diff options
author | Jason Wessel <jason.wessel@windriver.com> | 2009-05-19 08:49:32 -0400 |
---|---|---|
committer | Jason Wessel <jason.wessel@windriver.com> | 2010-05-20 22:04:18 -0400 |
commit | c433820971ffa854feda6adc17f5f24201354f11 (patch) | |
tree | efb8028cc56e36eeade40d3a96bb461a242bab51 /kernel/debug | |
parent | a0fe3cc5d36a5f5b4f60abfe1a4b1caf4a5cce5a (diff) |
Move kernel/kgdb.c to kernel/debug/debug_core.c
Move kgdb.c in preparation to separate the gdbstub from the debug
core and exception handling.
CC: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
Diffstat (limited to 'kernel/debug')
-rw-r--r-- | kernel/debug/Makefile | 6 | ||||
-rw-r--r-- | kernel/debug/debug_core.c | 1764 |
2 files changed, 1770 insertions, 0 deletions
diff --git a/kernel/debug/Makefile b/kernel/debug/Makefile new file mode 100644 index 000000000000..5d7850415266 --- /dev/null +++ b/kernel/debug/Makefile | |||
@@ -0,0 +1,6 @@ | |||
1 | # | ||
2 | # Makefile for the linux kernel debugger | ||
3 | # | ||
4 | |||
5 | obj-$(CONFIG_KGDB) += debug_core.o | ||
6 | |||
diff --git a/kernel/debug/debug_core.c b/kernel/debug/debug_core.c new file mode 100644 index 000000000000..11f3515ca83f --- /dev/null +++ b/kernel/debug/debug_core.c | |||
@@ -0,0 +1,1764 @@ | |||
1 | /* | ||
2 | * KGDB stub. | ||
3 | * | ||
4 | * Maintainer: Jason Wessel <jason.wessel@windriver.com> | ||
5 | * | ||
6 | * Copyright (C) 2000-2001 VERITAS Software Corporation. | ||
7 | * Copyright (C) 2002-2004 Timesys Corporation | ||
8 | * Copyright (C) 2003-2004 Amit S. Kale <amitkale@linsyssoft.com> | ||
9 | * Copyright (C) 2004 Pavel Machek <pavel@suse.cz> | ||
10 | * Copyright (C) 2004-2006 Tom Rini <trini@kernel.crashing.org> | ||
11 | * Copyright (C) 2004-2006 LinSysSoft Technologies Pvt. Ltd. | ||
12 | * Copyright (C) 2005-2008 Wind River Systems, Inc. | ||
13 | * Copyright (C) 2007 MontaVista Software, Inc. | ||
14 | * Copyright (C) 2008 Red Hat, Inc., Ingo Molnar <mingo@redhat.com> | ||
15 | * | ||
16 | * Contributors at various stages not listed above: | ||
17 | * Jason Wessel ( jason.wessel@windriver.com ) | ||
18 | * George Anzinger <george@mvista.com> | ||
19 | * Anurekh Saxena (anurekh.saxena@timesys.com) | ||
20 | * Lake Stevens Instrument Division (Glenn Engel) | ||
21 | * Jim Kingdon, Cygnus Support. | ||
22 | * | ||
23 | * Original KGDB stub: David Grothe <dave@gcom.com>, | ||
24 | * Tigran Aivazian <tigran@sco.com> | ||
25 | * | ||
26 | * This file is licensed under the terms of the GNU General Public License | ||
27 | * version 2. This program is licensed "as is" without any warranty of any | ||
28 | * kind, whether express or implied. | ||
29 | */ | ||
30 | #include <linux/pid_namespace.h> | ||
31 | #include <linux/clocksource.h> | ||
32 | #include <linux/interrupt.h> | ||
33 | #include <linux/spinlock.h> | ||
34 | #include <linux/console.h> | ||
35 | #include <linux/threads.h> | ||
36 | #include <linux/uaccess.h> | ||
37 | #include <linux/kernel.h> | ||
38 | #include <linux/module.h> | ||
39 | #include <linux/ptrace.h> | ||
40 | #include <linux/reboot.h> | ||
41 | #include <linux/string.h> | ||
42 | #include <linux/delay.h> | ||
43 | #include <linux/sched.h> | ||
44 | #include <linux/sysrq.h> | ||
45 | #include <linux/init.h> | ||
46 | #include <linux/kgdb.h> | ||
47 | #include <linux/pid.h> | ||
48 | #include <linux/smp.h> | ||
49 | #include <linux/mm.h> | ||
50 | |||
51 | #include <asm/cacheflush.h> | ||
52 | #include <asm/byteorder.h> | ||
53 | #include <asm/atomic.h> | ||
54 | #include <asm/system.h> | ||
55 | #include <asm/unaligned.h> | ||
56 | |||
57 | static int kgdb_break_asap; | ||
58 | |||
59 | #define KGDB_MAX_THREAD_QUERY 17 | ||
60 | struct kgdb_state { | ||
61 | int ex_vector; | ||
62 | int signo; | ||
63 | int err_code; | ||
64 | int cpu; | ||
65 | int pass_exception; | ||
66 | unsigned long thr_query; | ||
67 | unsigned long threadid; | ||
68 | long kgdb_usethreadid; | ||
69 | struct pt_regs *linux_regs; | ||
70 | }; | ||
71 | |||
72 | /* Exception state values */ | ||
73 | #define DCPU_WANT_MASTER 0x1 /* Waiting to become a master kgdb cpu */ | ||
74 | #define DCPU_NEXT_MASTER 0x2 /* Transition from one master cpu to another */ | ||
75 | #define DCPU_IS_SLAVE 0x4 /* Slave cpu enter exception */ | ||
76 | #define DCPU_SSTEP 0x8 /* CPU is single stepping */ | ||
77 | |||
78 | static struct debuggerinfo_struct { | ||
79 | void *debuggerinfo; | ||
80 | struct task_struct *task; | ||
81 | int exception_state; | ||
82 | } kgdb_info[NR_CPUS]; | ||
83 | |||
84 | /** | ||
85 | * kgdb_connected - Is a host GDB connected to us? | ||
86 | */ | ||
87 | int kgdb_connected; | ||
88 | EXPORT_SYMBOL_GPL(kgdb_connected); | ||
89 | |||
90 | /* All the KGDB handlers are installed */ | ||
91 | static int kgdb_io_module_registered; | ||
92 | |||
93 | /* Guard for recursive entry */ | ||
94 | static int exception_level; | ||
95 | |||
96 | static struct kgdb_io *kgdb_io_ops; | ||
97 | static DEFINE_SPINLOCK(kgdb_registration_lock); | ||
98 | |||
99 | /* kgdb console driver is loaded */ | ||
100 | static int kgdb_con_registered; | ||
101 | /* determine if kgdb console output should be used */ | ||
102 | static int kgdb_use_con; | ||
103 | |||
104 | static int __init opt_kgdb_con(char *str) | ||
105 | { | ||
106 | kgdb_use_con = 1; | ||
107 | return 0; | ||
108 | } | ||
109 | |||
110 | early_param("kgdbcon", opt_kgdb_con); | ||
111 | |||
112 | module_param(kgdb_use_con, int, 0644); | ||
113 | |||
114 | /* | ||
115 | * Holds information about breakpoints in a kernel. These breakpoints are | ||
116 | * added and removed by gdb. | ||
117 | */ | ||
118 | static struct kgdb_bkpt kgdb_break[KGDB_MAX_BREAKPOINTS] = { | ||
119 | [0 ... KGDB_MAX_BREAKPOINTS-1] = { .state = BP_UNDEFINED } | ||
120 | }; | ||
121 | |||
122 | /* | ||
123 | * The CPU# of the active CPU, or -1 if none: | ||
124 | */ | ||
125 | atomic_t kgdb_active = ATOMIC_INIT(-1); | ||
126 | |||
127 | /* | ||
128 | * We use NR_CPUs not PERCPU, in case kgdb is used to debug early | ||
129 | * bootup code (which might not have percpu set up yet): | ||
130 | */ | ||
131 | static atomic_t passive_cpu_wait[NR_CPUS]; | ||
132 | static atomic_t cpu_in_kgdb[NR_CPUS]; | ||
133 | atomic_t kgdb_setting_breakpoint; | ||
134 | |||
135 | struct task_struct *kgdb_usethread; | ||
136 | struct task_struct *kgdb_contthread; | ||
137 | |||
138 | int kgdb_single_step; | ||
139 | pid_t kgdb_sstep_pid; | ||
140 | |||
141 | /* Our I/O buffers. */ | ||
142 | static char remcom_in_buffer[BUFMAX]; | ||
143 | static char remcom_out_buffer[BUFMAX]; | ||
144 | |||
145 | /* Storage for the registers, in GDB format. */ | ||
146 | static unsigned long gdb_regs[(NUMREGBYTES + | ||
147 | sizeof(unsigned long) - 1) / | ||
148 | sizeof(unsigned long)]; | ||
149 | |||
150 | /* to keep track of the CPU which is doing the single stepping*/ | ||
151 | atomic_t kgdb_cpu_doing_single_step = ATOMIC_INIT(-1); | ||
152 | |||
153 | /* | ||
154 | * If you are debugging a problem where roundup (the collection of | ||
155 | * all other CPUs) is a problem [this should be extremely rare], | ||
156 | * then use the nokgdbroundup option to avoid roundup. In that case | ||
157 | * the other CPUs might interfere with your debugging context, so | ||
158 | * use this with care: | ||
159 | */ | ||
160 | static int kgdb_do_roundup = 1; | ||
161 | |||
162 | static int __init opt_nokgdbroundup(char *str) | ||
163 | { | ||
