1 /*
2  * PowerPC backend to the KGDB stub.
3  *
4  * 1998 (c) Michael AK Tesch (tesch@cs.wisc.edu)
5  * Copyright (C) 2003 Timesys Corporation.
6  * Copyright (C) 2004-2006 MontaVista Software, Inc.
7  * PPC64 Mods (C) 2005 Frank Rowand (frowand@mvista.com)
8  * PPC32 support restored by Vitaly Wool <vwool@ru.mvista.com> and
9  * Sergei Shtylyov <sshtylyov@ru.mvista.com>
10  * Copyright (C) 2007-2008 Wind River Systems, Inc.
11  *
12  * This file is licensed under the terms of the GNU General Public License
13  * version 2. This program as licensed "as is" without any warranty of any
14  * kind, whether express or implied.
15  */
16 
17 #include <linux/kernel.h>
18 #include <linux/init.h>
19 #include <linux/kgdb.h>
20 #include <linux/smp.h>
21 #include <linux/signal.h>
22 #include <linux/ptrace.h>
23 #include <linux/kdebug.h>
24 #include <asm/current.h>
25 #include <asm/processor.h>
26 #include <asm/machdep.h>
27 
28 /*
29  * This table contains the mapping between PowerPC hardware trap types, and
30  * signals, which are primarily what GDB understands.  GDB and the kernel
31  * don't always agree on values, so we use constants taken from gdb-6.2.
32  */
33 static struct hard_trap_info
34 {
35 	unsigned int tt;		/* Trap type code for powerpc */
36 	unsigned char signo;		/* Signal that we map this trap into */
37 } hard_trap_info[] = {
38 	{ 0x0100, 0x02 /* SIGINT */  },		/* system reset */
39 	{ 0x0200, 0x0b /* SIGSEGV */ },		/* machine check */
40 	{ 0x0300, 0x0b /* SIGSEGV */ },		/* data access */
41 	{ 0x0400, 0x0b /* SIGSEGV */ },		/* instruction access */
42 	{ 0x0500, 0x02 /* SIGINT */  },		/* external interrupt */
43 	{ 0x0600, 0x0a /* SIGBUS */  },		/* alignment */
44 	{ 0x0700, 0x05 /* SIGTRAP */ },		/* program check */
45 	{ 0x0800, 0x08 /* SIGFPE */  },		/* fp unavailable */
46 	{ 0x0900, 0x0e /* SIGALRM */ },		/* decrementer */
47 	{ 0x0c00, 0x14 /* SIGCHLD */ },		/* system call */
48 #if defined(CONFIG_40x) || defined(CONFIG_BOOKE)
49 	{ 0x2002, 0x05 /* SIGTRAP */ },		/* debug */
50 #if defined(CONFIG_FSL_BOOKE)
51 	{ 0x2010, 0x08 /* SIGFPE */  },		/* spe unavailable */
52 	{ 0x2020, 0x08 /* SIGFPE */  },		/* spe unavailable */
53 	{ 0x2030, 0x08 /* SIGFPE */  },		/* spe fp data */
54 	{ 0x2040, 0x08 /* SIGFPE */  },		/* spe fp data */
55 	{ 0x2050, 0x08 /* SIGFPE */  },		/* spe fp round */
56 	{ 0x2060, 0x0e /* SIGILL */  },		/* performance monitor */
57 	{ 0x2900, 0x08 /* SIGFPE */  },		/* apu unavailable */
58 	{ 0x3100, 0x0e /* SIGALRM */ },		/* fixed interval timer */
59 	{ 0x3200, 0x02 /* SIGINT */  }, 	/* watchdog */
60 #else /* ! CONFIG_FSL_BOOKE */
61 	{ 0x1000, 0x0e /* SIGALRM */ },		/* prog interval timer */
62 	{ 0x1010, 0x0e /* SIGALRM */ },		/* fixed interval timer */
63 	{ 0x1020, 0x02 /* SIGINT */  }, 	/* watchdog */
64 	{ 0x2010, 0x08 /* SIGFPE */  },		/* fp unavailable */
65 	{ 0x2020, 0x08 /* SIGFPE */  },		/* ap unavailable */
66 #endif
67 #else /* ! (defined(CONFIG_40x) || defined(CONFIG_BOOKE)) */
