alistair23-linux/include/linux/kdb.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

172 lines
5.5 KiB
C

#ifndef _KDB_H
#define _KDB_H
/*
* Kernel Debugger Architecture Independent Global Headers
*
* This file is subject to the terms and conditions of the GNU General Public
* License. See the file "COPYING" in the main directory of this archive
* for more details.
*
* Copyright (c) 2000-2007 Silicon Graphics, Inc. All Rights Reserved.
* Copyright (C) 2000 Stephane Eranian <eranian@hpl.hp.com>
* Copyright (C) 2009 Jason Wessel <jason.wessel@windriver.com>
*/
typedef enum {
KDB_REPEAT_NONE = 0, /* Do not repeat this command */
KDB_REPEAT_NO_ARGS, /* Repeat the command without arguments */
KDB_REPEAT_WITH_ARGS, /* Repeat the command including its arguments */
} kdb_repeat_t;
typedef int (*kdb_func_t)(int, const char **);
#ifdef CONFIG_KGDB_KDB
#include <linux/init.h>
#include <linux/sched.h>
#include <linux/atomic.h>
#define KDB_POLL_FUNC_MAX 5
extern int kdb_poll_idx;
/*
* kdb_initial_cpu is initialized to -1, and is set to the cpu
* number whenever the kernel debugger is entered.
*/
extern int kdb_initial_cpu;
extern atomic_t kdb_event;
/* Types and messages used for dynamically added kdb shell commands */
#define KDB_MAXARGS 16 /* Maximum number of arguments to a function */
/* KDB return codes from a command or internal kdb function */
#define KDB_NOTFOUND (-1)
#define KDB_ARGCOUNT (-2)
#define KDB_BADWIDTH (-3)
#define KDB_BADRADIX (-4)
#define KDB_NOTENV (-5)
#define KDB_NOENVVALUE (-6)
#define KDB_NOTIMP (-7)
#define KDB_ENVFULL (-8)
#define KDB_ENVBUFFULL (-9)
#define KDB_TOOMANYBPT (-10)
#define KDB_TOOMANYDBREGS (-11)
#define KDB_DUPBPT (-12)
#define KDB_BPTNOTFOUND (-13)
#define KDB_BADMODE (-14)
#define KDB_BADINT (-15)
#define KDB_INVADDRFMT (-16)
#define KDB_BADREG (-17)
#define KDB_BADCPUNUM (-18)
#define KDB_BADLENGTH (-19)
#define KDB_NOBP (-20)
#define KDB_BADADDR (-21)
/*
* kdb_diemsg
*
* Contains a pointer to the last string supplied to the
* kernel 'die' panic function.
*/
extern const char *kdb_diemsg;
#define KDB_FLAG_EARLYKDB (1 << 0) /* set from boot parameter kdb=early */
#define KDB_FLAG_CATASTROPHIC (1 << 1) /* A catastrophic event has occurred */
#define KDB_FLAG_CMD_INTERRUPT (1 << 2) /* Previous command was interrupted */
#define KDB_FLAG_NOIPI (1 << 3) /* Do not send IPIs */
#define KDB_FLAG_NO_CONSOLE (1 << 5) /* No console is available,
* kdb is disabled */
#define KDB_FLAG_NO_VT_CONSOLE (1 << 6) /* No VT console is available, do
* not use keyboard */
#define KDB_FLAG_NO_I8042 (1 << 7) /* No i8042 chip is available, do
* not use keyboard */
extern int kdb_flags; /* Global flags, see kdb_state for per cpu state */
extern void kdb_save_flags(void);
extern void kdb_restore_flags(void);
#define KDB_FLAG(flag) (kdb_flags & KDB_FLAG_##flag)
#define KDB_FLAG_SET(flag) ((void)(kdb_flags |= KDB_FLAG_##flag))
#define KDB_FLAG_CLEAR(flag) ((void)(kdb_flags &= ~KDB_FLAG_##flag))
/*
* External entry point for the kernel debugger. The pt_regs
* at the time of entry are supplied along with the reason for
* entry to the kernel debugger.
*/
typedef enum {
KDB_REASON_ENTER = 1, /* KDB_ENTER() trap/fault - regs valid */
KDB_REASON_ENTER_SLAVE, /* KDB_ENTER_SLAVE() trap/fault - regs valid */
KDB_REASON_BREAK, /* Breakpoint inst. - regs valid */
KDB_REASON_DEBUG, /* Debug Fault - regs valid */
KDB_REASON_OOPS, /* Kernel Oops - regs valid */
KDB_REASON_SWITCH, /* CPU switch - regs valid*/
KDB_REASON_KEYBOARD, /* Keyboard entry - regs valid */
KDB_REASON_NMI, /* Non-maskable interrupt; regs valid */
KDB_REASON_RECURSE, /* Recursive entry to kdb;
* regs probably valid */
KDB_REASON_SSTEP, /* Single Step trap. - regs valid */
KDB_REASON_SYSTEM_NMI, /* In NMI due to SYSTEM cmd; regs valid */
} kdb_reason_t;
extern int kdb_trap_printk;
extern __printf(1, 0) int vkdb_printf(const char *fmt, va_list args);
extern __printf(1, 2) int kdb_printf(const char *, ...);
typedef __printf(1, 2) int (*kdb_printf_t)(const char *, ...);
extern void kdb_init(int level);
/* Access to kdb specific polling devices */
typedef int (*get_char_func)(void);
extern get_char_func kdb_poll_funcs[];
extern int kdb_get_kbd_char(void);
static inline
int kdb_process_cpu(const struct task_struct *p)
{
unsigned int cpu = task_thread_info(p)->cpu;
if (cpu > num_possible_cpus())
cpu = 0;
return cpu;
}
/* kdb access to register set for stack dumping */
extern struct pt_regs *kdb_current_regs;
#ifdef CONFIG_KALLSYMS
extern const char *kdb_walk_kallsyms(loff_t *pos);
#else /* ! CONFIG_KALLSYMS */
static inline const char *kdb_walk_kallsyms(loff_t *pos)
{
return NULL;
}
#endif /* ! CONFIG_KALLSYMS */
/* Dynamic kdb shell command registration */
extern int kdb_register(char *, kdb_func_t, char *, char *, short);
extern int kdb_register_repeat(char *, kdb_func_t, char *, char *,
short, kdb_repeat_t);
extern int kdb_unregister(char *);
#else /* ! CONFIG_KGDB_KDB */
static inline __printf(1, 2) int kdb_printf(const char *fmt, ...) { return 0; }
static inline void kdb_init(int level) {}
static inline int kdb_register(char *cmd, kdb_func_t func, char *usage,
char *help, short minlen) { return 0; }
static inline int kdb_register_repeat(char *cmd, kdb_func_t func, char *usage,
char *help, short minlen,
kdb_repeat_t repeat) { return 0; }
static inline int kdb_unregister(char *cmd) { return 0; }
#endif /* CONFIG_KGDB_KDB */
enum {
KDB_NOT_INITIALIZED,
KDB_INIT_EARLY,
KDB_INIT_FULL,
};
extern int kdbgetintenv(const char *, int *);
extern int kdb_set(int, const char **);
#endif /* !_KDB_H */