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82da3ff8 IM |
1 | /* |
2 | * This program is free software; you can redistribute it and/or modify it | |
3 | * under the terms of the GNU General Public License as published by the | |
4 | * Free Software Foundation; either version 2, or (at your option) any | |
5 | * later version. | |
6 | * | |
7 | * This program is distributed in the hope that it will be useful, but | |
8 | * WITHOUT ANY WARRANTY; without even the implied warranty of | |
9 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
10 | * General Public License for more details. | |
11 | * | |
12 | */ | |
13 | ||
14 | /* | |
15 | * Copyright (C) 2004 Amit S. Kale <amitkale@linsyssoft.com> | |
16 | * Copyright (C) 2000-2001 VERITAS Software Corporation. | |
17 | * Copyright (C) 2002 Andi Kleen, SuSE Labs | |
18 | * Copyright (C) 2004 LinSysSoft Technologies Pvt. Ltd. | |
19 | * Copyright (C) 2007 MontaVista Software, Inc. | |
20 | * Copyright (C) 2007-2008 Jason Wessel, Wind River Systems, Inc. | |
21 | */ | |
22 | /**************************************************************************** | |
23 | * Contributor: Lake Stevens Instrument Division$ | |
24 | * Written by: Glenn Engel $ | |
25 | * Updated by: Amit Kale<akale@veritas.com> | |
26 | * Updated by: Tom Rini <trini@kernel.crashing.org> | |
27 | * Updated by: Jason Wessel <jason.wessel@windriver.com> | |
28 | * Modified for 386 by Jim Kingdon, Cygnus Support. | |
29 | * Origianl kgdb, compatibility with 2.1.xx kernel by | |
30 | * David Grothe <dave@gcom.com> | |
31 | * Integrated into 2.2.5 kernel by Tigran Aivazian <tigran@sco.com> | |
32 | * X86_64 changes from Andi Kleen's patch merged by Jim Houston | |
33 | */ | |
34 | #include <linux/spinlock.h> | |
35 | #include <linux/kdebug.h> | |
36 | #include <linux/string.h> | |
37 | #include <linux/kernel.h> | |
38 | #include <linux/ptrace.h> | |
39 | #include <linux/sched.h> | |
40 | #include <linux/delay.h> | |
41 | #include <linux/kgdb.h> | |
42 | #include <linux/init.h> | |
43 | #include <linux/smp.h> | |
d3597524 | 44 | #include <linux/nmi.h> |
82da3ff8 IM |
45 | |
46 | #include <asm/apicdef.h> | |
47 | #include <asm/system.h> | |
48 | ||
f8dfd5ed | 49 | #include <mach_ipi.h> |
82da3ff8 IM |
50 | |
51 | /* | |
52 | * Put the error code here just in case the user cares: | |
53 | */ | |
54 | static int gdb_x86errcode; | |
55 | ||
56 | /* | |
57 | * Likewise, the vector number here (since GDB only gets the signal | |
58 | * number through the usual means, and that's not very specific): | |
59 | */ | |
60 | static int gdb_x86vector = -1; | |
61 | ||
62 | /** | |
63 | * pt_regs_to_gdb_regs - Convert ptrace regs to GDB regs | |
64 | * @gdb_regs: A pointer to hold the registers in the order GDB wants. | |
65 | * @regs: The &struct pt_regs of the current process. | |
66 | * | |
67 | * Convert the pt_regs in @regs into the format for registers that | |
68 | * GDB expects, stored in @gdb_regs. | |
69 | */ | |
70 | void pt_regs_to_gdb_regs(unsigned long *gdb_regs, struct pt_regs *regs) | |
71 | { | |
72 | gdb_regs[GDB_AX] = regs->ax; | |
73 | gdb_regs[GDB_BX] = regs->bx; | |
74 | gdb_regs[GDB_CX] = regs->cx; | |
75 | gdb_regs[GDB_DX] = regs->dx; | |
76 | gdb_regs[GDB_SI] = regs->si; | |
77 | gdb_regs[GDB_DI] = regs->di; | |
78 | gdb_regs[GDB_BP] = regs->bp; | |
79 | gdb_regs[GDB_PS] = regs->flags; | |
80 | gdb_regs[GDB_PC] = regs->ip; | |
