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 | #include <linux/kprobes.h> |
20 | #ifdef CONFIG_HAVE_ARCH_KGDB |
21 | #include <asm/kgdb.h> |
22 | #endif |
23 | |
24 | #ifdef CONFIG_KGDB |
25 | struct pt_regs; |
26 | |
27 | /** |
28 | * kgdb_skipexception - (optional) exit kgdb_handle_exception early |
29 | * @exception: Exception vector number |
30 | * @regs: Current &struct pt_regs. |
31 | * |
32 | * On some architectures it is required to skip a breakpoint |
33 | * exception when it occurs after a breakpoint has been removed. |
34 | * This can be implemented in the architecture specific portion of kgdb. |
35 | */ |
36 | extern int kgdb_skipexception(int exception, struct pt_regs *regs); |
37 | |
38 | struct tasklet_struct; |
39 | struct task_struct; |
40 | struct uart_port; |
41 | |
42 | /** |
43 | * kgdb_breakpoint - compiled in breakpoint |
44 | * |
45 | * This will be implemented as a static inline per architecture. This |
46 | * function is called by the kgdb core to execute an architecture |
47 | * specific trap to cause kgdb to enter the exception processing. |
48 | * |
49 | */ |
50 | void kgdb_breakpoint(void); |
51 | |
52 | extern int kgdb_connected; |
53 | extern int kgdb_io_module_registered; |
54 | |
55 | extern atomic_t kgdb_setting_breakpoint; |
56 | extern atomic_t kgdb_cpu_doing_single_step; |
57 | |
58 | extern struct task_struct *kgdb_usethread; |
59 | extern struct task_struct *kgdb_contthread; |
60 | |
61 | enum kgdb_bptype { |
62 | BP_BREAKPOINT = 0, |
63 | BP_HARDWARE_BREAKPOINT, |
64 | BP_WRITE_WATCHPOINT, |
65 | BP_READ_WATCHPOINT, |
66 | BP_ACCESS_WATCHPOINT, |
67 | BP_POKE_BREAKPOINT, |
68 | }; |
69 | |
70 | enum kgdb_bpstate { |
71 | BP_UNDEFINED = 0, |
72 | BP_REMOVED, |
73 | BP_SET, |
74 | BP_ACTIVE |
75 | }; |
76 | |
77 | struct kgdb_bkpt { |
78 | unsigned long bpt_addr; |
79 | unsigned char saved_instr[BREAK_INSTR_SIZE]; |
80 | enum kgdb_bptype type; |
81 | enum kgdb_bpstate state; |
82 | }; |
83 | |
84 | struct dbg_reg_def_t { |
85 | char *name; |
86 | int size; |
87 | int offset; |
88 | }; |
89 | |
90 | #ifndef DBG_MAX_REG_NUM |
91 | #define DBG_MAX_REG_NUM 0 |
92 | #else |
93 | extern struct dbg_reg_def_t dbg_reg_def[]; |
94 | extern char *dbg_get_reg(int regno, void *mem, struct pt_regs *regs); |
95 | extern int dbg_set_reg(int regno, void *mem, struct pt_regs *regs); |
96 | #endif |
97 | #ifndef KGDB_MAX_BREAKPOINTS |
98 | # define KGDB_MAX_BREAKPOINTS 1000 |
99 | #endif |
100 | |
101 | #define KGDB_HW_BREAKPOINT 1 |
102 | |
103 | /* |
104 | * Functions each KGDB-supporting architecture must provide: |
105 | */ |
106 | |
107 | /** |
108 | * kgdb_arch_init - Perform any architecture specific initialization. |
109 | * |
110 | * This function will handle the initialization of any architecture |
111 | * specific callbacks. |
112 | */ |
113 | extern int kgdb_arch_init(void); |
114 | |
115 | /** |
116 | * kgdb_arch_exit - Perform any architecture specific uninitalization. |
117 | * |
118 | * This function will handle the uninitalization of any architecture |
119 | * specific callbacks, for dynamic registration and unregistration. |
120 | */ |
121 | extern void kgdb_arch_exit(void); |
122 | |
123 | /** |
124 | * pt_regs_to_gdb_regs - Convert ptrace regs to GDB regs |
125 | * @gdb_regs: A pointer to hold the registers in the order GDB wants. |
126 | * @regs: The &struct pt_regs of the current process. |
127 | * |
128 | * Convert the pt_regs in @regs into the format for registers that |
129 | * GDB expects, stored in @gdb_regs. |
130 | */ |
