1 /* $NetBSD: db_interface.c,v 1.4 2001/03/13 23:56:49 bjh21 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@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 <machine/katelib.h> 48 #include <machine/pte.h> 49 #include <machine/undefined.h> 50 #include <ddb/db_command.h> 51 #include <ddb/db_output.h> 52 #include <ddb/db_variables.h> 53 #include <ddb/db_sym.h> 54 #include <ddb/db_extern.h> 55 #include <ddb/db_interface.h> 56 #include <dev/cons.h> 57 58 static int nil; 59 60 int db_access_und_sp __P((const struct db_variable *, db_expr_t *, int)); 61 int db_access_abt_sp __P((const struct db_variable *, db_expr_t *, int)); 62 int db_access_irq_sp __P((const struct db_variable *, db_expr_t *, int)); 63 u_int db_fetch_reg __P((int, db_regs_t *)); 64 65 const struct db_variable db_regs[] = { 66 { "spsr", (long *)&DDB_REGS->tf_spsr, FCN_NULL, }, 67 { "r0", (long *)&DDB_REGS->tf_r0, FCN_NULL, }, 68 { "r1", (long *)&DDB_REGS->tf_r1, FCN_NULL, }, 69 { "r2", (long *)&DDB_REGS->tf_r2, FCN_NULL, }, 70 { "r3", (long *)&DDB_REGS->tf_r3, FCN_NULL, }, 71 { "r4", (long *)&DDB_REGS->tf_r4, FCN_NULL, }, 72 { "r5", (long *)&DDB_REGS->tf_r5, FCN_NULL, }, 73 { "r6", (long *)&DDB_REGS->tf_r6, FCN_NULL, }, 74 { "r7", (long *)&DDB_REGS->tf_r7, FCN_NULL, }, 75 { "r8", (long *)&DDB_REGS->tf_r8, FCN_NULL, }, 76 { "r9", (long *)&DDB_REGS->tf_r9, FCN_NULL, }, 77 { "r10", (long *)&DDB_REGS->tf_r10, FCN_NULL, }, 78 { "r11", (long *)&DDB_REGS->tf_r11, FCN_NULL, }, 79 { "r12", (long *)&DDB_REGS->tf_r12, FCN_NULL, }, 80 { "usr_sp", (long *)&DDB_REGS->tf_usr_sp, FCN_NULL, }, 81 { "usr_lr", (long *)&DDB_REGS->tf_usr_lr, FCN_NULL, }, 82 { "svc_sp", (long *)&DDB_REGS->tf_svc_sp, FCN_NULL, }, 83 { "svc_lr", (long *)&DDB_REGS->tf_svc_lr, FCN_NULL, }, 84 { "pc", (long *)&DDB_REGS->tf_pc, FCN_NULL, }, 85 { "und_sp", (long *)&nil, db_access_und_sp, }, 86 { "abt_sp", (long *)&nil, db_access_abt_sp, }, 87 { "irq_sp", (long *)&nil, db_access_irq_sp, }, 88 }; 89 90 const struct db_variable * const db_eregs = db_regs + sizeof(db_regs)/sizeof(db_regs[0]); 91 92 extern label_t *db_recover; 93 94 int db_active = 0; 95 96 int db_access_und_sp(vp, valp, rw) 97 const struct db_variable *vp; 98 db_expr_t *valp; 99 int rw; 100 { 101 if (rw == DB_VAR_GET) 102 *valp = get_stackptr(PSR_UND32_MODE); 103 return(0); 104 } 105 106 int db_access_abt_sp(vp, valp, rw) 107 const struct db_variable *vp; 108 db_expr_t *valp; 109 int rw; 110 { 111 if (rw == DB_VAR_GET) 112 *valp = get_stackptr(PSR_ABT32_MODE); 113 return(0); 114 } 115 116 int db_access_irq_sp(vp, valp, rw) 117 const struct db_variable *vp; 118 db_expr_t *valp; 119 int rw; 120 { 121 if (rw == DB_VAR_GET) 122 *valp = get_stackptr(PSR_IRQ32_MODE); 123 return(0); 124 } 125 126 /* 127 * kdb_trap - field a TRACE or BPT trap 128 */ 129 int 130 kdb_trap(type, regs) 131 int type; 132 db_regs_t *regs; 133 { 134 int s; 135 136 switch (type) { 137 case T_BREAKPOINT: /* breakpoint */ 138 case -1: /* keyboard interrupt */ 139 break; 140 default: 141 db_printf("kernel: trap"); 142 if (db_recover != 0) { 143 db_error("Faulted in DDB; continuing...\n"); 144 /*NOTREACHED*/ 145 } 146 } 147 148 /* Should switch to kdb`s own stack here. */ 149 150 ddb_regs = *regs; 151 152 s = splhigh(); 153 db_active++; 154 cnpollc(TRUE); 155 db_trap(type, 0/*code*/); 156 cnpollc(FALSE); 157 db_active--; 158 splx(s); 159 160 *regs = ddb_regs; 161 162 return (1); 163 } 164 165 166 /* 167 * Received keyboard interrupt sequence. 