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, Version 1.0 only
   6  * (the "License").  You may not use this file except in compliance
   7  * with the License.
   8  *
   9  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
  10  * or http://www.opensolaris.org/os/licensing.
  11  * See the License for the specific language governing permissions
  12  * and limitations under the License.
  13  *
  14  * When distributing Covered Code, include this CDDL HEADER in each
  15  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
  16  * If applicable, add the following below this CDDL HEADER, with the
  17  * fields enclosed by brackets "[]" replaced with your own identifying
  18  * information: Portions Copyright [yyyy] [name of copyright owner]
  19  *
  20  * CDDL HEADER END
  21  */
  22 /*
  23  * Copyright 2005 Sun Microsystems, Inc.  All rights reserved.
  24  * Use is subject to license terms.
  25  */
  26 /*
  27  * Copyright (c) 2013 by Delphix. All rights reserved.
  28  * Copyright (c) 2013 Joyent, Inc. All rights reserved.
  29  */
  30 
  31 #include <sys/types.h>
  32 #include <strings.h>
  33 #include <stdlib.h>
  34 #include <assert.h>
  35 
  36 #include <dt_impl.h>
  37 #include <dt_parser.h>
  38 #include <dt_as.h>
  39 
  40 void
  41 dt_irlist_create(dt_irlist_t *dlp)
  42 {
  43         bzero(dlp, sizeof (dt_irlist_t));
  44         dlp->dl_label = 1;
  45 }
  46 
  47 void
  48 dt_irlist_destroy(dt_irlist_t *dlp)
  49 {
  50         dt_irnode_t *dip, *nip;
  51 
  52         for (dip = dlp->dl_list; dip != NULL; dip = nip) {
  53                 nip = dip->di_next;
  54                 free(dip);
  55         }
  56 }
  57 
  58 void
  59 dt_irlist_append(dt_irlist_t *dlp, dt_irnode_t *dip)
  60 {
  61         if (dlp->dl_last != NULL)
  62                 dlp->dl_last->di_next = dip;
  63         else
  64                 dlp->dl_list = dip;
  65 
  66         dlp->dl_last = dip;
  67 
  68         if (dip->di_label == DT_LBL_NONE || dip->di_instr != DIF_INSTR_NOP)
  69                 dlp->dl_len++; /* don't count forward refs in instr count */
  70 }
  71 
  72 uint_t
  73 dt_irlist_label(dt_irlist_t *dlp)
  74 {
  75         return (dlp->dl_label++);
  76 }
  77 
  78 /*ARGSUSED*/
  79 static int
  80 dt_countvar(dt_idhash_t *dhp, dt_ident_t *idp, void *data)
  81 {
  82         size_t *np = data;
  83 
  84         if (idp->di_flags & (DT_IDFLG_DIFR | DT_IDFLG_DIFW))
  85                 (*np)++; /* include variable in vartab */
  86 
  87         return (0);
  88 }
  89 
  90 /*ARGSUSED*/
  91 static int
  92 dt_copyvar(dt_idhash_t *dhp, dt_ident_t *idp, void *data)
  93 {
  94         dt_pcb_t *pcb = data;
  95         dtrace_difv_t *dvp;
  96         ssize_t stroff;
  97         dt_node_t dn;
  98 
  99         if (!(idp->di_flags & (DT_IDFLG_DIFR | DT_IDFLG_DIFW)))
 100                 return (0); /* omit variable from vartab */
 101 
 102         dvp = &pcb->pcb_difo->dtdo_vartab[pcb->pcb_asvidx++];
 103         stroff = dt_strtab_insert(pcb->pcb_strtab, idp->di_name);
 104 
 105         if (stroff == -1L)
 106                 longjmp(pcb->pcb_jmpbuf, EDT_NOMEM);
 107         if (stroff > DIF_STROFF_MAX)
 108                 longjmp(pcb->pcb_jmpbuf, EDT_STR2BIG);
 109 
 110         dvp->dtdv_name = (uint_t)stroff;
 111         dvp->dtdv_id = idp->di_id;
 112         dvp->dtdv_flags = 0;
 113 
 114         dvp->dtdv_kind = (idp->di_kind == DT_IDENT_ARRAY) ?
