Merge tag 'io_uring-5.11-2021-01-16' of git://git.kernel.dk/linux-block
[linux/fpc-iii.git] / kernel / debug / kdb / kdb_bp.c
blobec49401466123fcee1ddc7de6a67845927b742e1
1 /*
2 * Kernel Debugger Architecture Independent Breakpoint Handler
4 * This file is subject to the terms and conditions of the GNU General Public
5 * License. See the file "COPYING" in the main directory of this archive
6 * for more details.
8 * Copyright (c) 1999-2004 Silicon Graphics, Inc. All Rights Reserved.
9 * Copyright (c) 2009 Wind River Systems, Inc. All Rights Reserved.
12 #include <linux/string.h>
13 #include <linux/kernel.h>
14 #include <linux/init.h>
15 #include <linux/kdb.h>
16 #include <linux/kgdb.h>
17 #include <linux/smp.h>
18 #include <linux/sched.h>
19 #include <linux/interrupt.h>
20 #include "kdb_private.h"
23 * Table of kdb_breakpoints
25 kdb_bp_t kdb_breakpoints[KDB_MAXBPT];
27 static void kdb_setsinglestep(struct pt_regs *regs)
29 KDB_STATE_SET(DOING_SS);
32 static char *kdb_rwtypes[] = {
33 "Instruction(i)",
34 "Instruction(Register)",
35 "Data Write",
36 "I/O",
37 "Data Access"
40 static char *kdb_bptype(kdb_bp_t *bp)
42 if (bp->bp_type < 0 || bp->bp_type > 4)
43 return "";
45 return kdb_rwtypes[bp->bp_type];
48 static int kdb_parsebp(int argc, const char **argv, int *nextargp, kdb_bp_t *bp)
50 int nextarg = *nextargp;
51 int diag;
53 bp->bph_length = 1;
54 if ((argc + 1) != nextarg) {
55 if (strncasecmp(argv[nextarg], "datar", sizeof("datar")) == 0)
56 bp->bp_type = BP_ACCESS_WATCHPOINT;
57 else if (strncasecmp(argv[nextarg], "dataw", sizeof("dataw")) == 0)
58 bp->bp_type = BP_WRITE_WATCHPOINT;
59 else if (strncasecmp(argv[nextarg], "inst", sizeof("inst")) == 0)
60 bp->bp_type = BP_HARDWARE_BREAKPOINT;
61 else
62 return KDB_ARGCOUNT;
64 bp->bph_length = 1;
66 nextarg++;
68 if ((argc + 1) != nextarg) {
69 unsigned long len;
71 diag = kdbgetularg((char *)argv[nextarg],
72 &len);
73 if (diag)
74 return diag;
77 if (len > 8)
78 return KDB_BADLENGTH;
80 bp->bph_length = len;
81 nextarg++;
84 if ((argc + 1) != nextarg)
85 return KDB_ARGCOUNT;
88 *nextargp = nextarg;
89 return 0;
92 static int _kdb_bp_remove(kdb_bp_t *bp)
94 int ret = 1;
95 if (!bp->bp_installed)
96 return ret;
97 if (!bp->bp_type)
98 ret = dbg_remove_sw_break(bp->bp_addr);
99 else
100 ret = arch_kgdb_ops.remove_hw_breakpoint(bp->bp_addr,
101 bp->bph_length,
102 bp->bp_type);
103 if (ret == 0)
104 bp->bp_installed = 0;
105 return ret;
108 static void kdb_handle_bp(struct pt_regs *regs, kdb_bp_t *bp)
110 if (KDB_DEBUG(BP))
111 kdb_printf("regs->ip = 0x%lx\n", instruction_pointer(regs));
114 * Setup single step
116 kdb_setsinglestep(regs);
119 * Reset delay attribute
121 bp->bp_delay = 0;
122 bp->bp_delayed = 1;
125 static int _kdb_bp_install(struct pt_regs *regs, kdb_bp_t *bp)
127 int ret;
129 * Install the breakpoint, if it is not already installed.
