1/* 2 * Copyright (c) 2004 Marcel Moolenaar 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 9 * 1. Redistributions of source code must retain the above copyright 10 * notice, this list of conditions and the following disclaimer. 11 * 2. Redistributions in binary form must reproduce the above copyright 12 * notice, this list of conditions and the following disclaimer in the 13 * documentation and/or other materials provided with the distribution. 14 * 15 * THIS SOFTWARE IS PROVIDED BY THE AUTHORS ``AS IS'' AND ANY EXPRESS OR 16 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 17 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 18 * IN NO EVENT SHALL THE AUTHORS BE LIABLE FOR ANY DIRECT, INDIRECT, 19 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 20 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 21 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 22 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 23 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 24 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 25 */ 26 27#include <sys/cdefs.h> 28__FBSDID("$FreeBSD$"); 29 30#include <sys/param.h> 31#include <sys/proc.h> 32#include <vm/vm.h> 33#include <vm/pmap.h> 34#include <machine/pcb.h> 35#include <machine/frame.h> 36#include <machine/segments.h> 37#include <machine/tss.h> 38#include <err.h> 39#include <kvm.h> 40#include <string.h> 41 42#include <defs.h> 43#include <target.h> 44#include <gdbthread.h> 45#include <inferior.h> 46#include <regcache.h> 47#include <frame-unwind.h> 48#include <i386-tdep.h> 49 50#include "kgdb.h" 51 52static int ofs_fix; 53 54CORE_ADDR 55kgdb_trgt_core_pcb(u_int cpuid) 56{ 57 return (kgdb_trgt_stop_pcb(cpuid, sizeof(struct pcb))); 58} 59 60void 61kgdb_trgt_fetch_registers(int regno __unused) 62{ 63 struct kthr *kt; 64 struct pcb pcb; 65 66 kt = kgdb_thr_lookup_tid(ptid_get_pid(inferior_ptid)); 67 if (kt == NULL) 68 return; 69 if (kvm_read(kvm, kt->pcb, &pcb, sizeof(pcb)) != sizeof(pcb)) { 70 warnx("kvm_read: %s", kvm_geterr(kvm)); 71 memset(&pcb, 0, sizeof(pcb)); 72 } 73 supply_register(I386_EBX_REGNUM, (char *)&pcb.pcb_ebx); 74 supply_register(I386_ESP_REGNUM, (char *)&pcb.pcb_esp); 75 supply_register(I386_EBP_REGNUM, (char *)&pcb.pcb_ebp); 76 supply_register(I386_ESI_REGNUM, (char *)&pcb.pcb_esi); 77 supply_register(I386_EDI_REGNUM, (char *)&pcb.pcb_edi); 78 supply_register(I386_EIP_REGNUM, (char *)&pcb.pcb_eip); 79} 80 81void 82kgdb_trgt_store_registers(int regno __unused) 83{ 84 fprintf_unfiltered(gdb_stderr, "XXX: %s\n", __func__); 85} 86 87void 88kgdb_trgt_new_objfile(struct objfile *objfile) 89{ 90 91 /* 92 * In revision 1.117 of i386/i386/exception.S trap handlers 93 * were changed to pass trapframes by reference rather than 94 * by value. Detect this by seeing if the first instruction 95 * at the 'calltrap' label is a "push %esp" which has the 96 * opcode 0x54. 