68 	{ 0x0d00, 0x05 /* SIGTRAP */ },		/* single-step */
69 #if defined(CONFIG_8xx)
70 	{ 0x1000, 0x04 /* SIGILL */  },		/* software emulation */
71 #else /* ! CONFIG_8xx */
72 	{ 0x0f00, 0x04 /* SIGILL */  },		/* performance monitor */
73 	{ 0x0f20, 0x08 /* SIGFPE */  },		/* altivec unavailable */
74 	{ 0x1300, 0x05 /* SIGTRAP */ }, 	/* instruction address break */
75 #if defined(CONFIG_PPC64)
76 	{ 0x1200, 0x05 /* SIGILL */  },		/* system error */
77 	{ 0x1500, 0x04 /* SIGILL */  },		/* soft patch */
78 	{ 0x1600, 0x04 /* SIGILL */  },		/* maintenance */
79 	{ 0x1700, 0x08 /* SIGFPE */  },		/* altivec assist */
80 	{ 0x1800, 0x04 /* SIGILL */  },		/* thermal */
81 #else /* ! CONFIG_PPC64 */
82 	{ 0x1400, 0x02 /* SIGINT */  },		/* SMI */
83 	{ 0x1600, 0x08 /* SIGFPE */  },		/* altivec assist */
84 	{ 0x1700, 0x04 /* SIGILL */  },		/* TAU */
85 	{ 0x2000, 0x05 /* SIGTRAP */ },		/* run mode */
86 #endif
87 #endif
88 #endif
89 	{ 0x0000, 0x00 }			/* Must be last */
90 };
91 
computeSignal(unsigned int tt)92 static int computeSignal(unsigned int tt)
93 {
94 	struct hard_trap_info *ht;
95 
96 	for (ht = hard_trap_info; ht->tt && ht->signo; ht++)
97 		if (ht->tt == tt)
98 			return ht->signo;
99 
100 	return SIGHUP;		/* default for things we don't know about */
101 }
102 
kgdb_call_nmi_hook(struct pt_regs * regs)103 static int kgdb_call_nmi_hook(struct pt_regs *regs)
104 {
105 	kgdb_nmicallback(raw_smp_processor_id(), regs);
106 	return 0;
107 }
108 
109 #ifdef CONFIG_SMP
kgdb_roundup_cpus(unsigned long flags)110 void kgdb_roundup_cpus(unsigned long flags)
111 {
112 	smp_send_debugger_break(MSG_ALL_BUT_SELF);
113 }
114 #endif
115 
116 /* KGDB functions to use existing PowerPC64 hooks. */
kgdb_debugger(struct pt_regs * regs)117 static int kgdb_debugger(struct pt_regs *regs)
118 {
119 	return !kgdb_handle_exception(1, computeSignal(TRAP(regs)),
120 				      DIE_OOPS, regs);
121 }
122 
kgdb_handle_breakpoint(struct pt_regs * regs)123 static int kgdb_handle_breakpoint(struct pt_regs *regs)
124 {
125 	if (user_mode(regs))
126 		return 0;
127 
128 	if (kgdb_handle_exception(1, SIGTRAP, 0, regs) != 0)
129 		return 0;
130 
131 	if (*(u32 *) (regs->nip) == *(u32 *) (&arch_kgdb_ops.gdb_bpt_instr))
132 		regs->nip += BREAK_INSTR_SIZE;
133 
134 	return 1;
135 }
136 
kgdb_singlestep(struct pt_regs * regs)137 static int kgdb_singlestep(struct pt_regs *regs)
138 {
139 	struct thread_info *thread_info, *exception_thread_info;
140 
141 	if (user_mode(regs))
142 		return 0;
143 
144 	/*
145 	 * On Book E and perhaps other processsors, singlestep is handled on
146 	 * the critical exception stack.  This causes current_thread_info()
147 	 * to fail, since it it locates the thread_info by masking off
148 	 * the low bits of the current stack pointer.  We work around
149 	 * this issue by copying the thread_info from the kernel stack
150 	 * before calling kgdb_handle_exception, and copying it back
151 	 * afterwards.  On most processors the copy is avoided since
152 	 * exception_thread_info == thread_info.