164 | kgdb_do_roundup = 0; | ||
165 | |||
166 | return 0; | ||
167 | } | ||
168 | |||
169 | early_param("nokgdbroundup", opt_nokgdbroundup); | ||
170 | |||
171 | /* | ||
172 | * Finally, some KGDB code :-) | ||
173 | */ | ||
174 | |||
175 | /* | ||
176 | * Weak aliases for breakpoint management, | ||
177 | * can be overriden by architectures when needed: | ||
178 | */ | ||
179 | int __weak kgdb_arch_set_breakpoint(unsigned long addr, char *saved_instr) | ||
180 | { | ||
181 | int err; | ||
182 | |||
183 | err = probe_kernel_read(saved_instr, (char *)addr, BREAK_INSTR_SIZE); | ||
184 | if (err) | ||
185 | return err; | ||
186 | |||
187 | return probe_kernel_write((char *)addr, arch_kgdb_ops.gdb_bpt_instr, | ||
188 | BREAK_INSTR_SIZE); | ||
189 | } | ||
190 | |||
191 | int __weak kgdb_arch_remove_breakpoint(unsigned long addr, char *bundle) | ||
192 | { | ||
193 | return probe_kernel_write((char *)addr, | ||
194 | (char *)bundle, BREAK_INSTR_SIZE); | ||
195 | } | ||
196 | |||
197 | int __weak kgdb_validate_break_address(unsigned long addr) | ||
198 | { | ||
199 | char tmp_variable[BREAK_INSTR_SIZE]; | ||
200 | int err; | ||
201 | /* Validate setting the breakpoint and then removing it. In the | ||
202 | * remove fails, the kernel needs to emit a bad message because we | ||
203 | * are deep trouble not being able to put things back the way we | ||
204 | * found them. | ||
205 | */ | ||
206 | err = kgdb_arch_set_breakpoint(addr, tmp_variable); | ||
207 | if (err) | ||
208 | return err; | ||
209 | err = kgdb_arch_remove_breakpoint(addr, tmp_variable); | ||
210 | if (err) | ||
211 | printk(KERN_ERR "KGDB: Critical breakpoint error, kernel " | ||
212 | "memory destroyed at: %lx", addr); | ||
213 | return err; | ||
214 | } | ||
215 | |||
216 | unsigned long __weak kgdb_arch_pc(int exception, struct pt_regs *regs) | ||
217 | { | ||
218 | return instruction_pointer(regs); | ||
219 | } | ||
220 | |||
221 | int __weak kgdb_arch_init(void) | ||
222 | { | ||
223 | return 0; | ||
224 | } | ||
225 | |||
226 | int __weak kgdb_skipexception(int exception, struct pt_regs *regs) | ||
227 | { | ||
228 | return 0; | ||
229 | } | ||
230 | |||
231 | void __weak | ||
232 | kgdb_post_primary_code(struct pt_regs *regs, int e_vector, int err_code) | ||
233 | { | ||
234 | return; | ||
235 | } | ||
236 | |||
237 | /** | ||
238 | * kgdb_disable_hw_debug - Disable hardware debugging while we in kgdb. | ||
239 | * @regs: Current &struct pt_regs. | ||
240 | * | ||
241 | * This function will be called if the particular architecture must | ||
242 | * disable hardware debugging while it is processing gdb packets or | ||
243 | * handling exception. | ||
244 | */ | ||
245 | void __weak kgdb_disable_hw_debug(struct pt_regs *regs) | ||
246 | { | ||
247 | } | ||
248 | |||
249 | /* | ||
250 | * GDB remote protocol parser: | ||
251 | */ | ||
252 | |||
253 | static int hex(char ch) | ||
254 | { | ||
255 | if ((ch >= 'a') && (ch <= 'f')) | ||
256 | return ch - 'a' + 10; | ||
257 | if ((ch >= '0') && (ch <= '9')) | ||
258 | return ch - '0'; | ||
259 | if ((ch >= 'A') && (ch <= 'F')) | ||
260 | return ch - 'A' + 10; | ||
261 | return -1; | ||
262 | } | ||
263 | |||
264 | /* scan for the sequence $<data>#<checksum> */ | ||
265 | static void get_packet(char *buffer) | ||
266 | { | ||
267 | unsigned char checksum; | ||
268 | unsigned char xmitcsum; | ||
269 | int count; | ||
270 | char ch; | ||
271 | |||
272 | do { | ||
273 | /* | ||
274 | * Spin and wait around for the start character, ignore all | ||
275 | * other characters: | ||
276 | */ | ||
277 | while ((ch = (kgdb_io_ops->read_char())) != '$') | ||
278 | /* nothing */; | ||
279 | |||
280 | kgdb_connected = 1; | ||
281 | checksum = 0; | ||
282 | xmitcsum = -1; | ||
283 | |||
284 | count = 0; | ||
285 | |||
286 | /* | ||
287 | * now, read until a # or end of buffer is found: | ||
288 | */ | ||
289 | while (count < (BUFMAX - 1)) { | ||
290 | ch = kgdb_io_ops->read_char(); | ||
291 | if (ch == '#') | ||
292 | break; | ||
293 | checksum = checksum + ch; | ||
294 | buffer[count] = ch; | ||
295 | count = count + 1; | ||
296 | } | ||
297 | buffer[count] = 0; | ||
298 | |||
299 | if (ch == '#') { | ||
300 | xmitcsum = hex(kgdb_io_ops->read_char()) << 4; | ||
301 | xmitcsum += hex(kgdb_io_ops->read_char()); | ||
302 | |||
303 | if (checksum != xmitcsum) | ||
304 | /* failed checksum */ | ||
305 | kgdb_io_ops->write_char('-'); | ||
306 | else | ||
307 | /* successful transfer */ | ||
308 | kgdb_io_ops->write_char('+'); | ||
309 | if (kgdb_io_ops->flush) | ||
310 | kgdb_io_ops->flush(); | ||
311 | } | ||
312 | } while (checksum != xmitcsum); | ||
313 | } | ||
314 | |||
315 | /* | ||
316 | * Send the packet in buffer. | ||
317 | * Check for gdb connection if asked for. | ||
318 | */ | ||
319 | static void put_packet(char *buffer) | ||
320 | { | ||
321 | unsigned char checksum; | ||
322 | int count; | ||
323 | char ch; | ||
324 | |||
325 | /* | ||
326 | * $<packet info>#<checksum>. | ||
327 | */ | ||
328 | while (1) { | ||
329 | kgdb_io_ops->write_char('$'); | ||
330 | checksum = 0; | ||
331 | count = 0; | ||
332 | |||
333 | while ((ch = buffer[count])) { | ||
334 | kgdb_io_ops->write_char(ch); | ||
335 | checksum += ch; | ||
336 | count++; | ||
337 | } | ||
338 | |||
339 | kgdb_io_ops->write_char('#'); | ||
340 | kgdb_io_ops->write_char(hex_asc_hi(checksum)); | ||
341 | kgdb_io_ops->write_char(hex_asc_lo(checksum)); | ||
342 | if (kgdb_io_ops->flush) | ||
343 | kgdb_io_ops->flush(); | ||
344 | |||
345 | /* Now see what we get in reply. */ | ||
346 | ch = kgdb_io_ops->read_char(); | ||
347 | |||
348 | if (ch == 3) | ||
349 | ch = kgdb_io_ops->read_char(); | ||
350 | |||
351 | /* If we get an ACK, we are done. */ | ||
352 | if (ch == '+') | ||
353 | return; | ||
354 | |||
355 | /* | ||
356 | * If we get the start of another packet, this means | ||
357 | * that GDB is attempting to reconnect. We will NAK | ||
358 | * the packet being sent, and stop trying to send this | ||
359 | * packet. | ||
360 | */ | ||
361 | if (ch == '$') { | ||
362 | kgdb_io_ops->write_char('-'); | ||
363 | if (kgdb_io_ops->flush) | ||
364 | kgdb_io_ops->flush(); | ||
365 | return; | ||
366 | } | ||
367 | } | ||
368 | } | ||
369 | |||
370 | /* | ||
371 | * Convert the memory pointed to by mem into hex, placing result in buf. | ||
372 | * Return a pointer to the last char put in buf (null). May return an error. | ||
373 | */ | ||
374 | int kgdb_mem2hex(char *mem, char *buf, int count) | ||
375 | { | ||
376 | char *tmp; | ||
377 | int err; | ||
378 | |||
379 | /* | ||
380 | * We use the upper half of buf as an intermediate buffer for the | ||
381 | * raw memory copy. Hex conversion will work against this one. | ||
382 | */ | ||
383 | tmp = buf + count; | ||
384 | |||
385 | err = probe_kernel_read(tmp, mem, count); | ||
386 | if (!err) { | ||
387 | while (count > 0) { | ||
388 | buf = pack_hex_byte(buf, *tmp); | ||
389 | tmp++; | ||
390 | count--; | ||
391 | } | ||
392 | |||
393 | *buf = 0; | ||
394 | } | ||
395 | |||
396 | return err; | ||
397 | } | ||
398 | |||
399 | /* | ||
400 | * Copy the binary array pointed to by buf into mem. Fix $, #, and | ||
401 | * 0x7d escaped with 0x7d. Return -EFAULT on failure or 0 on success. | ||
402 | * The input buf is overwitten with the result to write to mem. | ||
403 | */ | ||
404 | static int kgdb_ebin2mem(char *buf, char *mem, int count) | ||
405 | { | ||
406 | int size = 0; | ||
