kdb.h

  1#ifndef _KDB_H
  2#define _KDB_H
  3
  4/*
  5 * Kernel Debugger Architecture Independent Global Headers
  6 *
  7 * This file is subject to the terms and conditions of the GNU General Public
  8 * License.  See the file "COPYING" in the main directory of this archive
  9 * for more details.
 10 *
 11 * Copyright (c) 2000-2007 Silicon Graphics, Inc.  All Rights Reserved.
 12 * Copyright (C) 2000 Stephane Eranian <eranian@hpl.hp.com>
 13 * Copyright (C) 2009 Jason Wessel <jason.wessel@windriver.com>
 14 */
 15
 16#include <linux/list.h>
 17#include <linux/smp.h>
 18
 19/* Shifted versions of the command enable bits are be used if the command
 20 * has no arguments (see kdb_check_flags). This allows commands, such as
 21 * go, to have different permissions depending upon whether it is called
 22 * with an argument.
 23 */
 24#define KDB_ENABLE_NO_ARGS_SHIFT 10
 25
 26typedef enum {
 27	KDB_ENABLE_ALL = (1 << 0), /* Enable everything */
 28	KDB_ENABLE_MEM_READ = (1 << 1),
 29	KDB_ENABLE_MEM_WRITE = (1 << 2),
 30	KDB_ENABLE_REG_READ = (1 << 3),
 31	KDB_ENABLE_REG_WRITE = (1 << 4),
 32	KDB_ENABLE_INSPECT = (1 << 5),
 33	KDB_ENABLE_FLOW_CTRL = (1 << 6),
 34	KDB_ENABLE_SIGNAL = (1 << 7),
 35	KDB_ENABLE_REBOOT = (1 << 8),
 36	/* User exposed values stop here, all remaining flags are
 37	 * exclusively used to describe a commands behaviour.
 38	 */
 39
 40	KDB_ENABLE_ALWAYS_SAFE = (1 << 9),
 41	KDB_ENABLE_MASK = (1 << KDB_ENABLE_NO_ARGS_SHIFT) - 1,
 42
 43	KDB_ENABLE_ALL_NO_ARGS = KDB_ENABLE_ALL << KDB_ENABLE_NO_ARGS_SHIFT,
 44	KDB_ENABLE_MEM_READ_NO_ARGS = KDB_ENABLE_MEM_READ
 45				      << KDB_ENABLE_NO_ARGS_SHIFT,
 46	KDB_ENABLE_MEM_WRITE_NO_ARGS = KDB_ENABLE_MEM_WRITE
 47				       << KDB_ENABLE_NO_ARGS_SHIFT,
 48	KDB_ENABLE_REG_READ_NO_ARGS = KDB_ENABLE_REG_READ
 49				      << KDB_ENABLE_NO_ARGS_SHIFT,
 50	KDB_ENABLE_REG_WRITE_NO_ARGS = KDB_ENABLE_REG_WRITE
 51				       << KDB_ENABLE_NO_ARGS_SHIFT,
 52	KDB_ENABLE_INSPECT_NO_ARGS = KDB_ENABLE_INSPECT
 53				     << KDB_ENABLE_NO_ARGS_SHIFT,
 54	KDB_ENABLE_FLOW_CTRL_NO_ARGS = KDB_ENABLE_FLOW_CTRL
 55				       << KDB_ENABLE_NO_ARGS_SHIFT,
 56	KDB_ENABLE_SIGNAL_NO_ARGS = KDB_ENABLE_SIGNAL
 57				    << KDB_ENABLE_NO_ARGS_SHIFT,
 58	KDB_ENABLE_REBOOT_NO_ARGS = KDB_ENABLE_REBOOT
 59				    << KDB_ENABLE_NO_ARGS_SHIFT,
 60	KDB_ENABLE_ALWAYS_SAFE_NO_ARGS = KDB_ENABLE_ALWAYS_SAFE
 61					 << KDB_ENABLE_NO_ARGS_SHIFT,
 62	KDB_ENABLE_MASK_NO_ARGS = KDB_ENABLE_MASK << KDB_ENABLE_NO_ARGS_SHIFT,
 63
 64	KDB_REPEAT_NO_ARGS = 0x40000000, /* Repeat the command w/o arguments */
 65	KDB_REPEAT_WITH_ARGS = 0x80000000, /* Repeat the command with args */
 66} kdb_cmdflags_t;
 67
 68typedef int (*kdb_func_t)(int, const char **);
 69
 70/* The KDB shell command table */
 71typedef struct _kdbtab {
 72	char    *name;			/* Command name */
