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 <machine/pcb.h> 33#include <machine/frame.h> 34#include <machine/segments.h> 35#include <machine/tss.h> 36#include <err.h> 37#include <kvm.h> 38#include <string.h> 39 40#include <defs.h> 41#include <target.h> 42#include <gdbthread.h> 43#include <inferior.h> 44#include <regcache.h> 45#include <frame-unwind.h> 46#include <i386-tdep.h> 47 48#include "kgdb.h" 49 50static int ofs_fix; 51 52CORE_ADDR 53kgdb_trgt_core_pcb(u_int cpuid) 54{ 55 return (kgdb_trgt_stop_pcb(cpuid, sizeof(struct pcb))); 56} 57 58void 59kgdb_trgt_fetch_registers(int regno __unused) 60{ 61 struct kthr *kt; 62 struct pcb pcb; 63 64 kt = kgdb_thr_lookup_tid(ptid_get_pid(inferior_ptid)); 65 if (kt == NULL) 66 return; 67 if (kvm_read(kvm, kt->pcb, &pcb, sizeof(pcb)) != sizeof(pcb)) { 68 warnx("kvm_read: %s", kvm_geterr(kvm)); 69 memset(&pcb, 0, sizeof(pcb)); 70 } 71 supply_register(I386_EBX_REGNUM, (char *)&pcb.pcb_ebx); 72 supply_register(I386_ESP_REGNUM, (char *)&pcb.pcb_esp); 73 supply_register(I386_EBP_REGNUM, (char *)&pcb.pcb_ebp); 74 supply_register(I386_ESI_REGNUM, (char *)&pcb.pcb_esi); 75 supply_register(I386_EDI_REGNUM, (char *)&pcb.pcb_edi); 76 supply_register(I386_EIP_REGNUM, (char *)&pcb.pcb_eip); 77} 78 79void 80kgdb_trgt_store_registers(int regno __unused) 81{ 82 fprintf_unfiltered(gdb_stderr, "XXX: %s\n", __func__); 83} 84 85void 86kgdb_trgt_new_objfile(struct objfile *objfile) 87{ 88 89 /* 90 * In revision 1.117 of i386/i386/exception.S trap handlers 91 * were changed to pass trapframes by reference rather than 92 * by value. Detect this by seeing if the first instruction 93 * at the 'calltrap' label is a "push %esp" which has the 94 * opcode 0x54. 95 */ 96 if (kgdb_parse("((char *)calltrap)[0]") == 0x54) 97 ofs_fix = 4; 98 else 99 ofs_fix = 0; 100} 101 102struct kgdb_tss_cache { 103 CORE_ADDR pc; 104 CORE_ADDR sp; 105 CORE_ADDR tss; 106}; 107 108static int kgdb_trgt_tss_offset[15] = { 109 offsetof(struct i386tss, tss_eax), 110 offsetof(struct i386tss, tss_ecx), 111 offsetof(struct i386tss, tss_edx), 112 offsetof(struct i386tss, tss_ebx), 113 offsetof(struct i386tss, tss_esp), 114 offsetof(struct i386tss, tss_ebp), 115 offsetof(struct i386tss, tss_esi), 116 offsetof(struct i386tss, tss_edi), 117 offsetof(struct i386tss, tss_eip), 118 offsetof(struct i386tss, tss_eflags), 119 offsetof(struct i386tss, tss_cs), 120 offsetof(struct i386tss, tss_ss), 121 offsetof(struct i386tss, tss_ds), 122 offsetof(struct i386tss, tss_es), 123 offsetof(struct i386tss, tss_fs) 124}; 125 126/* 127 * If the current thread is executing on a CPU, fetch the common_tss 128 * for that CPU. 129 * 130 * This is painful because 'struct pcpu' is variant sized, so we can't 131 * use it. Instead, we lookup the GDT selector for this CPU and 132 * extract the base of the TSS from there. 133 */ 134static CORE_ADDR 135kgdb_trgt_fetch_tss(void) 136{ 137 struct kthr *kt; 138 struct segment_descriptor sd; 139 uintptr_t addr, cpu0prvpage, tss; 140 141 kt = kgdb_thr_lookup_tid(ptid_get_pid(inferior_ptid)); 142 if (kt == NULL || kt->cpu == NOCPU) 143 return (0); 144 145 addr = kgdb_lookup("gdt"); 146 if (addr == 0) 147 return (0); 148 addr += (kt->cpu * NGDT + GPROC0_SEL) * sizeof(sd); 149 if (kvm_read(kvm, addr, &sd, sizeof(sd)) != sizeof(sd)) { 150 warnx("kvm_read: %s", kvm_geterr(kvm)); 151 return (0); 152 } 153 if (sd.sd_type != SDT_SYS386BSY) { 154 warnx("descriptor is not a busy TSS"); 155 return (0); 156 } 157 tss = sd.sd_hibase << 24 | sd.sd_lobase; 158 159 /* 160 * In SMP kernels, the TSS is stored as part of the per-CPU 161 * data. On older kernels, the CPU0's private page 162 * is stored at an address that isn't mapped in minidumps. 