407 | char *c = buf; | ||
408 | |||
409 | while (count-- > 0) { | ||
410 | c[size] = *buf++; | ||
411 | if (c[size] == 0x7d) | ||
412 | c[size] = *buf++ ^ 0x20; | ||
413 | size++; | ||
414 | } | ||
415 | |||
416 | return probe_kernel_write(mem, c, size); | ||
417 | } | ||
418 | |||
419 | /* | ||
420 | * Convert the hex array pointed to by buf into binary to be placed in mem. | ||
421 | * Return a pointer to the character AFTER the last byte written. | ||
422 | * May return an error. | ||
423 | */ | ||
424 | int kgdb_hex2mem(char *buf, char *mem, int count) | ||
425 | { | ||
426 | char *tmp_raw; | ||
427 | char *tmp_hex; | ||
428 | |||
429 | /* | ||
430 | * We use the upper half of buf as an intermediate buffer for the | ||
431 | * raw memory that is converted from hex. | ||
432 | */ | ||
433 | tmp_raw = buf + count * 2; | ||
434 | |||
435 | tmp_hex = tmp_raw - 1; | ||
436 | while (tmp_hex >= buf) { | ||
437 | tmp_raw--; | ||
438 | *tmp_raw = hex(*tmp_hex--); | ||
439 | *tmp_raw |= hex(*tmp_hex--) << 4; | ||
440 | } | ||
441 | |||
442 | return probe_kernel_write(mem, tmp_raw, count); | ||
443 | } | ||
444 | |||
445 | /* | ||
446 | * While we find nice hex chars, build a long_val. | ||
447 | * Return number of chars processed. | ||
448 | */ | ||
449 | int kgdb_hex2long(char **ptr, unsigned long *long_val) | ||
450 | { | ||
451 | int hex_val; | ||
452 | int num = 0; | ||
453 | int negate = 0; | ||
454 | |||
455 | *long_val = 0; | ||
456 | |||
457 | if (**ptr == '-') { | ||
458 | negate = 1; | ||
459 | (*ptr)++; | ||
460 | } | ||
461 | while (**ptr) { | ||
462 | hex_val = hex(**ptr); | ||
463 | if (hex_val < 0) | ||
464 | break; | ||
465 | |||
466 | *long_val = (*long_val << 4) | hex_val; | ||
467 | num++; | ||
468 | (*ptr)++; | ||
469 | } | ||
470 | |||
471 | if (negate) | ||
472 | *long_val = -*long_val; | ||
473 | |||
474 | return num; | ||
475 | } | ||
476 | |||
477 | /* Write memory due to an 'M' or 'X' packet. */ | ||
478 | static int write_mem_msg(int binary) | ||
479 | { | ||
480 | char *ptr = &remcom_in_buffer[1]; | ||
481 | unsigned long addr; | ||
482 | unsigned long length; | ||
483 | int err; | ||
484 | |||
485 | if (kgdb_hex2long(&ptr, &addr) > 0 && *(ptr++) == ',' && | ||
486 | kgdb_hex2long(&ptr, &length) > 0 && *(ptr++) == ':') { | ||
487 | if (binary) | ||
488 | err = kgdb_ebin2mem(ptr, (char *)addr, length); | ||
489 | else | ||
490 | err = kgdb_hex2mem(ptr, (char *)addr, length); | ||
491 | if (err) | ||
492 | return err; | ||
493 | if (CACHE_FLUSH_IS_SAFE) | ||
494 | flush_icache_range(addr, addr + length); | ||
495 | return 0; | ||
496 | } | ||
497 | |||
498 | return -EINVAL; | ||
499 | } | ||
500 | |||
501 | static void error_packet(char *pkt, int error) | ||
502 | { | ||
503 | error = -error; | ||
504 | pkt[0] = 'E'; | ||
505 | pkt[1] = hex_asc[(error / 10)]; | ||
506 | pkt[2] = hex_asc[(error % 10)]; | ||
507 | pkt[3] = '\0'; | ||
508 | } | ||
509 | |||
510 | /* | ||
511 | * Thread ID accessors. We represent a flat TID space to GDB, where | ||
512 | * the per CPU idle threads (which under Linux all have PID 0) are | ||
513 | * remapped to negative TIDs. | ||
514 | */ | ||
515 | |||
516 | #define BUF_THREAD_ID_SIZE 16 | ||
517 | |||
518 | static char *pack_threadid(char *pkt, unsigned char *id) | ||
519 | { | ||
520 | char *limit; | ||
521 | |||
522 | limit = pkt + BUF_THREAD_ID_SIZE; | ||
523 | while (pkt < limit) | ||
524 | pkt = pack_hex_byte(pkt, *id++); | ||
525 | |||
526 | return pkt; | ||
527 | } | ||
528 | |||
529 | static void int_to_threadref(unsigned char *id, int value) | ||
530 | { | ||
531 | unsigned char *scan; | ||
532 | int i = 4; | ||
533 | |||
534 | scan = (unsigned char *)id; | ||
535 | while (i--) | ||
536 | *scan++ = 0; | ||
537 | put_unaligned_be32(value, scan); | ||
538 | } | ||
539 | |||
540 | static struct task_struct *getthread(struct pt_regs *regs, int tid) | ||
541 | { | ||
542 | /* | ||
543 | * Non-positive TIDs are remapped to the cpu shadow information | ||
544 | */ | ||
545 | if (tid == 0 || tid == -1) | ||
546 | tid = -atomic_read(&kgdb_active) - 2; | ||
547 | if (tid < -1 && tid > -NR_CPUS - 2) { | ||
548 | if (kgdb_info[-tid - 2].task) | ||
549 | return kgdb_info[-tid - 2].task; | ||
550 | else | ||
551 | return idle_task(-tid - 2); | ||
552 | } | ||
553 | if (tid <= 0) { | ||
554 | printk(KERN_ERR "KGDB: Internal thread select error\n"); | ||
555 | dump_stack(); | ||
556 | return NULL; | ||
557 | } | ||
558 | |||
559 | /* | ||
560 | * find_task_by_pid_ns() does not take the tasklist lock anymore | ||
561 | * but is nicely RCU locked - hence is a pretty resilient | ||
562 | * thing to use: | ||
563 | */ | ||
564 | return find_task_by_pid_ns(tid, &init_pid_ns); | ||
565 | } | ||
566 | |||
567 | /* | ||
568 | * Some architectures need cache flushes when we set/clear a | ||
569 | * breakpoint: | ||
570 | */ | ||
571 | static void kgdb_flush_swbreak_addr(unsigned long addr) | ||
572 | { | ||
573 | if (!CACHE_FLUSH_IS_SAFE) | ||
574 | return; | ||
575 | |||
576 | if (current->mm && current->mm->mmap_cache) { | ||
577 | flush_cache_range(current->mm->mmap_cache, | ||
578 | addr, addr + BREAK_INSTR_SIZE); | ||
579 | } | ||
580 | /* Force flush instruction cache if it was outside the mm */ | ||
581 | flush_icache_range(addr, addr + BREAK_INSTR_SIZE); | ||
582 | } | ||
583 | |||
584 | /* | ||
585 | * SW breakpoint management: | ||
586 | */ | ||
587 | static int kgdb_activate_sw_breakpoints(void) | ||
588 | { | ||
589 | unsigned long addr; | ||
590 | int error; | ||
591 | int ret = 0; | ||
592 | int i; | ||
593 | |||
594 | for (i = 0; i < KGDB_MAX_BREAKPOINTS; i++) { | ||
595 | if (kgdb_break[i].state != BP_SET) | ||
596 | continue; | ||
597 | |||
598 | addr = kgdb_break[i].bpt_addr; | ||
599 | error = kgdb_arch_set_breakpoint(addr, | ||
600 | kgdb_break[i].saved_instr); | ||
601 | if (error) { | ||
602 | ret = error; | ||
603 | printk(KERN_INFO "KGDB: BP install failed: %lx", addr); | ||
604 | continue; | ||
605 | } | ||
606 | |||
607 | kgdb_flush_swbreak_addr(addr); | ||
608 | kgdb_break[i].state = BP_ACTIVE; | ||
609 | } | ||
610 | return ret; | ||
611 | } | ||
612 | |||
613 | static int kgdb_set_sw_break(unsigned long addr) | ||
614 | { | ||
615 | int err = kgdb_validate_break_address(addr); | ||
616 | int breakno = -1; | ||
617 | int i; | ||
618 | |||
619 | if (err) | ||
620 | return err; | ||
621 | |||
622 | for (i = 0; i < KGDB_MAX_BREAKPOINTS; i++) { | ||
623 | if ((kgdb_break[i].state == BP_SET) && | ||
624 | (kgdb_break[i].bpt_addr == addr)) | ||
625 | return -EEXIST; | ||
626 | } | ||
627 | for (i = 0; i < KGDB_MAX_BREAKPOINTS; i++) { | ||
628 | if (kgdb_break[i].state == BP_REMOVED && | ||
629 | kgdb_break[i].bpt_addr == addr) { | ||
630 | breakno = i; | ||
631 | break; | ||
632 | } | ||
633 | } | ||
634 | |||
635 | if (breakno == -1) { | ||
636 | for (i = 0; i < KGDB_MAX_BREAKPOINTS; i++) { | ||
637 | if (kgdb_break[i].state == BP_UNDEFINED) { | ||
638 | breakno = i; | ||
639 | break; | ||
640 | } | ||
641 | } | ||
642 | } | ||
643 | |||
644 | if (breakno == -1) | ||
645 | return -E2BIG; | ||
646 | |||
647 | kgdb_break[breakno].state = BP_SET; | ||
648 | kgdb_break[breakno].type = BP_BREAKPOINT; | ||
649 | kgdb_break[breakno].bpt_addr = addr; | ||
650 | |||
651 | return 0; | ||
652 | } | ||
653 | |||
654 | static int kgdb_deactivate_sw_breakpoints(void) | ||
655 | { | ||
656 | unsigned long addr; | ||
657 | int error; | ||