132 if (KDB_DEBUG(BP))
133 kdb_printf("%s: bp_installed %d\n",
134 __func__, bp->bp_installed);
135 if (!KDB_STATE(SSBPT))
136 bp->bp_delay = 0;
137 if (bp->bp_installed)
138 return 1;
139 if (bp->bp_delay || (bp->bp_delayed && KDB_STATE(DOING_SS))) {
140 if (KDB_DEBUG(BP))
141 kdb_printf("%s: delayed bp\n", __func__);
142 kdb_handle_bp(regs, bp);
143 return 0;
145 if (!bp->bp_type)
146 ret = dbg_set_sw_break(bp->bp_addr);
147 else
148 ret = arch_kgdb_ops.set_hw_breakpoint(bp->bp_addr,
149 bp->bph_length,
150 bp->bp_type);
151 if (ret == 0) {
152 bp->bp_installed = 1;
153 } else {
154 kdb_printf("%s: failed to set breakpoint at 0x%lx\n",
155 __func__, bp->bp_addr);
156 if (!bp->bp_type) {
157 kdb_printf("Software breakpoints are unavailable.\n"
158 " Boot the kernel with rodata=off\n"
159 " OR use hw breaks: help bph\n");
161 return 1;
163 return 0;
167 * kdb_bp_install
169 * Install kdb_breakpoints prior to returning from the
170 * kernel debugger. This allows the kdb_breakpoints to be set
171 * upon functions that are used internally by kdb, such as
172 * printk(). This function is only called once per kdb session.
174 void kdb_bp_install(struct pt_regs *regs)
176 int i;
178 for (i = 0; i < KDB_MAXBPT; i++) {
179 kdb_bp_t *bp = &kdb_breakpoints[i];
181 if (KDB_DEBUG(BP)) {
182 kdb_printf("%s: bp %d bp_enabled %d\n",
183 __func__, i, bp->bp_enabled);
185 if (bp->bp_enabled)
186 _kdb_bp_install(regs, bp);
191 * kdb_bp_remove
193 * Remove kdb_breakpoints upon entry to the kernel debugger.
195 * Parameters:
196 * None.
197 * Outputs:
198 * None.
199 * Returns:
200 * None.
201 * Locking:
202 * None.
203 * Remarks:
205 void kdb_bp_remove(void)
207 int i;
209 for (i = KDB_MAXBPT - 1; i >= 0; i--) {
210 kdb_bp_t *bp = &kdb_breakpoints[i];
212 if (KDB_DEBUG(BP)) {
213 kdb_printf("%s: bp %d bp_enabled %d\n",
214 __func__, i, bp->bp_enabled);
216 if (bp->bp_enabled)
217 _kdb_bp_remove(bp);
223 * kdb_printbp
225 * Internal function to format and print a breakpoint entry.
227 * Parameters:
228 * None.
229 * Outputs:
230 * None.
231 * Returns:
232 * None.
233 * Locking:
234 * None.
235 * Remarks:
238 static void kdb_printbp(kdb_bp_t *bp, int i)
240 kdb_printf("%s ", kdb_bptype(bp));
241 kdb_printf("BP #%d at ", i);
242 kdb_symbol_print(bp->bp_addr, NULL, KDB_SP_DEFAULT);
244 if (bp->bp_enabled)
245 kdb_printf("\n is enabled ");
246 else
247 kdb_printf("\n is disabled");
249 kdb_printf(" addr at %016lx, hardtype=%d installed=%d\n",
250 bp->bp_addr, bp->bp_type, bp->bp_installed);
252 kdb_printf("\n");
256 * kdb_bp
258 * Handle the bp commands.
260 * [bp|bph] <addr-expression> [DATAR|DATAW]
262 * Parameters:
263 * argc Count of arguments in argv
264 * argv Space delimited command line arguments
265 * Outputs:
266 * None.
267 * Returns:
268 * Zero for success, a kdb diagnostic if failure.
269 * Locking:
270 * None.
271 * Remarks:
273 * bp Set breakpoint on all cpus. Only use hardware assist if need.
