1 /* 2 * CDDL HEADER START 3 * 4 * The contents of this file are subject to the terms of the 5 * Common Development and Distribution License (the "License"). 6 * You may not use this file except in compliance with the License. 7 * 8 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE 9 * or http://www.opensolaris.org/os/licensing. 10 * See the License for the specific language governing permissions 11 * and limitations under the License. 12 * 13 * When distributing Covered Code, include this CDDL HEADER in each 14 * file and include the License file at usr/src/OPENSOLARIS.LICENSE. 15 * If applicable, add the following below this CDDL HEADER, with the 16 * fields enclosed by brackets "[]" replaced with your own identifying 17 * information: Portions Copyright [yyyy] [name of copyright owner] 18 * 19 * CDDL HEADER END 20 */ 21 22 /* 23 * Copyright 2007 Sun Microsystems, Inc. All rights reserved. 24 * Use is subject to license terms. 25 */ 26 /* 27 * Copyright 2013 Nexenta Systems, Inc. All rights reserved. 28 */ 29 30 #include <sys/types.h> 31 #include <sys/reg.h> 32 #include <sys/privregs.h> 33 #include <sys/stack.h> 34 #include <sys/frame.h> 35 36 #include <mdb/mdb_target_impl.h> 37 #include <mdb/mdb_kreg_impl.h> 38 #include <mdb/mdb_debug.h> 39 #include <mdb/mdb_modapi.h> 40 #include <mdb/mdb_amd64util.h> 41 #include <mdb/mdb_ctf.h> 42 #include <mdb/mdb_err.h> 43 #include <mdb/mdb.h> 44 45 #include <saveargs.h> 46 47 /* 48 * This array is used by the getareg and putareg entry points, and also by our 49 * register variable discipline. 50 */ 51 52 const mdb_tgt_regdesc_t mdb_amd64_kregs[] = { 53 { "savfp", KREG_SAVFP, MDB_TGT_R_EXPORT }, 54 { "savpc", KREG_SAVPC, MDB_TGT_R_EXPORT }, 55 { "rdi", KREG_RDI, MDB_TGT_R_EXPORT }, 56 { "rsi", KREG_RSI, MDB_TGT_R_EXPORT }, 57 { "rdx", KREG_RDX, MDB_TGT_R_EXPORT }, 58 { "rcx", KREG_RCX, MDB_TGT_R_EXPORT }, 59 { "r8", KREG_R8, MDB_TGT_R_EXPORT }, 60 { "r9", KREG_R9, MDB_TGT_R_EXPORT }, 61 { "rax", KREG_RAX, MDB_TGT_R_EXPORT }, 62 { "rbx", KREG_RBX, MDB_TGT_R_EXPORT }, 63 { "rbp", KREG_RBP, MDB_TGT_R_EXPORT }, 64 { "r10", KREG_R10, MDB_TGT_R_EXPORT }, 65 { "r11", KREG_R11, MDB_TGT_R_EXPORT }, 66 { "r12", KREG_R12, MDB_TGT_R_EXPORT }, 67 { "r13", KREG_R13, MDB_TGT_R_EXPORT }, 68 { "r14", KREG_R14, MDB_TGT_R_EXPORT }, 69 { "r15", KREG_R15, MDB_TGT_R_EXPORT }, 70 { "ds", KREG_DS, MDB_TGT_R_EXPORT }, 71 { "es", KREG_ES, MDB_TGT_R_EXPORT }, 72 { "fs", KREG_FS, MDB_TGT_R_EXPORT }, 73 { "gs", KREG_GS, MDB_TGT_R_EXPORT }, 74 { "trapno", KREG_TRAPNO, MDB_TGT_R_EXPORT | MDB_TGT_R_PRIV }, 75 { "err", KREG_ERR, MDB_TGT_R_EXPORT | MDB_TGT_R_PRIV }, 76 { "rip", KREG_RIP, MDB_TGT_R_EXPORT }, 77 { "cs", KREG_CS, MDB_TGT_R_EXPORT }, 78 { "rflags", KREG_RFLAGS, MDB_TGT_R_EXPORT }, 79 { "rsp", KREG_RSP, MDB_TGT_R_EXPORT }, 80 { "ss", KREG_SS, MDB_TGT_R_EXPORT }, 81 { NULL, 0, 0 } 82 }; 83 84 void 85 mdb_amd64_printregs(const mdb_tgt_gregset_t *gregs) 86 { 87 const kreg_t *kregs = &gregs->kregs[0]; 88 kreg_t rflags = kregs[KREG_RFLAGS]; 89 90 #define GETREG2(x) ((uintptr_t)kregs[(x)]), ((uintptr_t)kregs[(x)]) 91 92 mdb_printf("%%rax = 0x%0?p %15A %%r9 = 0x%0?p %A\n", 93 GETREG2(KREG_RAX), GETREG2(KREG_R9)); 94 mdb_printf("%%rbx = 0x%0?p %15A %%r10 = 0x%0?p %A\n", 95 GETREG2(KREG_RBX), GETREG2(KREG_R10)); 96 mdb_printf("%%rcx = 0x%0?p %15A %%r11 = 0x%0?p %A\n", 97 GETREG2(KREG_RCX), GETREG2(KREG_R11)); 98 mdb_printf("%%rdx = 0x%0?p %15A %%r12 = 0x%0?p %A\n", 99 GETREG2(KREG_RDX), GETREG2(KREG_R12)); 100 mdb_printf("%%rsi = 0x%0?p %15A %%r13 = 0x%0?p %A\n", 101 GETREG2(KREG_RSI), GETREG2(KREG_R13)); 102 mdb_printf("%%rdi = 0x%0?p %15A %%r14 = 0x%0?p %A\n", 103 GETREG2(KREG_RDI), GETREG2(KREG_R14)); 104 mdb_printf("%%r8 = 0x%0?p %15A %%r15 = 0x%0?p %A\n\n", 105 GETREG2(KREG_R8), GETREG2(KREG_R15)); 106 107 mdb_printf("%%rip = 0x%0?p %A\n", GETREG2(KREG_RIP)); 108 mdb_printf("%%rbp = 0x%0?p\n", kregs[KREG_RBP]); 109 mdb_printf("%%rsp = 0x%0?p\n", kregs[KREG_RSP]); 110 111 mdb_printf("%%rflags = 0x%08x\n", rflags); 112 113 mdb_printf(" id=%u vip=%u vif=%u ac=%u vm=%u rf=%u nt=%u iopl=0x%x\n", 114 (rflags & KREG_EFLAGS_ID_MASK) >> KREG_EFLAGS_ID_SHIFT, 115 (rflags & KREG_EFLAGS_VIP_MASK) >> KREG_EFLAGS_VIP_SHIFT, 116 (rflags & KREG_EFLAGS_VIF_MASK) >> KREG_EFLAGS_VIF_SHIFT, 117 (rflags & KREG_EFLAGS_AC_MASK) >> KREG_EFLAGS_AC_SHIFT, 118 (rflags & KREG_EFLAGS_VM_MASK) >> KREG_EFLAGS_VM_SHIFT, 119 (rflags & KREG_EFLAGS_RF_MASK) >> KREG_EFLAGS_RF_SHIFT, 120 (rflags & KREG_EFLAGS_NT_MASK) >> KREG_EFLAGS_NT_SHIFT, 121 (rflags & KREG_EFLAGS_IOPL_MASK) >> KREG_EFLAGS_IOPL_SHIFT); 122 123 mdb_printf(" status=<%s,%s,%s,%s,%s,%s,%s,%s,%s>\n\n", 124 (rflags & KREG_EFLAGS_OF_MASK) ? "OF" : "of", 125 (rflags & KREG_EFLAGS_DF_MASK) ? "DF" : "df", 126 (rflags & KREG_EFLAGS_IF_MASK) ? "IF" : "if", 127 (rflags & KREG_EFLAGS_TF_MASK) ? "TF" : "tf", 128 (rflags & KREG_EFLAGS_SF_MASK) ? "SF" : "sf", 129 (rflags & KREG_EFLAGS_ZF_MASK) ? "ZF" : "zf", 130 (rflags & KREG_EFLAGS_AF_MASK) ? "AF" : "af", 131 (rflags & KREG_EFLAGS_PF_MASK) ? "PF" : "pf", 132 (rflags & KREG_EFLAGS_CF_MASK) ? "CF" : "cf"); 133 134 mdb_printf("%24s%%cs = 0x%04x\t%%ds = 0x%04x\t%%es = 0x%04x\n", 135 " ", kregs[KREG_CS], kregs[KREG_DS], kregs[KREG_ES]); 136 137 mdb_printf("%%trapno = 0x%x\t\t%%fs = 0x%04x\t%%gs = 0x%04x\n", 138 kregs[KREG_TRAPNO], (kregs[KREG_FS] & 0xffff), 139 (kregs[KREG_GS] & 0xffff)); 140 mdb_printf(" %%err = 0x%x\n", kregs[KREG_ERR]); 141 } 142 143 /* 144 * We expect all proper Solaris core files to have STACK_ALIGN-aligned stacks. 145 * Hence the name. However, if the core file resulted from a 146 * hypervisor-initiated panic, the hypervisor's frames may only be 64-bit 147 * aligned instead of 128. 