bsd/dev/dtrace/fbt.c

   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  * Copyright 2009 Sun Microsystems, Inc.  All rights reserved.
  23  * Use is subject to license terms.
  24  */
  25
  26 /* #pragma ident        "@(#)fbt.c      1.18    07/01/10 SMI" */
  27
  28 #ifdef KERNEL
  29 #ifndef _KERNEL
  30 #define _KERNEL /* Solaris vs. Darwin */
  31 #endif
  32 #endif
  33
  34 #include <mach-o/loader.h>
  35 #include <libkern/kernel_mach_header.h>
  36
  37 #include <sys/param.h>
  38 #include <sys/systm.h>
  39 #include <sys/errno.h>
  40 #include <sys/stat.h>
  41 #include <sys/ioctl.h>
  42 #include <sys/conf.h>
  43 #include <sys/fcntl.h>
  44 #include <miscfs/devfs/devfs.h>
  45 #include <pexpert/pexpert.h>
  46
  47 #include <sys/dtrace.h>
  48 #include <sys/dtrace_impl.h>
  49 #include <sys/fbt.h>
  50
  51 #include <sys/dtrace_glue.h>
  52
  53 /* #include <machine/trap.h> */
  54 struct savearea_t; /* Used anonymously */
  55 typedef kern_return_t (*perfCallback)(int, struct savearea_t *, uintptr_t *, int);
  56
  57 extern perfCallback tempDTraceTrapHook;
  58 extern kern_return_t fbt_perfCallback(int, struct savearea_t *, uintptr_t *);
  59
  60 #define FBT_ADDR2NDX(addr)      ((((uintptr_t)(addr)) >> 4) & fbt_probetab_mask)
  61 #define FBT_PROBETAB_SIZE       0x8000          /* 32k entries -- 128K total */
  62
  63 static dev_info_t               *fbt_devi;
  64 static int                              fbt_probetab_size;
  65 dtrace_provider_id_t    fbt_id;
  66 fbt_probe_t                             **fbt_probetab;
  67 int                                             fbt_probetab_mask;
  68 static int                              fbt_verbose = 0;
  69
  70 void fbt_init( void );
  71
  72 /*ARGSUSED*/
  73 static void
  74 fbt_destroy(void *arg, dtrace_id_t id, void *parg)
  75 {
  76 #pragma unused(arg,id)
  77         fbt_probe_t *fbt = parg, *next, *hash, *last;
  78         int ndx;
  79
  80         do {
  81                 /*
  82                  * Now we need to remove this probe from the fbt_probetab.
  83                  */
  84                 ndx = FBT_ADDR2NDX(fbt->fbtp_patchpoint);
  85                 last = NULL;
  86                 hash = fbt_probetab[ndx];
  87
  88                 while (hash != fbt) {
  89                         ASSERT(hash != NULL);
  90                         last = hash;
  91                         hash = hash->fbtp_hashnext;
  92                 }
  93
  94                 if (last != NULL) {
  95                         last->fbtp_hashnext = fbt->fbtp_hashnext;
  96                 } else {
  97                         fbt_probetab[ndx] = fbt->fbtp_hashnext;
  98                 }
  99
 100                 next = fbt->fbtp_next;
 101                 kmem_free(fbt, sizeof (fbt_probe_t));
 102
 103                 fbt = next;
 104         } while (fbt != NULL);
 105 }
 106
 107 /*ARGSUSED*/
 108 int
 109 fbt_enable(void *arg, dtrace_id_t id, void *parg)
 110 {
 111 #pragma unused(arg,id)
 112         fbt_probe_t *fbt = parg;
 113         struct modctl *ctl = NULL;
 114
 115     for (; fbt != NULL; fbt = fbt->fbtp_next) {
 116
 117         ctl = fbt->fbtp_ctl;
 118
 119         if (!ctl->mod_loaded) {
 120                 if (fbt_verbose) {
 121                         cmn_err(CE_NOTE, "fbt is failing for probe %s "
 122                             "(module %s unloaded)",
 123                             fbt->fbtp_name, ctl->mod_modname);
 124                 }
 125
 126                 continue;
 127         }
 128
 129         /*
 130          * Now check that our modctl has the expected load count.  If it
 131          * doesn't, this module must have been unloaded and reloaded -- and
 132          * we're not going to touch it.