97 */ 98 if (kgdb_parse("((char *)calltrap)[0]") == 0x54) 99 ofs_fix = 4; 100 else 101 ofs_fix = 0; 102} 103 104struct kgdb_tss_cache { 105 CORE_ADDR pc; 106 CORE_ADDR sp; 107 CORE_ADDR tss; 108}; 109 110static int kgdb_trgt_tss_offset[15] = { 111 offsetof(struct i386tss, tss_eax), 112 offsetof(struct i386tss, tss_ecx), 113 offsetof(struct i386tss, tss_edx), 114 offsetof(struct i386tss, tss_ebx), 115 offsetof(struct i386tss, tss_esp), 116 offsetof(struct i386tss, tss_ebp), 117 offsetof(struct i386tss, tss_esi), 118 offsetof(struct i386tss, tss_edi), 119 offsetof(struct i386tss, tss_eip), 120 offsetof(struct i386tss, tss_eflags), 121 offsetof(struct i386tss, tss_cs), 122 offsetof(struct i386tss, tss_ss), 123 offsetof(struct i386tss, tss_ds), 124 offsetof(struct i386tss, tss_es), 125 offsetof(struct i386tss, tss_fs) 126}; 127 128/* 129 * If the current thread is executing on a CPU, fetch the common_tss 130 * for that CPU. 131 * 132 * This is painful because 'struct pcpu' is variant sized, so we can't 133 * use it. Instead, we lookup the GDT selector for this CPU and 134 * extract the base of the TSS from there. 135 */ 136static CORE_ADDR 137kgdb_trgt_fetch_tss(void) 138{ 139 struct kthr *kt; 140 struct segment_descriptor sd; 141 uintptr_t addr, cpu0prvpage, tss; 142 143 kt = kgdb_thr_lookup_tid(ptid_get_pid(inferior_ptid)); 144 if (kt == NULL || kt->cpu == NOCPU || kt->cpu < 0) 145 return (0); 146 147 addr = kgdb_lookup("gdt"); 148 if (addr == 0) 149 return (0); 150 addr += (kt->cpu * NGDT + GPROC0_SEL) * sizeof(sd); 151 if (kvm_read(kvm, addr, &sd, sizeof(sd)) != sizeof(sd)) { 152 warnx("kvm_read: %s", kvm_geterr(kvm)); 153 return (0); 154 } 155 if (sd.sd_type != SDT_SYS386BSY) { 156 warnx("descriptor is not a busy TSS"); 157 return (0); 158 } 159 tss = sd.sd_hibase << 24 | sd.sd_lobase; 160 161 /* 162 * In SMP kernels, the TSS is stored as part of the per-CPU 163 * data. On older kernels, the CPU0's private page 164 * is stored at an address that isn't mapped in minidumps. 165 * However, the data is mapped at the alternate cpu0prvpage 166 * address. Thus, if the TSS is at the invalid address, 167 * change it to be relative to cpu0prvpage instead. 168 */ 169 if (trunc_page(tss) == 0xffc00000) { 170 addr = kgdb_lookup("cpu0prvpage"); 171 if (addr == 0) 172 return (0); 173 if (kvm_read(kvm, addr, &cpu0prvpage, sizeof(cpu0prvpage)) != 174 sizeof(cpu0prvpage)) { 175 warnx("kvm_read: %s", kvm_geterr(kvm)); 176 return (0); 177 } 178 tss = cpu0prvpage + (tss & PAGE_MASK); 179 } 180 return ((CORE_ADDR)tss); 181} 182 183static struct kgdb_tss_cache * 184kgdb_trgt_tss_cache(struct frame_info *next_frame, void **this_cache) 185{ 186 char buf[MAX_REGISTER_SIZE]; 187 struct kgdb_tss_cache *cache; 188 189 cache = *this_cache; 190 if (cache == NULL) { 191 cache = FRAME_OBSTACK_ZALLOC(struct kgdb_tss_cache); 192 *this_cache = cache; 193 cache->pc = frame_func_unwind(next_frame); 194 frame_unwind_register(next_frame, SP_REGNUM, buf); 195 cache->sp = extract_unsigned_integer(buf, 196 register_size(current_gdbarch, SP_REGNUM)); 197 cache->tss = kgdb_trgt_fetch_tss(); 198 } 199 return (cache); 200} 201 202static void 203kgdb_trgt_dblfault_this_id(struct frame_info *next_frame, void **this_cache, 204 struct frame_id *this_id) 205{ 206 struct kgdb_tss_cache *cache; 207 208 cache = kgdb_trgt_tss_cache(next_frame, this_cache); 209 *this_id = frame_id_build(cache->sp, cache->pc); 210} 211 212static void 213kgdb_trgt_dblfault_prev_register(struct frame_info *next_frame, 214 void **this_cache, int regnum, int *optimizedp, enum lval_type *lvalp, 215 CORE_ADDR *addrp, int *realnump, void *valuep) 216{ 217 char dummy_valuep[MAX_REGISTER_SIZE]; 218 struct kgdb_tss_cache *cache; 219 int ofs, regsz; 220 221 regsz = register_size(current_gdbarch, regnum); 222 223 if (valuep == NULL) 224 valuep = dummy_valuep; 225 memset(valuep, 0, regsz); 226 *optimizedp = 0; 227 *addrp = 0; 228 *lvalp = not_lval; 229 *realnump = -1; 230 231 ofs = (regnum >= I386_EAX_REGNUM && regnum <= I386_FS_REGNUM) 232 ? kgdb_trgt_tss_offset[regnum] : -1; 233 if (ofs == -1) 234 return; 235 236 cache = kgdb_trgt_tss_cache(next_frame, this_cache); 237 if (cache->tss == 0) 238 return; 239 *addrp = cache->tss + ofs; 240 *lvalp = lval_memory; 241 target_read_memory(*addrp, valuep, regsz); 242} 243 244static const struct frame_unwind kgdb_trgt_dblfault_unwind = { 245 UNKNOWN_FRAME, 246 &kgdb_trgt_dblfault_this_id, 247 &kgdb_trgt_dblfault_prev_register 248}; 249 250struct kgdb_frame_cache { 251 int frame_type; 252 CORE_ADDR pc; 253 CORE_ADDR sp; 254}; 255#define FT_NORMAL 1 256#define FT_INTRFRAME 2 257#define FT_INTRTRAPFRAME 3 258#define FT_TIMERFRAME 4 259 260static int kgdb_trgt_frame_offset[15] = { 261 offsetof(struct trapframe, tf_eax), 262 offsetof(struct trapframe, tf_ecx), 263 offsetof(struct trapframe, tf_edx), 264 offsetof(struct trapframe, tf_ebx), 265 offsetof(struct trapframe, tf_esp), 266 offsetof(struct trapframe, tf_ebp), 267 offsetof(struct trapframe, tf_esi), 268 offsetof(struct trapframe, tf_edi), 269 offsetof(struct trapframe, tf_eip), 270 offsetof(struct trapframe, tf_eflags), 271 offsetof(struct trapframe, tf_cs), 272 offsetof(struct trapframe, tf_ss), 273 offsetof(struct trapframe, tf_ds), 274 offsetof(struct trapframe, tf_es), 275 offsetof(struct trapframe, tf_fs) 276}; 277 278static struct kgdb_frame_cache * 279kgdb_trgt_frame_cache(struct frame_info *next_frame, void **this_cache) 280{ 281 char buf[MAX_REGISTER_SIZE]; 282 struct kgdb_frame_cache *cache; 283 char *pname; 284 CORE_ADDR pcx; 285 uintptr_t addr, setidt_disp; 286 287 cache = *this_cache; 288 if (cache == NULL) { 289 cache = FRAME_OBSTACK_ZALLOC(struct kgdb_frame_cache); 290 *this_cache = cache; 291 pcx = frame_pc_unwind(next_frame); 292 if (pcx >= PMAP_TRM_MIN_ADDRESS) { 293 addr = kgdb_lookup("setidt_disp"); 294 if (addr != 0) { 295 if (kvm_read(kvm, addr, &setidt_disp, 296 sizeof(setidt_disp)) != 297 sizeof(setidt_disp)) 298 warnx("kvm_read: %s", kvm_geterr(kvm)); 299 else 300 pcx -= setidt_disp; 301 } 302 } 303 cache->pc = pcx; 304 find_pc_partial_function(cache->pc, &pname, NULL, NULL); 305 if (pname[0] != 'X') 306 cache->frame_type = FT_NORMAL; 307 else if (strcmp(pname, "Xtimerint") == 0) 308 cache->frame_type = FT_TIMERFRAME; 