summaryrefslogtreecommitdiff
path: root/include/linux/kgdb.h
blob: 6c784ab6856ac006803c52d7d064595262caf345 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
/*
 * This provides the callbacks and functions that KGDB needs to share between
 * the core, I/O and arch-specific portions.
 *
 * Author: Amit Kale <amitkale@linsyssoft.com> and
 *         Tom Rini <trini@kernel.crashing.org>
 *
 * 2001-2004 (c) Amit S. Kale and 2003-2005 (c) MontaVista Software, Inc.
 * 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 _KGDB_H_
#define _KGDB_H_

#include <linux/serial_8250.h>
#include <linux/linkage.h>
#include <linux/init.h>
#include <asm/atomic.h>
#ifdef CONFIG_HAVE_ARCH_KGDB
#include <asm/kgdb.h>
#endif

#ifdef CONFIG_KGDB
struct pt_regs;

/**
 *	kgdb_skipexception - (optional) exit kgdb_handle_exception early
 *	@exception: Exception vector number
 *	@regs: Current &struct pt_regs.
 *
 *	On some architectures it is required to skip a breakpoint
 *	exception when it occurs after a breakpoint has been removed.
 *	This can be implemented in the architecture specific portion of kgdb.
 */
extern int kgdb_skipexception(int exception, struct pt_regs *regs);

/**
 *	kgdb_disable_hw_debug - (optional) Disable hardware debugging hook
 *	@regs: Current &struct pt_regs.
 *
 *	This function will be called if the particular architecture must
 *	disable hardware debugging while it is processing gdb packets or
 *	handling exception.
 */
extern void kgdb_disable_hw_debug(struct pt_regs *regs);

struct tasklet_struct;
struct task_struct;
struct uart_port;

/**
 *	kgdb_breakpoint - compiled in breakpoint
 *
 *	This will be implemented as a static inline per architecture.  This
 *	function is called by the kgdb core to execute an architecture
 *	specific trap to cause kgdb to enter the exception processing.
 *
 */
void kgdb_breakpoint(void);

extern int kgdb_connected;
extern int kgdb_io_module_registered;

extern atomic_t			kgdb_setting_breakpoint;
extern atomic_t			kgdb_cpu_doing_single_step;

extern struct task_struct	*kgdb_usethread;
extern struct task_struct	*kgdb_contthread;

enum kgdb_bptype {
	BP_BREAKPOINT = 0,
	BP_HARDWARE_BREAKPOINT,
	BP_WRITE_WATCHPOINT,
	BP_READ_WATCHPOINT,
	BP_ACCESS_WATCHPOINT
};

enum kgdb_bpstate {
	BP_UNDEFINED = 0,
	BP_REMOVED,
	BP_SET,
	BP_ACTIVE
};

struct kgdb_bkpt {
	unsigned long		bpt_addr;
	unsigned char		saved_instr[BREAK_INSTR_SIZE];
	enum kgdb_bptype	type;
	enum kgdb_bpstate	state;
};

#ifndef KGDB_MAX_BREAKPOINTS
# define KGDB_MAX_BREAKPOINTS	1000
#endif

#define KGDB_HW_BREAKPOINT	1

/*
 * Functions each KGDB-supporting architecture must provide:
 */

/**
 *	kgdb_arch_init - Perform any architecture specific initalization.
 *
 *	This function will handle the initalization of any architecture
 *	specific callbacks.
 */
extern int kgdb_arch_init(void);

/**
 *	kgdb_arch_exit - Perform any architecture specific uninitalization.
 *
 *	This function will handle the uninitalization of any architecture
 *	specific callbacks, for dynamic registration and unregistration.
 */
extern void kgdb_arch_exit(void);

/**
 *	pt_regs_to_gdb_regs - Convert ptrace regs to GDB regs
 *	@gdb_regs: A pointer to hold the registers in the order GDB wants.
 *	@regs: The &struct pt_regs of the current process.
 *
 *	Convert the pt_regs in @regs into the format for registers that
 *	GDB expects, stored in @gdb_regs.
 */
extern void pt_regs_to_gdb_regs(unsigned long *gdb_regs, struct pt_regs *regs);

/**
 *	sleeping_thread_to_gdb_regs - Convert ptrace regs to GDB regs
 *	@gdb_regs: A pointer to hold the registers in the order GDB wants.
 *	@p: The &struct task_struct of the desired process.
 *
 *	Convert the register values of the sleeping process in @p to
 *	the format that GDB expects.
 *	This function is called when kgdb does not have access to the
 *	&struct pt_regs and therefore it should fill the gdb registers
 *	@gdb_regs with what has	been saved in &struct thread_struct
 *	thread field during switch_to.
 */
extern void
sleeping_thread_to_gdb_regs(unsigned long *gdb_regs, struct task_struct *p);

/**
 *	gdb_regs_to_pt_regs - Convert GDB regs to ptrace regs.
 *	@gdb_regs: A pointer to hold the registers we've received from GDB.
 *	@regs: A pointer to a &struct pt_regs to hold these values in.
 *
 *	Convert the GDB regs in @gdb_regs into the pt_regs, and store them
 *	in @regs.
 */
extern void gdb_regs_to_pt_regs(unsigned long *gdb_regs, struct pt_regs *regs);