153 	 */
154 	thread_info = (struct thread_info *)(regs->gpr[1] & ~(THREAD_SIZE-1));
155 	exception_thread_info = current_thread_info();
156 
157 	if (thread_info != exception_thread_info)
158 		memcpy(exception_thread_info, thread_info, sizeof *thread_info);
159 
160 	kgdb_handle_exception(0, SIGTRAP, 0, regs);
161 
162 	if (thread_info != exception_thread_info)
163 		memcpy(thread_info, exception_thread_info, sizeof *thread_info);
164 
165 	return 1;
166 }
167 
kgdb_iabr_match(struct pt_regs * regs)168 static int kgdb_iabr_match(struct pt_regs *regs)
169 {
170 	if (user_mode(regs))
171 		return 0;
172 
173 	if (kgdb_handle_exception(0, computeSignal(TRAP(regs)), 0, regs) != 0)
174 		return 0;
175 	return 1;
176 }
177 
kgdb_dabr_match(struct pt_regs * regs)178 static int kgdb_dabr_match(struct pt_regs *regs)
179 {
180 	if (user_mode(regs))
181 		return 0;
182 
183 	if (kgdb_handle_exception(0, computeSignal(TRAP(regs)), 0, regs) != 0)
184 		return 0;
185 	return 1;
186 }
187 
188 #define PACK64(ptr, src) do { *(ptr++) = (src); } while (0)
189 
190 #define PACK32(ptr, src) do {          \
191 	u32 *ptr32;                   \
192 	ptr32 = (u32 *)ptr;           \
193 	*(ptr32++) = (src);           \
194 	ptr = (unsigned long *)ptr32; \
195 	} while (0)
196 
sleeping_thread_to_gdb_regs(unsigned long * gdb_regs,struct task_struct * p)197 void sleeping_thread_to_gdb_regs(unsigned long *gdb_regs, struct task_struct *p)
198 {
199 	struct pt_regs *regs = (struct pt_regs *)(p->thread.ksp +
200 						  STACK_FRAME_OVERHEAD);
201 	unsigned long *ptr = gdb_regs;
202 	int reg;
203 
204 	memset(gdb_regs, 0, NUMREGBYTES);
205 
206 	/* Regs GPR0-2 */
207 	for (reg = 0; reg < 3; reg++)
208 		PACK64(ptr, regs->gpr[reg]);
209 
210 	/* Regs GPR3-13 are caller saved, not in regs->gpr[] */
211 	ptr += 11;
212 
213 	/* Regs GPR14-31 */
214 	for (reg = 14; reg < 32; reg++)
215 		PACK64(ptr, regs->gpr[reg]);
216 
217 #ifdef CONFIG_FSL_BOOKE
218 #ifdef CONFIG_SPE
219 	for (reg = 0; reg < 32; reg++)
220 		PACK64(ptr, p->thread.evr[reg]);
221 #else
222 	ptr += 32;
223 #endif
224 #else
225 	/* fp registers not used by kernel, leave zero */
226 	ptr += 32 * 8 / sizeof(long);
227 #endif
228 
229 	PACK64(ptr, regs->nip);
230 	PACK64(ptr, regs->msr);
231 	PACK32(ptr, regs->ccr);
232 	PACK64(ptr, regs->link);
233 	PACK64(ptr, regs->ctr);
234 	PACK32(ptr, regs->xer);
235 
236 	BUG_ON((unsigned long)ptr >
237 	       (unsigned long)(((void *)gdb_regs) + NUMREGBYTES));
238 }
239 
240 #define GDB_SIZEOF_REG sizeof(unsigned long)
241 #define GDB_SIZEOF_REG_U32 sizeof(u32)
242 
243 #ifdef CONFIG_FSL_BOOKE
244 #define GDB_SIZEOF_FLOAT_REG sizeof(unsigned long)
245 #else
246 #define GDB_SIZEOF_FLOAT_REG sizeof(u64)
247 #endif
248 
249 struct dbg_reg_def_t dbg_reg_def[DBG_MAX_REG_NUM] =
250 {
