deinit_state(void);
#define KGDB_KDB_REASON_SYSTEM_NMI KDB_REASON_SYSTEM_NMI
#else /* ! CONFIG_KGDB_KDB */
static inline int kdb_stub(struct kgdb_state *ks)
{
return DBG_PASS_EVENT;
}
#define KGDB_KDB_REASON_SYSTEM_NMI 0
#endif /* CONFIG_KGDB_KDB */
#endif /* _DEBUG_CORE_H_ */