274 * bph Set breakpoint on all cpus. Force hardware register
277 static int kdb_bp(int argc, const char **argv)
279 int i, bpno;
280 kdb_bp_t *bp, *bp_check;
281 int diag;
282 char *symname = NULL;
283 long offset = 0ul;
284 int nextarg;
285 kdb_bp_t template = {0};
287 if (argc == 0) {
289 * Display breakpoint table
291 for (bpno = 0, bp = kdb_breakpoints; bpno < KDB_MAXBPT;
292 bpno++, bp++) {
293 if (bp->bp_free)
294 continue;
295 kdb_printbp(bp, bpno);
298 return 0;
301 nextarg = 1;
302 diag = kdbgetaddrarg(argc, argv, &nextarg, &template.bp_addr,
303 &offset, &symname);
304 if (diag)
305 return diag;
306 if (!template.bp_addr)
307 return KDB_BADINT;
310 * This check is redundant (since the breakpoint machinery should
311 * be doing the same check during kdb_bp_install) but gives the
312 * user immediate feedback.
314 diag = kgdb_validate_break_address(template.bp_addr);
315 if (diag)
316 return diag;
319 * Find an empty bp structure to allocate
321 for (bpno = 0, bp = kdb_breakpoints; bpno < KDB_MAXBPT; bpno++, bp++) {
322 if (bp->bp_free)
323 break;
326 if (bpno == KDB_MAXBPT)
327 return KDB_TOOMANYBPT;
329 if (strcmp(argv[0], "bph") == 0) {
330 template.bp_type = BP_HARDWARE_BREAKPOINT;
331 diag = kdb_parsebp(argc, argv, &nextarg, &template);
332 if (diag)
333 return diag;
334 } else {
335 template.bp_type = BP_BREAKPOINT;
339 * Check for clashing breakpoints.
341 * Note, in this design we can't have hardware breakpoints
342 * enabled for both read and write on the same address.
344 for (i = 0, bp_check = kdb_breakpoints; i < KDB_MAXBPT;
345 i++, bp_check++) {
346 if (!bp_check->bp_free &&
347 bp_check->bp_addr == template.bp_addr) {
348 kdb_printf("You already have a breakpoint at "
349 kdb_bfd_vma_fmt0 "\n", template.bp_addr);
350 return KDB_DUPBPT;
354 template.bp_enabled = 1;
357 * Actually allocate the breakpoint found earlier
359 *bp = template;
360 bp->bp_free = 0;
362 kdb_printbp(bp, bpno);
364 return 0;
368 * kdb_bc
370 * Handles the 'bc', 'be', and 'bd' commands
372 * [bd|bc|be] <breakpoint-number>
373 * [bd|bc|be] *
375 * Parameters:
376 * argc Count of arguments in argv
377 * argv Space delimited command line arguments
378 * Outputs:
379 * None.
380 * Returns:
381 * Zero for success, a kdb diagnostic for failure
382 * Locking:
383 * None.
384 * Remarks:
386 static int kdb_bc(int argc, const char **argv)
388 unsigned long addr;
389 kdb_bp_t *bp = NULL;
390 int lowbp = KDB_MAXBPT;
391 int highbp = 0;
392 int done = 0;
393 int i;
394 int diag = 0;
396 int cmd; /* KDBCMD_B? */
397 #define KDBCMD_BC 0
398 #define KDBCMD_BE 1
399 #define KDBCMD_BD 2
401 if (strcmp(argv[0], "be") == 0)
402 cmd = KDBCMD_BE;
403 else if (strcmp(argv[0], "bd") == 0)
404 cmd = KDBCMD_BD;
405 else
406 cmd = KDBCMD_BC;
408 if (argc != 1)
409 return KDB_ARGCOUNT;
411 if (strcmp(argv[1], "*") == 0) {
412 lowbp = 0;
413 highbp = KDB_MAXBPT;
414 } else {
415 diag = kdbgetularg(argv[1], &addr);
416 if (diag)
417 return diag;
420 * For addresses less than the maximum breakpoint number,
421 * assume that the breakpoint number is desired.
423 if (addr < KDB_MAXBPT) {
424 lowbp = highbp = addr;
425 highbp++;
426 } else {
427 for (i = 0, bp = kdb_breakpoints; i < KDB_MAXBPT;
428 i++, bp++) {
429 if (bp->bp_addr == addr) {
430 lowbp = highbp = i;
431 highbp++;
432 break;
439 * Now operate on the set of breakpoints matching the input
440 * criteria (either '*' for all, or an individual breakpoint).
