db_interface.c revision 1.46 1 /* $NetBSD: db_interface.c,v 1.46 2009/03/14 14:45:55 dsl Exp $ */
2
3 /*
4 * Copyright (c) 1996 Scott K. Stevens
5 *
6 * Mach Operating System
7 * Copyright (c) 1991,1990 Carnegie Mellon University
8 * All Rights Reserved.
9 *
10 * Permission to use, copy, modify and distribute this software and its
11 * documentation is hereby granted, provided that both the copyright
12 * notice and this permission notice appear in all copies of the
13 * software, derivative works or modified versions, and any portions
14 * thereof, and that both notices appear in supporting documentation.
15 *
16 * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
17 * CONDITION. CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND FOR
18 * ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
19 *
20 * Carnegie Mellon requests users of this software to return to
21 *
22 * Software Distribution Coordinator or Software.Distribution (at) CS.CMU.EDU
23 * School of Computer Science
24 * Carnegie Mellon University
25 * Pittsburgh PA 15213-3890
26 *
27 * any improvements or extensions that they make and grant Carnegie the
28 * rights to redistribute these changes.
29 *
30 * From: db_interface.c,v 2.4 1991/02/05 17:11:13 mrt (CMU)
31 */
32
33 /*
34 * Interface to new debugger.
35 */
36
37 #include <sys/cdefs.h>
38 __KERNEL_RCSID(0, "$NetBSD: db_interface.c,v 1.46 2009/03/14 14:45:55 dsl Exp $");
39
40 #include "opt_ddb.h"
41 #include "opt_kgdb.h"
42
43 #include <sys/param.h>
44 #include <sys/proc.h>
45 #include <sys/reboot.h>
46 #include <sys/systm.h> /* just for boothowto */
47 #include <sys/exec.h>
48
49 #include <uvm/uvm_extern.h>
50
51 #include <arm/arm32/db_machdep.h>
52 #include <arm/arm32/katelib.h>
53 #include <arm/undefined.h>
54 #include <ddb/db_access.h>
55 #include <ddb/db_command.h>
56 #include <ddb/db_output.h>
57 #include <ddb/db_variables.h>
58 #include <ddb/db_sym.h>
59 #include <ddb/db_extern.h>
60 #include <ddb/db_interface.h>
61 #include <dev/cons.h>
62
63 #if defined(KGDB) || !defined(DDB)
64 #define db_printf printf
65 #endif
66
67 static long nil;
68
69 int db_access_und_sp(const struct db_variable *, db_expr_t *, int);
70 int db_access_abt_sp(const struct db_variable *, db_expr_t *, int);
71 int db_access_irq_sp(const struct db_variable *, db_expr_t *, int);
72 u_int db_fetch_reg(int, db_regs_t *);
73
74 int db_trapper(u_int, u_int, trapframe_t *, int);
75
76 const struct db_variable db_regs[] = {
77 { "spsr", (long *)&DDB_REGS->tf_spsr, FCN_NULL, },
78 { "r0", (long *)&DDB_REGS->tf_r0, FCN_NULL, },
79 { "r1", (long *)&DDB_REGS->tf_r1, FCN_NULL, },
80 { "r2", (long *)&DDB_REGS->tf_r2, FCN_NULL, },
81 { "r3", (long *)&DDB_REGS->tf_r3, FCN_NULL, },
82 { "r4", (long *)&DDB_REGS->tf_r4, FCN_NULL, },