148 */ 149 static int 150 fp_is_aligned(uintptr_t fp, int xpv_panic) 151 { 152 if (!xpv_panic && (fp & (STACK_ALIGN -1))) 153 return (0); 154 if ((fp & sizeof (uintptr_t) - 1)) 155 return (0); 156 return (1); 157 } 158 159 int 160 mdb_amd64_kvm_stack_iter(mdb_tgt_t *t, const mdb_tgt_gregset_t *gsp, 161 mdb_tgt_stack_f *func, void *arg) 162 { 163 mdb_tgt_gregset_t gregs; 164 kreg_t *kregs = &gregs.kregs[0]; 165 int got_pc = (gsp->kregs[KREG_RIP] != 0); 166 uint_t argc, reg_argc; 167 long fr_argv[32]; 168 int start_index; /* index to save_instr where to start comparison */ 169 int i; 170 171 struct { 172 uintptr_t fr_savfp; 173 uintptr_t fr_savpc; 174 } fr; 175 176 uintptr_t fp = gsp->kregs[KREG_RBP]; 177 uintptr_t pc = gsp->kregs[KREG_RIP]; 178 uintptr_t lastfp; 179 180 ssize_t size; 181 ssize_t insnsize; 182 uint8_t ins[SAVEARGS_INSN_SEQ_LEN]; 183 184 GElf_Sym s; 185 mdb_syminfo_t sip; 186 mdb_ctf_funcinfo_t mfp; 187 int xpv_panic = 0; 188 #ifndef _KMDB 189 int xp; 190 191 if ((mdb_readsym(&xp, sizeof (xp), "xpv_panicking") != -1) && (xp > 0)) 192 xpv_panic = 1; 193 #endif 194 195 bcopy(gsp, &gregs, sizeof (gregs)); 196 197 while (fp != 0) { 198 int args_style = 0; 199 200 if (!fp_is_aligned(fp, xpv_panic)) 201 return (set_errno(EMDB_STKALIGN)); 202 203 if (mdb_tgt_vread(t, &fr, sizeof (fr), fp) != sizeof (fr)) 204 return (-1); /* errno has been set for us */ 205 206 if ((mdb_tgt_lookup_by_addr(t, pc, MDB_TGT_SYM_FUZZY, 207 NULL, 0, &s, &sip) == 0) && 208 (mdb_ctf_func_info(&s, &sip, &mfp) == 0)) { 209 int return_type = mdb_ctf_type_kind(mfp.mtf_return); 210 mdb_ctf_id_t args_types[5]; 211 212 argc = mfp.mtf_argc; 213 214 /* 215 * If the function returns a structure or union 216 * greater than 16 bytes in size %rdi contains the 217 * address in which to store the return value rather 218 * than for an argument. 219 */ 220 if ((return_type == CTF_K_STRUCT || 221 return_type == CTF_K_UNION) && 222 mdb_ctf_type_size(mfp.mtf_return) > 16) 223 start_index = 1; 224 else 225 start_index = 0; 226 227 /* 228 * If any of the first 5 arguments are a structure 229 * less than 16 bytes in size, it will be passed 230 * spread across two argument registers, and we will 231 * not cope. 232 */ 233 if (mdb_ctf_func_args(&mfp, 5, args_types) == CTF_ERR) 234 argc = 0; 235 236 for (i = 0; i < MIN(5, argc); i++) { 237 int t = mdb_ctf_type_kind(args_types[i]); 238 239 if (((t == CTF_K_STRUCT) || 240 (t == CTF_K_UNION)) && 241 mdb_ctf_type_size(args_types[i]) <= 16) { 242 argc = 0; 243 break; 244 } 245 } 246 } else { 247 argc = 0; 248 } 249 250 /* 251 * The number of instructions to search for argument saving is 252 * limited such that only instructions prior to %pc are 253 * considered such that we never read arguments from a 254 * function where the saving code has not in fact yet 255 * executed. 