309 else if (strcmp(pname, "Xcpustop") == 0 || 310 strcmp(pname, "Xrendezvous") == 0 || 311 strcmp(pname, "Xipi_intr_bitmap_handler") == 0 || 312 strcmp(pname, "Xlazypmap") == 0) 313 cache->frame_type = FT_INTRTRAPFRAME; 314 else 315 cache->frame_type = FT_INTRFRAME; 316 frame_unwind_register(next_frame, SP_REGNUM, buf); 317 cache->sp = extract_unsigned_integer(buf, 318 register_size(current_gdbarch, SP_REGNUM)); 319 } 320 return (cache); 321} 322 323static void 324kgdb_trgt_trapframe_this_id(struct frame_info *next_frame, void **this_cache, 325 struct frame_id *this_id) 326{ 327 struct kgdb_frame_cache *cache; 328 329 cache = kgdb_trgt_frame_cache(next_frame, this_cache); 330 *this_id = frame_id_build(cache->sp, cache->pc); 331} 332 333static void 334kgdb_trgt_trapframe_prev_register(struct frame_info *next_frame, 335 void **this_cache, int regnum, int *optimizedp, enum lval_type *lvalp, 336 CORE_ADDR *addrp, int *realnump, void *valuep) 337{ 338 char dummy_valuep[MAX_REGISTER_SIZE]; 339 struct kgdb_frame_cache *cache; 340 int ofs, regsz; 341 342 regsz = register_size(current_gdbarch, regnum); 343 344 if (valuep == NULL) 345 valuep = dummy_valuep; 346 memset(valuep, 0, regsz); 347 *optimizedp = 0; 348 *addrp = 0; 349 *lvalp = not_lval; 350 *realnump = -1; 351 352 ofs = (regnum >= I386_EAX_REGNUM && regnum <= I386_FS_REGNUM) 353 ? kgdb_trgt_frame_offset[regnum] + ofs_fix : -1; 354 if (ofs == -1) 355 return; 356 357 cache = kgdb_trgt_frame_cache(next_frame, this_cache); 358 switch (cache->frame_type) { 359 case FT_NORMAL: 360 break; 361 case FT_INTRFRAME: 362 ofs += 4; 363 break; 364 case FT_TIMERFRAME: 365 break; 366 case FT_INTRTRAPFRAME: 367 ofs -= ofs_fix; 368 break; 369 default: 370 fprintf_unfiltered(gdb_stderr, "Correct FT_XXX frame offsets " 371 "for %d\n", cache->frame_type); 372 break; 373 } 374 *addrp = cache->sp + ofs; 375 *lvalp = lval_memory; 376 target_read_memory(*addrp, valuep, regsz); 377} 378 379static const struct frame_unwind kgdb_trgt_trapframe_unwind = { 380 UNKNOWN_FRAME, 381 &kgdb_trgt_trapframe_this_id, 382 &kgdb_trgt_trapframe_prev_register 383}; 384 385const struct frame_unwind * 386kgdb_trgt_trapframe_sniffer(struct frame_info *next_frame) 387{ 388 char *pname; 389 CORE_ADDR pc; 390 391 pc = frame_pc_unwind(next_frame); 392 if (pc >= PMAP_TRM_MIN_ADDRESS) 393 return (&kgdb_trgt_trapframe_unwind); 394 pname = NULL; 395 find_pc_partial_function(pc, &pname, NULL, NULL); 396 if (pname == NULL) 397 return (NULL); 398 if (strcmp(pname, "dblfault_handler") == 0) 399 return (&kgdb_trgt_dblfault_unwind); 400 if (strcmp(pname, "calltrap") == 0 || 401 (pname[0] == 'X' && pname[1] != '_')) 402 return (&kgdb_trgt_trapframe_unwind); 403 /* printf("%s: %llx =%s\n", __func__, pc, pname); */ 404 return (NULL); 405} 406 407/* 408 * This function ensures, that the PC is inside the 409 * function section which is understood by GDB. 410 * 411 * Return 0 when fixup is necessary, -1 otherwise. 412 */ 413int 414kgdb_trgt_pc_fixup(CORE_ADDR *pc __unused) 415{ 416 417 return (-1); 418} 419