658 | int ret = 0; | ||
659 | int i; | ||
660 | |||
661 | for (i = 0; i < KGDB_MAX_BREAKPOINTS; i++) { | ||
662 | if (kgdb_break[i].state != BP_ACTIVE) | ||
663 | continue; | ||
664 | addr = kgdb_break[i].bpt_addr; | ||
665 | error = kgdb_arch_remove_breakpoint(addr, | ||
666 | kgdb_break[i].saved_instr); | ||
667 | if (error) { | ||
668 | printk(KERN_INFO "KGDB: BP remove failed: %lx\n", addr); | ||
669 | ret = error; | ||
670 | } | ||
671 | |||
672 | kgdb_flush_swbreak_addr(addr); | ||
673 | kgdb_break[i].state = BP_SET; | ||
674 | } | ||
675 | return ret; | ||
676 | } | ||
677 | |||
678 | static int kgdb_remove_sw_break(unsigned long addr) | ||
679 | { | ||
680 | int i; | ||
681 | |||
682 | for (i = 0; i < KGDB_MAX_BREAKPOINTS; i++) { | ||
683 | if ((kgdb_break[i].state == BP_SET) && | ||
684 | (kgdb_break[i].bpt_addr == addr)) { | ||
685 | kgdb_break[i].state = BP_REMOVED; | ||
686 | return 0; | ||
687 | } | ||
688 | } | ||
689 | return -ENOENT; | ||
690 | } | ||
691 | |||
692 | int kgdb_isremovedbreak(unsigned long addr) | ||
693 | { | ||
694 | int i; | ||
695 | |||
696 | for (i = 0; i < KGDB_MAX_BREAKPOINTS; i++) { | ||
697 | if ((kgdb_break[i].state == BP_REMOVED) && | ||
698 | (kgdb_break[i].bpt_addr == addr)) | ||
699 | return 1; | ||
700 | } | ||
701 | return 0; | ||
702 | } | ||
703 | |||
704 | static int remove_all_break(void) | ||
705 | { | ||
706 | unsigned long addr; | ||
707 | int error; | ||
708 | int i; | ||
709 | |||
710 | /* Clear memory breakpoints. */ | ||
711 | for (i = 0; i < KGDB_MAX_BREAKPOINTS; i++) { | ||
712 | if (kgdb_break[i].state != BP_ACTIVE) | ||
713 | goto setundefined; | ||
714 | addr = kgdb_break[i].bpt_addr; | ||
715 | error = kgdb_arch_remove_breakpoint(addr, | ||
716 | kgdb_break[i].saved_instr); | ||
717 | if (error) | ||
718 | printk(KERN_ERR "KGDB: breakpoint remove failed: %lx\n", | ||
719 | addr); | ||
720 | setundefined: | ||
721 | kgdb_break[i].state = BP_UNDEFINED; | ||
722 | } | ||
723 | |||
724 | /* Clear hardware breakpoints. */ | ||
725 | if (arch_kgdb_ops.remove_all_hw_break) | ||
726 | arch_kgdb_ops.remove_all_hw_break(); | ||
727 | |||
728 | return 0; | ||
729 | } | ||
730 | |||
731 | /* | ||
732 | * Remap normal tasks to their real PID, | ||
733 | * CPU shadow threads are mapped to -CPU - 2 | ||
734 | */ | ||
735 | static inline int shadow_pid(int realpid) | ||
736 | { | ||
737 | if (realpid) | ||
738 | return realpid; | ||
739 | |||
740 | return -raw_smp_processor_id() - 2; | ||
741 | } | ||
742 | |||
743 | static char gdbmsgbuf[BUFMAX + 1]; | ||
744 | |||
745 | static void kgdb_msg_write(const char *s, int len) | ||
746 | { | ||
747 | char *bufptr; | ||
748 | int wcount; | ||
749 | int i; | ||
750 | |||
751 | /* 'O'utput */ | ||
752 | gdbmsgbuf[0] = 'O'; | ||
753 | |||
754 | /* Fill and send buffers... */ | ||
755 | while (len > 0) { | ||
756 | bufptr = gdbmsgbuf + 1; | ||
757 | |||
758 | /* Calculate how many this time */ | ||
759 | if ((len << 1) > (BUFMAX - 2)) | ||
760 | wcount = (BUFMAX - 2) >> 1; | ||
761 | else | ||
762 | wcount = len; | ||
763 | |||
764 | /* Pack in hex chars */ | ||
765 | for (i = 0; i < wcount; i++) | ||
766 | bufptr = pack_hex_byte(bufptr, s[i]); | ||
767 | *bufptr = '\0'; | ||
768 | |||
769 | /* Move up */ | ||
770 | s += wcount; | ||
771 | len -= wcount; | ||
772 | |||
773 | /* Write packet */ | ||
774 | put_packet(gdbmsgbuf); | ||
775 | } | ||
776 | } | ||
777 | |||
778 | /* | ||
779 | * Return true if there is a valid kgdb I/O module. Also if no | ||
780 | * debugger is attached a message can be printed to the console about | ||
781 | * waiting for the debugger to attach. | ||
782 | * | ||
783 | * The print_wait argument is only to be true when called from inside | ||
784 | * the core kgdb_handle_exception, because it will wait for the | ||
785 | * debugger to attach. | ||
786 | */ | ||
787 | static int kgdb_io_ready(int print_wait) | ||
788 | { | ||
789 | if (!kgdb_io_ops) | ||
790 | return 0; | ||
791 | if (kgdb_connected) | ||
792 | return 1; | ||
793 | if (atomic_read(&kgdb_setting_breakpoint)) | ||
794 | return 1; | ||
795 | if (print_wait) | ||
796 | printk(KERN_CRIT "KGDB: Waiting for remote debugger\n"); | ||
797 | return 1; | ||
798 | } | ||
799 | |||
800 | /* | ||
801 | * All the functions that start with gdb_cmd are the various | ||
802 | * operations to implement the handlers for the gdbserial protocol | ||
803 | * where KGDB is communicating with an external debugger | ||
804 | */ | ||
805 | |||
806 | /* Handle the '?' status packets */ | ||
807 | static void gdb_cmd_status(struct kgdb_state *ks) | ||
808 | { | ||
809 | /* | ||
810 | * We know that this packet is only sent | ||
811 | * during initial connect. So to be safe, | ||
812 | * we clear out our breakpoints now in case | ||
813 | * GDB is reconnecting. | ||
814 | */ | ||
815 | remove_all_break(); | ||
816 | |||
817 | remcom_out_buffer[0] = 'S'; | ||
818 | pack_hex_byte(&remcom_out_buffer[1], ks->signo); | ||
819 | } | ||
820 | |||
821 | /* Handle the 'g' get registers request */ | ||
822 | static void gdb_cmd_getregs(struct kgdb_state *ks) | ||
823 | { | ||
824 | struct task_struct *thread; | ||
825 | void *local_debuggerinfo; | ||
826 | int i; | ||
827 | |||
828 | thread = kgdb_usethread; | ||
829 | if (!thread) { | ||
830 | thread = kgdb_info[ks->cpu].task; | ||
831 | local_debuggerinfo = kgdb_info[ks->cpu].debuggerinfo; | ||
832 | } else { | ||
833 | local_debuggerinfo = NULL; | ||
834 | for_each_online_cpu(i) { | ||
835 | /* | ||
836 | * Try to find the task on some other | ||
837 | * or possibly this node if we do not | ||
838 | * find the matching task then we try | ||
839 | * to approximate the results. | ||
840 | */ | ||
841 | if (thread == kgdb_info[i].task) | ||
842 | local_debuggerinfo = kgdb_info[i].debuggerinfo; | ||
843 | } | ||
844 | } | ||
845 | |||
846 | /* | ||
847 | * All threads that don't have debuggerinfo should be | ||
848 | * in schedule() sleeping, since all other CPUs | ||
849 | * are in kgdb_wait, and thus have debuggerinfo. | ||
850 | */ | ||
851 | if (local_debuggerinfo) { | ||
852 | pt_regs_to_gdb_regs(gdb_regs, local_debuggerinfo); | ||
853 | } else { | ||
854 | /* | ||
855 | * Pull stuff saved during switch_to; nothing | ||
856 | * else is accessible (or even particularly | ||
857 | * relevant). | ||
858 | * | ||
859 | * This should be enough for a stack trace. | ||
860 | */ | ||
861 | sleeping_thread_to_gdb_regs(gdb_regs, thread); | ||
862 | } | ||
863 | kgdb_mem2hex((char *)gdb_regs, remcom_out_buffer, NUMREGBYTES); | ||
864 | } | ||
865 | |||
866 | /* Handle the 'G' set registers request */ | ||
867 | static void gdb_cmd_setregs(struct kgdb_state *ks) | ||
868 | { | ||
869 | kgdb_hex2mem(&remcom_in_buffer[1], (char *)gdb_regs, NUMREGBYTES); | ||
870 | |||
871 | if (kgdb_usethread && kgdb_usethread != current) { | ||
872 | error_packet(remcom_out_buffer, -EINVAL); | ||
873 | } else { | ||
874 | gdb_regs_to_pt_regs(gdb_regs, ks->linux_regs); | ||
875 | strcpy(remcom_out_buffer, "OK"); | ||
876 | } | ||
877 | } | ||
878 | |||
879 | /* Handle the 'm' memory read bytes */ | ||
880 | static void gdb_cmd_memread(struct kgdb_state *ks) | ||
881 | { | ||
882 | char *ptr = &remcom_in_buffer[1]; | ||
883 | unsigned long length; | ||
884 | unsigned long addr; | ||
885 | int err; | ||
886 | |||
887 | if (kgdb_hex2long(&ptr, &addr) > 0 && *ptr++ == ',' && | ||
888 | kgdb_hex2long(&ptr, &length) > 0) { | ||
