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
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[] = {
34 "Instruction(Register)",
40 static char *kdb_bptype(kdb_bp_t *bp)
42 if (bp->bp_type < 0 || bp->bp_type > 4)
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;
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;
68 if ((argc + 1) != nextarg) {
71 diag = kdbgetularg((char *)argv[nextarg],
84 if ((argc + 1) != nextarg)
92 static int _kdb_bp_remove(kdb_bp_t *bp)
95 if (!bp->bp_installed)
98 ret = dbg_remove_sw_break(bp->bp_addr);
100 ret = arch_kgdb_ops.remove_hw_breakpoint(bp->bp_addr,
104 bp->bp_installed = 0;
108 static void kdb_handle_bp(struct pt_regs *regs, kdb_bp_t *bp)
111 kdb_printf("regs->ip = 0x%lx\n", instruction_pointer(regs));
116 kdb_setsinglestep(regs);
119 * Reset delay attribute
125 static int _kdb_bp_install(struct pt_regs *regs, kdb_bp_t *bp)
129 * Install the breakpoint, if it is not already installed.
133 kdb_printf("%s: bp_installed %d\n",
134 __func__, bp->bp_installed);
135 if (!KDB_STATE(SSBPT))
137 if (bp->bp_installed)
139 if (bp->bp_delay || (bp->bp_delayed && KDB_STATE(DOING_SS))) {
141 kdb_printf("%s: delayed bp\n", __func__);
142 kdb_handle_bp(regs, bp);
146 ret = dbg_set_sw_break(bp->bp_addr);
148 ret = arch_kgdb_ops.set_hw_breakpoint(bp->bp_addr,
152 bp->bp_installed = 1;
154 kdb_printf("%s: failed to set breakpoint at 0x%lx\n",
155 __func__, bp->bp_addr);
157 kdb_printf("Software breakpoints are unavailable.\n"
158 " Boot the kernel with rodata=off\n"
159 " OR use hw breaks: help bph\n");
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)
178 for (i = 0; i < KDB_MAXBPT; i++) {
179 kdb_bp_t *bp = &kdb_breakpoints[i];
182 kdb_printf("%s: bp %d bp_enabled %d\n",
183 __func__, i, bp->bp_enabled);
186 _kdb_bp_install(regs, bp);
193 * Remove kdb_breakpoints upon entry to the kernel debugger.
205 void kdb_bp_remove(void)
209 for (i = KDB_MAXBPT - 1; i >= 0; i--) {
210 kdb_bp_t *bp = &kdb_breakpoints[i];
213 kdb_printf("%s: bp %d bp_enabled %d\n",
214 __func__, i, bp->bp_enabled);
225 * Internal function to format and print a breakpoint entry.
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);
245 kdb_printf("\n is enabled ");
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);
258 * Handle the bp commands.
260 * [bp|bph] <addr-expression> [DATAR|DATAW]
263 * argc Count of arguments in argv
264 * argv Space delimited command line arguments
268 * Zero for success, a kdb diagnostic if failure.
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)
280 kdb_bp_t *bp, *bp_check;
282 char *symname = NULL;
285 kdb_bp_t template = {0};
289 * Display breakpoint table
291 for (bpno = 0, bp = kdb_breakpoints; bpno < KDB_MAXBPT;
295 kdb_printbp(bp, bpno);
302 diag = kdbgetaddrarg(argc, argv, &nextarg, &template.bp_addr,
306 if (!template.bp_addr)
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);
319 * Find an empty bp structure to allocate
321 for (bpno = 0, bp = kdb_breakpoints; bpno < KDB_MAXBPT; bpno++, bp++) {
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);
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;
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);
354 template.bp_enabled = 1;
357 * Actually allocate the breakpoint found earlier
362 kdb_printbp(bp, bpno);
370 * Handles the 'bc', 'be', and 'bd' commands
372 * [bd|bc|be] <breakpoint-number>
376 * argc Count of arguments in argv
377 * argv Space delimited command line arguments
381 * Zero for success, a kdb diagnostic for failure
386 static int kdb_bc(int argc, const char **argv)
390 int lowbp = KDB_MAXBPT;
396 int cmd; /* KDBCMD_B? */
401 if (strcmp(argv[0], "be") == 0)
403 else if (strcmp(argv[0], "bd") == 0)
411 if (strcmp(argv[1], "*") == 0) {
415 diag = kdbgetularg(argv[1], &addr);
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;
427 for (i = 0, bp = kdb_breakpoints; i < KDB_MAXBPT;
429 if (bp->bp_addr == addr) {
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;
454 kdb_printf("Breakpoint %d at "
455 kdb_bfd_vma_fmt " cleared\n",
465 kdb_printf("Breakpoint %d at "
466 kdb_bfd_vma_fmt " enabled",
477 kdb_printf("Breakpoint %d at "
478 kdb_bfd_vma_fmt " disabled\n",
483 if (bp->bp_delay && (cmd == KDBCMD_BC || cmd == KDBCMD_BD)) {
485 KDB_STATE_CLEAR(SSBPT);
489 return (!done) ? KDB_BPTNOTFOUND : 0;
495 * Process the 'ss' (Single Step) command.
500 * argc Argument count
501 * argv Argument vector
505 * KDB_CMD_SS for success, a kdb error if failure.
510 * Set the arch specific option to trigger a debug trap after the next
514 static int kdb_ss(int argc, const char **argv)
519 * Set trace flag and go.
521 KDB_STATE_SET(DOING_SS);
525 /* Initialize the breakpoint table and register breakpoint commands. */
527 void __init kdb_initbptab(void)
533 * First time initialization.
535 memset(&kdb_breakpoints, '\0', sizeof(kdb_breakpoints));
537 for (i = 0, bp = kdb_breakpoints; i < KDB_MAXBPT; i++, bp++)
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, "",
562 KDB_ENABLE_FLOW_CTRL | KDB_REPEAT_NO_ARGS);
564 * Architecture dependent initialization.