251 	{ "r0", GDB_SIZEOF_REG, offsetof(struct pt_regs, gpr[0]) },
252 	{ "r1", GDB_SIZEOF_REG, offsetof(struct pt_regs, gpr[1]) },
253 	{ "r2", GDB_SIZEOF_REG, offsetof(struct pt_regs, gpr[2]) },
254 	{ "r3", GDB_SIZEOF_REG, offsetof(struct pt_regs, gpr[3]) },
255 	{ "r4", GDB_SIZEOF_REG, offsetof(struct pt_regs, gpr[4]) },
256 	{ "r5", GDB_SIZEOF_REG, offsetof(struct pt_regs, gpr[5]) },
257 	{ "r6", GDB_SIZEOF_REG, offsetof(struct pt_regs, gpr[6]) },
258 	{ "r7", GDB_SIZEOF_REG, offsetof(struct pt_regs, gpr[7]) },
259 	{ "r8", GDB_SIZEOF_REG, offsetof(struct pt_regs, gpr[8]) },
260 	{ "r9", GDB_SIZEOF_REG, offsetof(struct pt_regs, gpr[9]) },
261 	{ "r10", GDB_SIZEOF_REG, offsetof(struct pt_regs, gpr[10]) },
262 	{ "r11", GDB_SIZEOF_REG, offsetof(struct pt_regs, gpr[11]) },
263 	{ "r12", GDB_SIZEOF_REG, offsetof(struct pt_regs, gpr[12]) },
264 	{ "r13", GDB_SIZEOF_REG, offsetof(struct pt_regs, gpr[13]) },
265 	{ "r14", GDB_SIZEOF_REG, offsetof(struct pt_regs, gpr[14]) },
266 	{ "r15", GDB_SIZEOF_REG, offsetof(struct pt_regs, gpr[15]) },
267 	{ "r16", GDB_SIZEOF_REG, offsetof(struct pt_regs, gpr[16]) },
268 	{ "r17", GDB_SIZEOF_REG, offsetof(struct pt_regs, gpr[17]) },
269 	{ "r18", GDB_SIZEOF_REG, offsetof(struct pt_regs, gpr[18]) },
270 	{ "r19", GDB_SIZEOF_REG, offsetof(struct pt_regs, gpr[19]) },
271 	{ "r20", GDB_SIZEOF_REG, offsetof(struct pt_regs, gpr[20]) },
272 	{ "r21", GDB_SIZEOF_REG, offsetof(struct pt_regs, gpr[21]) },
273 	{ "r22", GDB_SIZEOF_REG, offsetof(struct pt_regs, gpr[22]) },
274 	{ "r23", GDB_SIZEOF_REG, offsetof(struct pt_regs, gpr[23]) },
275 	{ "r24", GDB_SIZEOF_REG, offsetof(struct pt_regs, gpr[24]) },
276 	{ "r25", GDB_SIZEOF_REG, offsetof(struct pt_regs, gpr[25]) },
277 	{ "r26", GDB_SIZEOF_REG, offsetof(struct pt_regs, gpr[26]) },
278 	{ "r27", GDB_SIZEOF_REG, offsetof(struct pt_regs, gpr[27]) },
279 	{ "r28", GDB_SIZEOF_REG, offsetof(struct pt_regs, gpr[28]) },
280 	{ "r29", GDB_SIZEOF_REG, offsetof(struct pt_regs, gpr[29]) },
281 	{ "r30", GDB_SIZEOF_REG, offsetof(struct pt_regs, gpr[30]) },
282 	{ "r31", GDB_SIZEOF_REG, offsetof(struct pt_regs, gpr[31]) },
283 
284 	{ "f0", GDB_SIZEOF_FLOAT_REG, 0 },
285 	{ "f1", GDB_SIZEOF_FLOAT_REG, 1 },
286 	{ "f2", GDB_SIZEOF_FLOAT_REG, 2 },
287 	{ "f3", GDB_SIZEOF_FLOAT_REG, 3 },
288 	{ "f4", GDB_SIZEOF_FLOAT_REG, 4 },
289 	{ "f5", GDB_SIZEOF_FLOAT_REG, 5 },
290 	{ "f6", GDB_SIZEOF_FLOAT_REG, 6 },
291 	{ "f7", GDB_SIZEOF_FLOAT_REG, 7 },
292 	{ "f8", GDB_SIZEOF_FLOAT_REG, 8 },
293 	{ "f9", GDB_SIZEOF_FLOAT_REG, 9 },
294 	{ "f10", GDB_SIZEOF_FLOAT_REG, 10 },
295 	{ "f11", GDB_SIZEOF_FLOAT_REG, 11 },
296 	{ "f12", GDB_SIZEOF_FLOAT_REG, 12 },
297 	{ "f13", GDB_SIZEOF_FLOAT_REG, 13 },
298 	{ "f14", GDB_SIZEOF_FLOAT_REG, 14 },
299 	{ "f15", GDB_SIZEOF_FLOAT_REG, 15 },
300 	{ "f16", GDB_SIZEOF_FLOAT_REG, 16 },
301 	{ "f17", GDB_SIZEOF_FLOAT_REG, 17 },
