1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef _KDB_H
3 #define _KDB_H
4
5 /*
6 * Kernel Debugger Architecture Independent Global Headers
7 *
8 * Copyright (c) 2000-2007 Silicon Graphics, Inc. All Rights Reserved.
9 * Copyright (C) 2000 Stephane Eranian <eranian@hpl.hp.com>
10 * Copyright (C) 2009 Jason Wessel <jason.wessel@windriver.com>
11 */
12
13 #include <linux/list.h>
14 #include <linux/smp.h>
15
16 /* Shifted versions of the command enable bits are be used if the command
17 * has no arguments (see kdb_check_flags). This allows commands, such as
18 * go, to have different permissions depending upon whether it is called
19 * with an argument.
20 */
21 #define KDB_ENABLE_NO_ARGS_SHIFT 10
22
23 typedef enum {
24 KDB_ENABLE_ALL = (1 << 0), /* Enable everything */
25 KDB_ENABLE_MEM_READ = (1 << 1),
26 KDB_ENABLE_MEM_WRITE = (1 << 2),
27 KDB_ENABLE_REG_READ = (1 << 3),
28 KDB_ENABLE_REG_WRITE = (1 << 4),
29 KDB_ENABLE_INSPECT = (1 << 5),
30 KDB_ENABLE_FLOW_CTRL = (1 << 6),
31 KDB_ENABLE_SIGNAL = (1 << 7),
32 KDB_ENABLE_REBOOT = (1 << 8),
33 /* User exposed values stop here, all remaining flags are
34 * exclusively used to describe a commands behaviour.
35 */
36
37 KDB_ENABLE_ALWAYS_SAFE = (1 << 9),
38 KDB_ENABLE_MASK = (1 << KDB_ENABLE_NO_ARGS_SHIFT) - 1,
39
40 KDB_ENABLE_ALL_NO_ARGS = KDB_ENABLE_ALL << KDB_ENABLE_NO_ARGS_SHIFT,
41 KDB_ENABLE_MEM_READ_NO_ARGS = KDB_ENABLE_MEM_READ
42 << KDB_ENABLE_NO_ARGS_SHIFT,
43 KDB_ENABLE_MEM_WRITE_NO_ARGS = KDB_ENABLE_MEM_WRITE
44 << KDB_ENABLE_NO_ARGS_SHIFT,
45 KDB_ENABLE_REG_READ_NO_ARGS = KDB_ENABLE_REG_READ
46 << KDB_ENABLE_NO_ARGS_SHIFT,
47 KDB_ENABLE_REG_WRITE_NO_ARGS = KDB_ENABLE_REG_WRITE
48 << KDB_ENABLE_NO_ARGS_SHIFT,
49 KDB_ENABLE_INSPECT_NO_ARGS = KDB_ENABLE_INSPECT
50 << KDB_ENABLE_NO_ARGS_SHIFT,
51 KDB_ENABLE_FLOW_CTRL_NO_ARGS = KDB_ENABLE_FLOW_CTRL
52 << KDB_ENABLE_NO_ARGS_SHIFT,
53 KDB_ENABLE_SIGNAL_NO_ARGS = KDB_ENABLE_SIGNAL
54 << KDB_ENABLE_NO_ARGS_SHIFT,
55 KDB_ENABLE_REBOOT_NO_ARGS = KDB_ENABLE_REBOOT
56 << KDB_ENABLE_NO_ARGS_SHIFT,
57 KDB_ENABLE_ALWAYS_SAFE_NO_ARGS = KDB_ENABLE_ALWAYS_SAFE
58 << KDB_ENABLE_NO_ARGS_SHIFT,
59 KDB_ENABLE_MASK_NO_ARGS = KDB_ENABLE_MASK << KDB_ENABLE_NO_ARGS_SHIFT,
60
61 KDB_REPEAT_NO_ARGS = 0x40000000, /* Repeat the command w/o arguments */
62 KDB_REPEAT_WITH_ARGS = 0x80000000, /* Repeat the command with args */
63 } kdb_cmdflags_t;
64
65 typedef int (*kdb_func_t)(int, const char **);
66
67 /* The KDB shell command table */
68 typedef struct _kdbtab {
69 char *name; /* Command name */
70 kdb_func_t func; /* Function to execute command */
71 char *usage; /* Usage String for this command */
72 char *help; /* Help message for this command */
73 short minlen; /* Minimum legal # cmd chars required */
74 kdb_cmdflags_t flags; /* Command behaviour flags */
75 struct list_head list_node; /* Command list */
76 } kdbtab_t;
77
78 #ifdef CONFIG_KGDB_KDB
79 #include <linux/init.h>
80 #include <linux/sched.h>
81 #include <linux/atomic.h>
82
83 #define KDB_POLL_FUNC_MAX 5
84 extern int kdb_poll_idx;
85
86 /*
87 * kdb_initial_cpu is initialized to -1, and is set to the cpu
88 * number whenever the kernel debugger is entered.