131 | extern void pt_regs_to_gdb_regs(unsigned long *gdb_regs, struct pt_regs *regs); |
132 | |
133 | /** |
134 | * sleeping_thread_to_gdb_regs - Convert ptrace regs to GDB regs |
135 | * @gdb_regs: A pointer to hold the registers in the order GDB wants. |
136 | * @p: The &struct task_struct of the desired process. |
137 | * |
138 | * Convert the register values of the sleeping process in @p to |
139 | * the format that GDB expects. |
140 | * This function is called when kgdb does not have access to the |
141 | * &struct pt_regs and therefore it should fill the gdb registers |
142 | * @gdb_regs with what has been saved in &struct thread_struct |
143 | * thread field during switch_to. |
144 | */ |
145 | extern void |
146 | sleeping_thread_to_gdb_regs(unsigned long *gdb_regs, struct task_struct *p); |
147 | |
148 | /** |
149 | * gdb_regs_to_pt_regs - Convert GDB regs to ptrace regs. |
150 | * @gdb_regs: A pointer to hold the registers we've received from GDB. |
151 | * @regs: A pointer to a &struct pt_regs to hold these values in. |
152 | * |
153 | * Convert the GDB regs in @gdb_regs into the pt_regs, and store them |
154 | * in @regs. |
155 | */ |
156 | extern void gdb_regs_to_pt_regs(unsigned long *gdb_regs, struct pt_regs *regs); |
157 | |
158 | /** |
159 | * kgdb_arch_handle_exception - Handle architecture specific GDB packets. |
160 | * @vector: The error vector of the exception that happened. |
161 | * @signo: The signal number of the exception that happened. |
162 | * @err_code: The error code of the exception that happened. |
163 | * @remcom_in_buffer: The buffer of the packet we have read. |
164 | * @remcom_out_buffer: The buffer of %BUFMAX bytes to write a packet into. |
165 | * @regs: The &struct pt_regs of the current process. |
166 | * |
167 | * This function MUST handle the 'c' and 's' command packets, |
168 | * as well packets to set / remove a hardware breakpoint, if used. |
169 | * If there are additional packets which the hardware needs to handle, |
170 | * they are handled here. The code should return -1 if it wants to |
171 | * process more packets, and a %0 or %1 if it wants to exit from the |
172 | * kgdb callback. |
173 | */ |
174 | extern int |
175 | kgdb_arch_handle_exception(int vector, int signo, int err_code, |
176 | char *remcom_in_buffer, |
177 | char *remcom_out_buffer, |
178 | struct pt_regs *regs); |
179 | |
180 | /** |
181 | * kgdb_arch_handle_qxfer_pkt - Handle architecture specific GDB XML |
182 | * packets. |
183 | * @remcom_in_buffer: The buffer of the packet we have read. |
184 | * @remcom_out_buffer: The buffer of %BUFMAX bytes to write a packet into. |
185 | */ |
186 | |
187 | extern void |
188 | kgdb_arch_handle_qxfer_pkt(char *remcom_in_buffer, |
189 | char *remcom_out_buffer); |
190 | |
191 | /** |
192 | * kgdb_call_nmi_hook - Call kgdb_nmicallback() on the current CPU |
193 | * @ignored: This parameter is only here to match the prototype. |
194 | * |
195 | * If you're using the default implementation of kgdb_roundup_cpus() |
196 | * this function will be called per CPU. If you don't implement |
197 | * kgdb_call_nmi_hook() a default will be used. |
198 | */ |
199 | |
200 | extern void kgdb_call_nmi_hook(void *ignored); |
201 | |
202 | /** |
203 | * kgdb_roundup_cpus - Get other CPUs into a holding pattern |
204 | * |
205 | * On SMP systems, we need to get the attention of the other CPUs |
206 | * and get them into a known state. This should do what is needed |
207 | * to get the other CPUs to call kgdb_wait(). Note that on some arches, |
208 | * the NMI approach is not used for rounding up all the CPUs. Normally |