302 	{ "f18", GDB_SIZEOF_FLOAT_REG, 18 },
303 	{ "f19", GDB_SIZEOF_FLOAT_REG, 19 },
304 	{ "f20", GDB_SIZEOF_FLOAT_REG, 20 },
305 	{ "f21", GDB_SIZEOF_FLOAT_REG, 21 },
306 	{ "f22", GDB_SIZEOF_FLOAT_REG, 22 },
307 	{ "f23", GDB_SIZEOF_FLOAT_REG, 23 },
308 	{ "f24", GDB_SIZEOF_FLOAT_REG, 24 },
309 	{ "f25", GDB_SIZEOF_FLOAT_REG, 25 },
310 	{ "f26", GDB_SIZEOF_FLOAT_REG, 26 },
311 	{ "f27", GDB_SIZEOF_FLOAT_REG, 27 },
312 	{ "f28", GDB_SIZEOF_FLOAT_REG, 28 },
313 	{ "f29", GDB_SIZEOF_FLOAT_REG, 29 },
314 	{ "f30", GDB_SIZEOF_FLOAT_REG, 30 },
315 	{ "f31", GDB_SIZEOF_FLOAT_REG, 31 },
316 
317 	{ "pc", GDB_SIZEOF_REG, offsetof(struct pt_regs, nip) },
318 	{ "msr", GDB_SIZEOF_REG, offsetof(struct pt_regs, msr) },
319 	{ "cr", GDB_SIZEOF_REG_U32, offsetof(struct pt_regs, ccr) },
320 	{ "lr", GDB_SIZEOF_REG, offsetof(struct pt_regs, link) },
321 	{ "ctr", GDB_SIZEOF_REG_U32, offsetof(struct pt_regs, ctr) },
322 	{ "xer", GDB_SIZEOF_REG, offsetof(struct pt_regs, xer) },
323 };
324 
dbg_get_reg(int regno,void * mem,struct pt_regs * regs)325 char *dbg_get_reg(int regno, void *mem, struct pt_regs *regs)
326 {
327 	if (regno >= DBG_MAX_REG_NUM || regno < 0)
328 		return NULL;
329 
330 	if (regno < 32 || regno >= 64)
331 		/* First 0 -> 31 gpr registers*/
332 		/* pc, msr, ls... registers 64 -> 69 */
333 		memcpy(mem, (void *)regs + dbg_reg_def[regno].offset,
334 				dbg_reg_def[regno].size);
335 
336 	if (regno >= 32 && regno < 64) {
337 		/* FP registers 32 -> 63 */
338 #if defined(CONFIG_FSL_BOOKE) && defined(CONFIG_SPE)
339 		if (current)
340 			memcpy(mem, &current->thread.evr[regno-32],
341 					dbg_reg_def[regno].size);
342 #else
343 		/* fp registers not used by kernel, leave zero */
344 		memset(mem, 0, dbg_reg_def[regno].size);
345 #endif
346 	}
347 
348 	return dbg_reg_def[regno].name;
349 }
350 
dbg_set_reg(int regno,void * mem,struct pt_regs * regs)351 int dbg_set_reg(int regno, void *mem, struct pt_regs *regs)
352 {
353 	if (regno >= DBG_MAX_REG_NUM || regno < 0)
354 		return -EINVAL;
355 
356 	if (regno < 32 || regno >= 64)
357 		/* First 0 -> 31 gpr registers*/
358 		/* pc, msr, ls... registers 64 -> 69 */
359 		memcpy((void *)regs + dbg_reg_def[regno].offset, mem,
360 				dbg_reg_def[regno].size);
361 
362 	if (regno >= 32 && regno < 64) {
363 		/* FP registers 32 -> 63 */
364 #if defined(CONFIG_FSL_BOOKE) && defined(CONFIG_SPE)
365 		memcpy(&current->thread.evr[regno-32], mem,
366 				dbg_reg_def[regno].size);
367 #else
368 		/* fp registers not used by kernel, leave zero */
369 		return 0;
370 #endif
371 	}
372 
373 	return 0;
374 }
375 
kgdb_arch_set_pc(struct pt_regs * regs,unsigned long pc)376 void kgdb_arch_set_pc(struct pt_regs *regs, unsigned long pc)
377 {
378 	regs->nip = pc;
379 }
380 
381 /*
382  * This function does PowerPC specific procesing for interfacing to gdb.
