1 /*
2 * This provides the callbacks and functions that KGDB needs to share between
3 * the core, I/O and arch-specific portions.
4 *
5 * Author: Amit Kale <amitkale@linsyssoft.com> and
6 * Tom Rini <trini@kernel.crashing.org>
7 *
8 * 2001-2004 (c) Amit S. Kale and 2003-2005 (c) MontaVista Software, Inc.
9 * This file is licensed under the terms of the GNU General Public License
10 * version 2. This program is licensed "as is" without any warranty of any
11 * kind, whether express or implied.
12 */
13 #ifndef _KGDB_H_
14 #define _KGDB_H_
15
16 #include <linux/linkage.h>
17 #include <linux/init.h>
18 #include <linux/atomic.h>
19 #ifdef CONFIG_HAVE_ARCH_KGDB
20 #include <asm/kgdb.h>
21 #endif
22
23 #ifdef CONFIG_KGDB
24 struct pt_regs;
25
26 /**
27 * kgdb_skipexception - (optional) exit kgdb_handle_exception early
28 * @exception: Exception vector number
29 * @regs: Current &struct pt_regs.
30 *
31 * On some architectures it is required to skip a breakpoint
32 * exception when it occurs after a breakpoint has been removed.
33 * This can be implemented in the architecture specific portion of kgdb.
34 */
35 extern int kgdb_skipexception(int exception, struct pt_regs *regs);
36
37 struct tasklet_struct;
38 struct task_struct;
39 struct uart_port;
40
41 /**
42 * kgdb_breakpoint - compiled in breakpoint
43 *
44 * This will be implemented as a static inline per architecture. This
45 * function is called by the kgdb core to execute an architecture
46 * specific trap to cause kgdb to enter the exception processing.
47 *
48 */
49 void kgdb_breakpoint(void);
50
51 extern int kgdb_connected;
52 extern int kgdb_io_module_registered;
53
54 extern atomic_t kgdb_setting_breakpoint;
55 extern atomic_t kgdb_cpu_doing_single_step;
56
57 extern struct task_struct *kgdb_usethread;
58 extern struct task_struct *kgdb_contthread;
59
60 enum kgdb_bptype {
61 BP_BREAKPOINT = 0,
62 BP_HARDWARE_BREAKPOINT,
63 BP_WRITE_WATCHPOINT,
64 BP_READ_WATCHPOINT,
65 BP_ACCESS_WATCHPOINT,
66 BP_POKE_BREAKPOINT,
67 };
68
69 enum kgdb_bpstate {
70 BP_UNDEFINED = 0,
71 BP_REMOVED,
72 BP_SET,
73 BP_ACTIVE
74 };
75
76 struct kgdb_bkpt {
77 unsigned long bpt_addr;
78 unsigned char saved_instr[BREAK_INSTR_SIZE];
79 enum kgdb_bptype type;
80 enum kgdb_bpstate state;
81 };
82
83 struct dbg_reg_def_t {
84 char *name;
85 int size;
86 int offset;
87 };
88
89 #ifndef DBG_MAX_REG_NUM
90 #define DBG_MAX_REG_NUM 0
91 #else
92 extern struct dbg_reg_def_t dbg_reg_def[];
93 extern char *dbg_get_reg(int regno, void *mem, struct pt_regs *regs);
94 extern int dbg_set_reg(int regno, void *mem, struct pt_regs *regs);
95 #endif
96 #ifndef KGDB_MAX_BREAKPOINTS
97 # define KGDB_MAX_BREAKPOINTS 1000
98 #endif
99
100 #define KGDB_HW_BREAKPOINT 1
101
102 /*
103 * Functions each KGDB-supporting architecture must provide:
104 */
105
106 /**
107 * kgdb_arch_init - Perform any architecture specific initalization.
108 *
109 * This function will handle the initalization of any architecture
110 * specific callbacks.
111 */
112 extern int kgdb_arch_init(void);
113
114 /**
115 * kgdb_arch_exit - Perform any architecture specific uninitalization.
116 *
117 * This function will handle the uninitalization of any architecture
118 * specific callbacks, for dynamic registration and unregistration.
119 */
120 extern void kgdb_arch_exit(void);
121
122 /**
123 * pt_regs_to_gdb_regs - Convert ptrace regs to GDB regs
124 * @gdb_regs: A pointer to hold the registers in the order GDB wants.
125 * @regs: The &struct pt_regs of the current process.
126 *
127 * Convert the pt_regs in @regs into the format for registers that
128 * GDB expects, stored in @gdb_regs.