209 | * those architectures can just not implement this and get the default. |
210 | * |
211 | * On non-SMP systems, this is not called. |
212 | */ |
213 | extern void kgdb_roundup_cpus(void); |
214 | |
215 | /** |
216 | * kgdb_arch_set_pc - Generic call back to the program counter |
217 | * @regs: Current &struct pt_regs. |
218 | * @pc: The new value for the program counter |
219 | * |
220 | * This function handles updating the program counter and requires an |
221 | * architecture specific implementation. |
222 | */ |
223 | extern void kgdb_arch_set_pc(struct pt_regs *regs, unsigned long pc); |
224 | |
225 | |
226 | /* Optional functions. */ |
227 | extern int kgdb_validate_break_address(unsigned long addr); |
228 | extern int kgdb_arch_set_breakpoint(struct kgdb_bkpt *bpt); |
229 | extern int kgdb_arch_remove_breakpoint(struct kgdb_bkpt *bpt); |
230 | |
231 | /** |
232 | * kgdb_arch_late - Perform any architecture specific initialization. |
233 | * |
234 | * This function will handle the late initialization of any |
235 | * architecture specific callbacks. This is an optional function for |
236 | * handling things like late initialization of hw breakpoints. The |
237 | * default implementation does nothing. |
238 | */ |
239 | extern void kgdb_arch_late(void); |
240 | |
241 | |
242 | /** |
243 | * struct kgdb_arch - Describe architecture specific values. |
244 | * @gdb_bpt_instr: The instruction to trigger a breakpoint. |
245 | * @flags: Flags for the breakpoint, currently just %KGDB_HW_BREAKPOINT. |
246 | * @set_breakpoint: Allow an architecture to specify how to set a software |
247 | * breakpoint. |
248 | * @remove_breakpoint: Allow an architecture to specify how to remove a |
249 | * software breakpoint. |
250 | * @set_hw_breakpoint: Allow an architecture to specify how to set a hardware |
251 | * breakpoint. |
252 | * @remove_hw_breakpoint: Allow an architecture to specify how to remove a |
253 | * hardware breakpoint. |
254 | * @disable_hw_break: Allow an architecture to specify how to disable |
255 | * hardware breakpoints for a single cpu. |
256 | * @remove_all_hw_break: Allow an architecture to specify how to remove all |
257 | * hardware breakpoints. |
258 | * @correct_hw_break: Allow an architecture to specify how to correct the |
259 | * hardware debug registers. |
260 | * @enable_nmi: Manage NMI-triggered entry to KGDB |
261 | */ |
262 | struct kgdb_arch { |
263 | unsigned char gdb_bpt_instr[BREAK_INSTR_SIZE]; |
264 | unsigned long flags; |
265 | |
266 | int (*set_breakpoint)(unsigned long, char *); |
267 | int (*remove_breakpoint)(unsigned long, char *); |
268 | int (*set_hw_breakpoint)(unsigned long, int, enum kgdb_bptype); |
269 | int (*remove_hw_breakpoint)(unsigned long, int, enum kgdb_bptype); |
270 | void (*disable_hw_break)(struct pt_regs *regs); |
271 | void (*remove_all_hw_break)(void); |
272 | void (*correct_hw_break)(void); |
273 | |
274 | void (*enable_nmi)(bool on); |
275 | }; |
276 | |
277 | /** |
278 | * struct kgdb_io - Describe the interface for an I/O driver to talk with KGDB. |
279 | * @name: Name of the I/O driver. |
280 | * @read_char: Pointer to a function that will return one char. |
281 | * @write_char: Pointer to a function that will write one char. |
282 | * @flush: Pointer to a function that will flush any pending writes. |
283 | * @init: Pointer to a function that will initialize the device. |
284 | * @deinit: Pointer to a function that will deinit the device. Implies that |
285 | * this I/O driver is temporary and expects to be replaced. Called when |