383  */
kgdb_arch_handle_exception(int vector,int signo,int err_code,char * remcom_in_buffer,char * remcom_out_buffer,struct pt_regs * linux_regs)384 int kgdb_arch_handle_exception(int vector, int signo, int err_code,
385 			       char *remcom_in_buffer, char *remcom_out_buffer,
386 			       struct pt_regs *linux_regs)
387 {
388 	char *ptr = &remcom_in_buffer[1];
389 	unsigned long addr;
390 
391 	switch (remcom_in_buffer[0]) {
392 		/*
393 		 * sAA..AA   Step one instruction from AA..AA
394 		 * This will return an error to gdb ..
395 		 */
396 	case 's':
397 	case 'c':
398 		/* handle the optional parameter */
399 		if (kgdb_hex2long(&ptr, &addr))
400 			linux_regs->nip = addr;
401 
402 		atomic_set(&kgdb_cpu_doing_single_step, -1);
403 		/* set the trace bit if we're stepping */
404 		if (remcom_in_buffer[0] == 's') {
405 #ifdef CONFIG_PPC_ADV_DEBUG_REGS
406 			mtspr(SPRN_DBCR0,
407 			      mfspr(SPRN_DBCR0) | DBCR0_IC | DBCR0_IDM);
408 			linux_regs->msr |= MSR_DE;
409 #else
410 			linux_regs->msr |= MSR_SE;
411 #endif
412 			kgdb_single_step = 1;
413 			atomic_set(&kgdb_cpu_doing_single_step,
414 				   raw_smp_processor_id());
415 		}
416 		return 0;
417 	}
418 
419 	return -1;
420 }
421 
422 /*
423  * Global data
424  */
425 struct kgdb_arch arch_kgdb_ops = {
426 	.gdb_bpt_instr = {0x7d, 0x82, 0x10, 0x08},
427 };
428 
kgdb_not_implemented(struct pt_regs * regs)429 static int kgdb_not_implemented(struct pt_regs *regs)
430 {
431 	return 0;
432 }
433 
434 static void *old__debugger_ipi;
435 static void *old__debugger;
436 static void *old__debugger_bpt;
437 static void *old__debugger_sstep;
438 static void *old__debugger_iabr_match;
439 static void *old__debugger_dabr_match;
440 static void *old__debugger_fault_handler;
441 
kgdb_arch_init(void)442 int kgdb_arch_init(void)
443 {
444 	old__debugger_ipi = __debugger_ipi;
445 	old__debugger = __debugger;
446 	old__debugger_bpt = __debugger_bpt;
447 	old__debugger_sstep = __debugger_sstep;
448 	old__debugger_iabr_match = __debugger_iabr_match;
449 	old__debugger_dabr_match = __debugger_dabr_match;
450 	old__debugger_fault_handler = __debugger_fault_handler;
451 
452 	__debugger_ipi = kgdb_call_nmi_hook;
453 	__debugger = kgdb_debugger;
454 	__debugger_bpt = kgdb_handle_breakpoint;
455 	__debugger_sstep = kgdb_singlestep;
456 	__debugger_iabr_match = kgdb_iabr_match;
457 	__debugger_dabr_match = kgdb_dabr_match;
458 	__debugger_fault_handler = kgdb_not_implemented;
459 
460 	return 0;
461 }
462 
kgdb_arch_exit(void)463 void kgdb_arch_exit(void)
464 {
465 	__debugger_ipi = old__debugger_ipi;
466 	__debugger = old__debugger;
467 	__debugger_bpt = old__debugger_bpt;
468 	__debugger_sstep = old__debugger_sstep;
469 	__debugger_iabr_match = old__debugger_iabr_match;
470 	__debugger_dabr_match = old__debugger_dabr_match;
471 	__debugger_fault_handler = old__debugger_fault_handler;
472 }
473