db_interface.c revision 1.8.2.3 1 /* $NetBSD: db_interface.c,v 1.8.2.3 2002/01/08 00:23:08 nathanw 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 #include "opt_ddb.h"
37
38 #include <sys/param.h>
39 #include <sys/proc.h>
40 #include <sys/reboot.h>
41 #include <sys/systm.h> /* just for boothowto */
42 #include <sys/exec.h>
43
44 #include <uvm/uvm_extern.h>
45
46 #include <machine/db_machdep.h>
47 #include <arm/arm32/katelib.h>
48 #include <arm/undefined.h>
49 #include <ddb/db_command.h>
50 #include <ddb/db_output.h>
51 #include <ddb/db_variables.h>
52 #include <ddb/db_sym.h>
53 #include <ddb/db_extern.h>
54 #include <ddb/db_interface.h>
55 #include <dev/cons.h>
56
57 static int nil;
58
59 int db_access_und_sp __P((const struct db_variable *, db_expr_t *, int));
60 int db_access_abt_sp __P((const struct db_variable *, db_expr_t *, int));
61 int db_access_irq_sp __P((const struct db_variable *, db_expr_t *, int));
62 u_int db_fetch_reg __P((int, db_regs_t *));
63
64 const struct db_variable db_regs[] = {
65 { "spsr", (long *)&DDB_REGS->tf_spsr, FCN_NULL, },
66 { "r0", (long *)&DDB_REGS->tf_r0, FCN_NULL, },
67 { "r1", (long *)&DDB_REGS->tf_r1, FCN_NULL, },
68 { "r2", (long *)&DDB_REGS->tf_r2, FCN_NULL, },
69 { "r3", (long *)&DDB_REGS->tf_r3, FCN_NULL, },
70 { "r4", (long *)&DDB_REGS->tf_r4, FCN_NULL, },
71 { "r5", (long *)&DDB_REGS->tf_r5, FCN_NULL, },
72 { "r6", (long *)&DDB_REGS->tf_r6, FCN_NULL, },
73 { "r7", (long *)&DDB_REGS->tf_r7, FCN_NULL, },
74 { "r8", (long *)&DDB_REGS->tf_r8, FCN_NULL, },
75 { "r9", (long *)&DDB_REGS->tf_r9, FCN_NULL, },
76 { "r10", (long *)&DDB_REGS->tf_r10, FCN_NULL, },
77 { "r11", (long *)&DDB_REGS->tf_r11, FCN_NULL, },
78 { "r12", (long *)&DDB_REGS->tf_r12, FCN_NULL, },
79 { "usr_sp", (long *)&DDB_REGS->tf_usr_sp, FCN_NULL, },
80 { "usr_lr", (long *)&DDB_REGS->tf_usr_lr, FCN_NULL, },
81 { "svc_sp", (long *)&DDB_REGS->tf_svc_sp, FCN_NULL, },
82 { "svc_lr", (long *)&DDB_REGS->tf_svc_lr, FCN_NULL, },
83 { "pc", (long *)&DDB_REGS->tf_pc, FCN_NULL, },
84 { "und_sp", (long *)&nil, db_access_und_sp, },
85 { "abt_sp", (long *)&nil, db_access_abt_sp, },
86 { "irq_sp", (long *)&nil, db_access_irq_sp, },
87 };
88
89 const struct db_variable * const db_eregs = db_regs + sizeof(db_regs)/sizeof(db_regs[0]);
90
91 extern label_t *db_recover;
92
93 int db_active = 0;
94
95 int db_access_und_sp(vp, valp, rw)
96 const struct db_variable *vp;
97 db_expr_t *valp;
98 int rw;
99 {
100 if (rw == DB_VAR_GET)
101 *valp = get_stackptr(PSR_UND32_MODE);
102 return(0);
103 }
104
105 int db_access_abt_sp(vp, valp, rw)
106 const struct db_variable *vp;
107 db_expr_t *valp;
108 int rw;
109 {
110 if (rw == DB_VAR_GET)
111 *valp = get_stackptr(PSR_ABT32_MODE);
112 return(0);
113 }
114
115 int db_access_irq_sp(vp, valp, rw)
116 const struct db_variable *vp;
117 db_expr_t *valp;
118 int rw;
119 {
120 if (rw == DB_VAR_GET)
121 *valp = get_stackptr(PSR_IRQ32_MODE);
122 return(0);
123 }
124
125 /*
126 * kdb_trap - field a TRACE or BPT trap
127 */
128 int
129 kdb_trap(type, regs)
130 int type;
131 db_regs_t *regs;
132 {
133 int s;
134
135 switch (type) {
136 case T_BREAKPOINT: /* breakpoint */
137 case -1: /* keyboard interrupt */
138 break;
139 default:
140 db_printf("kernel: trap");
141 if (db_recover != 0) {
142 db_error("Faulted in DDB; continuing...\n");
143 /*NOTREACHED*/
144 }
145 }
146
147 /* Should switch to kdb`s own stack here. */
148
149 ddb_regs = *regs;
150
151 s = splhigh();
152 db_active++;
153 cnpollc(TRUE);
154 db_trap(type, 0/*code*/);
155 cnpollc(FALSE);
156 db_active--;
157 splx(s);
158
159 *regs = ddb_regs;
160
161 return (1);
162 }
163
164
165 /*
166 * Received keyboard interrupt sequence.