 73	kdb_func_t func;		/* Function to execute command */
 74	char    *usage;			/* Usage String for this command */
 75	char    *help;			/* Help message for this command */
 76	short    minlen;		/* Minimum legal # cmd chars required */
 77	kdb_cmdflags_t flags;		/* Command behaviour flags */
 78	struct list_head list_node;	/* Command list */
 79} kdbtab_t;
 80
 81#ifdef	CONFIG_KGDB_KDB
 82#include <linux/init.h>
 83#include <linux/sched.h>
 84#include <linux/atomic.h>
 85
 86#define KDB_POLL_FUNC_MAX	5
 87extern int kdb_poll_idx;
 88
 89/*
 90 * kdb_initial_cpu is initialized to -1, and is set to the cpu
 91 * number whenever the kernel debugger is entered.
 92 */
 93extern int kdb_initial_cpu;
 94
 95/* Types and messages used for dynamically added kdb shell commands */
 96
 97#define KDB_MAXARGS    16 /* Maximum number of arguments to a function  */
 98
 99/* KDB return codes from a command or internal kdb function */
100#define KDB_NOTFOUND	(-1)
101#define KDB_ARGCOUNT	(-2)
102#define KDB_BADWIDTH	(-3)
103#define KDB_BADRADIX	(-4)
104#define KDB_NOTENV	(-5)
105#define KDB_NOENVVALUE	(-6)
106#define KDB_NOTIMP	(-7)
107#define KDB_ENVFULL	(-8)
108#define KDB_KMALLOCFAILED	(-9)
109#define KDB_TOOMANYBPT	(-10)
110#define KDB_TOOMANYDBREGS (-11)
111#define KDB_DUPBPT	(-12)
112#define KDB_BPTNOTFOUND	(-13)
113#define KDB_BADMODE	(-14)
114#define KDB_BADINT	(-15)
115#define KDB_INVADDRFMT  (-16)
116#define KDB_BADREG      (-17)
117#define KDB_BADCPUNUM   (-18)
118#define KDB_BADLENGTH	(-19)
119#define KDB_NOBP	(-20)
120#define KDB_BADADDR	(-21)
121#define KDB_NOPERM	(-22)
122
123/*
124 * kdb_diemsg
125 *
126 *	Contains a pointer to the last string supplied to the
127 *	kernel 'die' panic function.
128 */
129extern const char *kdb_diemsg;
130
131#define KDB_FLAG_EARLYKDB	(1 << 0) /* set from boot parameter kdb=early */
132#define KDB_FLAG_CATASTROPHIC	(1 << 1) /* A catastrophic event has occurred */
133#define KDB_FLAG_CMD_INTERRUPT	(1 << 2) /* Previous command was interrupted */
134#define KDB_FLAG_NOIPI		(1 << 3) /* Do not send IPIs */
135#define KDB_FLAG_NO_CONSOLE	(1 << 5) /* No console is available,
136					  * kdb is disabled */
137#define KDB_FLAG_NO_VT_CONSOLE	(1 << 6) /* No VT console is available, do
138					  * not use keyboard */
139#define KDB_FLAG_NO_I8042	(1 << 7) /* No i8042 chip is available, do
140					  * not use keyboard */
141
142extern unsigned int kdb_flags;	/* Global flags, see kdb_state for per cpu state */
143
144#define KDB_FLAG(flag)		(kdb_flags & KDB_FLAG_##flag)
145#define KDB_FLAG_SET(flag)	((void)(kdb_flags |= KDB_FLAG_##flag))
146#define KDB_FLAG_CLEAR(flag)	((void)(kdb_flags &= ~KDB_FLAG_##flag))
147
148/*
149 * External entry point for the kernel debugger.  The pt_regs
150 * at the time of entry are supplied along with the reason for
151 * entry to the kernel debugger.