81 | #ifdef CONFIG_X86_32 | |
82 | gdb_regs[GDB_DS] = regs->ds; | |
83 | gdb_regs[GDB_ES] = regs->es; | |
84 | gdb_regs[GDB_CS] = regs->cs; | |
85 | gdb_regs[GDB_SS] = __KERNEL_DS; | |
86 | gdb_regs[GDB_FS] = 0xFFFF; | |
87 | gdb_regs[GDB_GS] = 0xFFFF; | |
88 | #else | |
89 | gdb_regs[GDB_R8] = regs->r8; | |
90 | gdb_regs[GDB_R9] = regs->r9; | |
91 | gdb_regs[GDB_R10] = regs->r10; | |
92 | gdb_regs[GDB_R11] = regs->r11; | |
93 | gdb_regs[GDB_R12] = regs->r12; | |
94 | gdb_regs[GDB_R13] = regs->r13; | |
95 | gdb_regs[GDB_R14] = regs->r14; | |
96 | gdb_regs[GDB_R15] = regs->r15; | |
97 | #endif | |
98 | gdb_regs[GDB_SP] = regs->sp; | |
99 | } | |
100 | ||
101 | /** | |
102 | * sleeping_thread_to_gdb_regs - Convert ptrace regs to GDB regs | |
103 | * @gdb_regs: A pointer to hold the registers in the order GDB wants. | |
104 | * @p: The &struct task_struct of the desired process. | |
105 | * | |
106 | * Convert the register values of the sleeping process in @p to | |
107 | * the format that GDB expects. | |
108 | * This function is called when kgdb does not have access to the | |
109 | * &struct pt_regs and therefore it should fill the gdb registers | |
110 | * @gdb_regs with what has been saved in &struct thread_struct | |
111 | * thread field during switch_to. | |
112 | */ | |
113 | void sleeping_thread_to_gdb_regs(unsigned long *gdb_regs, struct task_struct *p) | |
114 | { | |
115 | gdb_regs[GDB_AX] = 0; | |
116 | gdb_regs[GDB_BX] = 0; | |
117 | gdb_regs[GDB_CX] = 0; | |
118 | gdb_regs[GDB_DX] = 0; | |
119 | gdb_regs[GDB_SI] = 0; | |
120 | gdb_regs[GDB_DI] = 0; | |
121 | gdb_regs[GDB_BP] = *(unsigned long *)p->thread.sp; | |
122 | #ifdef CONFIG_X86_32 | |
123 | gdb_regs[GDB_DS] = __KERNEL_DS; | |
124 | gdb_regs[GDB_ES] = __KERNEL_DS; | |
125 | gdb_regs[GDB_PS] = 0; | |
126 | gdb_regs[GDB_CS] = __KERNEL_CS; | |
127 | gdb_regs[GDB_PC] = p->thread.ip; | |
128 | gdb_regs[GDB_SS] = __KERNEL_DS; | |
129 | gdb_regs[GDB_FS] = 0xFFFF; | |
130 | gdb_regs[GDB_GS] = 0xFFFF; | |
131 | #else | |
132 | gdb_regs[GDB_PS] = *(unsigned long *)(p->thread.sp + 8); | |
133 | gdb_regs[GDB_PC] = 0; | |
134 | gdb_regs[GDB_R8] = 0; | |
135 | gdb_regs[GDB_R9] = 0; | |
136 | gdb_regs[GDB_R10] = 0; | |
137 | gdb_regs[GDB_R11] = 0; | |
138 | gdb_regs[GDB_R12] = 0; | |
139 | gdb_regs[GDB_R13] = 0; | |
140 | gdb_regs[GDB_R14] = 0; | |
141 | gdb_regs[GDB_R15] = 0; | |
142 | #endif | |
143 | gdb_regs[GDB_SP] = p->thread.sp; | |
144 | } | |
145 | ||
146 | /** | |
147 | * gdb_regs_to_pt_regs - Convert GDB regs to ptrace regs. | |
148 | * @gdb_regs: A pointer to hold the registers we've received from GDB. | |
149 | * @regs: A pointer to a &struct pt_regs to hold these values in. | |
150 | * | |
151 | * Convert the GDB regs in @gdb_regs into the pt_regs, and store them | |
152 | * in @regs. | |
153 | */ | |
154 | void gdb_regs_to_pt_regs(unsigned long *gdb_regs, struct pt_regs *regs) | |
155 | { | |
156 | regs->ax = gdb_regs[GDB_AX]; | |
157 | regs->bx = gdb_regs[GDB_BX]; | |
158 | regs->cx = gdb_regs[GDB_CX]; | |
159 | regs->dx = gdb_regs[GDB_DX]; | |
160 | regs->si = gdb_regs[GDB_SI]; | |
161 | regs->di = gdb_regs[GDB_DI]; | |
162 | regs->bp = gdb_regs[GDB_BP]; | |
163 | regs->flags = gdb_regs[GDB_PS]; | |
164 | regs->ip = gdb_regs[GDB_PC]; | |
165 | #ifdef CONFIG_X86_32 | |
166 | regs->ds = gdb_regs[GDB_DS]; | |
167 | regs->es = gdb_regs[GDB_ES]; | |