 133          */
 134         if (ctl->mod_loadcnt != fbt->fbtp_loadcnt) {
 135                 if (fbt_verbose) {
 136                         cmn_err(CE_NOTE, "fbt is failing for probe %s "
 137                             "(module %s reloaded)",
 138                             fbt->fbtp_name, ctl->mod_modname);
 139                 }
 140
 141                 continue;
 142         }
 143
 144         dtrace_casptr(&tempDTraceTrapHook, NULL, fbt_perfCallback);
 145         if (tempDTraceTrapHook != (perfCallback)fbt_perfCallback) {
 146                 if (fbt_verbose) {
 147                         cmn_err(CE_NOTE, "fbt_enable is failing for probe %s "
 148                             "in module %s: tempDTraceTrapHook already occupied.",
 149                             fbt->fbtp_name, ctl->mod_modname);
 150                 }
 151                 continue;
 152         }
 153
 154         if (fbt->fbtp_currentval != fbt->fbtp_patchval) {
 155                 (void)ml_nofault_copy( (vm_offset_t)&fbt->fbtp_patchval, (vm_offset_t)fbt->fbtp_patchpoint,
 156                                                                 sizeof(fbt->fbtp_patchval));
 157                 fbt->fbtp_currentval = fbt->fbtp_patchval;
 158                 ctl->mod_nenabled++;
 159         }
 160
 161     }
 162
 163     dtrace_membar_consumer();
 164
 165     return (0);
 166 }
 167
 168 /*ARGSUSED*/
 169 static void
 170 fbt_disable(void *arg, dtrace_id_t id, void *parg)
 171 {
 172 #pragma unused(arg,id)
 173         fbt_probe_t *fbt = parg;
 174         struct modctl *ctl = NULL;
 175
 176         for (; fbt != NULL; fbt = fbt->fbtp_next) {
 177             ctl = fbt->fbtp_ctl;
 178
 179             if (!ctl->mod_loaded || (ctl->mod_loadcnt != fbt->fbtp_loadcnt))
 180                 continue;
 181
 182             if (fbt->fbtp_currentval != fbt->fbtp_savedval) {
 183                 (void)ml_nofault_copy( (vm_offset_t)&fbt->fbtp_savedval, (vm_offset_t)fbt->fbtp_patchpoint,
 184                                                                 sizeof(fbt->fbtp_savedval));
 185                 fbt->fbtp_currentval = fbt->fbtp_savedval;
 186                 ASSERT(ctl->mod_nenabled > 0);
 187                 ctl->mod_nenabled--;
 188             }
 189         }
 190         dtrace_membar_consumer();
 191 }
 192
 193 /*ARGSUSED*/
 194 static void
 195 fbt_suspend(void *arg, dtrace_id_t id, void *parg)
 196 {
 197 #pragma unused(arg,id)
 198         fbt_probe_t *fbt = parg;
 199         struct modctl *ctl = NULL;
 200
 201         for (; fbt != NULL; fbt = fbt->fbtp_next) {
 202             ctl = fbt->fbtp_ctl;
 203
 204             ASSERT(ctl->mod_nenabled > 0);
 205             if (!ctl->mod_loaded || (ctl->mod_loadcnt != fbt->fbtp_loadcnt))
 206                 continue;
 207
 208             (void)ml_nofault_copy( (vm_offset_t)&fbt->fbtp_savedval, (vm_offset_t)fbt->fbtp_patchpoint,
 209                                                                 sizeof(fbt->fbtp_savedval));
 210             fbt->fbtp_currentval = fbt->fbtp_savedval;
 211         }
 212
 213         dtrace_membar_consumer();
 214 }
 215
 216 /*ARGSUSED*/
 217 static void
 218 fbt_resume(void *arg, dtrace_id_t id, void *parg)
 219 {
 220 #pragma unused(arg,id)
 221         fbt_probe_t *fbt = parg;
 222         struct modctl *ctl = NULL;
 223
 224         for (; fbt != NULL; fbt = fbt->fbtp_next) {
 225             ctl = fbt->fbtp_ctl;
 226
 227             ASSERT(ctl->mod_nenabled > 0);
 228             if (!ctl->mod_loaded || (ctl->mod_loadcnt != fbt->fbtp_loadcnt))
 229                 continue;
 230
 231             dtrace_casptr(&tempDTraceTrapHook, NULL, fbt_perfCallback);
 232             if (tempDTraceTrapHook != (perfCallback)fbt_perfCallback) {
 233                 if (fbt_verbose) {
 234                         cmn_err(CE_NOTE, "fbt_resume is failing for probe %s "
 235                             "in module %s: tempDTraceTrapHook already occupied.",
 236                             fbt->fbtp_name, ctl->mod_modname);
 237                 }
 238                 return;
 239             }
 240
 241             (void)ml_nofault_copy( (vm_offset_t)&fbt->fbtp_patchval, (vm_offset_t)fbt->fbtp_patchpoint,
 242                                                                 sizeof(fbt->fbtp_patchval));
 243             fbt->fbtp_currentval = fbt->fbtp_patchval;
 244         }
 245
 246         dtrace_membar_consumer();
 247 }
 248
 249 #if !defined(__APPLE__)
 250 /*ARGSUSED*/
 251 static void
 252 fbt_getargdesc(void *arg, dtrace_id_t id, void *parg, dtrace_argdesc_t *desc)
 253 {
 254         fbt_probe_t *fbt = parg;
 255         struct modctl *ctl = fbt->fbtp_ctl;
 256         struct module *mp = ctl->mod_mp;
 257         ctf_file_t *fp = NULL, *pfp;
 258         ctf_funcinfo_t f;
 259         int error;
 260         ctf_id_t argv[32], type;
 261         int argc = sizeof (argv) / sizeof (ctf_id_t);
 262         const char *parent;
 263
 264         if (!ctl->mod_loaded || (ctl->mod_loadcnt != fbt->fbtp_loadcnt))
 265                 goto err;
 266
 267         if (fbt->fbtp_roffset != 0 && desc->dtargd_ndx == 0) {
 268                 (void) strlcpy(desc->dtargd_native, "int",
 269                                sizeof(desc->dtargd_native));
 270                 return;
 271         }
 272
 273         if ((fp = ctf_modopen(mp, &error)) == NULL) {
 274                 /*
 275                  * We have no CTF information for this module -- and therefore
 276                  * no args[] information.
