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_roundup_cpus - Get other CPUs into a holding pattern
181 * @flags: Current IRQ state
182 *
183 * On SMP systems, we need to get the attention of the other CPUs
184 * and get them into a known state. This should do what is needed
185 * to get the other CPUs to call kgdb_wait(). Note that on some arches,
186 * the NMI approach is not used for rounding up all the CPUs. For example,
187 * in case of MIPS, smp_call_function() is used to roundup CPUs. In
188 * this case, we have to make sure that interrupts are enabled before
189 * calling smp_call_function(). The argument to this function is
190 * the flags that will be used when restoring the interrupts. There is
191 * local_irq_save() call before kgdb_roundup_cpus().
192 *
193 * On non-SMP systems, this is not called.
194 */
195 extern void kgdb_roundup_cpus(unsigned long flags);
196
197 /**
198 * kgdb_arch_set_pc - Generic call back to the program counter
199 * @regs: Current &struct pt_regs.
200 * @pc: The new value for the program counter
201 *
202 * This function handles updating the program counter and requires an
203 * architecture specific implementation.
204 */
205 extern void kgdb_arch_set_pc(struct pt_regs *regs, unsigned long pc);
206
207
208 /* Optional functions. */
209 extern int kgdb_validate_break_address(unsigned long addr);
210 extern int kgdb_arch_set_breakpoint(struct kgdb_bkpt *bpt);
211 extern int kgdb_arch_remove_breakpoint(struct kgdb_bkpt *bpt);
212
213 /**
214 * kgdb_arch_late - Perform any architecture specific initalization.
215 *
216 * This function will handle the late initalization of any
217 * architecture specific callbacks. This is an optional function for
218 * handling things like late initialization of hw breakpoints. The
219 * default implementation does nothing.
220 */
221 extern void kgdb_arch_late(void);
222
223
224 /**
225 * struct kgdb_arch - Describe architecture specific values.
226 * @gdb_bpt_instr: The instruction to trigger a breakpoint.
227 * @flags: Flags for the breakpoint, currently just %KGDB_HW_BREAKPOINT.
228 * @set_breakpoint: Allow an architecture to specify how to set a software
229 * breakpoint.
230 * @remove_breakpoint: Allow an architecture to specify how to remove a
231 * software breakpoint.
232 * @set_hw_breakpoint: Allow an architecture to specify how to set a hardware
233 * breakpoint.
234 * @remove_hw_breakpoint: Allow an architecture to specify how to remove a
235 * hardware breakpoint.
236 * @disable_hw_break: Allow an architecture to specify how to disable
237 * hardware breakpoints for a single cpu.
238 * @remove_all_hw_break: Allow an architecture to specify how to remove all
239 * hardware breakpoints.
240 * @correct_hw_break: Allow an architecture to specify how to correct the
241 * hardware debug registers.
242 * @enable_nmi: Manage NMI-triggered entry to KGDB
243 */
244 struct kgdb_arch {
245 unsigned char gdb_bpt_instr[BREAK_INSTR_SIZE];
246 unsigned long flags;
247
248 int (*set_breakpoint)(unsigned long, char *);
249 int (*remove_breakpoint)(unsigned long, char *);
250 int (*set_hw_breakpoint)(unsigned long, int, enum kgdb_bptype);
251 int (*remove_hw_breakpoint)(unsigned long, int, enum kgdb_bptype);
252 void (*disable_hw_break)(struct pt_regs *regs);
253 void (*remove_all_hw_break)(void);
254 void (*correct_hw_break)(void);
255
256 void (*enable_nmi)(bool on);
257 };
258
259 /**
260 * struct kgdb_io - Describe the interface for an I/O driver to talk with KGDB.
261 * @name: Name of the I/O driver.
262 * @read_char: Pointer to a function that will return one char.
263 * @write_char: Pointer to a function that will write one char.
264 * @flush: Pointer to a function that will flush any pending writes.
265 * @init: Pointer to a function that will initialize the device.
266 * @pre_exception: Pointer to a function that will do any prep work for
267 * the I/O driver.
268 * @post_exception: Pointer to a function that will do any cleanup work
269 * for the I/O driver.
270 * @is_console: 1 if the end device is a console 0 if the I/O device is
271 * not a console
272 */
273 struct kgdb_io {
274 const char *name;
275 int (*read_char) (void);
276 void (*write_char) (u8);
277 void (*flush) (void);
278 int (*init) (void);
279 void (*pre_exception) (void);
280 void (*post_exception) (void);
281 int is_console;
282 };
283
284 extern struct kgdb_arch arch_kgdb_ops;
285
286 extern unsigned long kgdb_arch_pc(int exception, struct pt_regs *regs);
287
288 #ifdef CONFIG_SERIAL_KGDB_NMI
289 extern int kgdb_register_nmi_console(void);
290 extern int kgdb_unregister_nmi_console(void);
291 extern bool kgdb_nmi_poll_knock(void);
292 #else
kgdb_register_nmi_console(void)293 static inline int kgdb_register_nmi_console(void) { return 0; }
kgdb_unregister_nmi_console(void)294 static inline int kgdb_unregister_nmi_console(void) { return 0; }
kgdb_nmi_poll_knock(void)295 static inline bool kgdb_nmi_poll_knock(void) { return 1; }
296 #endif
297
298 extern int kgdb_register_io_module(struct kgdb_io *local_kgdb_io_ops);
299 extern void kgdb_unregister_io_module(struct kgdb_io *local_kgdb_io_ops);
300 extern struct kgdb_io *dbg_io_ops;
301
302 extern int kgdb_hex2long(char **ptr, unsigned long *long_val);
303 extern char *kgdb_mem2hex(char *mem, char *buf, int count);
304 extern int kgdb_hex2mem(char *buf, char *mem, int count);
305
306 extern int kgdb_isremovedbreak(unsigned long addr);
307 extern void kgdb_schedule_breakpoint(void);
308
309 extern int
310 kgdb_handle_exception(int ex_vector, int signo, int err_code,
311 struct pt_regs *regs);
312 extern int kgdb_nmicallback(int cpu, void *regs);
313 extern int kgdb_nmicallin(int cpu, int trapnr, void *regs, int err_code,
314 atomic_t *snd_rdy);
315 extern void gdbstub_exit(int status);
316
317 extern int kgdb_single_step;
318 extern atomic_t kgdb_active;
319 #define in_dbg_master() \
320 (raw_smp_processor_id() == atomic_read(&kgdb_active))
321 extern bool dbg_is_early;
322 extern void __init dbg_late_init(void);
323 #else /* ! CONFIG_KGDB */
324 #define in_dbg_master() (0)
325 #define dbg_late_init()
326 #endif /* ! CONFIG_KGDB */
327 #endif /* _KGDB_H_ */
328