286 | * an I/O driver is replaced or explicitly unregistered. |
287 | * @pre_exception: Pointer to a function that will do any prep work for |
288 | * the I/O driver. |
289 | * @post_exception: Pointer to a function that will do any cleanup work |
290 | * for the I/O driver. |
291 | * @cons: valid if the I/O device is a console; else NULL. |
292 | */ |
293 | struct kgdb_io { |
294 | const char *name; |
295 | int (*read_char) (void); |
296 | void (*write_char) (u8); |
297 | void (*flush) (void); |
298 | int (*init) (void); |
299 | void (*deinit) (void); |
300 | void (*pre_exception) (void); |
301 | void (*post_exception) (void); |
302 | struct console *cons; |
303 | }; |
304 | |
305 | extern const struct kgdb_arch arch_kgdb_ops; |
306 | |
307 | extern unsigned long kgdb_arch_pc(int exception, struct pt_regs *regs); |
308 | |
309 | #ifdef CONFIG_SERIAL_KGDB_NMI |
310 | extern int kgdb_register_nmi_console(void); |
311 | extern int kgdb_unregister_nmi_console(void); |
312 | extern bool kgdb_nmi_poll_knock(void); |
313 | #else |
314 | static inline int kgdb_register_nmi_console(void) { return 0; } |
315 | static inline int kgdb_unregister_nmi_console(void) { return 0; } |
316 | static inline bool kgdb_nmi_poll_knock(void) { return true; } |
317 | #endif |
318 | |
319 | extern int kgdb_register_io_module(struct kgdb_io *local_kgdb_io_ops); |
320 | extern void kgdb_unregister_io_module(struct kgdb_io *local_kgdb_io_ops); |
321 | extern struct kgdb_io *dbg_io_ops; |
322 | |
323 | extern int kgdb_hex2long(char **ptr, unsigned long *long_val); |
324 | extern char *kgdb_mem2hex(char *mem, char *buf, int count); |
325 | extern int kgdb_hex2mem(char *buf, char *mem, int count); |
326 | |
327 | extern int kgdb_isremovedbreak(unsigned long addr); |
328 | extern int kgdb_has_hit_break(unsigned long addr); |
329 | |
330 | extern int |
331 | kgdb_handle_exception(int ex_vector, int signo, int err_code, |
332 | struct pt_regs *regs); |
333 | extern int kgdb_nmicallback(int cpu, void *regs); |
334 | extern int kgdb_nmicallin(int cpu, int trapnr, void *regs, int err_code, |
335 | atomic_t *snd_rdy); |
336 | extern void gdbstub_exit(int status); |
337 | |
338 | /* |
339 | * kgdb and kprobes both use the same (kprobe) blocklist (which makes sense |
340 | * given they are both typically hooked up to the same trap meaning on most |
341 | * architectures one cannot be used to debug the other) |
342 | * |
343 | * However on architectures where kprobes is not (yet) implemented we permit |
344 | * breakpoints everywhere rather than blocking everything by default. |
345 | */ |
346 | static inline bool kgdb_within_blocklist(unsigned long addr) |
347 | { |
348 | #ifdef CONFIG_KGDB_HONOUR_BLOCKLIST |
349 | return within_kprobe_blacklist(addr); |
350 | #else |
351 | return false; |
352 | #endif |
353 | } |
354 | |
355 | extern int kgdb_single_step; |
356 | extern atomic_t kgdb_active; |
357 | #define in_dbg_master() \ |
358 | (irqs_disabled() && (smp_processor_id() == atomic_read(&kgdb_active))) |
359 | extern bool dbg_is_early; |
360 | extern void __init dbg_late_init(void); |
361 | extern void kgdb_panic(const char *msg); |
362 | extern void kgdb_free_init_mem(void); |
363 | #else /* ! CONFIG_KGDB */ |
364 | #define in_dbg_master() (0) |
365 | #define dbg_late_init() |
366 | static inline void kgdb_panic(const char *msg) {} |
367 | static inline void kgdb_free_init_mem(void) { } |
368 | static inline int kgdb_nmicallback(int cpu, void *regs) { return 1; } |
369 | #endif /* ! CONFIG_KGDB */ |
370 | #endif /* _KGDB_H_ */ |
371 | |