/**
 *	kgdb_arch_handle_exception - Handle architecture specific GDB packets.
 *	@vector: The error vector of the exception that happened.
 *	@signo: The signal number of the exception that happened.
 *	@err_code: The error code of the exception that happened.
 *	@remcom_in_buffer: The buffer of the packet we have read.
 *	@remcom_out_buffer: The buffer of %BUFMAX bytes to write a packet into.
 *	@regs: The &struct pt_regs of the current process.
 *
 *	This function MUST handle the 'c' and 's' command packets,
 *	as well packets to set / remove a hardware breakpoint, if used.
 *	If there are additional packets which the hardware needs to handle,
 *	they are handled here.  The code should return -1 if it wants to
 *	process more packets, and a %0 or %1 if it wants to exit from the
 *	kgdb callback.
 */
extern int
kgdb_arch_handle_exception(int vector, int signo, int err_code,
			   char *remcom_in_buffer,
			   char *remcom_out_buffer,
			   struct pt_regs *regs);

/**
 *	kgdb_roundup_cpus - Get other CPUs into a holding pattern
 *	@flags: Current IRQ state
 *
 *	On SMP systems, we need to get the attention of the other CPUs
 *	and get them into a known state.  This should do what is needed
 *	to get the other CPUs to call kgdb_wait(). Note that on some arches,
 *	the NMI approach is not used for rounding up all the CPUs. For example,
 *	in case of MIPS, smp_call_function() is used to roundup CPUs. In
 *	this case, we have to make sure that interrupts are enabled before
 *	calling smp_call_function(). The argument to this function is
 *	the flags that will be used when restoring the interrupts. There is
 *	local_irq_save() call before kgdb_roundup_cpus().
 *
 *	On non-SMP systems, this is not called.
 */
extern void kgdb_roundup_cpus(unsigned long flags);

/**
 *	kgdb_arch_set_pc - Generic call back to the program counter
 *	@regs: Current &struct pt_regs.
 *  @pc: The new value for the program counter
 *
 *	This function handles updating the program counter and requires an
 *	architecture specific implementation.
 */
extern void kgdb_arch_set_pc(struct pt_regs *regs, unsigned long pc);


/* Optional functions. */
extern int kgdb_validate_break_address(unsigned long addr);
extern int kgdb_arch_set_breakpoint(unsigned long addr, char *saved_instr);
extern int kgdb_arch_remove_breakpoint(unsigned long addr, char *bundle);

/**
 * struct kgdb_arch - Describe architecture specific values.
 * @gdb_bpt_instr: The instruction to trigger a breakpoint.
 * @flags: Flags for the breakpoint, currently just %KGDB_HW_BREAKPOINT.
 * @set_breakpoint: Allow an architecture to specify how to set a software
 * breakpoint.
 * @remove_breakpoint: Allow an architecture to specify how to remove a
 * software breakpoint.
 * @set_hw_breakpoint: Allow an architecture to specify how to set a hardware
 * breakpoint.
 * @remove_hw_breakpoint: Allow an architecture to specify how to remove a
 * hardware breakpoint.
 * @remove_all_hw_break: Allow an architecture to specify how to remove all
 * hardware breakpoints.
 * @correct_hw_break: Allow an architecture to specify how to correct the
 * hardware debug registers.
 */
struct kgdb_arch {
	unsigned char		gdb_bpt_instr[BREAK_INSTR_SIZE];
	unsigned long		flags;

	int	(*set_breakpoint)(unsigned long, char *);
	int	(*remove_breakpoint)(unsigned long, char *);
	int	(*set_hw_breakpoint)(unsigned long, int, enum kgdb_bptype);
	int	(*remove_hw_breakpoint)(unsigned long, int, enum kgdb_bptype);
	void	(*remove_all_hw_break)(void);
	void	(*correct_hw_break)(void);
};

/**
 * struct kgdb_io - Describe the interface for an I/O driver to talk with KGDB.
 * @name: Name of the I/O driver.
 * @read_char: Pointer to a function that will return one char.
 * @write_char: Pointer to a function that will write one char.
 * @flush: Pointer to a function that will flush any pending writes.
 * @init: Pointer to a function that will initialize the device.
 * @pre_exception: Pointer to a function that will do any prep work for
 * the I/O driver.
 * @post_exception: Pointer to a function that will do any cleanup work
 * for the I/O driver.
 * @is_console: 1 if the end device is a console 0 if the I/O device is
 * not a console
 */
struct kgdb_io {
	const char		*name;
	int			(*read_char) (void);
	void			(*write_char) (u8);
	void			(*flush) (void);
	int			(*init) (void);
	void			(*pre_exception) (void);
	void			(*post_exception) (void);
	int			is_console;
};

extern struct kgdb_arch		arch_kgdb_ops;

extern unsigned long __weak kgdb_arch_pc(int exception, struct pt_regs *regs);

extern int kgdb_register_io_module(struct kgdb_io *local_kgdb_io_ops);
extern void kgdb_unregister_io_module(struct kgdb_io *local_kgdb_io_ops);
extern struct kgdb_io *dbg_io_ops;

extern int kgdb_hex2long(char **ptr, unsigned long *long_val);
extern int kgdb_mem2hex(char *mem, char *buf, int count);
extern int kgdb_hex2mem(char *buf, char *mem, int count);

extern int kgdb_isremovedbreak(unsigned long addr);
extern void kgdb_schedule_breakpoint(void);

extern int
kgdb_handle_exception(int ex_vector, int signo, int err_code,
		      struct pt_regs *regs);
extern int kgdb_nmicallback(int cpu, void *regs);

extern int			kgdb_single_step;
extern atomic_t			kgdb_active;
#define in_dbg_master() \
	(raw_smp_processor_id() == atomic_read(&kgdb_active))
#else /* ! CONFIG_KGDB */
#define in_dbg_master() (0)
#endif /* ! CONFIG_KGDB */
#endif /* _KGDB_H_ */