163 * However, the data is mapped at the alternate cpu0prvpage 164 * address. Thus, if the TSS is at the invalid address, 165 * change it to be relative to cpu0prvpage instead. 166 */ 167 if (trunc_page(tss) == 0xffc00000) { 168 addr = kgdb_lookup("cpu0prvpage"); 169 if (addr == 0) 170 return (0); 171 if (kvm_read(kvm, addr, &cpu0prvpage, sizeof(cpu0prvpage)) != 172 sizeof(cpu0prvpage)) { 173 warnx("kvm_read: %s", kvm_geterr(kvm)); 174 return (0); 175 } 176 tss = cpu0prvpage + (tss & PAGE_MASK); 177 } 178 return ((CORE_ADDR)tss); 179} 180 181static struct kgdb_tss_cache * 182kgdb_trgt_tss_cache(struct frame_info *next_frame, void **this_cache) 183{ 184 char buf[MAX_REGISTER_SIZE]; 185 struct kgdb_tss_cache *cache; 186 187 cache = *this_cache; 188 if (cache == NULL) { 189 cache = FRAME_OBSTACK_ZALLOC(struct kgdb_tss_cache); 190 *this_cache = cache; 191 cache->pc = frame_func_unwind(next_frame); 192 frame_unwind_register(next_frame, SP_REGNUM, buf); 193 cache->sp = extract_unsigned_integer(buf, 194 register_size(current_gdbarch, SP_REGNUM)); 195 cache->tss = kgdb_trgt_fetch_tss(); 196 } 197 return (cache); 198} 199 200static void 201kgdb_trgt_dblfault_this_id(struct frame_info *next_frame, void **this_cache, 202 struct frame_id *this_id) 203{ 204 struct kgdb_tss_cache *cache; 205 206 cache = kgdb_trgt_tss_cache(next_frame, this_cache); 207 *this_id = frame_id_build(cache->sp, cache->pc); 208} 209 210static void 211kgdb_trgt_dblfault_prev_register(struct frame_info *next_frame, 212 void **this_cache, int regnum, int *optimizedp, enum lval_type *lvalp, 213 CORE_ADDR *addrp, int *realnump, void *valuep) 214{ 215 char dummy_valuep[MAX_REGISTER_SIZE]; 216 struct kgdb_tss_cache *cache; 217 int ofs, regsz; 218 219 regsz = register_size(current_gdbarch, regnum); 220 221 if (valuep == NULL) 222 valuep = dummy_valuep; 223 memset(valuep, 0, regsz); 224 *optimizedp = 0; 225 *addrp = 0; 226 *lvalp = not_lval; 227 *realnump = -1; 228 229 ofs = (regnum >= I386_EAX_REGNUM && regnum <= I386_FS_REGNUM) 230 ? kgdb_trgt_tss_offset[regnum] : -1; 231 if (ofs == -1) 232 return; 233 234 cache = kgdb_trgt_tss_cache(next_frame, this_cache); 235 if (cache->tss == 0) 236 return; 237 *addrp = cache->tss + ofs; 238 *lvalp = lval_memory; 239 target_read_memory(*addrp, valuep, regsz); 240} 241 242static const struct frame_unwind kgdb_trgt_dblfault_unwind = { 243 UNKNOWN_FRAME, 244 &kgdb_trgt_dblfault_this_id, 245 &kgdb_trgt_dblfault_prev_register 246}; 247 248struct kgdb_frame_cache { 249 int frame_type; 250 CORE_ADDR pc; 251 CORE_ADDR sp; 252}; 253#define FT_NORMAL 1 254#define FT_INTRFRAME 2 255#define FT_INTRTRAPFRAME 3 256#define FT_TIMERFRAME 4 257 258static int kgdb_trgt_frame_offset[15] = { 259 offsetof(struct trapframe, tf_eax), 260 offsetof(struct trapframe, tf_ecx), 261 offsetof(struct trapframe, tf_edx), 262 offsetof(struct trapframe, tf_ebx), 263 offsetof(struct trapframe, tf_esp), 264 offsetof(struct trapframe, tf_ebp), 265 offsetof(struct trapframe, tf_esi), 266 offsetof(struct trapframe, tf_edi), 267 offsetof(struct trapframe, tf_eip), 268 offsetof(struct trapframe, tf_eflags), 269 offsetof(struct trapframe, tf_cs), 270 offsetof(struct