168 | regs->cs = gdb_regs[GDB_CS]; | |
169 | #else | |
170 | regs->r8 = gdb_regs[GDB_R8]; | |
171 | regs->r9 = gdb_regs[GDB_R9]; | |
172 | regs->r10 = gdb_regs[GDB_R10]; | |
173 | regs->r11 = gdb_regs[GDB_R11]; | |
174 | regs->r12 = gdb_regs[GDB_R12]; | |
175 | regs->r13 = gdb_regs[GDB_R13]; | |
176 | regs->r14 = gdb_regs[GDB_R14]; | |
177 | regs->r15 = gdb_regs[GDB_R15]; | |
178 | #endif | |
179 | } | |
180 | ||
64e9ee30 JW |
181 | static struct hw_breakpoint { |
182 | unsigned enabled; | |
183 | unsigned type; | |
184 | unsigned len; | |
185 | unsigned long addr; | |
186 | } breakinfo[4]; | |
187 | ||
188 | static void kgdb_correct_hw_break(void) | |
189 | { | |
190 | unsigned long dr7; | |
191 | int correctit = 0; | |
192 | int breakbit; | |
193 | int breakno; | |
194 | ||
195 | get_debugreg(dr7, 7); | |
196 | for (breakno = 0; breakno < 4; breakno++) { | |
197 | breakbit = 2 << (breakno << 1); | |
198 | if (!(dr7 & breakbit) && breakinfo[breakno].enabled) { | |
199 | correctit = 1; | |
200 | dr7 |= breakbit; | |
201 | dr7 &= ~(0xf0000 << (breakno << 2)); | |
202 | dr7 |= ((breakinfo[breakno].len << 2) | | |
203 | breakinfo[breakno].type) << | |
204 | ((breakno << 2) + 16); | |
205 | if (breakno >= 0 && breakno <= 3) | |
206 | set_debugreg(breakinfo[breakno].addr, breakno); | |
207 | ||
208 | } else { | |
209 | if ((dr7 & breakbit) && !breakinfo[breakno].enabled) { | |
210 | correctit = 1; | |
211 | dr7 &= ~breakbit; | |
212 | dr7 &= ~(0xf0000 << (breakno << 2)); | |
213 | } | |
214 | } | |
215 | } | |
216 | if (correctit) | |
217 | set_debugreg(dr7, 7); | |
218 | } | |
219 | ||
220 | static int | |
221 | kgdb_remove_hw_break(unsigned long addr, int len, enum kgdb_bptype bptype) | |
222 | { | |
223 | int i; | |
224 | ||
225 | for (i = 0; i < 4; i++) | |
226 | if (breakinfo[i].addr == addr && breakinfo[i].enabled) | |
227 | break; | |
228 | if (i == 4) | |
229 | return -1; | |
230 | ||
231 | breakinfo[i].enabled = 0; | |
232 | ||
233 | return 0; | |
234 | } | |
235 | ||
236 | static void kgdb_remove_all_hw_break(void) | |
237 | { | |
238 | int i; | |
239 | ||
240 | for (i = 0; i < 4; i++) | |
241 | memset(&breakinfo[i], 0, sizeof(struct hw_breakpoint)); | |
242 | } | |
243 | ||
244 | static int | |
245 | kgdb_set_hw_break(unsigned long addr, int len, enum kgdb_bptype bptype) | |
246 | { | |
247 | unsigned type; | |
248 | int i; | |
249 | ||
250 | for (i = 0; i < 4; i++) | |
251 | if (!breakinfo[i].enabled) | |
252 | break; | |
253 | if (i == 4) | |
254 | return -1; | |
255 | ||
256 | switch (bptype) { | |
257 | case BP_HARDWARE_BREAKPOINT: | |
258 | type = 0; | |
259 | len = 1; | |
260 | break; | |
261 | case BP_WRITE_WATCHPOINT: | |
262 | type = 1; | |
263 | break; | |
264 | case BP_ACCESS_WATCHPOINT: | |
265 | type = 3; | |
266 | break; | |
267 | default: | |
268 | return -1; | |
269 | } | |
270 | ||
271 | if (len == 1 || len == 2 || len == 4) | |
272 | breakinfo[i].len = len - 1; | |
273 | else | |
274 | return -1; | |
275 | ||
276 | breakinfo[i].enabled = 1; | |
277 | breakinfo[i].addr = addr; | |
278 | breakinfo[i].type = type; | |
279 | ||
280 | return 0; | |
281 | } | |
282 | ||
283 | /** | |
284 | * kgdb_disable_hw_debug - Disable hardware debugging while we in kgdb. | |
285 | * @regs: Current &struct pt_regs. | |
286 | * | |
287 | * This function will be called if the particular architecture must | |
288 | * disable hardware debugging while it is processing gdb packets or | |