 115             DIFV_KIND_ARRAY : DIFV_KIND_SCALAR;
 116 
 117         if (idp->di_flags & DT_IDFLG_LOCAL)
 118                 dvp->dtdv_scope = DIFV_SCOPE_LOCAL;
 119         else if (idp->di_flags & DT_IDFLG_TLS)
 120                 dvp->dtdv_scope = DIFV_SCOPE_THREAD;
 121         else
 122                 dvp->dtdv_scope = DIFV_SCOPE_GLOBAL;
 123 
 124         if (idp->di_flags & DT_IDFLG_DIFR)
 125                 dvp->dtdv_flags |= DIFV_F_REF;
 126         if (idp->di_flags & DT_IDFLG_DIFW)
 127                 dvp->dtdv_flags |= DIFV_F_MOD;
 128 
 129         bzero(&dn, sizeof (dn));
 130         dt_node_type_assign(&dn, idp->di_ctfp, idp->di_type, B_FALSE);
 131         dt_node_diftype(pcb->pcb_hdl, &dn, &dvp->dtdv_type);
 132 
 133         idp->di_flags &= ~(DT_IDFLG_DIFR | DT_IDFLG_DIFW);
 134         return (0);
 135 }
 136 
 137 static ssize_t
 138 dt_copystr(const char *s, size_t n, size_t off, dt_pcb_t *pcb)
 139 {
 140         bcopy(s, pcb->pcb_difo->dtdo_strtab + off, n);
 141         return (n);
 142 }
 143 
 144 /*
 145  * Rewrite the xlate/xlarg instruction at dtdo_buf[i] so that the instruction's
 146  * xltab index reflects the offset 'xi' of the assigned dtdo_xlmtab[] location.
 147  * We track the cumulative references to translators and members in the pcb's
 148  * pcb_asxrefs[] array, a two-dimensional array of bitmaps indexed by the
 149  * global translator id and then by the corresponding translator member id.
 150  */
 151 static void
 152 dt_as_xlate(dt_pcb_t *pcb, dtrace_difo_t *dp,
 153     uint_t i, uint_t xi, dt_node_t *dnp)
 154 {
 155         dtrace_hdl_t *dtp = pcb->pcb_hdl;
 156         dt_xlator_t *dxp = dnp->dn_membexpr->dn_xlator;
 157 
 158         assert(i < dp->dtdo_len);
 159         assert(xi < dp->dtdo_xlmlen);
 160 
 161         assert(dnp->dn_kind == DT_NODE_MEMBER);
 162         assert(dnp->dn_membexpr->dn_kind == DT_NODE_XLATOR);
 163 
 164         assert(dxp->dx_id < dtp->dt_xlatorid);
 165         assert(dnp->dn_membid < dxp->dx_nmembers);
 166 
 167         if (pcb->pcb_asxrefs == NULL) {
 168                 pcb->pcb_asxreflen = dtp->dt_xlatorid;
 169                 pcb->pcb_asxrefs =
 170                     dt_zalloc(dtp, sizeof (ulong_t *) * pcb->pcb_asxreflen);
 171                 if (pcb->pcb_asxrefs == NULL)
 172                         longjmp(pcb->pcb_jmpbuf, EDT_NOMEM);
 173         }
 174 
 175         if (pcb->pcb_asxrefs[dxp->dx_id] == NULL) {
 176                 pcb->pcb_asxrefs[dxp->dx_id] =
 177                     dt_zalloc(dtp, BT_SIZEOFMAP(dxp->dx_nmembers));
 178                 if (pcb->pcb_asxrefs[dxp->dx_id] == NULL)
 179                         longjmp(pcb->pcb_jmpbuf, EDT_NOMEM);
 180         }
 181 
 182         dp->dtdo_buf[i] = DIF_INSTR_XLATE(
 183             DIF_INSTR_OP(dp->dtdo_buf[i]), xi, DIF_INSTR_RD(dp->dtdo_buf[i]));
 184 
 185         BT_SET(pcb->pcb_asxrefs[dxp->dx_id], dnp->dn_membid);
 186         dp->dtdo_xlmtab[xi] = dnp;
 187 }
 188 
 189 static void
 190 dt_as_undef(const dt_ident_t *idp, uint_t offset)
 191 {
 192         const char *kind, *mark = (idp->di_flags & DT_IDFLG_USER) ? "``" : "`";
 193         const dtrace_syminfo_t *dts = idp->di_data;
 194 
 195         if (idp->di_flags & DT_IDFLG_USER)
 196                 kind = "user";
 197         else if (idp->di_flags & DT_IDFLG_PRIM)