129 */
130 extern void pt_regs_to_gdb_regs(unsigned long *gdb_regs, struct pt_regs *regs);
131
132 /**
133 * sleeping_thread_to_gdb_regs - Convert ptrace regs to GDB regs
134 * @gdb_regs: A pointer to hold the registers in the order GDB wants.
135 * @p: The &struct task_struct of the desired process.
136 *
137 * Convert the register values of the sleeping process in @p to
138 * the format that GDB expects.
139 * This function is called when kgdb does not have access to the
140 * &struct pt_regs and therefore it should fill the gdb registers
141 * @gdb_regs with what has been saved in &struct thread_struct
142 * thread field during switch_to.
143 */
144 extern void
145 sleeping_thread_to_gdb_regs(unsigned long *gdb_regs, struct task_struct *p);
146
147 /**
148 * gdb_regs_to_pt_regs - Convert GDB regs to ptrace regs.
149 * @gdb_regs: A pointer to hold the registers we've received from GDB.
150 * @regs: A pointer to a &struct pt_regs to hold these values in.
151 *
152 * Convert the GDB regs in @gdb_regs into the pt_regs, and store them
153 * in @regs.
154 */
155 extern void gdb_regs_to_pt_regs(unsigned long *gdb_regs, struct pt_regs *regs);
156
157 /**
158 * kgdb_arch_handle_exception - Handle architecture specific GDB packets.
159 * @vector: The error vector of the exception that happened.
160 * @signo: The signal number of the exception that happened.
161 * @err_code: The error code of the exception that happened.
162 * @remcom_in_buffer: The buffer of the packet we have read.
163 * @remcom_out_buffer: The buffer of %BUFMAX bytes to write a packet into.
164 * @regs: The &struct pt_regs of the current process.
165 *
166 * This function MUST handle the 'c' and 's' command packets,
167 * as well packets to set / remove a hardware breakpoint, if used.
168 * If there are additional packets which the hardware needs to handle,
169 * they are handled here. The code should return -1 if it wants to
170 * process more packets, and a %0 or %1 if it wants to exit from the
171 * kgdb callback.
172 */
173 extern int
174 kgdb_arch_handle_exception(int vector, int signo, int err_code,
175 char *remcom_in_buffer,
176 char *remcom_out_buffer,
177 struct pt_regs *regs);
178
179 /**
180 * kgdb_call_nmi_hook - Call kgdb_nmicallback() on the current CPU
181 * @ignored: This parameter is only here to match the prototype.
182 *
183 * If you're using the default implementation of kgdb_roundup_cpus()
184 * this function will be called per CPU. If you don't implement
185 * kgdb_call_nmi_hook() a default will be used.
186 */
187
188 extern void kgdb_call_nmi_hook(void *ignored);
189
190 /**
191 * kgdb_roundup_cpus - Get other CPUs into a holding pattern
192 *
193 * On SMP systems, we need to get the attention of the other CPUs
194 * and get them into a known state. This should do what is needed
195 * to get the other CPUs to call kgdb_wait(). Note that on some arches,
196 * the NMI approach is not used for rounding up all the CPUs. Normally
197 * those architectures can just not implement this and get the default.
198 *
199 * On non-SMP systems, this is not called.
200 */
201 extern void kgdb_roundup_cpus(void);
202
203 /**
204 * kgdb_arch_set_pc - Generic call back to the program counter
205 * @regs: Current &struct pt_regs.
206 * @pc: The new value for the program counter
207 *
208 * This function handles updating the program counter and requires an
209 * architecture specific implementation.
210 */
211 extern void kgdb_arch_set_pc(struct pt_regs *regs, unsigned long pc);
212
213
214 /* Optional functions. */
215 extern int kgdb_validate_break_address(unsigned long addr);
216 extern int kgdb_arch_set_breakpoint(struct kgdb_bkpt *bpt);
217 extern int kgdb_arch_remove_breakpoint(struct kgdb_bkpt *bpt);
218
219 /**
220 * kgdb_arch_late - Perform any architecture specific initalization.
221 *
222 * This function will handle the late initalization of any
223 * architecture specific callbacks. This is an optional function for
224 * handling things like late initialization of hw breakpoints. The
225 * default implementation does nothing.
226 */
227 extern void kgdb_arch_late(void);
228
229
230 /**
231 * struct kgdb_arch - Describe architecture specific values.
232 * @gdb_bpt_instr: The instruction to trigger a breakpoint.
233 * @flags: Flags for the breakpoint, currently just %KGDB_HW_BREAKPOINT.
234 * @set_breakpoint: Allow an architecture to specify how to set a software
235 * breakpoint.
236 * @remove_breakpoint: Allow an architecture to specify how to remove a
237 * software breakpoint.