83 { "r5", (long *)&DDB_REGS->tf_r5, FCN_NULL, },
84 { "r6", (long *)&DDB_REGS->tf_r6, FCN_NULL, },
85 { "r7", (long *)&DDB_REGS->tf_r7, FCN_NULL, },
86 { "r8", (long *)&DDB_REGS->tf_r8, FCN_NULL, },
87 { "r9", (long *)&DDB_REGS->tf_r9, FCN_NULL, },
88 { "r10", (long *)&DDB_REGS->tf_r10, FCN_NULL, },
89 { "r11", (long *)&DDB_REGS->tf_r11, FCN_NULL, },
90 { "r12", (long *)&DDB_REGS->tf_r12, FCN_NULL, },
91 { "usr_sp", (long *)&DDB_REGS->tf_usr_sp, FCN_NULL, },
92 { "usr_lr", (long *)&DDB_REGS->tf_usr_lr, FCN_NULL, },
93 { "svc_sp", (long *)&DDB_REGS->tf_svc_sp, FCN_NULL, },
94 { "svc_lr", (long *)&DDB_REGS->tf_svc_lr, FCN_NULL, },
95 { "pc", (long *)&DDB_REGS->tf_pc, FCN_NULL, },
96 { "und_sp", &nil, db_access_und_sp, },
97 { "abt_sp", &nil, db_access_abt_sp, },
98 { "irq_sp", &nil, db_access_irq_sp, },
99 };
100
101 const struct db_variable * const db_eregs = db_regs + sizeof(db_regs)/sizeof(db_regs[0]);
102
103 int db_active = 0;
104 db_regs_t ddb_regs; /* register state */
105
106 int
107 db_access_und_sp(const struct db_variable *vp, db_expr_t *valp, int rw)
108 {
109
110 if (rw == DB_VAR_GET)
111 *valp = get_stackptr(PSR_UND32_MODE);
112 return(0);
113 }
114
115 int
116 db_access_abt_sp(const struct db_variable *vp, db_expr_t *valp, int rw)
117 {
118
119 if (rw == DB_VAR_GET)
120 *valp = get_stackptr(PSR_ABT32_MODE);
121 return(0);
122 }
123
124 int
125 db_access_irq_sp(const struct db_variable *vp, db_expr_t *valp, int rw)
126 {
127
128 if (rw == DB_VAR_GET)
129 *valp = get_stackptr(PSR_IRQ32_MODE);
130 return(0);
131 }
132
133 #ifdef DDB
134 /*
135 * kdb_trap - field a TRACE or BPT trap
136 */
137 int
138 kdb_trap(int type, db_regs_t *regs)
139 {
140 int s;
141
142 switch (type) {
143 case T_BREAKPOINT: /* breakpoint */
144 case -1: /* keyboard interrupt */
145 break;
146 default:
147 if (db_recover != 0) {
148 /* This will longjmp back into db_command_loop() */
149 db_error("Faulted in DDB; continuing...\n");
150 /*NOTREACHED*/
151 }
152 }
153
154 /* Should switch to kdb`s own stack here. */
155
156 ddb_regs = *regs;
157
158 s = splhigh();
159 db_active++;
160 cnpollc(true);
161 db_trap(type, 0/*code*/);
162 cnpollc(false);
163 db_active--;
164 splx(s);
165
166 *regs = ddb_regs;
167
168 return (1);
169 }
170 #endif
171
172 int
173 db_validate_address(vaddr_t addr)
174 {
175 struct proc *p = curproc;
176 struct pmap *pmap;
177
178 if (!p || !p->p_vmspace || !p->p_vmspace->vm_map.pmap ||
179 #ifndef ARM32_NEW_VM_LAYOUT
180 addr >= VM_MAXUSER_ADDRESS
181 #else
182 addr >= VM_MIN_KERNEL_ADDRESS
183 #endif
184 )
185 pmap = pmap_kernel();
186 else
187 pmap = p->p_vmspace->vm_map.pmap;
188
189 return (pmap_extract(pmap, addr, NULL) == false);
190 }
191
192 /*
193 * Read bytes from kernel address space for debugger.