256 */ 257 insnsize = MIN(MIN(s.st_size, SAVEARGS_INSN_SEQ_LEN), 258 pc - s.st_value); 259 260 if (mdb_tgt_vread(t, ins, insnsize, s.st_value) != insnsize) 261 argc = 0; 262 263 if ((argc != 0) && 264 ((args_style = saveargs_has_args(ins, insnsize, argc, 265 start_index)) != SAVEARGS_NO_ARGS)) { 266 /* Up to 6 arguments are passed via registers */ 267 reg_argc = MIN((6 - start_index), mfp.mtf_argc); 268 size = reg_argc * sizeof (long); 269 270 /* 271 * If Studio pushed a structure return address as an 272 * argument, we need to read one more argument than 273 * actually exists (the addr) to make everything line 274 * up. 275 */ 276 if (args_style == SAVEARGS_STRUCT_ARGS) 277 size += sizeof (long); 278 279 if (mdb_tgt_vread(t, fr_argv, size, (fp - size)) 280 != size) 281 return (-1); /* errno has been set for us */ 282 283 /* 284 * Arrange the arguments in the right order for 285 * printing. 286 */ 287 for (i = 0; i < (reg_argc / 2); i++) { 288 long t = fr_argv[i]; 289 290 fr_argv[i] = fr_argv[reg_argc - i - 1]; 291 fr_argv[reg_argc - i - 1] = t; 292 } 293 294 if (argc > reg_argc) { 295 size = MIN((argc - reg_argc) * sizeof (long), 296 sizeof (fr_argv) - 297 (reg_argc * sizeof (long))); 298 299 if (mdb_tgt_vread(t, &fr_argv[reg_argc], size, 300 fp + sizeof (fr)) != size) 301 return (-1); /* errno has been set */ 302 } 303 } else { 304 argc = 0; 305 } 306 307 if (got_pc && func(arg, pc, argc, fr_argv, &gregs) != 0) 308 break; 309 310 kregs[KREG_RSP] = kregs[KREG_RBP]; 311 312 lastfp = fp; 313 fp = fr.fr_savfp; 314 /* 315 * The Xen hypervisor marks a stack frame as belonging to 316 * an exception by inverting the bits of the pointer to 317 * that frame. We attempt to identify these frames by 318 * inverting the pointer and seeing if it is within 0xfff 319 * bytes of the last frame. 320 */ 321 if (xpv_panic) 322 if ((fp != 0) && (fp < lastfp) && 323 ((lastfp ^ ~fp) < 0xfff)) 324 fp = ~fp; 325 326 kregs[KREG_RBP] = fp; 327 kregs[KREG_RIP] = pc = fr.fr_savpc; 328 329 got_pc = (pc != 0); 330 } 331 332 return (0); 333 } 334 335 /* 336 * Determine the return address for the current frame. Typically this is the 337 * fr_savpc value from the current frame, but we also perform some special 338 * handling to see if we are stopped on one of the first two instructions of 339 * a typical function prologue, in which case %rbp will not be set up yet. 340 */ 341 int 342 mdb_amd64_step_out(mdb_tgt_t *t, uintptr_t *p, kreg_t pc, kreg_t fp, kreg_t sp, 343 mdb_instr_t curinstr) 344 { 345 struct frame fr; 346 GElf_Sym s; 347 char buf[1]; 348 349 enum { 350 M_PUSHQ_RBP = 0x55, /* pushq %rbp */ 351 M_REX_W = 0x48, /* REX prefix with only W set */ 352 M_MOVL_RBP = 0x8b /* movq %rsp, %rbp with prefix */ 353 }; 354 355 if (mdb_tgt_lookup_by_addr(t, pc, MDB_TGT_SYM_FUZZY, 356 buf, 0, &s, NULL) == 0) { 357 if (pc == s.st_value && curinstr == M_PUSHQ_RBP) 358 fp = sp - 8; 359 else if (pc == s.st_value + 1 && curinstr == M_REX_W) { 360 if (mdb_tgt_vread(t, &curinstr, sizeof (curinstr), 361 pc + 1) == sizeof (curinstr) && curinstr == 362 M_MOVL_RBP) 363 fp = sp; 364 } 365 } 366 367 if (mdb_tgt_vread(t, &fr, sizeof (fr), fp) == sizeof (fr)) { 368 *p = fr.fr_savpc; 369 return (0); 370 } 371 372 return (-1); /* errno is set for us */ 373 } 374 375 /*ARGSUSED*/ 376 int 377 mdb_amd64_next(mdb_tgt_t *t, uintptr_t *p, kreg_t pc, mdb_instr_t curinstr) 378 { 379 mdb_tgt_addr_t npc; 380 mdb_tgt_addr_t callpc; 381 382 enum { 383 M_CALL_REL = 0xe8, /* call near with relative displacement */ 384 M_CALL_REG = 0xff, /* call near indirect or call far register */ 385 386 M_REX_LO = 0x40, 387 M_REX_HI = 0x4f 388 }; 389 390 /* 391 * If the opcode is a near call with relative displacement, assume the 392 * displacement is a rel32 from the next instruction. 393 */ 394 if (curinstr == M_CALL_REL) { 395 *p = pc + sizeof (mdb_instr_t) + sizeof (uint32_t); 396 return (0); 397 } 398 399 /* Skip the rex prefix, if any */ 400 callpc = pc; 401 while (curinstr >= M_REX_LO && curinstr <= M_REX_HI) { 402 if (mdb_tgt_vread(t, &curinstr, sizeof (curinstr), ++callpc) != 403 sizeof (curinstr)) 404 return (-1); /* errno is set for us */ 405 } 406 407 if (curinstr != M_CALL_REG) { 408 /* It's not a call */ 409 return (set_errno(EAGAIN)); 410 } 411 412 if ((npc = mdb_dis_nextins(mdb.m_disasm, t, MDB_TGT_AS_VIRT, pc)) == pc) 413 return (-1); /* errno is set for us */ 414 415 *p = npc; 416 return (0); 417 } 418 419 /*ARGSUSED*/ 420 int 421 mdb_amd64_kvm_frame(void *arglim, uintptr_t pc, uint_t argc, const long *argv, 422 const mdb_tgt_gregset_t *gregs) 423 { 424 argc = MIN(argc, (uintptr_t)arglim); 425 mdb_printf("%a(", pc); 426 427 if (argc != 0) { 428 mdb_printf("%lr", *argv++); 429 for (argc--; argc != 0; argc--) 430 mdb_printf(", %lr", *argv++); 431 } 432 433 mdb_printf(")\n"); 434 return (0); 435 } 436 437 int 438 mdb_amd64_kvm_framev(void *arglim, uintptr_t pc, uint_t argc, const long *argv, 439 const mdb_tgt_gregset_t *gregs) 440 { 441 /* 442 * Historically adb limited stack trace argument display to a fixed- 443 * size number of arguments since no symbolic debugging info existed. 444 * On amd64 we can detect the true number of saved arguments so only 445 * respect an arglim of zero; otherwise display the entire argv[]. 446 */ 447 if (arglim == 0) 448 argc = 0; 449 450 mdb_printf("%0?lr %a(", gregs->kregs[KREG_RBP], pc); 451 452 if (argc != 0) { 453 mdb_printf("%lr", *argv++); 454 for (argc--; argc != 0; argc--) 455 mdb_printf(", %lr", *argv++); 456 } 457 458 mdb_printf(")\n"); 459 return (0); 460 } 461