167 */
168 void
169 kdb_kbd_trap(regs)
170 db_regs_t *regs;
171 {
172 if (db_active == 0 && (boothowto & RB_KDB)) {
173 printf("\n\nkernel: keyboard interrupt\n");
174 kdb_trap(-1, regs);
175 }
176 }
177
178
179 static int
180 db_validate_address(addr)
181 vm_offset_t addr;
182 {
183 pt_entry_t *ptep;
184 pd_entry_t *pdep;
185 struct proc *p = curproc == NULL ? NULL : curproc->l_proc;
186
187 /*
188 * If we have a valid pmap for curproc, use it's page directory
189 * otherwise use the kernel pmap's page directory.
190 */
191 if (!p || !p->p_vmspace || !p->p_vmspace->vm_map.pmap)
192 pdep = pmap_kernel()->pm_pdir;
193 else
194 pdep = p->p_vmspace->vm_map.pmap->pm_pdir;
195
196 /* Make sure the address we are reading is valid */
197 switch ((pdep[(addr >> 20) + 0] & L1_MASK)) {
198 case L1_SECTION:
199 break;
200 case L1_PAGE:
201 /* Check the L2 page table for validity */
202 ptep = vtopte(addr);
203 if ((*ptep & L2_MASK) != L2_INVAL)
204 break;
205 /* FALLTHROUGH */
206 default:
207 return 1;
208 }
209
210 return 0;
211 }
212
213 /*
214 * Read bytes from kernel address space for debugger.
215 */
216 void
217 db_read_bytes(addr, size, data)
218 vm_offset_t addr;
219 int size;
220 char *data;
221 {
222 char *src;
223
224 src = (char *)addr;
225 while (--size >= 0) {
226 if (db_validate_address((u_int)src)) {
227 db_printf("address %p is invalid\n", src);
228 return;
229 }
230 *data++ = *src++;
231 }
232 }
233
234 static void
235 db_write_text(dst, ch)
236 unsigned char *dst;
237 int ch;
238 {
239 pt_entry_t *ptep, pteo;
240 vm_offset_t va;
241
242 va = (unsigned long)dst & (~PGOFSET);
243 ptep = vtopte(va);
244
245 if (db_validate_address((u_int)dst)) {
246 db_printf(" address %p not a valid page\n", dst);
247 return;
248 }
249
250 pteo = *ptep;
251 *ptep = pteo | PT_AP(AP_KRW);
252 cpu_tlb_flushD_SE(va);
253
254 *dst = (unsigned char)ch;
255
256 /* make sure the caches and memory are in sync */
257 cpu_cache_syncI_rng((u_int)dst, 4);
258
259 *ptep = pteo;
260 cpu_tlb_flushD_SE(va);
261 }
262
263 /*
264 * Write bytes to kernel address space for debugger.
265 */
266 void
267 db_write_bytes(addr, size, data)
268 vm_offset_t addr;
269 int size;
270 char *data;
271 {
272 extern char etext[];
273 char *dst;
274 int loop;
275
276 dst = (char *)addr;
277 loop = size;
278 while (--loop >= 0) {
279 if ((dst >= (char *)KERNEL_TEXT_BASE) && (dst < etext))
280 db_write_text(dst, *data);
281 else {
282 if (db_validate_address((u_int)dst)) {
283 db_printf("address %p is invalid\n", dst);
284 return;
285 }
286 *dst = *data;
287 }
288 dst++, data++;
289 }
290 /* make sure the caches and memory are in sync */
291 cpu_cache_syncI_rng(addr, size);
292
293 /* In case the current page tables have been modified ... */
294 cpu_tlb_flushID();
295 }
296
297 void
298 cpu_Debugger()
299 {
300 asm(".word 0xe7ffffff");
301 }
302
303 void db_show_panic_cmd __P((db_expr_t addr, int have_addr, db_expr_t count, char *modif));
304 void db_show_frame_cmd __P((db_expr_t addr, int have_addr, db_expr_t count, char *modif));
305
306 const struct db_command db_machine_command_table[] = {
307 { "frame", db_show_frame_cmd, 0, NULL },
308 { "panic", db_show_panic_cmd, 0, NULL },
309 #ifdef ARM32_DB_COMMANDS
310 ARM32_DB_COMMANDS,
311 #endif
312 { NULL, NULL, 0, NULL }
313 };
314
315 int
316 db_trapper(addr, inst, frame, fault_code)
317 u_int addr;
318 u_int inst;
319 trapframe_t *frame;
320 int fault_code;
321 {
322 if (fault_code == 0) {
323 if ((inst & ~INSN_COND_MASK) == (BKPT_INST & ~INSN_COND_MASK))
324 kdb_trap(T_BREAKPOINT, frame);
325 else
326 kdb_trap(-1, frame);
327 } else
328 return (1);
329 return (0);
330 }
331
332 extern u_int esym;
333 extern u_int end;
334
335 static struct undefined_handler db_uh;
336
337 void
338 db_machine_init()
339 {
340 #ifndef __ELF__
341 struct exec *kernexec = (struct exec *)KERNEL_TEXT_BASE;
342 int len;
343
344 /*
345 * The boot loader currently loads the kernel with the a.out
346 * header still attached.