889 | err = kgdb_mem2hex((char *)addr, remcom_out_buffer, length); | ||
890 | if (err) | ||
891 | error_packet(remcom_out_buffer, err); | ||
892 | } else { | ||
893 | error_packet(remcom_out_buffer, -EINVAL); | ||
894 | } | ||
895 | } | ||
896 | |||
897 | /* Handle the 'M' memory write bytes */ | ||
898 | static void gdb_cmd_memwrite(struct kgdb_state *ks) | ||
899 | { | ||
900 | int err = write_mem_msg(0); | ||
901 | |||
902 | if (err) | ||
903 | error_packet(remcom_out_buffer, err); | ||
904 | else | ||
905 | strcpy(remcom_out_buffer, "OK"); | ||
906 | } | ||
907 | |||
908 | /* Handle the 'X' memory binary write bytes */ | ||
909 | static void gdb_cmd_binwrite(struct kgdb_state *ks) | ||
910 | { | ||
911 | int err = write_mem_msg(1); | ||
912 | |||
913 | if (err) | ||
914 | error_packet(remcom_out_buffer, err); | ||
915 | else | ||
916 | strcpy(remcom_out_buffer, "OK"); | ||
917 | } | ||
918 | |||
919 | /* Handle the 'D' or 'k', detach or kill packets */ | ||
920 | static void gdb_cmd_detachkill(struct kgdb_state *ks) | ||
921 | { | ||
922 | int error; | ||
923 | |||
924 | /* The detach case */ | ||
925 | if (remcom_in_buffer[0] == 'D') { | ||
926 | error = remove_all_break(); | ||
927 | if (error < 0) { | ||
928 | error_packet(remcom_out_buffer, error); | ||
929 | } else { | ||
930 | strcpy(remcom_out_buffer, "OK"); | ||
931 | kgdb_connected = 0; | ||
932 | } | ||
933 | put_packet(remcom_out_buffer); | ||
934 | } else { | ||
935 | /* | ||
936 | * Assume the kill case, with no exit code checking, | ||
937 | * trying to force detach the debugger: | ||
938 | */ | ||
939 | remove_all_break(); | ||
940 | kgdb_connected = 0; | ||
941 | } | ||
942 | } | ||
943 | |||
944 | /* Handle the 'R' reboot packets */ | ||
945 | static int gdb_cmd_reboot(struct kgdb_state *ks) | ||
946 | { | ||
947 | /* For now, only honor R0 */ | ||
948 | if (strcmp(remcom_in_buffer, "R0") == 0) { | ||
949 | printk(KERN_CRIT "Executing emergency reboot\n"); | ||
950 | strcpy(remcom_out_buffer, "OK"); | ||
951 | put_packet(remcom_out_buffer); | ||
952 | |||
953 | /* | ||
954 | * Execution should not return from | ||
955 | * machine_emergency_restart() | ||
956 | */ | ||
957 | machine_emergency_restart(); | ||
958 | kgdb_connected = 0; | ||
959 | |||
960 | return 1; | ||
961 | } | ||
962 | return 0; | ||
963 | } | ||
964 | |||
965 | /* Handle the 'q' query packets */ | ||
966 | static void gdb_cmd_query(struct kgdb_state *ks) | ||
967 | { | ||
968 | struct task_struct *g; | ||
969 | struct task_struct *p; | ||
970 | unsigned char thref[8]; | ||
971 | char *ptr; | ||
972 | int i; | ||
973 | int cpu; | ||
974 | int finished = 0; | ||
975 | |||
976 | switch (remcom_in_buffer[1]) { | ||
977 | case 's': | ||
978 | case 'f': | ||
979 | if (memcmp(remcom_in_buffer + 2, "ThreadInfo", 10)) { | ||
980 | error_packet(remcom_out_buffer, -EINVAL); | ||
981 | break; | ||
982 | } | ||
983 | |||
984 | i = 0; | ||
985 | remcom_out_buffer[0] = 'm'; | ||
986 | ptr = remcom_out_buffer + 1; | ||
987 | if (remcom_in_buffer[1] == 'f') { | ||
988 | /* Each cpu is a shadow thread */ | ||
989 | for_each_online_cpu(cpu) { | ||
990 | ks->thr_query = 0; | ||
991 | int_to_threadref(thref, -cpu - 2); | ||
992 | pack_threadid(ptr, thref); | ||
993 | ptr += BUF_THREAD_ID_SIZE; | ||
994 | *(ptr++) = ','; | ||
995 | i++; | ||
996 | } | ||
997 | } | ||
998 | |||
999 | do_each_thread(g, p) { | ||
1000 | if (i >= ks->thr_query && !finished) { | ||
1001 | int_to_threadref(thref, p->pid); | ||
1002 | pack_threadid(ptr, thref); | ||
1003 | ptr += BUF_THREAD_ID_SIZE; | ||
1004 | *(ptr++) = ','; | ||
1005 | ks->thr_query++; | ||
1006 | if (ks->thr_query % KGDB_MAX_THREAD_QUERY == 0) | ||
1007 | finished = 1; | ||
1008 | } | ||
1009 | i++; | ||
1010 | } while_each_thread(g, p); | ||
1011 | |||
1012 | *(--ptr) = '\0'; | ||
1013 | break; | ||
1014 | |||
1015 | case 'C': | ||
1016 | /* Current thread id */ | ||
1017 | strcpy(remcom_out_buffer, "QC"); | ||
1018 | ks->threadid = shadow_pid(current->pid); | ||
1019 | int_to_threadref(thref, ks->threadid); | ||
1020 | pack_threadid(remcom_out_buffer + 2, thref); | ||
1021 | break; | ||
1022 | case 'T': | ||
1023 | if (memcmp(remcom_in_buffer + 1, "ThreadExtraInfo,", 16)) { | ||
1024 | error_packet(remcom_out_buffer, -EINVAL); | ||
1025 | break; | ||
1026 | } | ||
1027 | ks->threadid = 0; | ||
1028 | ptr = remcom_in_buffer + 17; | ||
1029 | kgdb_hex2long(&ptr, &ks->threadid); | ||
1030 | if (!getthread(ks->linux_regs, ks->threadid)) { | ||
1031 | error_packet(remcom_out_buffer, -EINVAL); | ||
1032 | break; | ||
1033 | } | ||
1034 | if ((int)ks->threadid > 0) { | ||
1035 | kgdb_mem2hex(getthread(ks->linux_regs, | ||
1036 | ks->threadid)->comm, | ||
1037 | remcom_out_buffer, 16); | ||
1038 | } else { | ||
1039 | static char tmpstr[23 + BUF_THREAD_ID_SIZE]; | ||
1040 | |||
1041 | sprintf(tmpstr, "shadowCPU%d", | ||
1042 | (int)(-ks->threadid - 2)); | ||
1043 | kgdb_mem2hex(tmpstr, remcom_out_buffer, strlen(tmpstr)); | ||
1044 | } | ||
1045 | break; | ||
1046 | } | ||
1047 | } | ||
1048 | |||
1049 | /* Handle the 'H' task query packets */ | ||
1050 | static void gdb_cmd_task(struct kgdb_state *ks) | ||
1051 | { | ||
1052 | struct task_struct *thread; | ||
1053 | char *ptr; | ||
1054 | |||
1055 | switch (remcom_in_buffer[1]) { | ||
1056 | case 'g': | ||
1057 | ptr = &remcom_in_buffer[2]; | ||
1058 | kgdb_hex2long(&ptr, &ks->threadid); | ||
1059 | thread = getthread(ks->linux_regs, ks->threadid); | ||
1060 | if (!thread && ks->threadid > 0) { | ||
1061 | error_packet(remcom_out_buffer, -EINVAL); | ||
1062 | break; | ||
1063 | } | ||
1064 | kgdb_usethread = thread; | ||
1065 | ks->kgdb_usethreadid = ks->threadid; | ||
1066 | strcpy(remcom_out_buffer, "OK"); | ||
1067 | break; | ||
1068 | case 'c': | ||
1069 | ptr = &remcom_in_buffer[2]; | ||
1070 | kgdb_hex2long(&ptr, &ks->threadid); | ||
1071 | if (!ks->threadid) { | ||
1072 | kgdb_contthread = NULL; | ||
1073 | } else { | ||
1074 | thread = getthread(ks->linux_regs, ks->threadid); | ||
1075 | if (!thread && ks->threadid > 0) { | ||
1076 | error_packet(remcom_out_buffer, -EINVAL); | ||
1077 | break; | ||
1078 | } | ||
1079 | kgdb_contthread = thread; | ||
1080 | } | ||
1081 | strcpy(remcom_out_buffer, "OK"); | ||
1082 | break; | ||
1083 | } | ||
1084 | } | ||
1085 | |||
1086 | /* Handle the 'T' thread query packets */ | ||
1087 | static void gdb_cmd_thread(struct kgdb_state *ks) | ||
1088 | { | ||
1089 | char *ptr = &remcom_in_buffer[1]; | ||
1090 | struct task_struct *thread; | ||
1091 | |||
1092 | kgdb_hex2long(&ptr, &ks->threadid); | ||
1093 | thread = getthread(ks->linux_regs, ks->threadid); | ||
1094 | if (thread) | ||
1095 | strcpy(remcom_out_buffer, "OK"); | ||
1096 | else | ||
1097 | error_packet(remcom_out_buffer, -EINVAL); | ||
1098 | } | ||
1099 | |||
1100 | /* Handle the 'z' or 'Z' breakpoint remove or set packets */ | ||
1101 | static void gdb_cmd_break(struct kgdb_state *ks) | ||
1102 | { | ||
1103 | /* | ||
1104 | * Since GDB-5.3, it's been drafted that '0' is a software | ||
1105 | * breakpoint, '1' is a hardware breakpoint, so let's do that. | ||
1106 | */ | ||
1107 | char *bpt_type = &remcom_in_buffer[1]; | ||
1108 | char *ptr = &remcom_in_buffer[2]; | ||
1109 | unsigned long addr; | ||
1110 | unsigned long length; | ||
1111 | int error = 0; | ||
1112 | |||
1113 | if (arch_kgdb_ops.set_hw_breakpoint && *bpt_type >= '1') { | ||
1114 | /* Unsupported */ | ||