 198                 kind = "primary kernel";
 199         else
 200                 kind = "loadable kernel";
 201 
 202         yylineno = idp->di_lineno;
 203 
 204         xyerror(D_ASRELO, "relocation remains against %s symbol %s%s%s (offset "
 205             "0x%x)\n", kind, dts->dts_object, mark, dts->dts_name, offset);
 206 }
 207 
 208 dtrace_difo_t *
 209 dt_as(dt_pcb_t *pcb)
 210 {
 211         dtrace_hdl_t *dtp = pcb->pcb_hdl;
 212         dt_irlist_t *dlp = &pcb->pcb_ir;
 213         uint_t *labels = NULL;
 214         dt_irnode_t *dip;
 215         dtrace_difo_t *dp;
 216         dt_ident_t *idp;
 217 
 218         size_t n = 0;
 219         uint_t i;
 220 
 221         uint_t kmask, kbits, umask, ubits;
 222         uint_t krel = 0, urel = 0, xlrefs = 0;
 223 
 224         /*
 225          * Select bitmasks based upon the desired symbol linking policy.  We
 226          * test (di_extern->di_flags & xmask) == xbits to determine if the
 227          * symbol should have a relocation entry generated in the loop below.
 228          *
 229          * DT_LINK_KERNEL = kernel symbols static, user symbols dynamic
 230          * DT_LINK_PRIMARY = primary kernel symbols static, others dynamic
 231          * DT_LINK_DYNAMIC = all symbols dynamic
 232          * DT_LINK_STATIC = all symbols static
 233          *
 234          * By 'static' we mean that we use the symbol's value at compile-time
 235          * in the final DIF.  By 'dynamic' we mean that we create a relocation
 236          * table entry for the symbol's value so it can be relocated later.
 237          */
 238         switch (dtp->dt_linkmode) {
 239         case DT_LINK_KERNEL:
 240                 kmask = 0;
 241                 kbits = -1u;
 242                 umask = DT_IDFLG_USER;
 243                 ubits = DT_IDFLG_USER;
 244                 break;
 245         case DT_LINK_PRIMARY:
 246                 kmask = DT_IDFLG_USER | DT_IDFLG_PRIM;
 247                 kbits = 0;
 248                 umask = DT_IDFLG_USER;
 249                 ubits = DT_IDFLG_USER;
 250                 break;
 251         case DT_LINK_DYNAMIC:
 252                 kmask = DT_IDFLG_USER;
 253                 kbits = 0;
 254                 umask = DT_IDFLG_USER;
 255                 ubits = DT_IDFLG_USER;
 256                 break;
 257         case DT_LINK_STATIC:
 258                 kmask = umask = 0;
 259                 kbits = ubits = -1u;
 260                 break;
 261         default:
 262                 xyerror(D_UNKNOWN, "internal error -- invalid link mode %u\n",
 263                     dtp->dt_linkmode);
 264         }
 265 
 266         assert(pcb->pcb_difo == NULL);
 267         pcb->pcb_difo = dt_zalloc(dtp, sizeof (dtrace_difo_t));
 268 
 269         if ((dp = pcb->pcb_difo) == NULL)
 270                 longjmp(pcb->pcb_jmpbuf, EDT_NOMEM);
 271 
 272         dp->dtdo_buf = dt_alloc(dtp, sizeof (dif_instr_t) * dlp->dl_len);
 273 
 274         if (dp->dtdo_buf == NULL)
 275                 longjmp(pcb->pcb_jmpbuf, EDT_NOMEM);
 276 
 277         if ((labels = dt_alloc(dtp, sizeof (uint_t) * dlp->dl_label)) == NULL)
 278                 longjmp(pcb->pcb_jmpbuf, EDT_NOMEM);
 279 
 280         /*
 281          * Make an initial pass through the instruction list, filling in the
 282          * instruction buffer with valid instructions and skipping labeled nops.