238 * @set_hw_breakpoint: Allow an architecture to specify how to set a hardware
239 * breakpoint.
240 * @remove_hw_breakpoint: Allow an architecture to specify how to remove a
241 * hardware breakpoint.
242 * @disable_hw_break: Allow an architecture to specify how to disable
243 * hardware breakpoints for a single cpu.
244 * @remove_all_hw_break: Allow an architecture to specify how to remove all
245 * hardware breakpoints.
246 * @correct_hw_break: Allow an architecture to specify how to correct the
247 * hardware debug registers.
248 * @enable_nmi: Manage NMI-triggered entry to KGDB
249 */
250 struct kgdb_arch {
251 unsigned char gdb_bpt_instr[BREAK_INSTR_SIZE];
252 unsigned long flags;
253
254 int (*set_breakpoint)(unsigned long, char *);
255 int (*remove_breakpoint)(unsigned long, char *);
256 int (*set_hw_breakpoint)(unsigned long, int, enum kgdb_bptype);
257 int (*remove_hw_breakpoint)(unsigned long, int, enum kgdb_bptype);
258 void (*disable_hw_break)(struct pt_regs *regs);
259 void (*remove_all_hw_break)(void);
260 void (*correct_hw_break)(void);
261
262 void (*enable_nmi)(bool on);
263 };
264
265 /**
266 * struct kgdb_io - Describe the interface for an I/O driver to talk with KGDB.
267 * @name: Name of the I/O driver.
268 * @read_char: Pointer to a function that will return one char.
269 * @write_char: Pointer to a function that will write one char.
270 * @flush: Pointer to a function that will flush any pending writes.
271 * @init: Pointer to a function that will initialize the device.
272 * @pre_exception: Pointer to a function that will do any prep work for
273 * the I/O driver.
274 * @post_exception: Pointer to a function that will do any cleanup work
275 * for the I/O driver.
276 * @is_console: 1 if the end device is a console 0 if the I/O device is
277 * not a console
278 */
279 struct kgdb_io {
280 const char *name;
281 int (*read_char) (void);
282 void (*write_char) (u8);
283 void (*flush) (void);
284 int (*init) (void);
285 void (*pre_exception) (void);
286 void (*post_exception) (void);
287 int is_console;
288 };
289
290 extern const struct kgdb_arch arch_kgdb_ops;
291
292 extern unsigned long kgdb_arch_pc(int exception, struct pt_regs *regs);
293
294 #ifdef CONFIG_SERIAL_KGDB_NMI
295 extern int kgdb_register_nmi_console(void);
296 extern int kgdb_unregister_nmi_console(void);
297 extern bool kgdb_nmi_poll_knock(void);
298 #else
kgdb_register_nmi_console(void)299 static inline int kgdb_register_nmi_console(void) { return 0; }
kgdb_unregister_nmi_console(void)300 static inline int kgdb_unregister_nmi_console(void) { return 0; }
kgdb_nmi_poll_knock(void)301 static inline bool kgdb_nmi_poll_knock(void) { return 1; }
302 #endif
303
304 extern int kgdb_register_io_module(struct kgdb_io *local_kgdb_io_ops);
305 extern void kgdb_unregister_io_module(struct kgdb_io *local_kgdb_io_ops);
306 extern struct kgdb_io *dbg_io_ops;
307
308 extern int kgdb_hex2long(char **ptr, unsigned long *long_val);
309 extern char *kgdb_mem2hex(char *mem, char *buf, int count);
310 extern int kgdb_hex2mem(char *buf, char *mem, int count);
311
312 extern int kgdb_isremovedbreak(unsigned long addr);
313 extern void kgdb_schedule_breakpoint(void);
314
315 extern int
316 kgdb_handle_exception(int ex_vector, int signo, int err_code,
317 struct pt_regs *regs);
318 extern int kgdb_nmicallback(int cpu, void *regs);
319 extern int kgdb_nmicallin(int cpu, int trapnr, void *regs, int err_code,
320 atomic_t *snd_rdy);
321 extern void gdbstub_exit(int status);
322
323 extern int kgdb_single_step;
324 extern atomic_t kgdb_active;
325 #define in_dbg_master() \
326 (raw_smp_processor_id() == atomic_read(&kgdb_active))
327 extern bool dbg_is_early;
328 extern void __init dbg_late_init(void);
329 extern void kgdb_panic(const char *msg);
330 #else /* ! CONFIG_KGDB */
331 #define in_dbg_master() (0)
332 #define dbg_late_init()
kgdb_panic(const char * msg)333 static inline void kgdb_panic(const char *msg) {}
334 #endif /* ! CONFIG_KGDB */
335 #endif /* _KGDB_H_ */
336