289 | * handling exception. | |
290 | */ | |
291 | void kgdb_disable_hw_debug(struct pt_regs *regs) | |
292 | { | |
293 | /* Disable hardware debugging while we are in kgdb: */ | |
294 | set_debugreg(0UL, 7); | |
295 | } | |
296 | ||
82da3ff8 IM |
297 | /** |
298 | * kgdb_post_primary_code - Save error vector/code numbers. | |
299 | * @regs: Original pt_regs. | |
300 | * @e_vector: Original error vector. | |
301 | * @err_code: Original error code. | |
302 | * | |
303 | * This is needed on architectures which support SMP and KGDB. | |
304 | * This function is called after all the slave cpus have been put | |
305 | * to a know spin state and the primary CPU has control over KGDB. | |
306 | */ | |
307 | void kgdb_post_primary_code(struct pt_regs *regs, int e_vector, int err_code) | |
308 | { | |
309 | /* primary processor is completely in the debugger */ | |
310 | gdb_x86vector = e_vector; | |
311 | gdb_x86errcode = err_code; | |
312 | } | |
313 | ||
314 | #ifdef CONFIG_SMP | |
315 | /** | |
316 | * kgdb_roundup_cpus - Get other CPUs into a holding pattern | |
317 | * @flags: Current IRQ state | |
318 | * | |
319 | * On SMP systems, we need to get the attention of the other CPUs | |
320 | * and get them be in a known state. This should do what is needed | |
321 | * to get the other CPUs to call kgdb_wait(). Note that on some arches, | |
322 | * the NMI approach is not used for rounding up all the CPUs. For example, | |
323 | * in case of MIPS, smp_call_function() is used to roundup CPUs. In | |
324 | * this case, we have to make sure that interrupts are enabled before | |
325 | * calling smp_call_function(). The argument to this function is | |
326 | * the flags that will be used when restoring the interrupts. There is | |
327 | * local_irq_save() call before kgdb_roundup_cpus(). | |
328 | * | |
329 | * On non-SMP systems, this is not called. | |
330 | */ | |
331 | void kgdb_roundup_cpus(unsigned long flags) | |
332 | { | |
333 | send_IPI_allbutself(APIC_DM_NMI); | |
334 | } | |
335 | #endif | |
336 | ||
337 | /** | |
338 | * kgdb_arch_handle_exception - Handle architecture specific GDB packets. | |
339 | * @vector: The error vector of the exception that happened. | |
340 | * @signo: The signal number of the exception that happened. | |
341 | * @err_code: The error code of the exception that happened. | |
342 | * @remcom_in_buffer: The buffer of the packet we have read. | |
343 | * @remcom_out_buffer: The buffer of %BUFMAX bytes to write a packet into. | |
344 | * @regs: The &struct pt_regs of the current process. | |
345 | * | |
346 | * This function MUST handle the 'c' and 's' command packets, | |
347 | * as well packets to set / remove a hardware breakpoint, if used. | |
348 | * If there are additional packets which the hardware needs to handle, | |
349 | * they are handled here. The code should return -1 if it wants to | |
350 | * process more packets, and a %0 or %1 if it wants to exit from the | |
351 | * kgdb callback. | |
352 | */ | |
353 | int kgdb_arch_handle_exception(int e_vector, int signo, int err_code, | |
354 | char *remcomInBuffer, char *remcomOutBuffer, | |
355 | struct pt_regs *linux_regs) | |
356 | { | |
357 | unsigned long addr; | |
64e9ee30 | 358 | unsigned long dr6; |
82da3ff8 IM |
359 | char *ptr; |
360 | int newPC; | |
361 | ||
362 | switch (remcomInBuffer[0]) { | |
363 | case 'c': | |