 283          * While doing this, we also fill in our labels[] translation table
 284          * and we count up the number of relocation table entries we will need.
 285          */
 286         for (i = 0, dip = dlp->dl_list; dip != NULL; dip = dip->di_next) {
 287                 if (dip->di_label != DT_LBL_NONE)
 288                         labels[dip->di_label] = i;
 289 
 290                 if (dip->di_label == DT_LBL_NONE ||
 291                     dip->di_instr != DIF_INSTR_NOP)
 292                         dp->dtdo_buf[i++] = dip->di_instr;
 293 
 294                 if (dip->di_extern == NULL)
 295                         continue; /* no external references needed */
 296 
 297                 switch (DIF_INSTR_OP(dip->di_instr)) {
 298                 case DIF_OP_SETX:
 299                         idp = dip->di_extern;
 300                         if ((idp->di_flags & kmask) == kbits)
 301                                 krel++;
 302                         else if ((idp->di_flags & umask) == ubits)
 303                                 urel++;
 304                         break;
 305                 case DIF_OP_XLATE:
 306                 case DIF_OP_XLARG:
 307                         xlrefs++;
 308                         break;
 309                 default:
 310                         xyerror(D_UNKNOWN, "unexpected assembler relocation "
 311                             "for opcode 0x%x\n", DIF_INSTR_OP(dip->di_instr));
 312                 }
 313         }
 314 
 315         assert(i == dlp->dl_len);
 316         dp->dtdo_len = dlp->dl_len;
 317 
 318         /*
 319          * Make a second pass through the instructions, relocating each branch
 320          * label to the index of the final instruction in the buffer and noting
 321          * any other instruction-specific DIFO flags such as dtdo_destructive.
 322          */
 323         for (i = 0; i < dp->dtdo_len; i++) {
 324                 dif_instr_t instr = dp->dtdo_buf[i];
 325                 uint_t op = DIF_INSTR_OP(instr);
 326 
 327                 if (op == DIF_OP_CALL) {
 328                         if (DIF_INSTR_SUBR(instr) == DIF_SUBR_COPYOUT ||
 329                             DIF_INSTR_SUBR(instr) == DIF_SUBR_COPYOUTSTR)
 330                                 dp->dtdo_destructive = 1;
 331                         continue;
 332                 }
 333 
 334                 if (op >= DIF_OP_BA && op <= DIF_OP_BLEU) {
 335                         assert(DIF_INSTR_LABEL(instr) < dlp->dl_label);
 336                         dp->dtdo_buf[i] = DIF_INSTR_BRANCH(op,
 337                             labels[DIF_INSTR_LABEL(instr)]);
 338                 }
 339         }
 340 
 341         dt_free(dtp, labels);
 342         pcb->pcb_asvidx = 0;
 343 
 344         /*
 345          * Allocate memory for the appropriate number of variable records and
 346          * then fill in each variable record.  As we populate the variable
 347          * table we insert the corresponding variable names into the strtab.