 277                  */
 278                 goto err;
 279         }
 280
 281         /*
 282          * If we have a parent container, we must manually import it.
 283          */
 284         if ((parent = ctf_parent_name(fp)) != NULL) {
 285                 struct modctl *mp = &modules;
 286                 struct modctl *mod = NULL;
 287
 288                 /*
 289                  * We must iterate over all modules to find the module that
 290                  * is our parent.
 291                  */
 292                 do {
 293                         if (strcmp(mp->mod_modname, parent) == 0) {
 294                                 mod = mp;
 295                                 break;
 296                         }
 297                 } while ((mp = mp->mod_next) != &modules);
 298
 299                 if (mod == NULL)
 300                         goto err;
 301
 302                 if ((pfp = ctf_modopen(mod->mod_mp, &error)) == NULL) {
 303                         goto err;
 304                 }
 305
 306                 if (ctf_import(fp, pfp) != 0) {
 307                         ctf_close(pfp);
 308                         goto err;
 309                 }
 310
 311                 ctf_close(pfp);
 312         }
 313
 314         if (ctf_func_info(fp, fbt->fbtp_symndx, &f) == CTF_ERR)
 315                 goto err;
 316
 317         if (fbt->fbtp_roffset != 0) {
 318                 if (desc->dtargd_ndx > 1)
 319                         goto err;
 320
 321                 ASSERT(desc->dtargd_ndx == 1);
 322                 type = f.ctc_return;
 323         } else {
 324                 if (desc->dtargd_ndx + 1 > f.ctc_argc)
 325                         goto err;
 326
 327                 if (ctf_func_args(fp, fbt->fbtp_symndx, argc, argv) == CTF_ERR)
 328                         goto err;
 329
 330                 type = argv[desc->dtargd_ndx];
 331         }
 332
 333         if (ctf_type_name(fp, type, desc->dtargd_native,
 334             DTRACE_ARGTYPELEN) != NULL) {
 335                 ctf_close(fp);
 336                 return;
 337         }
 338 err:
 339         if (fp != NULL)
 340                 ctf_close(fp);
 341
 342         desc->dtargd_ndx = DTRACE_ARGNONE;
 343 }
 344 #endif /* __APPLE__ */
 345
 346 static dtrace_pattr_t fbt_attr = {
 347 { DTRACE_STABILITY_EVOLVING, DTRACE_STABILITY_EVOLVING, DTRACE_CLASS_ISA },
 348 { DTRACE_STABILITY_PRIVATE, DTRACE_STABILITY_PRIVATE, DTRACE_CLASS_UNKNOWN },
 349 { DTRACE_STABILITY_PRIVATE, DTRACE_STABILITY_PRIVATE, DTRACE_CLASS_UNKNOWN },
 350 { DTRACE_STABILITY_EVOLVING, DTRACE_STABILITY_EVOLVING, DTRACE_CLASS_ISA },
 351 { DTRACE_STABILITY_PRIVATE, DTRACE_STABILITY_PRIVATE, DTRACE_CLASS_ISA },
 352 };
 353
 354 static dtrace_pops_t fbt_pops = {
 355         NULL,
 356         fbt_provide_module,
 357         fbt_enable,
 358         fbt_disable,
 359         fbt_suspend,
 360         fbt_resume,
 361 #if !defined(__APPLE__)
 362         fbt_getargdesc,
 363 #else
 364         NULL, /* FIXME: where to look for xnu? */
 365 #endif /* __APPLE__ */
 366         NULL,
 367         NULL,
 368         fbt_destroy
 369 };
 370
 371 static void
 372 fbt_cleanup(dev_info_t *devi)
 373 {
 374         dtrace_invop_remove(fbt_invop);
 375         ddi_remove_minor_node(devi, NULL);
 376         kmem_free(fbt_probetab, fbt_probetab_size * sizeof (fbt_probe_t *));
 377         fbt_probetab = NULL;
 378         fbt_probetab_mask = 0;
 379 }
 380
 381 static int
 382 fbt_attach(dev_info_t *devi, ddi_attach_cmd_t cmd)
 383 {
 384         switch (cmd) {
 385         case DDI_ATTACH:
 386                 break;
 387         case DDI_RESUME:
 388                 return (DDI_SUCCESS);
 389         default:
 390                 return (DDI_FAILURE);
 391         }
 392
 393         if (fbt_probetab_size == 0)
 394                 fbt_probetab_size = FBT_PROBETAB_SIZE;
 395
 396         fbt_probetab_mask = fbt_probetab_size - 1;
 397         fbt_probetab =
 398             kmem_zalloc(fbt_probetab_size * sizeof (fbt_probe_t *), KM_SLEEP);
 399
 400         dtrace_invop_add(fbt_invop);
 401
 402 #if !defined(__APPLE__)
 403         if (ddi_create_minor_node(devi, "fbt", S_IFCHR, 0,
 404             DDI_PSEUDO, NULL) == DDI_FAILURE ||
 405             dtrace_register("fbt", &fbt_attr, DTRACE_PRIV_KERNEL, NULL,
 406             &fbt_pops, NULL, &fbt_id) != 0) {
 407                 fbt_cleanup(devi);
 408                 return (DDI_FAILURE);
 409         }
 410 #else
 411         if (ddi_create_minor_node(devi, "fbt", S_IFCHR, 0,
 412             DDI_PSEUDO, 0) == DDI_FAILURE ||
 413             dtrace_register("fbt", &fbt_attr, DTRACE_PRIV_KERNEL, NULL,
 414             &fbt_pops, NULL, &fbt_id) != 0) {
 415                 fbt_cleanup(devi);
 416                 return (DDI_FAILURE);
 417         }
 418 #endif /* __APPLE__ */
 419
 420         ddi_report_dev(devi);
 421         fbt_devi = devi;
 422
 423         return (DDI_SUCCESS);
 424 }
 425
 426 static d_open_t _fbt_open;
 427
 428 static int
 429 _fbt_open(dev_t dev, int flags, int devtype, struct proc *p)
 430 {
 431 #pragma unused(dev,flags,devtype,p)
 432         return 0;
 433 }
 434
 435 #define FBT_MAJOR  -24 /* let the kernel pick the device number */
 436
 437 /*
 438  * A struct describing which functions will get invoked for certain
 439  * actions.
 440  */
 441 static struct cdevsw fbt_cdevsw =
 442 {
 443         _fbt_open,              /* open */
 444         eno_opcl,                       /* close */
 445         eno_rdwrt,                      /* read */
 446         eno_rdwrt,                      /* write */
 447         eno_ioctl,                      /* ioctl */
 448         (stop_fcn_t *)nulldev, /* stop */
 449         (reset_fcn_t *)nulldev, /* reset */
 450         NULL,                           /* tty's */
 451         eno_select,                     /* select */
 452         eno_mmap,                       /* mmap */
 453         eno_strat,                      /* strategy */
 454         eno_getc,                       /* getc */
 455         eno_putc,                       /* putc */
 456         0                                       /* type */
 457 };
 458
 459 int gIgnoreFBTBlacklist = 0;
 460 static int gFBTInited = 0;
 461 #undef kmem_alloc /* from its binding to dt_kmem_alloc glue */
 462 #undef kmem_free /* from its binding to dt_kmem_free glue */
 463 #include <vm/vm_kern.h>
 464
 465 void
 466 fbt_init( void )
 467 {
 468         if (0 == gFBTInited)
 469         {
 470                 int majdevno = cdevsw_add(FBT_MAJOR, &fbt_cdevsw);
 471
 472                 if (majdevno < 0) {
 473                         printf("fbt_init: failed to allocate a major number!\n");
 474                         return;
 475                 }
 476
 477                 PE_parse_boot_argn("IgnoreFBTBlacklist", &gIgnoreFBTBlacklist, sizeof (gIgnoreFBTBlacklist));
 478
 479                 fbt_attach( (dev_info_t *)(uintptr_t)majdevno, DDI_ATTACH );
 480
 481                 gFBTInited = 1; /* Ensure this initialization occurs just one time. */
 482         }
 483         else
 484                 panic("fbt_init: called twice!\n");
 485 }
 486 #undef FBT_MAJOR