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
  56 #if   defined(__x86_64__)
  57 typedef kern_return_t (*perfCallback)(int, struct savearea_t *, uintptr_t *, __unused int);
  58 extern perfCallback tempDTraceTrapHook;
  59 extern kern_return_t fbt_perfCallback(int, struct savearea_t *, uintptr_t *, __unused int);
  60 #else
  61 #error Unknown architecture
  62 #endif
  63
  64 #define FBT_ADDR2NDX(addr)      ((((uintptr_t)(addr)) >> 4) & fbt_probetab_mask)
  65 #define FBT_PROBETAB_SIZE       0x8000          /* 32k entries -- 128K total */
  66
  67 static dev_info_t               *fbt_devi;
  68 static int                              fbt_probetab_size;
  69 dtrace_provider_id_t    fbt_id;
  70 fbt_probe_t                             **fbt_probetab;
  71 int                                             fbt_probetab_mask;
  72 static int                              fbt_verbose = 0;
  73
  74 void fbt_init( void );
  75
  76 /*ARGSUSED*/
  77 static void
  78 fbt_destroy(void *arg, dtrace_id_t id, void *parg)
  79 {
  80 #pragma unused(arg,id)
  81         fbt_probe_t *fbt = parg, *next, *hash, *last;
  82         int ndx;
  83
  84         do {
  85                 /*
  86                  * Now we need to remove this probe from the fbt_probetab.
  87                  */
  88                 ndx = FBT_ADDR2NDX(fbt->fbtp_patchpoint);
  89                 last = NULL;
  90                 hash = fbt_probetab[ndx];
  91
  92                 while (hash != fbt) {
  93                         ASSERT(hash != NULL);
  94                         last = hash;
  95                         hash = hash->fbtp_hashnext;
  96                 }
  97
  98                 if (last != NULL) {
  99                         last->fbtp_hashnext = fbt->fbtp_hashnext;
 100                 } else {
 101                         fbt_probetab[ndx] = fbt->fbtp_hashnext;
 102                 }
 103
 104                 next = fbt->fbtp_next;
 105                 kmem_free(fbt, sizeof (fbt_probe_t));
 106
 107                 fbt = next;
 108         } while (fbt != NULL);
 109 }
 110
 111 /*ARGSUSED*/
 112 int
 113 fbt_enable(void *arg, dtrace_id_t id, void *parg)
 114 {
 115 #pragma unused(arg,id)
 116         fbt_probe_t *fbt = parg;
 117         struct modctl *ctl = NULL;
 118
 119     for (; fbt != NULL; fbt = fbt->fbtp_next) {
 120
 121         ctl = fbt->fbtp_ctl;
 122
 123         if (!ctl->mod_loaded) {
 124                 if (fbt_verbose) {
 125                         cmn_err(CE_NOTE, "fbt is failing for probe %s "
 126                             "(module %s unloaded)",
 127                             fbt->fbtp_name, ctl->mod_modname);
 128                 }
 129
 130                 continue;
 131         }
 132
 133         /*
 134          * Now check that our modctl has the expected load count.  If it
 135          * doesn't, this module must have been unloaded and reloaded -- and
 136          * we're not going to touch it.