 348          */
 349         (void) dt_idhash_iter(dtp->dt_tls, dt_countvar, &n);
 350         (void) dt_idhash_iter(dtp->dt_globals, dt_countvar, &n);
 351         (void) dt_idhash_iter(pcb->pcb_locals, dt_countvar, &n);
 352 
 353         if (n != 0) {
 354                 dp->dtdo_vartab = dt_alloc(dtp, n * sizeof (dtrace_difv_t));
 355                 dp->dtdo_varlen = (uint32_t)n;
 356 
 357                 if (dp->dtdo_vartab == NULL)
 358                         longjmp(pcb->pcb_jmpbuf, EDT_NOMEM);
 359 
 360                 (void) dt_idhash_iter(dtp->dt_tls, dt_copyvar, pcb);
 361                 (void) dt_idhash_iter(dtp->dt_globals, dt_copyvar, pcb);
 362                 (void) dt_idhash_iter(pcb->pcb_locals, dt_copyvar, pcb);
 363         }
 364 
 365         /*
 366          * Allocate memory for the appropriate number of relocation table
 367          * entries based upon our kernel and user counts from the first pass.
 368          */
 369         if (krel != 0) {
 370                 dp->dtdo_kreltab = dt_alloc(dtp,
 371                     krel * sizeof (dof_relodesc_t));
 372                 dp->dtdo_krelen = krel;
 373 
 374                 if (dp->dtdo_kreltab == NULL)
 375                         longjmp(pcb->pcb_jmpbuf, EDT_NOMEM);
 376         }
 377 
 378         if (urel != 0) {
 379                 dp->dtdo_ureltab = dt_alloc(dtp,
 380                     urel * sizeof (dof_relodesc_t));
 381                 dp->dtdo_urelen = urel;
 382 
 383                 if (dp->dtdo_ureltab == NULL)
 384                         longjmp(pcb->pcb_jmpbuf, EDT_NOMEM);
 385         }
 386 
 387         if (xlrefs != 0) {
 388                 dp->dtdo_xlmtab = dt_zalloc(dtp, sizeof (dt_node_t *) * xlrefs);
 389                 dp->dtdo_xlmlen = xlrefs;
 390 
 391                 if (dp->dtdo_xlmtab == NULL)
 392                         longjmp(pcb->pcb_jmpbuf, EDT_NOMEM);
 393         }
 394 
 395         /*
 396          * If any relocations are needed, make another pass through the
 397          * instruction list and fill in the relocation table entries.
 398          */
 399         if (krel + urel + xlrefs != 0) {
 400                 uint_t knodef = pcb->pcb_cflags & DTRACE_C_KNODEF;
 401                 uint_t unodef = pcb->pcb_cflags & DTRACE_C_UNODEF;
 402 
 403                 dof_relodesc_t *krp = dp->dtdo_kreltab;
 404                 dof_relodesc_t *urp = dp->dtdo_ureltab;
 405                 dt_node_t **xlp = dp->dtdo_xlmtab;
 406 
 407                 i = 0; /* dtdo_buf[] index */
 408 
 409                 for (dip = dlp->dl_list; dip != NULL; dip = dip->di_next) {
 410                         dof_relodesc_t *rp;
 411                         ssize_t soff;
 412                         uint_t nodef;
 413 
 414                         if (dip->di_label != DT_LBL_NONE &&
 415                             dip->di_instr == DIF_INSTR_NOP)
 416                                 continue; /* skip label declarations */
 417 
 418                         i++; /* advance dtdo_buf[] index */
 419 
 420                         if (DIF_INSTR_OP(dip->di_instr) == DIF_OP_XLATE ||
 421                             DIF_INSTR_OP(dip->di_instr) == DIF_OP_XLARG) {
 422                                 assert(dp->dtdo_buf[i - 1] == dip->di_instr);
 423                                 dt_as_xlate(pcb, dp, i - 1, (uint_t)
 424                                     (xlp++ - dp->dtdo_xlmtab), dip->di_extern);
 425                                 continue;