89 */
90 extern int kdb_initial_cpu;
91
92 /* Types and messages used for dynamically added kdb shell commands */
93
94 #define KDB_MAXARGS 16 /* Maximum number of arguments to a function */
95
96 /* KDB return codes from a command or internal kdb function */
97 #define KDB_NOTFOUND (-1)
98 #define KDB_ARGCOUNT (-2)
99 #define KDB_BADWIDTH (-3)
100 #define KDB_BADRADIX (-4)
101 #define KDB_NOTENV (-5)
102 #define KDB_NOENVVALUE (-6)
103 #define KDB_NOTIMP (-7)
104 #define KDB_ENVFULL (-8)
105 #define KDB_KMALLOCFAILED (-9)
106 #define KDB_TOOMANYBPT (-10)
107 #define KDB_TOOMANYDBREGS (-11)
108 #define KDB_DUPBPT (-12)
109 #define KDB_BPTNOTFOUND (-13)
110 #define KDB_BADMODE (-14)
111 #define KDB_BADINT (-15)
112 #define KDB_INVADDRFMT (-16)
113 #define KDB_BADREG (-17)
114 #define KDB_BADCPUNUM (-18)
115 #define KDB_BADLENGTH (-19)
116 #define KDB_NOBP (-20)
117 #define KDB_BADADDR (-21)
118 #define KDB_NOPERM (-22)
119
120 /*
121 * kdb_diemsg
122 *
123 * Contains a pointer to the last string supplied to the
124 * kernel 'die' panic function.
125 */
126 extern const char *kdb_diemsg;
127
128 #define KDB_FLAG_EARLYKDB (1 << 0) /* set from boot parameter kdb=early */
129 #define KDB_FLAG_CATASTROPHIC (1 << 1) /* A catastrophic event has occurred */
130 #define KDB_FLAG_CMD_INTERRUPT (1 << 2) /* Previous command was interrupted */
131 #define KDB_FLAG_NOIPI (1 << 3) /* Do not send IPIs */
132 #define KDB_FLAG_NO_CONSOLE (1 << 5) /* No console is available,
133 * kdb is disabled */
134 #define KDB_FLAG_NO_VT_CONSOLE (1 << 6) /* No VT console is available, do
135 * not use keyboard */
136 #define KDB_FLAG_NO_I8042 (1 << 7) /* No i8042 chip is available, do
137 * not use keyboard */
138
139 extern unsigned int kdb_flags; /* Global flags, see kdb_state for per cpu state */
140
141 #define KDB_FLAG(flag) (kdb_flags & KDB_FLAG_##flag)
142 #define KDB_FLAG_SET(flag) ((void)(kdb_flags |= KDB_FLAG_##flag))
143 #define KDB_FLAG_CLEAR(flag) ((void)(kdb_flags &= ~KDB_FLAG_##flag))
144
145 /*
146 * External entry point for the kernel debugger. The pt_regs
147 * at the time of entry are supplied along with the reason for
148 * entry to the kernel debugger.