347 */
348
349 if (kernexec->a_syms == 0) {
350 printf("ddb: No symbol table\n");
351 } else {
352 /* cover the symbols themselves (what is the int for?? XXX) */
353 esym = (int)&end + kernexec->a_syms + sizeof(int);
354
355 /*
356 * and the string table. (int containing size of string
357 * table is included in string table size).
358 */
359 len = *((u_int *)esym);
360 esym += (len + (sizeof(u_int) - 1)) & ~(sizeof(u_int) - 1);
361 }
362 #endif
363
364 /*
365 * We get called before malloc() is available, so supply a static
366 * struct undefined_handler.
367 */
368 db_uh.uh_handler = db_trapper;
369 install_coproc_handler_static(0, &db_uh);
370 }
371
372 u_int
373 db_fetch_reg(reg, db_regs)
374 int reg;
375 db_regs_t *db_regs;
376 {
377
378 switch (reg) {
379 case 0:
380 return (db_regs->tf_r0);
381 case 1:
382 return (db_regs->tf_r1);
383 case 2:
384 return (db_regs->tf_r2);
385 case 3:
386 return (db_regs->tf_r3);
387 case 4:
388 return (db_regs->tf_r4);
389 case 5:
390 return (db_regs->tf_r5);
391 case 6:
392 return (db_regs->tf_r6);
393 case 7:
394 return (db_regs->tf_r7);
395 case 8:
396 return (db_regs->tf_r8);
397 case 9:
398 return (db_regs->tf_r9);
399 case 10:
400 return (db_regs->tf_r10);
401 case 11:
402 return (db_regs->tf_r11);
403 case 12:
404 return (db_regs->tf_r12);
405 case 13:
406 return (db_regs->tf_svc_sp);
407 case 14:
408 return (db_regs->tf_svc_lr);
409 case 15:
410 return (db_regs->tf_pc);
411 default:
412 panic("db_fetch_reg: botch");
413 }
414 }
415
416 u_int
417 branch_taken(insn, pc, db_regs)
418 u_int insn;
419 u_int pc;
420 db_regs_t *db_regs;
421 {
422 u_int addr, nregs;
423
424 switch ((insn >> 24) & 0xf) {
425 case 0xa: /* b ... */
426 case 0xb: /* bl ... */
427 addr = ((insn << 2) & 0x03ffffff);
428 if (addr & 0x02000000)
429 addr |= 0xfc000000;
430 return (pc + 8 + addr);
431 case 0x7: /* ldr pc, [pc, reg, lsl #2] */
432 addr = db_fetch_reg(insn & 0xf, db_regs);
433 addr = pc + 8 + (addr << 2);
434 db_read_bytes(addr, 4, (char *)&addr);
435 return (addr);
436 case 0x1: /* mov pc, reg */
437 addr = db_fetch_reg(insn & 0xf, db_regs);
438 return (addr);
439 case 0x8: /* ldmxx reg, {..., pc} */
440 case 0x9:
441 addr = db_fetch_reg((insn >> 16) & 0xf, db_regs);
442 nregs = (insn & 0x5555) + ((insn >> 1) & 0x5555);
443 nregs = (nregs & 0x3333) + ((nregs >> 2) & 0x3333);
444 nregs = (nregs + (nregs >> 4)) & 0x0f0f;
445 nregs = (nregs + (nregs >> 8)) & 0x001f;
446 switch ((insn >> 23) & 0x3) {
447 case 0x0: /* ldmda */
448 addr = addr - 0;
449 break;
450 case 0x1: /* ldmia */
451 addr = addr + 0 + ((nregs - 1) << 2);
452 break;
453 case 0x2: /* ldmdb */
454 addr = addr - 4;
455 break;
456 case 0x3: /* ldmib */
457 addr = addr + 4 + ((nregs - 1) << 2);
458 break;
459 }
460 db_read_bytes(addr, 4, (char *)&addr);
461 return (addr);
462 default:
463 panic("branch_taken: botch");
464 }
465 }
466