442 for (bp = &kdb_breakpoints[lowbp], i = lowbp;
443 i < highbp;
444 i++, bp++) {
445 if (bp->bp_free)
446 continue;
448 done++;
450 switch (cmd) {
451 case KDBCMD_BC:
452 bp->bp_enabled = 0;
454 kdb_printf("Breakpoint %d at "
455 kdb_bfd_vma_fmt " cleared\n",
456 i, bp->bp_addr);
458 bp->bp_addr = 0;
459 bp->bp_free = 1;
461 break;
462 case KDBCMD_BE:
463 bp->bp_enabled = 1;
465 kdb_printf("Breakpoint %d at "
466 kdb_bfd_vma_fmt " enabled",
467 i, bp->bp_addr);
469 kdb_printf("\n");
470 break;
471 case KDBCMD_BD:
472 if (!bp->bp_enabled)
473 break;
475 bp->bp_enabled = 0;
477 kdb_printf("Breakpoint %d at "
478 kdb_bfd_vma_fmt " disabled\n",
479 i, bp->bp_addr);
481 break;
483 if (bp->bp_delay && (cmd == KDBCMD_BC || cmd == KDBCMD_BD)) {
484 bp->bp_delay = 0;
485 KDB_STATE_CLEAR(SSBPT);
489 return (!done) ? KDB_BPTNOTFOUND : 0;
493 * kdb_ss
495 * Process the 'ss' (Single Step) command.
497 * ss
499 * Parameters:
500 * argc Argument count
501 * argv Argument vector
502 * Outputs:
503 * None.
504 * Returns:
505 * KDB_CMD_SS for success, a kdb error if failure.
506 * Locking:
507 * None.
508 * Remarks:
510 * Set the arch specific option to trigger a debug trap after the next
511 * instruction.
514 static int kdb_ss(int argc, const char **argv)
516 if (argc != 0)
517 return KDB_ARGCOUNT;
519 * Set trace flag and go.
521 KDB_STATE_SET(DOING_SS);
522 return KDB_CMD_SS;
525 /* Initialize the breakpoint table and register breakpoint commands. */
527 void __init kdb_initbptab(void)
529 int i;
530 kdb_bp_t *bp;
533 * First time initialization.
535 memset(&kdb_breakpoints, '\0', sizeof(kdb_breakpoints));
537 for (i = 0, bp = kdb_breakpoints; i < KDB_MAXBPT; i++, bp++)
538 bp->bp_free = 1;
540 kdb_register_flags("bp", kdb_bp, "[<vaddr>]",
541 "Set/Display breakpoints", 0,
542 KDB_ENABLE_FLOW_CTRL | KDB_REPEAT_NO_ARGS);
543 kdb_register_flags("bl", kdb_bp, "[<vaddr>]",
544 "Display breakpoints", 0,
545 KDB_ENABLE_FLOW_CTRL | KDB_REPEAT_NO_ARGS);
546 if (arch_kgdb_ops.flags & KGDB_HW_BREAKPOINT)
547 kdb_register_flags("bph", kdb_bp, "[<vaddr>]",
548 "[datar [length]|dataw [length]] Set hw brk", 0,
549 KDB_ENABLE_FLOW_CTRL | KDB_REPEAT_NO_ARGS);
550 kdb_register_flags("bc", kdb_bc, "<bpnum>",
551 "Clear Breakpoint", 0,
552 KDB_ENABLE_FLOW_CTRL);
553 kdb_register_flags("be", kdb_bc, "<bpnum>",
554 "Enable Breakpoint", 0,
555 KDB_ENABLE_FLOW_CTRL);
556 kdb_register_flags("bd", kdb_bc, "<bpnum>",
557 "Disable Breakpoint", 0,
558 KDB_ENABLE_FLOW_CTRL);
560 kdb_register_flags("ss", kdb_ss, "",
561 "Single Step", 1,
562 KDB_ENABLE_FLOW_CTRL | KDB_REPEAT_NO_ARGS);
564 * Architecture dependent initialization.