194 */
195 void
196 db_read_bytes(addr, size, data)
197 vaddr_t addr;
198 size_t size;
199 char *data;
200 {
201 char *src = (char *)addr;
202
203 if (db_validate_address((u_int)src)) {
204 db_printf("address %p is invalid\n", src);
205 return;
206 }
207
208 if (size == 4 && (addr & 3) == 0 && ((uintptr_t)data & 3) == 0) {
209 *((int*)data) = *((int*)src);
210 return;
211 }
212
213 if (size == 2 && (addr & 1) == 0 && ((uintptr_t)data & 1) == 0) {
214 *((short*)data) = *((short*)src);
215 return;
216 }
217
218 while (size-- > 0) {
219 if (db_validate_address((u_int)src)) {
220 db_printf("address %p is invalid\n", src);
221 return;
222 }
223 *data++ = *src++;
224 }
225 }
226
227 static void
228 db_write_text(vaddr_t addr, size_t size, const char *data)
229 {
230 struct pmap *pmap = pmap_kernel();
231 pd_entry_t *pde, oldpde, tmppde;
232 pt_entry_t *pte, oldpte, tmppte;
233 vaddr_t pgva;
234 size_t limit, savesize;
235 char *dst;
236
237 /* XXX: gcc */
238 oldpte = 0;
239
240 if ((savesize = size) == 0)
241 return;
242
243 dst = (char *) addr;
244
245 do {
246 /* Get the PDE of the current VA. */
247 if (pmap_get_pde_pte(pmap, (vaddr_t) dst, &pde, &pte) == false)
248 goto no_mapping;
249 switch ((oldpde = *pde) & L1_TYPE_MASK) {
250 case L1_TYPE_S:
251 pgva = (vaddr_t)dst & L1_S_FRAME;
252 limit = L1_S_SIZE - ((vaddr_t)dst & L1_S_OFFSET);
253
254 tmppde = oldpde | L1_S_PROT_W;
255 *pde = tmppde;
256 PTE_SYNC(pde);
257 break;
258
259 case L1_TYPE_C:
260 pgva = (vaddr_t)dst & L2_S_FRAME;
261 limit = L2_S_SIZE - ((vaddr_t)dst & L2_S_OFFSET);
262
263 if (pte == NULL)
264 goto no_mapping;
265 oldpte = *pte;
266 tmppte = oldpte | L2_S_PROT_W;
267 *pte = tmppte;
268 PTE_SYNC(pte);
269 break;
270
271 default:
272 no_mapping:
273 printf(" address 0x%08lx not a valid page\n",
274 (vaddr_t) dst);
275 return;
276 }
277 cpu_tlb_flushD_SE(pgva);
278 cpu_cpwait();
279
280 if (limit > size)
281 limit = size;
282 size -= limit;
283
284 /*
285 * Page is now writable. Do as much access as we
286 * can in this page.
287 */
288 for (; limit > 0; limit--)
289 *dst++ = *data++;
290
291 /*
292 * Restore old mapping permissions.
293 */
294 switch (oldpde & L1_TYPE_MASK) {
295 case L1_TYPE_S:
296 *pde = oldpde;
297 PTE_SYNC(pde);
298 break;
299
300 case L1_TYPE_C:
301 *pte = oldpte;
302 PTE_SYNC(pte);
303 break;
304 }
305 cpu_tlb_flushD_SE(pgva);
306 cpu_cpwait();
307 } while (size != 0);
308
309 /* Sync the I-cache. */
310 cpu_icache_sync_range(addr, savesize);
311 }
312
313 /*
314 * Write bytes to kernel address space for debugger.
315 */
316 void
317 db_write_bytes(vaddr_t addr, size_t size, const char *data)
318 {
319 extern char kernel_text[];
320 extern char etext[];
321 char *dst;
322 size_t loop;
323
324 /* If any part is in kernel text, use db_write_text() */
325 if (addr >= (vaddr_t) kernel_text && addr < (vaddr_t) etext) {
326 db_write_text(addr, size, data);
327 return;
328 }
329
330 dst = (char *)addr;
331 if (db_validate_address((u_int)dst)) {
332 db_printf("address %p is invalid\n", dst);
333 return;
334 }
335
336 if (size == 4 && (addr & 3) == 0 && ((uintptr_t)data & 3) == 0)
337 *((int*)dst) = *((const int *)data);
338 else
339 if (size == 2 && (addr & 1) == 0 && ((uintptr_t)data & 1) == 0)
340 *((short*)dst) = *((const short *)data);
341 else {
342 loop = size;
343 while (loop-- > 0) {
344 if (db_validate_address((u_int)dst)) {
345 db_printf("address %p is invalid\n", dst);
346 return;
347 }
348 *dst++ = *data++;
349 }
350 }
351
352 /* make sure the caches and memory are in sync */
353 cpu_icache_sync_range(addr, size);
354
355 /* In case the current page tables have been modified ... */
356 cpu_tlb_flushID();
357 cpu_cpwait();
358 }
359
360 #ifdef DDB
361 void
362 cpu_Debugger(void)
363 {
364 __asm(".word 0xe7ffffff");
365 }
366
367 const struct db_command db_machine_command_table[] = {
368 { DDB_ADD_CMD("frame", db_show_frame_cmd, 0,
369 "Displays the contents of a trapframe",
370 "[address]",
371 " address:\taddress of trapfame to display")},
372 { DDB_ADD_CMD("panic", db_show_panic_cmd, 0,
373 "Displays the last panic string",
374 NULL,NULL) },
375 #ifdef ARM32_DB_COMMANDS
376 ARM32_DB_COMMANDS,
377 #endif
378 { DDB_ADD_CMD(NULL, NULL, 0,NULL,NULL,NULL) }
379 };
380
381 int
382 db_trapper(u_int addr, u_int inst, trapframe_t *frame, int fault_code)
383 {
384
385 if (fault_code == 0) {
386 if ((inst & ~INSN_COND_MASK) == (BKPT_INST & ~INSN_COND_MASK))
387 kdb_trap(T_BREAKPOINT, frame);
388 else
389 kdb_trap(-1, frame);
390 } else
391 return (1);
392 return (0);
393 }
394
395 extern u_int esym;
396 extern u_int end;
397
398 static struct undefined_handler db_uh;
399
400 void
401 db_machine_init(void)
402 {
403
404 /*
405 * We get called before malloc() is available, so supply a static
406 * struct undefined_handler.