168 */ 169 void 170 kdb_kbd_trap(regs) 171 db_regs_t *regs; 172 { 173 if (db_active == 0 && (boothowto & RB_KDB)) { 174 printf("\n\nkernel: keyboard interrupt\n"); 175 kdb_trap(-1, regs); 176 } 177 } 178 179 180 static int 181 db_validate_address(addr) 182 vm_offset_t addr; 183 { 184 pt_entry_t *ptep; 185 pd_entry_t *pdep; 186 struct proc *p = curproc; 187 188 /* 189 * If we have a valid pmap for curproc, use it's page directory 190 * otherwise use the kernel pmap's page directory. 191 */ 192 if (!p || !p->p_vmspace || !p->p_vmspace->vm_map.pmap) 193 pdep = kernel_pmap->pm_pdir; 194 else 195 pdep = p->p_vmspace->vm_map.pmap->pm_pdir; 196 197 /* Make sure the address we are reading is valid */ 198 switch ((pdep[(addr >> 20) + 0] & L1_MASK)) { 199 case L1_SECTION: 200 break; 201 case L1_PAGE: 202 /* Check the L2 page table for validity */ 203 ptep = vtopte(addr); 204 if ((*ptep & L2_MASK) != L2_INVAL) 205 break; 206 /* FALLTHROUGH */ 207 default: 208 return 1; 209 } 210 211 return 0; 212 } 213 214 /* 215 * Read bytes from kernel address space for debugger. 216 */ 217 void 218 db_read_bytes(addr, size, data) 219 vm_offset_t addr; 220 int size; 221 char *data; 222 { 223 char *src; 224 225 src = (char *)addr; 226 while (--size >= 0) { 227 if (db_validate_address((u_int)src)) { 228 db_printf("address %p is invalid\n", src); 229 return; 230 } 231 *data++ = *src++; 232 } 233 } 234 235 static void 236 db_write_text(dst, ch) 237 unsigned char *dst; 238 int ch; 239 { 240 pt_entry_t *ptep, pteo; 241 vm_offset_t va; 242 243 va = (unsigned long)dst & (~PGOFSET); 244 ptep = vtopte(va); 245 246 if (db_validate_address((u_int)dst)) { 247 db_printf(" address %p not a valid page\n", dst); 248 return; 249 } 250 251 pteo = *ptep; 252 *ptep = pteo | PT_AP(AP_KRW); 253 cpu_tlb_flushD_SE(va); 254 255 *dst = (unsigned char)ch; 256 257 /* make sure the caches and memory are in sync */ 258 cpu_cache_syncI_rng((u_int)dst, 4); 259 260 *ptep = pteo; 261 cpu_tlb_flushD_SE(va); 262 } 263 264 /* 265 * Write bytes to kernel address space for debugger. 266 */ 267 void 268 db_write_bytes(addr, size, data) 269 vm_offset_t addr; 270 int size; 271 char *data; 272 { 273 extern char etext[]; 274 char *dst; 275 int loop; 276 277 dst = (char *)addr; 278 loop = size; 279 while (--loop >= 0) { 280 if ((dst >= (char *)KERNEL_TEXT_BASE) && (dst < etext)) 281 db_write_text(dst, *data); 282 else { 283 if (db_validate_address((u_int)dst)) { 284 db_printf("address %p is invalid\n", dst); 285 return; 286 } 287 *dst = *data; 288 } 289 dst++, data++; 290 } 291 /* make sure the caches and memory are in sync */ 292 cpu_cache_syncI_rng(addr, size); 293 294 /* In case the current page tables have been modified ... */ 295 cpu_tlb_flushID(); 296 } 297 298 void 299 cpu_Debugger() 300 { 301 asm(".word 0xe7ffffff"); 302 } 303 304 void db_show_vmstat_cmd __P((db_expr_t addr, int have_addr, db_expr_t count, char *modif)); 305 void db_show_intrchain_cmd __P((db_expr_t addr, int have_addr, db_expr_t count, char *modif)); 306 void db_show_panic_cmd __P((db_expr_t addr, int have_addr, db_expr_t count, char *modif)); 307 void db_show_frame_cmd __P((db_expr_t addr, int have_addr, db_expr_t count, char *modif)); 308 309 const struct db_command db_machine_command_table[] = { 310 { "frame", db_show_frame_cmd, 0, NULL }, 311 { "intrchain", db_show_intrchain_cmd, 0, NULL }, 312 { "panic", db_show_panic_cmd, 0, NULL }, 313 { "vmstat", db_show_vmstat_cmd, 0, NULL }, 314 #ifdef ARM32_DB_COMMANDS 315 ARM32_DB_COMMANDS, 316 #endif 317 { NULL, NULL, 0, NULL } 318 }; 319 320 int 