364 | case 's': | |
365 | /* try to read optional parameter, pc unchanged if no parm */ | |
366 | ptr = &remcomInBuffer[1]; | |
367 | if (kgdb_hex2long(&ptr, &addr)) | |
368 | linux_regs->ip = addr; | |
737a460f JW |
369 | case 'D': |
370 | case 'k': | |
82da3ff8 IM |
371 | newPC = linux_regs->ip; |
372 | ||
373 | /* clear the trace bit */ | |
fda31d7d | 374 | linux_regs->flags &= ~X86_EFLAGS_TF; |
82da3ff8 IM |
375 | atomic_set(&kgdb_cpu_doing_single_step, -1); |
376 | ||
377 | /* set the trace bit if we're stepping */ | |
378 | if (remcomInBuffer[0] == 's') { | |
fda31d7d | 379 | linux_regs->flags |= X86_EFLAGS_TF; |
82da3ff8 IM |
380 | kgdb_single_step = 1; |
381 | if (kgdb_contthread) { | |
382 | atomic_set(&kgdb_cpu_doing_single_step, | |
383 | raw_smp_processor_id()); | |
384 | } | |
385 | } | |
386 | ||
64e9ee30 JW |
387 | get_debugreg(dr6, 6); |
388 | if (!(dr6 & 0x4000)) { | |
389 | int breakno; | |
390 | ||
391 | for (breakno = 0; breakno < 4; breakno++) { | |
392 | if (dr6 & (1 << breakno) && | |
393 | breakinfo[breakno].type == 0) { | |
394 | /* Set restore flag: */ | |
395 | linux_regs->flags |= X86_EFLAGS_RF; | |
396 | break; | |
397 | } | |
398 | } | |
399 | } | |
400 | set_debugreg(0UL, 6); | |
401 | kgdb_correct_hw_break(); | |
402 | ||
82da3ff8 IM |
403 | return 0; |
404 | } | |
405 | ||
406 | /* this means that we do not want to exit from the handler: */ | |
407 | return -1; | |
408 | } | |
409 | ||
410 | static inline int | |
411 | single_step_cont(struct pt_regs *regs, struct die_args *args) | |
412 | { | |
413 | /* | |
414 | * Single step exception from kernel space to user space so | |
415 | * eat the exception and continue the process: | |
416 | */ | |
417 | printk(KERN_ERR "KGDB: trap/step from kernel to user space, " | |
418 | "resuming...\n"); | |
419 | kgdb_arch_handle_exception(args->trapnr, args->signr, | |
420 | args->err, "c", "", regs); | |
421 | ||
422 | return NOTIFY_STOP; | |
423 | } | |
424 | ||
d3597524 JW |
425 | static int was_in_debug_nmi[NR_CPUS]; |
426 | ||
82da3ff8 IM |
427 | static int __kgdb_notify(struct die_args *args, unsigned long cmd) |
428 | { | |
429 | struct pt_regs *regs = args->regs; | |
430 | ||
431 | switch (cmd) { | |
432 | case DIE_NMI: | |
433 | if (atomic_read(&kgdb_active) != -1) { | |
434 | /* KGDB CPU roundup */ | |
435 | kgdb_nmicallback(raw_smp_processor_id(), regs); | |
d3597524 JW |
436 | was_in_debug_nmi[raw_smp_processor_id()] = 1; |
437 | touch_nmi_watchdog(); | |
82da3ff8 IM |
438 | return NOTIFY_STOP; |
439 | } | |
440 | return NOTIFY_DONE; | |
441 | ||
442 | case DIE_NMI_IPI: | |
443 | if (atomic_read(&kgdb_active) != -1) { | |
d3597524 JW |
444 | /* KGDB CPU roundup */ |
445 | kgdb_nmicallback(raw_smp_processor_id(), regs); | |
446 | was_in_debug_nmi[raw_smp_processor_id()] = 1; | |
447 | touch_nmi_watchdog(); | |
448 | } | |
449 | return NOTIFY_DONE; | |
450 | ||
451 | case DIE_NMIUNKNOWN: | |
452 | if (was_in_debug_nmi[raw_smp_processor_id()]) { | |
453 | was_in_debug_nmi[raw_smp_processor_id()] = 0; | |
82da3ff8 IM |
454 | return NOTIFY_STOP; |
455 | } | |
456 | return NOTIFY_DONE; | |
457 | ||
458 | case DIE_NMIWATCHDOG: | |
459 | if (atomic_read(&kgdb_active) != -1) { | |
460 | /* KGDB CPU roundup: */ | |
461 | kgdb_nmicallback(raw_smp_processor_id(), regs); | |
462 | return NOTIFY_STOP; | |
463 | } | |
464 | /* Enter debugger: */ | |
465 | break; | |
466 | ||