trapframe, tf_ss), 271 offsetof(struct trapframe, tf_ds), 272 offsetof(struct trapframe, tf_es), 273 offsetof(struct trapframe, tf_fs) 274}; 275 276static struct kgdb_frame_cache * 277kgdb_trgt_frame_cache(struct frame_info *next_frame, void **this_cache) 278{ 279 char buf[MAX_REGISTER_SIZE]; 280 struct kgdb_frame_cache *cache; 281 char *pname; 282 283 cache = *this_cache; 284 if (cache == NULL) { 285 cache = FRAME_OBSTACK_ZALLOC(struct kgdb_frame_cache); 286 *this_cache = cache; 287 cache->pc = frame_func_unwind(next_frame); 288 find_pc_partial_function(cache->pc, &pname, NULL, NULL); 289 if (pname[0] != 'X') 290 cache->frame_type = FT_NORMAL; 291 else if (strcmp(pname, "Xtimerint") == 0) 292 cache->frame_type = FT_TIMERFRAME; 293 else if (strcmp(pname, "Xcpustop") == 0 || 294 strcmp(pname, "Xrendezvous") == 0 || 295 strcmp(pname, "Xipi_intr_bitmap_handler") == 0 || 296 strcmp(pname, "Xlazypmap") == 0) 297 cache->frame_type = FT_INTRTRAPFRAME; 298 else 299 cache->frame_type = FT_INTRFRAME; 300 frame_unwind_register(next_frame, SP_REGNUM, buf); 301 cache->sp = extract_unsigned_integer(buf, 302 register_size(current_gdbarch, SP_REGNUM)); 303 } 304 return (cache); 305} 306 307static void 308kgdb_trgt_trapframe_this_id(struct frame_info *next_frame, void **this_cache, 309 struct frame_id *this_id) 310{ 311 struct kgdb_frame_cache *cache; 312 313 cache = kgdb_trgt_frame_cache(next_frame, this_cache); 314 *this_id = frame_id_build(cache->sp, cache->pc); 315} 316 317static void 318kgdb_trgt_trapframe_prev_register(struct frame_info *next_frame, 319 void **this_cache, int regnum, int *optimizedp, enum lval_type *lvalp, 320 CORE_ADDR *addrp, int *realnump, void *valuep) 321{ 322 char dummy_valuep[MAX_REGISTER_SIZE]; 323 struct kgdb_frame_cache *cache; 324 int ofs, regsz; 325 326 regsz = register_size(current_gdbarch, regnum); 327 328 if (valuep == NULL) 329 valuep = dummy_valuep; 330 memset(valuep, 0, regsz); 331 *optimizedp = 0; 332 *addrp = 0; 333 *lvalp = not_lval; 334 *realnump = -1; 335 336 ofs = (regnum >= I386_EAX_REGNUM && regnum <= I386_FS_REGNUM) 337 ? kgdb_trgt_frame_offset[regnum] + ofs_fix : -1; 338 if (ofs == -1) 339 return; 340 341 cache = kgdb_trgt_frame_cache(next_frame, this_cache); 342 switch (cache->frame_type) { 343 case FT_NORMAL: 344 break; 345 case FT_INTRFRAME: 346 ofs += 4; 347 break; 348 case FT_TIMERFRAME: 349 break; 350 case FT_INTRTRAPFRAME: 351 ofs -= ofs_fix; 352 break; 353 default: 354 fprintf_unfiltered(gdb_stderr, "Correct FT_XXX frame offsets " 355 "for %d\n", cache->frame_type); 356 break; 357 } 358 *addrp = cache->sp + ofs; 359 *lvalp = lval_memory; 360 target_read_memory(*addrp, valuep, regsz); 361} 362 363static const struct frame_unwind kgdb_trgt_trapframe_unwind = { 364 UNKNOWN_FRAME, 365 &kgdb_trgt_trapframe_this_id, 366 &kgdb_trgt_trapframe_prev_register 367}; 368 369const struct frame_unwind * 370kgdb_trgt_trapframe_sniffer(struct frame_info *next_frame) 371{ 372 char *pname; 373 CORE_ADDR pc; 374 375 pc = frame_pc_unwind(next_frame); 376 pname = NULL; 377 find_pc_partial_function(pc, &pname, NULL, NULL); 378 if (pname == NULL) 379 return (NULL); 380 if (strcmp(pname, "dblfault_handler") == 0) 381 return (&kgdb_trgt_dblfault_unwind); 382 if (strcmp(pname, "calltrap") == 0 || 383 (pname[0] == 'X' && pname[1] != '_')) 384 return (&kgdb_trgt_trapframe_unwind); 385 /* printf("%s: %llx =%s\n", __func__, pc, pname); */ 386 return (NULL); 387} 388