321 db_trapper(addr, inst, frame, fault_code) 322 u_int addr; 323 u_int inst; 324 trapframe_t *frame; 325 int fault_code; 326 { 327 if (fault_code == 0) { 328 if ((inst & ~INSN_COND_MASK) == (BKPT_INST & ~INSN_COND_MASK)) 329 kdb_trap(T_BREAKPOINT, frame); 330 else 331 kdb_trap(-1, frame); 332 } else 333 return (1); 334 return (0); 335 } 336 337 extern u_int esym; 338 extern u_int end; 339 340 static struct undefined_handler db_uh; 341 342 void 343 db_machine_init() 344 { 345 struct exec *kernexec = (struct exec *)KERNEL_TEXT_BASE; 346 int len; 347 348 /* 349 * The boot loader currently loads the kernel with the a.out 350 * header still attached. 351 */ 352 353 if (kernexec->a_syms == 0) { 354 printf("[No symbol table]\n"); 355 } else { 356 /* cover the symbols themselves (what is the int for?? XXX) */ 357 esym = (int)&end + kernexec->a_syms + sizeof(int); 358 359 /* 360 * and the string table. (int containing size of string 361 * table is included in string table size). 362 */ 363 len = *((u_int *)esym); 364 esym += (len + (sizeof(u_int) - 1)) & ~(sizeof(u_int) - 1); 365 } 366 367 /* 368 * We get called before malloc() is available, so supply a static 369 * struct undefined_handler. 370 */ 371 db_uh.uh_handler = db_trapper; 372 install_coproc_handler_static(0, &db_uh); 373 } 374 375 u_int 376 db_fetch_reg(reg, db_regs) 377 int reg; 378 db_regs_t *db_regs; 379 { 380 381 switch (reg) { 382 case 0: 383 return (db_regs->tf_r0); 384 case 1: 385 return (db_regs->tf_r1); 386 case 2: 387 return (db_regs->tf_r2); 388 case 3: 389 return (db_regs->tf_r3); 390 case 4: 391 return (db_regs->tf_r4); 392 case 5: 393 return (db_regs->tf_r5); 394 case 6: 395 return (db_regs->tf_r6); 396 case 7: 397 return (db_regs->tf_r7); 398 case 8: 399 return (db_regs->tf_r8); 400 case 9: 401 return (db_regs->tf_r9); 402 case 10: 403 return (db_regs->tf_r10); 404 case 11: 405 return (db_regs->tf_r11); 406 case 12: 407 return (db_regs->tf_r12); 408 case 13: 409 return (db_regs->tf_svc_sp); 410 case 14: 411 return (db_regs->tf_svc_lr); 412 case 15: 413 return (db_regs->tf_pc); 414 default: 415 panic("db_fetch_reg: botch"); 416 } 417 } 418 419 u_int 420 branch_taken(insn, pc, db_regs) 421 u_int insn; 422 u_int pc; 423 db_regs_t *db_regs; 424 { 425 u_int addr, nregs; 426 427 switch ((insn >> 24) & 0xf) { 428 case 0xa: /* b ... */ 429 case 0xb: /* bl ... */ 430 addr = ((insn << 2) & 0x03ffffff); 431 if (addr & 0x02000000) 432 addr |= 0xfc000000; 433 return (pc + 8 + addr); 434 case 0x7: /* ldr pc, [pc, reg, lsl #2] */ 435 addr = db_fetch_reg(insn & 0xf, db_regs); 436 addr = pc + 8 + (addr << 2); 437 db_read_bytes(addr, 4, (char *)&addr); 438 return (addr); 439 case 0x1: /* mov pc, reg */ 440 addr = db_fetch_reg(insn & 0xf, db_regs); 441 return (addr); 442 case 0x8: /* ldmxx reg, {..., pc} */ 443 case 0x9: 444 addr = db_fetch_reg((insn >> 16) & 0xf, db_regs); 445 nregs = (insn & 0x5555) + ((insn >> 1) & 0x5555); 446 nregs = (nregs & 0x3333) + ((nregs >> 2) & 0x3333); 447 nregs = (nregs + (nregs >> 4)) & 0x0f0f; 448 nregs = (nregs + (nregs >> 8)) & 0x001f; 449 switch ((insn >> 23) & 0x3) { 450 case 0x0: /* ldmda */ 451 addr = addr - 0; 452 break; 453 case 0x1: /* ldmia */ 454 addr = addr + 0 + ((nregs - 1) << 2); 455 break; 456 case 0x2: /* ldmdb */ 457 addr = addr - 4; 458 break; 459 case 0x3: /* ldmib */ 460 addr = addr + 4 + ((nregs - 1) << 2); 461 break; 462 } 463 db_read_bytes(addr, 4, (char *)&addr); 464 return (addr); 465 default: 466 panic("branch_taken: botch"); 467 } 468 } 469