467 | case DIE_DEBUG: | |
468 | if (atomic_read(&kgdb_cpu_doing_single_step) == | |
469 | raw_smp_processor_id() && | |
470 | user_mode(regs)) | |
471 | return single_step_cont(regs, args); | |
472 | /* fall through */ | |
473 | default: | |
474 | if (user_mode(regs)) | |
475 | return NOTIFY_DONE; | |
476 | } | |
477 | ||
478 | if (kgdb_handle_exception(args->trapnr, args->signr, args->err, regs)) | |
479 | return NOTIFY_DONE; | |
480 | ||
737a460f JW |
481 | /* Must touch watchdog before return to normal operation */ |
482 | touch_nmi_watchdog(); | |
82da3ff8 IM |
483 | return NOTIFY_STOP; |
484 | } | |
485 | ||
486 | static int | |
487 | kgdb_notify(struct notifier_block *self, unsigned long cmd, void *ptr) | |
488 | { | |
489 | unsigned long flags; | |
490 | int ret; | |
491 | ||
492 | local_irq_save(flags); | |
493 | ret = __kgdb_notify(ptr, cmd); | |
494 | local_irq_restore(flags); | |
495 | ||
496 | return ret; | |
497 | } | |
498 | ||
499 | static struct notifier_block kgdb_notifier = { | |
500 | .notifier_call = kgdb_notify, | |
501 | ||
502 | /* | |
503 | * Lowest-prio notifier priority, we want to be notified last: | |
504 | */ | |
505 | .priority = -INT_MAX, | |
506 | }; | |
507 | ||
508 | /** | |
509 | * kgdb_arch_init - Perform any architecture specific initalization. | |
510 | * | |
511 | * This function will handle the initalization of any architecture | |
512 | * specific callbacks. | |
513 | */ | |
514 | int kgdb_arch_init(void) | |
515 | { | |
516 | return register_die_notifier(&kgdb_notifier); | |
517 | } | |
518 | ||
519 | /** | |
520 | * kgdb_arch_exit - Perform any architecture specific uninitalization. | |
521 | * | |
522 | * This function will handle the uninitalization of any architecture | |
523 | * specific callbacks, for dynamic registration and unregistration. | |
524 | */ | |
525 | void kgdb_arch_exit(void) | |
526 | { | |
527 | unregister_die_notifier(&kgdb_notifier); | |
528 | } | |
529 | ||
530 | /** | |
531 | * | |
532 | * kgdb_skipexception - Bail out of KGDB when we've been triggered. | |
533 | * @exception: Exception vector number | |
534 | * @regs: Current &struct pt_regs. | |
535 | * | |
536 | * On some architectures we need to skip a breakpoint exception when | |
537 | * it occurs after a breakpoint has been removed. | |
538 | * | |
539 | * Skip an int3 exception when it occurs after a breakpoint has been | |
540 | * removed. Backtrack eip by 1 since the int3 would have caused it to | |
541 | * increment by 1. | |
542 | */ | |
543 | int kgdb_skipexception(int exception, struct pt_regs *regs) | |
544 | { | |
545 | if (exception == 3 && kgdb_isremovedbreak(regs->ip - 1)) { | |
546 | regs->ip -= 1; | |
547 | return 1; | |
548 | } | |
549 | return 0; | |
550 | } | |
551 | ||
552 | unsigned long kgdb_arch_pc(int exception, struct pt_regs *regs) | |
553 | { | |
554 | if (exception == 3) | |
555 | return instruction_pointer(regs) - 1; | |
556 | return instruction_pointer(regs); | |
557 | } | |
558 | ||
559 | struct kgdb_arch arch_kgdb_ops = { | |
560 | /* Breakpoint instruction: */ | |
561 | .gdb_bpt_instr = { 0xcc }, | |
64e9ee30 JW |
562 | .flags = KGDB_HW_BREAKPOINT, |
563 | .set_hw_breakpoint = kgdb_set_hw_break, | |
564 | .remove_hw_breakpoint = kgdb_remove_hw_break, | |
565 | .remove_all_hw_break = kgdb_remove_all_hw_break, | |
566 | .correct_hw_break = kgdb_correct_hw_break, | |
82da3ff8 | 567 | }; |