407 */
408 db_uh.uh_handler = db_trapper;
409 install_coproc_handler_static(CORE_UNKNOWN_HANDLER, &db_uh);
410 }
411 #endif
412
413 u_int
414 db_fetch_reg(int reg, db_regs_t *regs)
415 {
416
417 switch (reg) {
418 case 0:
419 return (regs->tf_r0);
420 case 1:
421 return (regs->tf_r1);
422 case 2:
423 return (regs->tf_r2);
424 case 3:
425 return (regs->tf_r3);
426 case 4:
427 return (regs->tf_r4);
428 case 5:
429 return (regs->tf_r5);
430 case 6:
431 return (regs->tf_r6);
432 case 7:
433 return (regs->tf_r7);
434 case 8:
435 return (regs->tf_r8);
436 case 9:
437 return (regs->tf_r9);
438 case 10:
439 return (regs->tf_r10);
440 case 11:
441 return (regs->tf_r11);
442 case 12:
443 return (regs->tf_r12);
444 case 13:
445 return (regs->tf_svc_sp);
446 case 14:
447 return (regs->tf_svc_lr);
448 case 15:
449 return (regs->tf_pc);
450 default:
451 panic("db_fetch_reg: botch");
452 }
453 }
454
455 u_int
456 branch_taken(u_int insn, u_int pc, db_regs_t *regs)
457 {
458 u_int addr, nregs;
459
460 switch ((insn >> 24) & 0xf) {
461 case 0xa: /* b ... */
462 case 0xb: /* bl ... */
463 addr = ((insn << 2) & 0x03ffffff);
464 if (addr & 0x02000000)
465 addr |= 0xfc000000;
466 return (pc + 8 + addr);
467 case 0x7: /* ldr pc, [pc, reg, lsl #2] */
468 addr = db_fetch_reg(insn & 0xf, regs);
469 addr = pc + 8 + (addr << 2);
470 db_read_bytes(addr, 4, (char *)&addr);
471 return (addr);
472 case 0x5: /* ldr pc, [reg] */
473 addr = db_fetch_reg((insn >> 16) & 0xf, regs);
474 db_read_bytes(addr, 4, (char *)&addr);
475 return (addr);
476 case 0x1: /* mov pc, reg */
477 addr = db_fetch_reg(insn & 0xf, regs);
478 return (addr);
479 case 0x8: /* ldmxx reg, {..., pc} */
480 case 0x9:
481 addr = db_fetch_reg((insn >> 16) & 0xf, regs);
482 nregs = (insn & 0x5555) + ((insn >> 1) & 0x5555);
483 nregs = (nregs & 0x3333) + ((nregs >> 2) & 0x3333);
484 nregs = (nregs + (nregs >> 4)) & 0x0f0f;
485 nregs = (nregs + (nregs >> 8)) & 0x001f;
486 switch ((insn >> 23) & 0x3) {
487 case 0x0: /* ldmda */
488 addr = addr - 0;
489 break;
490 case 0x1: /* ldmia */
491 addr = addr + 0 + ((nregs - 1) << 2);
492 break;
493 case 0x2: /* ldmdb */
494 addr = addr - 4;
495 break;
496 case 0x3: /* ldmib */
497 addr = addr + 4 + ((nregs - 1) << 2);
498 break;
499 }
500 db_read_bytes(addr, 4, (char *)&addr);
501 return (addr);
502 default:
503 panic("branch_taken: botch");
504 }
505 }
506