1115 | if (*bpt_type > '4') | ||
1116 | return; | ||
1117 | } else { | ||
1118 | if (*bpt_type != '0' && *bpt_type != '1') | ||
1119 | /* Unsupported. */ | ||
1120 | return; | ||
1121 | } | ||
1122 | |||
1123 | /* | ||
1124 | * Test if this is a hardware breakpoint, and | ||
1125 | * if we support it: | ||
1126 | */ | ||
1127 | if (*bpt_type == '1' && !(arch_kgdb_ops.flags & KGDB_HW_BREAKPOINT)) | ||
1128 | /* Unsupported. */ | ||
1129 | return; | ||
1130 | |||
1131 | if (*(ptr++) != ',') { | ||
1132 | error_packet(remcom_out_buffer, -EINVAL); | ||
1133 | return; | ||
1134 | } | ||
1135 | if (!kgdb_hex2long(&ptr, &addr)) { | ||
1136 | error_packet(remcom_out_buffer, -EINVAL); | ||
1137 | return; | ||
1138 | } | ||
1139 | if (*(ptr++) != ',' || | ||
1140 | !kgdb_hex2long(&ptr, &length)) { | ||
1141 | error_packet(remcom_out_buffer, -EINVAL); | ||
1142 | return; | ||
1143 | } | ||
1144 | |||
1145 | if (remcom_in_buffer[0] == 'Z' && *bpt_type == '0') | ||
1146 | error = kgdb_set_sw_break(addr); | ||
1147 | else if (remcom_in_buffer[0] == 'z' && *bpt_type == '0') | ||
1148 | error = kgdb_remove_sw_break(addr); | ||
1149 | else if (remcom_in_buffer[0] == 'Z') | ||
1150 | error = arch_kgdb_ops.set_hw_breakpoint(addr, | ||
1151 | (int)length, *bpt_type - '0'); | ||
1152 | else if (remcom_in_buffer[0] == 'z') | ||
1153 | error = arch_kgdb_ops.remove_hw_breakpoint(addr, | ||
1154 | (int) length, *bpt_type - '0'); | ||
1155 | |||
1156 | if (error == 0) | ||
1157 | strcpy(remcom_out_buffer, "OK"); | ||
1158 | else | ||
1159 | error_packet(remcom_out_buffer, error); | ||
1160 | } | ||
1161 | |||
1162 | /* Handle the 'C' signal / exception passing packets */ | ||
1163 | static int gdb_cmd_exception_pass(struct kgdb_state *ks) | ||
1164 | { | ||
1165 | /* C09 == pass exception | ||
1166 | * C15 == detach kgdb, pass exception | ||
1167 | */ | ||
1168 | if (remcom_in_buffer[1] == '0' && remcom_in_buffer[2] == '9') { | ||
1169 | |||
1170 | ks->pass_exception = 1; | ||
1171 | remcom_in_buffer[0] = 'c'; | ||
1172 | |||
1173 | } else if (remcom_in_buffer[1] == '1' && remcom_in_buffer[2] == '5') { | ||
1174 | |||
1175 | ks->pass_exception = 1; | ||
1176 | remcom_in_buffer[0] = 'D'; | ||
1177 | remove_all_break(); | ||
1178 | kgdb_connected = 0; | ||
1179 | return 1; | ||
1180 | |||
1181 | } else { | ||
1182 | kgdb_msg_write("KGDB only knows signal 9 (pass)" | ||
1183 | " and 15 (pass and disconnect)\n" | ||
1184 | "Executing a continue without signal passing\n", 0); | ||
1185 | remcom_in_buffer[0] = 'c'; | ||
1186 | } | ||
1187 | |||
1188 | /* Indicate fall through */ | ||
1189 | return -1; | ||
1190 | } | ||
1191 | |||
1192 | /* | ||
1193 | * This function performs all gdbserial command procesing | ||
1194 | */ | ||
1195 | static int gdb_serial_stub(struct kgdb_state *ks) | ||
1196 | { | ||
1197 | int error = 0; | ||
1198 | int tmp; | ||
1199 | |||
1200 | /* Clear the out buffer. */ | ||
1201 | memset(remcom_out_buffer, 0, sizeof(remcom_out_buffer)); | ||
1202 | |||
1203 | if (kgdb_connected) { | ||
1204 | unsigned char thref[8]; | ||
1205 | char *ptr; | ||
1206 | |||
1207 | /* Reply to host that an exception has occurred */ | ||
1208 | ptr = remcom_out_buffer; | ||
1209 | *ptr++ = 'T'; | ||
1210 | ptr = pack_hex_byte(ptr, ks->signo); | ||
1211 | ptr += strlen(strcpy(ptr, "thread:")); | ||
1212 | int_to_threadref(thref, shadow_pid(current->pid)); | ||
1213 | ptr = pack_threadid(ptr, thref); | ||
1214 | *ptr++ = ';'; | ||
1215 | put_packet(remcom_out_buffer); | ||
1216 | } | ||
1217 | |||
1218 | kgdb_usethread = kgdb_info[ks->cpu].task; | ||
1219 | ks->kgdb_usethreadid = shadow_pid(kgdb_info[ks->cpu].task->pid); | ||
1220 | ks->pass_exception = 0; | ||
1221 | |||
1222 | while (1) { | ||
1223 | error = 0; | ||
1224 | |||
1225 | /* Clear the out buffer. */ | ||
1226 | memset(remcom_out_buffer, 0, sizeof(remcom_out_buffer)); | ||
1227 | |||
1228 | get_packet(remcom_in_buffer); | ||
1229 | |||
1230 | switch (remcom_in_buffer[0]) { | ||
1231 | case '?': /* gdbserial status */ | ||
1232 | gdb_cmd_status(ks); | ||
1233 | break; | ||
1234 | case 'g': /* return the value of the CPU registers */ | ||
1235 | gdb_cmd_getregs(ks); | ||
1236 | break; | ||
1237 | case 'G': /* set the value of the CPU registers - return OK */ | ||
1238 | gdb_cmd_setregs(ks); | ||
1239 | break; | ||
1240 | case 'm': /* mAA..AA,LLLL Read LLLL bytes at address AA..AA */ | ||
1241 | gdb_cmd_memread(ks); | ||
1242 | break; | ||
1243 | case 'M': /* MAA..AA,LLLL: Write LLLL bytes at address AA..AA */ | ||
1244 | gdb_cmd_memwrite(ks); | ||
1245 | break; | ||
1246 | case 'X': /* XAA..AA,LLLL: Write LLLL bytes at address AA..AA */ | ||
1247 | gdb_cmd_binwrite(ks); | ||
1248 | break; | ||
1249 | /* kill or detach. KGDB should treat this like a | ||
1250 | * continue. | ||
1251 | */ | ||
1252 | case 'D': /* Debugger detach */ | ||
1253 | case 'k': /* Debugger detach via kill */ | ||
1254 | gdb_cmd_detachkill(ks); | ||
1255 | goto default_handle; | ||
1256 | case 'R': /* Reboot */ | ||
1257 | if (gdb_cmd_reboot(ks)) | ||
1258 | goto default_handle; | ||
1259 | break; | ||
1260 | case 'q': /* query command */ | ||
1261 | gdb_cmd_query(ks); | ||
1262 | break; | ||
1263 | case 'H': /* task related */ | ||
1264 | gdb_cmd_task(ks); | ||
1265 | break; | ||
1266 | case 'T': /* Query thread status */ | ||
1267 | gdb_cmd_thread(ks); | ||
1268 | break; | ||
1269 | case 'z': /* Break point remove */ | ||
1270 | case 'Z': /* Break point set */ | ||
1271 | gdb_cmd_break(ks); | ||
1272 | break; | ||
1273 | case 'C': /* Exception passing */ | ||
1274 | tmp = gdb_cmd_exception_pass(ks); | ||
1275 | if (tmp > 0) | ||
1276 | goto default_handle; | ||
1277 | if (tmp == 0) | ||
1278 | break; | ||
1279 | /* Fall through on tmp < 0 */ | ||
1280 | case 'c': /* Continue packet */ | ||
1281 | case 's': /* Single step packet */ | ||
1282 | if (kgdb_contthread && kgdb_contthread != current) { | ||
1283 | /* Can't switch threads in kgdb */ | ||
1284 | error_packet(remcom_out_buffer, -EINVAL); | ||
1285 | break; | ||
1286 | } | ||
1287 | kgdb_activate_sw_breakpoints(); | ||
1288 | /* Fall through to default processing */ | ||
1289 | default: | ||
1290 | default_handle: | ||
1291 | error = kgdb_arch_handle_exception(ks->ex_vector, | ||
1292 | ks->signo, | ||
1293 | ks->err_code, | ||
1294 | remcom_in_buffer, | ||
1295 | remcom_out_buffer, | ||
1296 | ks->linux_regs); | ||
1297 | /* | ||
1298 | * Leave cmd processing on error, detach, | ||
1299 | * kill, continue, or single step. | ||
1300 | */ | ||
1301 | if (error >= 0 || remcom_in_buffer[0] == 'D' || | ||
1302 | remcom_in_buffer[0] == 'k') { | ||
1303 | error = 0; | ||
1304 | goto kgdb_exit; | ||
1305 | } | ||
1306 | |||
1307 | } | ||
1308 | |||
1309 | /* reply to the request */ | ||
1310 | put_packet(remcom_out_buffer); | ||
1311 | } | ||
1312 | |||
1313 | kgdb_exit: | ||
1314 | if (ks->pass_exception) | ||
1315 | error = 1; | ||
1316 | return error; | ||
1317 | } | ||
1318 | |||
1319 | static int kgdb_reenter_check(struct kgdb_state *ks) | ||
1320 | { | ||
1321 | unsigned long addr; | ||
1322 | |||
1323 | if (atomic_read(&kgdb_active) != raw_smp_processor_id()) | ||
1324 | return 0; | ||
1325 | |||
1326 | /* Panic on recursive debugger calls: */ | ||
1327 | exception_level++; | ||
1328 | addr = kgdb_arch_pc(ks->ex_vector, ks->linux_regs); | ||
1329 | kgdb_deactivate_sw_breakpoints(); | ||
1330 | |||
1331 | /* | ||