149 */
150
151 typedef enum {
152 KDB_REASON_ENTER = 1, /* KDB_ENTER() trap/fault - regs valid */
153 KDB_REASON_ENTER_SLAVE, /* KDB_ENTER_SLAVE() trap/fault - regs valid */
154 KDB_REASON_BREAK, /* Breakpoint inst. - regs valid */
155 KDB_REASON_DEBUG, /* Debug Fault - regs valid */
156 KDB_REASON_OOPS, /* Kernel Oops - regs valid */
157 KDB_REASON_SWITCH, /* CPU switch - regs valid*/
158 KDB_REASON_KEYBOARD, /* Keyboard entry - regs valid */
159 KDB_REASON_NMI, /* Non-maskable interrupt; regs valid */
160 KDB_REASON_RECURSE, /* Recursive entry to kdb;
161 * regs probably valid */
162 KDB_REASON_SSTEP, /* Single Step trap. - regs valid */
163 KDB_REASON_SYSTEM_NMI, /* In NMI due to SYSTEM cmd; regs valid */
164 } kdb_reason_t;
165
166 enum kdb_msgsrc {
167 KDB_MSGSRC_INTERNAL, /* direct call to kdb_printf() */
168 KDB_MSGSRC_PRINTK, /* trapped from printk() */
169 };
170
171 extern int kdb_trap_printk;
172 extern int kdb_printf_cpu;
173 extern __printf(2, 0) int vkdb_printf(enum kdb_msgsrc src, const char *fmt,
174 va_list args);
175 extern __printf(1, 2) int kdb_printf(const char *, ...);
176 typedef __printf(1, 2) int (*kdb_printf_t)(const char *, ...);
177
178 extern void kdb_init(int level);
179
180 /* Access to kdb specific polling devices */
181 typedef int (*get_char_func)(void);
182 extern get_char_func kdb_poll_funcs[];
183 extern int kdb_get_kbd_char(void);
184
185 static inline
kdb_process_cpu(const struct task_struct * p)186 int kdb_process_cpu(const struct task_struct *p)
187 {
188 unsigned int cpu = task_cpu(p);
189 if (cpu > num_possible_cpus())
190 cpu = 0;
191 return cpu;
192 }
193
194 extern void kdb_send_sig(struct task_struct *p, int sig);
195
196 #ifdef CONFIG_KALLSYMS
197 extern const char *kdb_walk_kallsyms(loff_t *pos);
198 #else /* ! CONFIG_KALLSYMS */
kdb_walk_kallsyms(loff_t * pos)199 static inline const char *kdb_walk_kallsyms(loff_t *pos)
200 {
201 return NULL;
202 }
203 #endif /* ! CONFIG_KALLSYMS */
204
205 /* Dynamic kdb shell command registration */
206 extern int kdb_register(kdbtab_t *cmd);
207 extern void kdb_unregister(kdbtab_t *cmd);
208
209 /* Return true when KDB as locked for printing a message on this CPU. */
210 static inline
kdb_printf_on_this_cpu(void)211 bool kdb_printf_on_this_cpu(void)
212 {
213 /*
214 * We can use raw_smp_processor_id() here because the task could
215 * not get migrated when KDB has locked for printing on this CPU.
216 */
217 return unlikely(READ_ONCE(kdb_printf_cpu) == raw_smp_processor_id());
218 }
219
220 #else /* ! CONFIG_KGDB_KDB */
kdb_printf(const char * fmt,...)221 static inline __printf(1, 2) int kdb_printf(const char *fmt, ...) { return 0; }
kdb_init(int level)222 static inline void kdb_init(int level) {}
kdb_register(kdbtab_t * cmd)223 static inline int kdb_register(kdbtab_t *cmd) { return 0; }
kdb_unregister(kdbtab_t * cmd)224 static inline void kdb_unregister(kdbtab_t *cmd) {}
225
kdb_printf_on_this_cpu(void)226 static inline bool kdb_printf_on_this_cpu(void) { return false; }
227
228 #endif /* CONFIG_KGDB_KDB */
229 enum {
230 KDB_NOT_INITIALIZED,
231 KDB_INIT_EARLY,
232 KDB_INIT_FULL,
233 };
234
235 extern int kdbgetintenv(const char *, int *);
236 extern int kdb_set(int, const char **);
237 int kdb_lsmod(int argc, const char **argv);
238
239 #endif /* !_KDB_H */
240