 137          */
 138         if (ctl->mod_loadcnt != fbt->fbtp_loadcnt) {
 139                 if (fbt_verbose) {
 140                         cmn_err(CE_NOTE, "fbt is failing for probe %s "
 141                             "(module %s reloaded)",
 142                             fbt->fbtp_name, ctl->mod_modname);
 143                 }
 144
 145                 continue;
 146         }
 147
 148         dtrace_casptr(&tempDTraceTrapHook, NULL, fbt_perfCallback);
 149         if (tempDTraceTrapHook != (perfCallback)fbt_perfCallback) {
 150                 if (fbt_verbose) {
 151                         cmn_err(CE_NOTE, "fbt_enable is failing for probe %s "
 152                             "in module %s: tempDTraceTrapHook already occupied.",
 153                             fbt->fbtp_name, ctl->mod_modname);
 154                 }
 155                 continue;
 156         }
 157
 158         if (fbt->fbtp_currentval != fbt->fbtp_patchval) {
 159                 (void)ml_nofault_copy( (vm_offset_t)&fbt->fbtp_patchval, (vm_offset_t)fbt->fbtp_patchpoint,
 160                                                                 sizeof(fbt->fbtp_patchval));
 161                 fbt->fbtp_currentval = fbt->fbtp_patchval;
 162                 ctl->mod_nenabled++;
 163         }
 164
 165     }
 166
 167     dtrace_membar_consumer();
 168
 169     return (0);
 170 }
 171
 172 /*ARGSUSED*/
 173 static void
 174 fbt_disable(void *arg, dtrace_id_t id, void *parg)
 175 {
 176 #pragma unused(arg,id)
 177         fbt_probe_t *fbt = parg;
 178         struct modctl *ctl = NULL;
 179
 180         for (; fbt != NULL; fbt = fbt->fbtp_next) {
 181             ctl = fbt->fbtp_ctl;
 182
 183             if (!ctl->mod_loaded || (ctl->mod_loadcnt != fbt->fbtp_loadcnt))
 184                 continue;
 185
 186             if (fbt->fbtp_currentval != fbt->fbtp_savedval) {
 187                 (void)ml_nofault_copy( (vm_offset_t)&fbt->fbtp_savedval, (vm_offset_t)fbt->fbtp_patchpoint,
 188                                                                 sizeof(fbt->fbtp_savedval));
 189                 fbt->fbtp_currentval = fbt->fbtp_savedval;
 190                 ASSERT(ctl->mod_nenabled > 0);
 191                 ctl->mod_nenabled--;
 192             }
 193         }
 194         dtrace_membar_consumer();
 195 }
 196
 197 /*ARGSUSED*/
 198 static void
 199 fbt_suspend(void *arg, dtrace_id_t id, void *parg)
 200 {
 201 #pragma unused(arg,id)
 202         fbt_probe_t *fbt = parg;
 203         struct modctl *ctl = NULL;
 204
 205         for (; fbt != NULL; fbt = fbt->fbtp_next) {
 206             ctl = fbt->fbtp_ctl;
 207
 208             ASSERT(ctl->mod_nenabled > 0);
 209             if (!ctl->mod_loaded || (ctl->mod_loadcnt != fbt->fbtp_loadcnt))
 210                 continue;
 211
 212             (void)ml_nofault_copy( (vm_offset_t)&fbt->fbtp_savedval, (vm_offset_t)fbt->fbtp_patchpoint,
 213                                                                 sizeof(fbt->fbtp_savedval));
 214
 215
 216             fbt->fbtp_currentval = fbt->fbtp_savedval;
 217         }
 218
 219         dtrace_membar_consumer();
 220 }
 221
 222 /*ARGSUSED*/
 223 static void
 224 fbt_resume(void *arg, dtrace_id_t id, void *parg)
 225 {
 226 #pragma unused(arg,id)
 227         fbt_probe_t *fbt = parg;
 228         struct modctl *ctl = NULL;
 229
 230         for (; fbt != NULL; fbt = fbt->fbtp_next) {
 231             ctl = fbt->fbtp_ctl;
 232
 233             ASSERT(ctl->mod_nenabled > 0);
 234             if (!ctl->mod_loaded || (ctl->mod_loadcnt != fbt->fbtp_loadcnt))
 235                 continue;
 236
 237             dtrace_casptr(&tempDTraceTrapHook, NULL, fbt_perfCallback);
 238             if (tempDTraceTrapHook != (perfCallback)fbt_perfCallback) {
 239                 if (fbt_verbose) {
 240                         cmn_err(CE_NOTE, "fbt_resume is failing for probe %s "
 241                             "in module %s: tempDTraceTrapHook already occupied.",
 242                             fbt->fbtp_name, ctl->mod_modname);
 243                 }
 244                 return;
 245             }
 246
 247             (void)ml_nofault_copy( (vm_offset_t)&fbt->fbtp_patchval, (vm_offset_t)fbt->fbtp_patchpoint,
 248                                                                 sizeof(fbt->fbtp_patchval));
 249
 250
 251             fbt->fbtp_currentval = fbt->fbtp_patchval;
 252         }
 253
 254         dtrace_membar_consumer();
 255 }
 256
 257 /*
 258  * APPLE NOTE: fbt_getargdesc not implemented
 259  */
 260 #if !defined(__APPLE__)
 261 /*ARGSUSED*/
 262 static void
 263 fbt_getargdesc(void *arg, dtrace_id_t id, void *parg, dtrace_argdesc_t *desc)
 264 {
 265         fbt_probe_t *fbt = parg;
 266         struct modctl *ctl = fbt->fbtp_ctl;
 267         struct module *mp = ctl->mod_mp;
 268         ctf_file_t *fp = NULL, *pfp;
 269         ctf_funcinfo_t f;
 270         int error;
 271         ctf_id_t argv[32], type;
 272         int argc = sizeof (argv) / sizeof (ctf_id_t);
 273         const char *parent;
 274
 275         if (!ctl->mod_loaded || (ctl->mod_loadcnt != fbt->fbtp_loadcnt))
 276                 goto err;
 277
 278         if (fbt->fbtp_roffset != 0 && desc->dtargd_ndx == 0) {
 279                 (void) strlcpy(desc->dtargd_native, "int",
 280                                sizeof(desc->dtargd_native));
 281                 return;
 282         }
 283
 284         if ((fp = ctf_modopen(mp, &error)) == NULL) {
 285                 /*
 286                  * We have no CTF information for this module -- and therefore
 287                  * no args[] information.