1332 | * If the break point removed ok at the place exception | ||
1333 | * occurred, try to recover and print a warning to the end | ||
1334 | * user because the user planted a breakpoint in a place that | ||
1335 | * KGDB needs in order to function. | ||
1336 | */ | ||
1337 | if (kgdb_remove_sw_break(addr) == 0) { | ||
1338 | exception_level = 0; | ||
1339 | kgdb_skipexception(ks->ex_vector, ks->linux_regs); | ||
1340 | kgdb_activate_sw_breakpoints(); | ||
1341 | printk(KERN_CRIT "KGDB: re-enter error: breakpoint removed %lx\n", | ||
1342 | addr); | ||
1343 | WARN_ON_ONCE(1); | ||
1344 | |||
1345 | return 1; | ||
1346 | } | ||
1347 | remove_all_break(); | ||
1348 | kgdb_skipexception(ks->ex_vector, ks->linux_regs); | ||
1349 | |||
1350 | if (exception_level > 1) { | ||
1351 | dump_stack(); | ||
1352 | panic("Recursive entry to debugger"); | ||
1353 | } | ||
1354 | |||
1355 | printk(KERN_CRIT "KGDB: re-enter exception: ALL breakpoints killed\n"); | ||
1356 | dump_stack(); | ||
1357 | panic("Recursive entry to debugger"); | ||
1358 | |||
1359 | return 1; | ||
1360 | } | ||
1361 | |||
1362 | static int kgdb_cpu_enter(struct kgdb_state *ks, struct pt_regs *regs) | ||
1363 | { | ||
1364 | unsigned long flags; | ||
1365 | int sstep_tries = 100; | ||
1366 | int error = 0; | ||
1367 | int i, cpu; | ||
1368 | int trace_on = 0; | ||
1369 | acquirelock: | ||
1370 | /* | ||
1371 | * Interrupts will be restored by the 'trap return' code, except when | ||
1372 | * single stepping. | ||
1373 | */ | ||
1374 | local_irq_save(flags); | ||
1375 | |||
1376 | cpu = ks->cpu; | ||
1377 | kgdb_info[cpu].debuggerinfo = regs; | ||
1378 | kgdb_info[cpu].task = current; | ||
1379 | /* | ||
1380 | * Make sure the above info reaches the primary CPU before | ||
1381 | * our cpu_in_kgdb[] flag setting does: | ||
1382 | */ | ||
1383 | atomic_inc(&cpu_in_kgdb[cpu]); | ||
1384 | |||
1385 | /* | ||
1386 | * CPU will loop if it is a slave or request to become a kgdb | ||
1387 | * master cpu and acquire the kgdb_active lock: | ||
1388 | */ | ||
1389 | while (1) { | ||
1390 | if (kgdb_info[cpu].exception_state & DCPU_WANT_MASTER) { | ||
1391 | if (atomic_cmpxchg(&kgdb_active, -1, cpu) == cpu) | ||
1392 | break; | ||
1393 | } else if (kgdb_info[cpu].exception_state & DCPU_IS_SLAVE) { | ||
1394 | if (!atomic_read(&passive_cpu_wait[cpu])) | ||
1395 | goto return_normal; | ||
1396 | } else { | ||
1397 | return_normal: | ||
1398 | /* Return to normal operation by executing any | ||
1399 | * hw breakpoint fixup. | ||
1400 | */ | ||
1401 | if (arch_kgdb_ops.correct_hw_break) | ||
1402 | arch_kgdb_ops.correct_hw_break(); | ||
1403 | if (trace_on) | ||
1404 | tracing_on(); | ||
1405 | atomic_dec(&cpu_in_kgdb[cpu]); | ||
1406 | touch_softlockup_watchdog_sync(); | ||
1407 | clocksource_touch_watchdog(); | ||
1408 | local_irq_restore(flags); | ||
1409 | return 0; | ||
1410 | } | ||
1411 | cpu_relax(); | ||
1412 | } | ||
1413 | |||
1414 | /* | ||
1415 | * For single stepping, try to only enter on the processor | ||
1416 | * that was single stepping. To gaurd against a deadlock, the | ||
1417 | * kernel will only try for the value of sstep_tries before | ||
1418 | * giving up and continuing on. | ||
1419 | */ | ||
1420 | if (atomic_read(&kgdb_cpu_doing_single_step) != -1 && | ||
1421 | (kgdb_info[cpu].task && | ||
1422 | kgdb_info[cpu].task->pid != kgdb_sstep_pid) && --sstep_tries) { | ||
1423 | atomic_set(&kgdb_active, -1); | ||
1424 | touch_softlockup_watchdog_sync(); | ||
1425 | clocksource_touch_watchdog(); | ||
1426 | local_irq_restore(flags); | ||
1427 | |||
1428 | goto acquirelock; | ||
1429 | } | ||
1430 | |||
1431 | if (!kgdb_io_ready(1)) { | ||
1432 | error = 1; | ||
1433 | goto kgdb_restore; /* No I/O connection, so resume the system */ | ||
1434 | } | ||
1435 | |||
1436 | /* | ||
1437 | * Don't enter if we have hit a removed breakpoint. | ||
1438 | */ | ||
1439 | if (kgdb_skipexception(ks->ex_vector, ks->linux_regs)) | ||
1440 | goto kgdb_restore; | ||
1441 | |||
1442 | /* Call the I/O driver's pre_exception routine */ | ||
1443 | if (kgdb_io_ops->pre_exception) | ||
1444 | kgdb_io_ops->pre_exception(); | ||
1445 | |||
1446 | kgdb_disable_hw_debug(ks->linux_regs); | ||
1447 | |||
1448 | /* | ||
1449 | * Get the passive CPU lock which will hold all the non-primary | ||
1450 | * CPU in a spin state while the debugger is active | ||
1451 | */ | ||
1452 | if (!kgdb_single_step) { | ||
1453 | for (i = 0; i < NR_CPUS; i++) | ||
1454 | atomic_inc(&passive_cpu_wait[i]); | ||
1455 | } | ||
1456 | |||
1457 | #ifdef CONFIG_SMP | ||
1458 | /* Signal the other CPUs to enter kgdb_wait() */ | ||
1459 | if ((!kgdb_single_step) && kgdb_do_roundup) | ||
1460 | kgdb_roundup_cpus(flags); | ||
1461 | #endif | ||
1462 | |||
1463 | /* | ||
1464 | * Wait for the other CPUs to be notified and be waiting for us: | ||
1465 | */ | ||
1466 | for_each_online_cpu(i) { | ||
1467 | while (!atomic_read(&cpu_in_kgdb[i])) | ||
1468 | cpu_relax(); | ||
1469 | } | ||
1470 | |||
1471 | /* | ||
1472 | * At this point the primary processor is completely | ||
1473 | * in the debugger and all secondary CPUs are quiescent | ||
1474 | */ | ||
1475 | kgdb_post_primary_code(ks->linux_regs, ks->ex_vector, ks->err_code); | ||
1476 | kgdb_deactivate_sw_breakpoints(); | ||
1477 | kgdb_single_step = 0; | ||
1478 | kgdb_contthread = current; | ||
1479 | exception_level = 0; | ||
1480 | trace_on = tracing_is_on(); | ||
1481 | if (trace_on) | ||
1482 | tracing_off(); | ||
1483 | |||
1484 | /* Talk to debugger with gdbserial protocol */ | ||
1485 | error = gdb_serial_stub(ks); | ||
1486 | |||
1487 | /* Call the I/O driver's post_exception routine */ | ||
1488 | if (kgdb_io_ops->post_exception) | ||
1489 | kgdb_io_ops->post_exception(); | ||
1490 | |||
1491 | atomic_dec(&cpu_in_kgdb[ks->cpu]); | ||
1492 | |||
1493 | if (!kgdb_single_step) { | ||
1494 | for (i = NR_CPUS-1; i >= 0; i--) | ||
1495 | atomic_dec(&passive_cpu_wait[i]); | ||
1496 | /* | ||
1497 | * Wait till all the CPUs have quit | ||
1498 | * from the debugger. | ||
1499 | */ | ||
1500 | for_each_online_cpu(i) { | ||
1501 | while (atomic_read(&cpu_in_kgdb[i])) | ||
1502 | cpu_relax(); | ||
1503 | } | ||
1504 | } | ||
1505 | |||
1506 | kgdb_restore: | ||
1507 | if (atomic_read(&kgdb_cpu_doing_single_step) != -1) { | ||
1508 | int sstep_cpu = atomic_read(&kgdb_cpu_doing_single_step); | ||
1509 | if (kgdb_info[sstep_cpu].task) | ||
1510 | kgdb_sstep_pid = kgdb_info[sstep_cpu].task->pid; | ||
1511 | else | ||
1512 | kgdb_sstep_pid = 0; | ||
1513 | } | ||
1514 | if (trace_on) | ||
1515 | tracing_on(); | ||
1516 | /* Free kgdb_active */ | ||
1517 | atomic_set(&kgdb_active, -1); | ||
1518 | touch_softlockup_watchdog_sync(); | ||
1519 | clocksource_touch_watchdog(); | ||
1520 | local_irq_restore(flags); | ||
1521 | |||
1522 | return error; | ||
1523 | } | ||
1524 | |||
1525 | /* | ||
1526 | * kgdb_handle_exception() - main entry point from a kernel exception | ||
1527 | * | ||
1528 | * Locking hierarchy: | ||
1529 | * interface locks, if any (begin_session) | ||
1530 | * kgdb lock (kgdb_active) | ||
1531 | */ | ||
1532 | int | ||
1533 | kgdb_handle_exception(int evector, int signo, int ecode, struct pt_regs *regs) | ||
1534 | { | ||
1535 | struct kgdb_state kgdb_var; | ||
1536 | struct kgdb_state *ks = &kgdb_var; | ||
1537 | int ret; | ||
1538 | |||
1539 | ks->cpu = raw_smp_processor_id(); | ||
1540 | ks->ex_vector = evector; | ||