152 */
153
154typedef enum {
155	KDB_REASON_ENTER = 1,	/* KDB_ENTER() trap/fault - regs valid */
156	KDB_REASON_ENTER_SLAVE,	/* KDB_ENTER_SLAVE() trap/fault - regs valid */
157	KDB_REASON_BREAK,	/* Breakpoint inst. - regs valid */
158	KDB_REASON_DEBUG,	/* Debug Fault - regs valid */
159	KDB_REASON_OOPS,	/* Kernel Oops - regs valid */
160	KDB_REASON_SWITCH,	/* CPU switch - regs valid*/
161	KDB_REASON_KEYBOARD,	/* Keyboard entry - regs valid */
162	KDB_REASON_NMI,		/* Non-maskable interrupt; regs valid */
163	KDB_REASON_RECURSE,	/* Recursive entry to kdb;
164				 * regs probably valid */
165	KDB_REASON_SSTEP,	/* Single Step trap. - regs valid */
166	KDB_REASON_SYSTEM_NMI,	/* In NMI due to SYSTEM cmd; regs valid */
167} kdb_reason_t;
168
169enum kdb_msgsrc {
170	KDB_MSGSRC_INTERNAL, /* direct call to kdb_printf() */
171	KDB_MSGSRC_PRINTK, /* trapped from printk() */
172};
173
174extern int kdb_trap_printk;
175extern int kdb_printf_cpu;
176extern __printf(2, 0) int vkdb_printf(enum kdb_msgsrc src, const char *fmt,
177				      va_list args);
178extern __printf(1, 2) int kdb_printf(const char *, ...);
179typedef __printf(1, 2) int (*kdb_printf_t)(const char *, ...);
180
181extern void kdb_init(int level);
182
183/* Access to kdb specific polling devices */
184typedef int (*get_char_func)(void);
185extern get_char_func kdb_poll_funcs[];
186extern int kdb_get_kbd_char(void);
187
188static inline
189int kdb_process_cpu(const struct task_struct *p)
190{
191	unsigned int cpu = task_cpu(p);
192	if (cpu > num_possible_cpus())
193		cpu = 0;
194	return cpu;
195}
196
197extern void kdb_send_sig(struct task_struct *p, int sig);
198
199#ifdef CONFIG_KALLSYMS
200extern const char *kdb_walk_kallsyms(loff_t *pos);
201#else /* ! CONFIG_KALLSYMS */
202static inline const char *kdb_walk_kallsyms(loff_t *pos)
203{
204	return NULL;
205}
206#endif /* ! CONFIG_KALLSYMS */
207
208/* Dynamic kdb shell command registration */
209extern int kdb_register(kdbtab_t *cmd);
210extern void kdb_unregister(kdbtab_t *cmd);
211
212/* Return true when KDB as locked for printing a message on this CPU. */
213static inline
214bool kdb_printf_on_this_cpu(void)
215{
216	/*
217	 * We can use raw_smp_processor_id() here because the task could
218	 * not get migrated when KDB has locked for printing on this CPU.
219	 */
220	return unlikely(READ_ONCE(kdb_printf_cpu) == raw_smp_processor_id());
221}
222
223#else /* ! CONFIG_KGDB_KDB */
224static inline __printf(1, 2) int kdb_printf(const char *fmt, ...) { return 0; }
225static inline void kdb_init(int level) {}
226static inline int kdb_register(kdbtab_t *cmd) { return 0; }
227static inline void kdb_unregister(kdbtab_t *cmd) {}
228
229static inline bool kdb_printf_on_this_cpu(void) { return false; }
230
231#endif	/* CONFIG_KGDB_KDB */
232enum {
233	KDB_NOT_INITIALIZED,
234	KDB_INIT_EARLY,
235	KDB_INIT_FULL,
236};
237
238extern int kdbgetintenv(const char *, int *);
239extern int kdb_set(int, const char **);
240int kdb_lsmod(int argc, const char **argv);
241
242#endif	/* !_KDB_H */