 288                  */
 289                 goto err;
 290         }
 291
 292         /*
 293          * If we have a parent container, we must manually import it.
 294          */
 295         if ((parent = ctf_parent_name(fp)) != NULL) {
 296                 struct modctl *mp = &modules;
 297                 struct modctl *mod = NULL;
 298
 299                 /*
 300                  * We must iterate over all modules to find the module that
 301                  * is our parent.
 302                  */
 303                 do {
 304                         if (strcmp(mp->mod_modname, parent) == 0) {
 305                                 mod = mp;
 306                                 break;
 307                         }
 308                 } while ((mp = mp->mod_next) != &modules);
 309
 310                 if (mod == NULL)
 311                         goto err;
 312
 313                 if ((pfp = ctf_modopen(mod->mod_mp, &error)) == NULL) {
 314                         goto err;
 315                 }
 316
 317                 if (ctf_import(fp, pfp) != 0) {
 318                         ctf_close(pfp);
 319                         goto err;
 320                 }
 321
 322                 ctf_close(pfp);
 323         }
 324
 325         if (ctf_func_info(fp, fbt->fbtp_symndx, &f) == CTF_ERR)
 326                 goto err;
 327
 328         if (fbt->fbtp_roffset != 0) {
 329                 if (desc->dtargd_ndx > 1)
 330                         goto err;
 331
 332                 ASSERT(desc->dtargd_ndx == 1);
 333                 type = f.ctc_return;
 334         } else {
 335                 if (desc->dtargd_ndx + 1 > f.ctc_argc)
 336                         goto err;
 337
 338                 if (ctf_func_args(fp, fbt->fbtp_symndx, argc, argv) == CTF_ERR)
 339                         goto err;
 340
 341                 type = argv[desc->dtargd_ndx];
 342         }
 343
 344         if (ctf_type_name(fp, type, desc->dtargd_native,
 345             DTRACE_ARGTYPELEN) != NULL) {
 346                 ctf_close(fp);
 347                 return;
 348         }
 349 err:
 350         if (fp != NULL)
 351                 ctf_close(fp);
 352
 353         desc->dtargd_ndx = DTRACE_ARGNONE;
 354 }
 355 #endif /* __APPLE__ */
 356
 357 static dtrace_pattr_t fbt_attr = {
 358 { DTRACE_STABILITY_EVOLVING, DTRACE_STABILITY_EVOLVING, DTRACE_CLASS_ISA },
 359 { DTRACE_STABILITY_PRIVATE, DTRACE_STABILITY_PRIVATE, DTRACE_CLASS_UNKNOWN },
 360 { DTRACE_STABILITY_PRIVATE, DTRACE_STABILITY_PRIVATE, DTRACE_CLASS_UNKNOWN },
 361 { DTRACE_STABILITY_EVOLVING, DTRACE_STABILITY_EVOLVING, DTRACE_CLASS_ISA },
 362 { DTRACE_STABILITY_PRIVATE, DTRACE_STABILITY_PRIVATE, DTRACE_CLASS_ISA },
 363 };
 364
 365 static dtrace_pops_t fbt_pops = {
 366         NULL,
 367         fbt_provide_module,
 368         fbt_enable,
 369         fbt_disable,
 370         fbt_suspend,
 371         fbt_resume,
 372         NULL, /*  APPLE NOTE: fbt_getargdesc not implemented */
 373         NULL,
 374         NULL,
 375         fbt_destroy
 376 };
 377
 378 static void
 379 fbt_cleanup(dev_info_t *devi)
 380 {
 381         dtrace_invop_remove(fbt_invop);
 382         ddi_remove_minor_node(devi, NULL);
 383         kmem_free(fbt_probetab, fbt_probetab_size * sizeof (fbt_probe_t *));
 384         fbt_probetab = NULL;
 385         fbt_probetab_mask = 0;