 426                         }
 427 
 428                         if ((idp = dip->di_extern) == NULL)
 429                                 continue; /* no relocation entry needed */
 430 
 431                         if ((idp->di_flags & kmask) == kbits) {
 432                                 nodef = knodef;
 433                                 rp = krp++;
 434                         } else if ((idp->di_flags & umask) == ubits) {
 435                                 nodef = unodef;
 436                                 rp = urp++;
 437                         } else
 438                                 continue;
 439 
 440                         if (!nodef)
 441                                 dt_as_undef(idp, i);
 442 
 443                         assert(DIF_INSTR_OP(dip->di_instr) == DIF_OP_SETX);
 444                         soff = dt_strtab_insert(pcb->pcb_strtab, idp->di_name);
 445 
 446                         if (soff == -1L)
 447                                 longjmp(pcb->pcb_jmpbuf, EDT_NOMEM);
 448                         if (soff > DIF_STROFF_MAX)
 449                                 longjmp(pcb->pcb_jmpbuf, EDT_STR2BIG);
 450 
 451                         rp->dofr_name = (dof_stridx_t)soff;
 452                         rp->dofr_type = DOF_RELO_SETX;
 453                         rp->dofr_offset = DIF_INSTR_INTEGER(dip->di_instr) *
 454                             sizeof (uint64_t);
 455                         rp->dofr_data = 0;
 456                 }
 457 
 458                 assert(krp == dp->dtdo_kreltab + dp->dtdo_krelen);
 459                 assert(urp == dp->dtdo_ureltab + dp->dtdo_urelen);
 460                 assert(xlp == dp->dtdo_xlmtab + dp->dtdo_xlmlen);
 461                 assert(i == dp->dtdo_len);
 462         }
 463 
 464         /*
 465          * Allocate memory for the compiled string table and then copy the
 466          * chunks from the string table into the final string buffer.
 467          */
 468         if ((n = dt_strtab_size(pcb->pcb_strtab)) != 0) {
 469                 if ((dp->dtdo_strtab = dt_alloc(dtp, n)) == NULL)
 470                         longjmp(pcb->pcb_jmpbuf, EDT_NOMEM);
 471 
 472                 (void) dt_strtab_write(pcb->pcb_strtab,
 473                     (dt_strtab_write_f *)dt_copystr, pcb);
 474                 dp->dtdo_strlen = (uint32_t)n;
 475         }
 476 
 477         /*
 478          * Allocate memory for the compiled integer table and then copy the
 479          * integer constants from the table into the final integer buffer.
 480          */
 481         if ((n = dt_inttab_size(pcb->pcb_inttab)) != 0) {
 482                 if ((dp->dtdo_inttab = dt_alloc(dtp,
 483                     n * sizeof (uint64_t))) == NULL)
 484                         longjmp(pcb->pcb_jmpbuf, EDT_NOMEM);
 485 
 486                 dt_inttab_write(pcb->pcb_inttab, dp->dtdo_inttab);
 487                 dp->dtdo_intlen = (uint32_t)n;
 488         }
 489 
 490         /*
 491          * Fill in the DIFO return type from the type associated with the
 492          * node saved in pcb_dret, and then clear pcb_difo and pcb_dret
 493          * now that the assembler has completed successfully.
 494          */
 495         dt_node_diftype(dtp, pcb->pcb_dret, &dp->dtdo_rtype);
 496         pcb->pcb_difo = NULL;
 497         pcb->pcb_dret = NULL;
 498 
 499         if (pcb->pcb_cflags & DTRACE_C_DIFV)
 500                 dt_dis(dp, stderr);
 501 
 502         return (dp);
 503 }