1541 | ks->signo = signo; | ||
1542 | ks->ex_vector = evector; | ||
1543 | ks->err_code = ecode; | ||
1544 | ks->kgdb_usethreadid = 0; | ||
1545 | ks->linux_regs = regs; | ||
1546 | |||
1547 | if (kgdb_reenter_check(ks)) | ||
1548 | return 0; /* Ouch, double exception ! */ | ||
1549 | kgdb_info[ks->cpu].exception_state |= DCPU_WANT_MASTER; | ||
1550 | ret = kgdb_cpu_enter(ks, regs); | ||
1551 | kgdb_info[ks->cpu].exception_state &= ~DCPU_WANT_MASTER; | ||
1552 | return ret; | ||
1553 | } | ||
1554 | |||
1555 | int kgdb_nmicallback(int cpu, void *regs) | ||
1556 | { | ||
1557 | #ifdef CONFIG_SMP | ||
1558 | struct kgdb_state kgdb_var; | ||
1559 | struct kgdb_state *ks = &kgdb_var; | ||
1560 | |||
1561 | memset(ks, 0, sizeof(struct kgdb_state)); | ||
1562 | ks->cpu = cpu; | ||
1563 | ks->linux_regs = regs; | ||
1564 | |||
1565 | if (!atomic_read(&cpu_in_kgdb[cpu]) && | ||
1566 | atomic_read(&kgdb_active) != -1 && | ||
1567 | atomic_read(&kgdb_active) != cpu) { | ||
1568 | kgdb_info[cpu].exception_state |= DCPU_IS_SLAVE; | ||
1569 | kgdb_cpu_enter(ks, regs); | ||
1570 | kgdb_info[cpu].exception_state &= ~DCPU_IS_SLAVE; | ||
1571 | return 0; | ||
1572 | } | ||
1573 | #endif | ||
1574 | return 1; | ||
1575 | } | ||
1576 | |||
1577 | static void kgdb_console_write(struct console *co, const char *s, | ||
1578 | unsigned count) | ||
1579 | { | ||
1580 | unsigned long flags; | ||
1581 | |||
1582 | /* If we're debugging, or KGDB has not connected, don't try | ||
1583 | * and print. */ | ||
1584 | if (!kgdb_connected || atomic_read(&kgdb_active) != -1) | ||
1585 | return; | ||
1586 | |||
1587 | local_irq_save(flags); | ||
1588 | kgdb_msg_write(s, count); | ||
1589 | local_irq_restore(flags); | ||
1590 | } | ||
1591 | |||
1592 | static struct console kgdbcons = { | ||
1593 | .name = "kgdb", | ||
1594 | .write = kgdb_console_write, | ||
1595 | .flags = CON_PRINTBUFFER | CON_ENABLED, | ||
1596 | .index = -1, | ||
1597 | }; | ||
1598 | |||
1599 | #ifdef CONFIG_MAGIC_SYSRQ | ||
1600 | static void sysrq_handle_gdb(int key, struct tty_struct *tty) | ||
1601 | { | ||
1602 | if (!kgdb_io_ops) { | ||
1603 | printk(KERN_CRIT "ERROR: No KGDB I/O module available\n"); | ||
1604 | return; | ||
1605 | } | ||
1606 | if (!kgdb_connected) | ||
1607 | printk(KERN_CRIT "Entering KGDB\n"); | ||
1608 | |||
1609 | kgdb_breakpoint(); | ||
1610 | } | ||
1611 | |||
1612 | static struct sysrq_key_op sysrq_gdb_op = { | ||
1613 | .handler = sysrq_handle_gdb, | ||
1614 | .help_msg = "debug(G)", | ||
1615 | .action_msg = "DEBUG", | ||
1616 | }; | ||
1617 | #endif | ||
1618 | |||
1619 | static void kgdb_register_callbacks(void) | ||
1620 | { | ||
1621 | if (!kgdb_io_module_registered) { | ||
1622 | kgdb_io_module_registered = 1; | ||
1623 | kgdb_arch_init(); | ||
1624 | #ifdef CONFIG_MAGIC_SYSRQ | ||
1625 | register_sysrq_key('g', &sysrq_gdb_op); | ||
1626 | #endif | ||
1627 | if (kgdb_use_con && !kgdb_con_registered) { | ||
1628 | register_console(&kgdbcons); | ||
1629 | kgdb_con_registered = 1; | ||
1630 | } | ||
1631 | } | ||
1632 | } | ||
1633 | |||
1634 | static void kgdb_unregister_callbacks(void) | ||
1635 | { | ||
1636 | /* | ||
1637 | * When this routine is called KGDB should unregister from the | ||
1638 | * panic handler and clean up, making sure it is not handling any | ||
1639 | * break exceptions at the time. | ||
1640 | */ | ||
1641 | if (kgdb_io_module_registered) { | ||
1642 | kgdb_io_module_registered = 0; | ||
1643 | kgdb_arch_exit(); | ||
1644 | #ifdef CONFIG_MAGIC_SYSRQ | ||
1645 | unregister_sysrq_key('g', &sysrq_gdb_op); | ||
1646 | #endif | ||
1647 | if (kgdb_con_registered) { | ||
1648 | unregister_console(&kgdbcons); | ||
1649 | kgdb_con_registered = 0; | ||
1650 | } | ||
1651 | } | ||
1652 | } | ||
1653 | |||
1654 | static void kgdb_initial_breakpoint(void) | ||
1655 | { | ||
1656 | kgdb_break_asap = 0; | ||
1657 | |||
1658 | printk(KERN_CRIT "kgdb: Waiting for connection from remote gdb...\n"); | ||
1659 | kgdb_breakpoint(); | ||
1660 | } | ||
1661 | |||
1662 | /** | ||
1663 | * kgdb_register_io_module - register KGDB IO module | ||
1664 | * @new_kgdb_io_ops: the io ops vector | ||
1665 | * | ||
1666 | * Register it with the KGDB core. | ||
1667 | */ | ||
1668 | int kgdb_register_io_module(struct kgdb_io *new_kgdb_io_ops) | ||
1669 | { | ||
1670 | int err; | ||
1671 | |||
1672 | spin_lock(&kgdb_registration_lock); | ||
1673 | |||
1674 | if (kgdb_io_ops) { | ||
1675 | spin_unlock(&kgdb_registration_lock); | ||
1676 | |||
1677 | printk(KERN_ERR "kgdb: Another I/O driver is already " | ||
1678 | "registered with KGDB.\n"); | ||
1679 | return -EBUSY; | ||
1680 | } | ||
1681 | |||
1682 | if (new_kgdb_io_ops->init) { | ||
1683 | err = new_kgdb_io_ops->init(); | ||
1684 | if (err) { | ||
1685 | spin_unlock(&kgdb_registration_lock); | ||
1686 | return err; | ||
1687 | } | ||
1688 | } | ||
1689 | |||
1690 | kgdb_io_ops = new_kgdb_io_ops; | ||
1691 | |||
1692 | spin_unlock(&kgdb_registration_lock); | ||
1693 | |||
1694 | printk(KERN_INFO "kgdb: Registered I/O driver %s.\n", | ||
1695 | new_kgdb_io_ops->name); | ||
1696 | |||
1697 | /* Arm KGDB now. */ | ||
1698 | kgdb_register_callbacks(); | ||
1699 | |||
1700 | if (kgdb_break_asap) | ||
1701 | kgdb_initial_breakpoint(); | ||
1702 | |||
1703 | return 0; | ||
1704 | } | ||
1705 | EXPORT_SYMBOL_GPL(kgdb_register_io_module); | ||
1706 | |||
1707 | /** | ||
1708 | * kkgdb_unregister_io_module - unregister KGDB IO module | ||
1709 | * @old_kgdb_io_ops: the io ops vector | ||
1710 | * | ||
1711 | * Unregister it with the KGDB core. | ||
1712 | */ | ||
1713 | void kgdb_unregister_io_module(struct kgdb_io *old_kgdb_io_ops) | ||
1714 | { | ||
1715 | BUG_ON(kgdb_connected); | ||
1716 | |||
1717 | /* | ||
1718 | * KGDB is no longer able to communicate out, so | ||
1719 | * unregister our callbacks and reset state. | ||
1720 | */ | ||
1721 | kgdb_unregister_callbacks(); | ||
1722 | |||
1723 | spin_lock(&kgdb_registration_lock); | ||
1724 | |||
1725 | WARN_ON_ONCE(kgdb_io_ops != old_kgdb_io_ops); | ||
1726 | kgdb_io_ops = NULL; | ||
1727 | |||
1728 | spin_unlock(&kgdb_registration_lock); | ||
1729 | |||
1730 | printk(KERN_INFO | ||
1731 | "kgdb: Unregistered I/O driver %s, debugger disabled.\n", | ||
1732 | old_kgdb_io_ops->name); | ||
1733 | } | ||
1734 | EXPORT_SYMBOL_GPL(kgdb_unregister_io_module); | ||
1735 | |||
1736 | /** | ||
1737 | * kgdb_breakpoint - generate breakpoint exception | ||
1738 | * | ||
1739 | * This function will generate a breakpoint exception. It is used at the | ||
1740 | * beginning of a program to sync up with a debugger and can be used | ||
1741 | * otherwise as a quick means to stop program execution and "break" into | ||
1742 | * the debugger. | ||
1743 | */ | ||
1744 | void kgdb_breakpoint(void) | ||
1745 | { | ||
1746 | atomic_inc(&kgdb_setting_breakpoint); | ||
1747 | wmb(); /* Sync point before breakpoint */ | ||
1748 | arch_kgdb_breakpoint(); | ||
1749 | wmb(); /* Sync point after breakpoint */ | ||
1750 | atomic_dec(&kgdb_setting_breakpoint); | ||
1751 | } | ||
1752 | EXPORT_SYMBOL_GPL(kgdb_breakpoint); | ||
1753 | |||
1754 | static int __init opt_kgdb_wait(char *str) | ||
1755 | { | ||
1756 | kgdb_break_asap = 1; | ||
1757 | |||
1758 | if (kgdb_io_module_registered) | ||
1759 | kgdb_initial_breakpoint(); | ||
1760 | |||
1761 | return 0; | ||
1762 | } | ||
1763 | |||
1764 | early_param("kgdbwait", opt_kgdb_wait); | ||