 386 }
 387
 388 static int
 389 fbt_attach(dev_info_t *devi, ddi_attach_cmd_t cmd)
 390 {
 391         switch (cmd) {
 392         case DDI_ATTACH:
 393                 break;
 394         case DDI_RESUME:
 395                 return (DDI_SUCCESS);
 396         default:
 397                 return (DDI_FAILURE);
 398         }
 399
 400         if (fbt_probetab_size == 0)
 401                 fbt_probetab_size = FBT_PROBETAB_SIZE;
 402
 403         fbt_probetab_mask = fbt_probetab_size - 1;
 404         fbt_probetab =
 405             kmem_zalloc(fbt_probetab_size * sizeof (fbt_probe_t *), KM_SLEEP);
 406
 407         dtrace_invop_add(fbt_invop);
 408
 409         if (ddi_create_minor_node(devi, "fbt", S_IFCHR, 0,
 410             DDI_PSEUDO, 0) == DDI_FAILURE ||
 411             dtrace_register("fbt", &fbt_attr, DTRACE_PRIV_KERNEL, NULL,
 412             &fbt_pops, NULL, &fbt_id) != 0) {
 413                 fbt_cleanup(devi);
 414                 return (DDI_FAILURE);
 415         }
 416
 417         ddi_report_dev(devi);
 418         fbt_devi = devi;
 419
 420         return (DDI_SUCCESS);
 421 }
 422
 423 static d_open_t _fbt_open;
 424
 425 static int
 426 _fbt_open(dev_t dev, int flags, int devtype, struct proc *p)
 427 {
 428 #pragma unused(dev,flags,devtype,p)
 429         return 0;
 430 }
 431
 432 #define FBT_MAJOR  -24 /* let the kernel pick the device number */
 433
 434 /*
 435  * A struct describing which functions will get invoked for certain
 436  * actions.
 437  */
 438 static struct cdevsw fbt_cdevsw =
 439 {
 440         _fbt_open,              /* open */
 441         eno_opcl,                       /* close */
 442         eno_rdwrt,                      /* read */
 443         eno_rdwrt,                      /* write */
 444         eno_ioctl,                      /* ioctl */
 445         (stop_fcn_t *)nulldev, /* stop */
 446         (reset_fcn_t *)nulldev, /* reset */
 447         NULL,                           /* tty's */
 448         eno_select,                     /* select */
 449         eno_mmap,                       /* mmap */
 450         eno_strat,                      /* strategy */
 451         eno_getc,                       /* getc */
 452         eno_putc,                       /* putc */
 453         0                                       /* type */
 454 };
 455
 456 int gIgnoreFBTBlacklist = 0;
 457 static int gFBTInited = 0;
 458 #undef kmem_alloc /* from its binding to dt_kmem_alloc glue */
 459 #undef kmem_free /* from its binding to dt_kmem_free glue */
 460 #include <vm/vm_kern.h>
 461
 462 void
 463 fbt_init( void )
 464 {
 465         if (0 == gFBTInited)
 466         {
 467                 int majdevno = cdevsw_add(FBT_MAJOR, &fbt_cdevsw);
 468
 469                 if (majdevno < 0) {
 470                         printf("fbt_init: failed to allocate a major number!\n");
 471                         return;
 472                 }
 473
 474                 PE_parse_boot_argn("IgnoreFBTBlacklist", &gIgnoreFBTBlacklist, sizeof (gIgnoreFBTBlacklist));
 475
 476                 fbt_attach( (dev_info_t *)(uintptr_t)majdevno, DDI_ATTACH );
 477
 478                 gFBTInited = 1; /* Ensure this initialization occurs just one time. */
 479         }
 480         else
 481                 panic("fbt_init: called twice!\n");
 482 }
 483 #undef FBT_MAJOR