workbench/libs/mesa/src/egl/main/egldriver.c

   1 /**************************************************************************
   2  *
   3  * Copyright 2008 Tungsten Graphics, Inc., Cedar Park, Texas.
   4  * Copyright 2009-2010 Chia-I Wu <olvaffe@gmail.com>
   5  * Copyright 2010-2011 LunarG, Inc.
   6  * All Rights Reserved.
   7  *
   8  * Permission is hereby granted, free of charge, to any person obtaining a
   9  * copy of this software and associated documentation files (the
  10  * "Software"), to deal in the Software without restriction, including
  11  * without limitation the rights to use, copy, modify, merge, publish,
  12  * distribute, sub license, and/or sell copies of the Software, and to
  13  * permit persons to whom the Software is furnished to do so, subject to
  14  * the following conditions:
  15  *
  16  * The above copyright notice and this permission notice (including the
  17  * next paragraph) shall be included in all copies or substantial portions
  18  * of the Software.
  19  *
  20  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  21  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  22  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
  23  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  24  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
  25  * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
  26  * DEALINGS IN THE SOFTWARE.
  27  *
  28  **************************************************************************/
  29
  30
  31 /**
  32  * Functions for choosing and opening/loading device drivers.
  33  */
  34
  35 #include <assert.h>
  36 #include <string.h>
  37 #include <stdio.h>
  38 #include <stdlib.h>
  39
  40 #include "eglstring.h"
  41 #include "egldefines.h"
  42 #include "egldisplay.h"
  43 #include "egldriver.h"
  44 #include "egllog.h"
  45 #include "eglmutex.h"
  46
  47 #if defined(_EGL_OS_UNIX)
  48 #include <dlfcn.h>
  49 #include <sys/types.h>
  50 #include <dirent.h>
  51 #include <unistd.h>
  52 #endif
  53
  54
  55 typedef struct _egl_module {
  56    char *Path;
  57    _EGLMain_t BuiltIn;
  58    void *Handle;
  59    _EGLDriver *Driver;
  60 } _EGLModule;
  61
  62 static _EGL_DECLARE_MUTEX(_eglModuleMutex);
  63 static _EGLArray *_eglModules;
  64
  65 const struct {
  66    const char *name;
  67    _EGLMain_t main;
  68 } _eglBuiltInDrivers[] = {
  69 #ifdef _EGL_BUILT_IN_DRIVER_GALLIUM
  70    { "egl_gallium", _eglBuiltInDriverGALLIUM },
  71 #endif
  72 #ifdef _EGL_BUILT_IN_DRIVER_DRI2
  73    { "egl_dri2", _eglBuiltInDriverDRI2 },
  74 #endif
  75 #ifdef _EGL_BUILT_IN_DRIVER_GLX
  76    { "egl_glx", _eglBuiltInDriverGLX },
  77 #endif
  78    { NULL, NULL }
  79 };
  80
  81
  82 /**
  83  * Wrappers for dlopen/dlclose()
  84  */
  85 #if defined(_EGL_OS_WINDOWS)
  86
  87
  88 typedef HMODULE lib_handle;
  89
  90 static HMODULE
  91 open_library(const char *filename)
  92 {
  93    return LoadLibrary(filename);
  94 }
  95
  96 static void
  97 close_library(HMODULE lib)
  98 {
  99    FreeLibrary(lib);
 100 }
 101
 102
 103 static const char *
 104 library_suffix(void)
 105 {
 106    return ".dll";
 107 }
 108
 109
 110 #elif defined(_EGL_OS_AROS)
 111
 112 typedef void * lib_handle;
 113
 114 static void
 115 close_library(void *lib)
 116 {
 117     /* No-Op */
 118 }
 119
 120 #elif defined(_EGL_OS_UNIX)
 121
 122
 123 typedef void * lib_handle;
 124
 125 static void *
 126 open_library(const char *filename)
 127 {
 128    return dlopen(filename, RTLD_LAZY);
 129 }
 130
 131 static void
 132 close_library(void *lib)
 133 {
 134    dlclose(lib);
 135 }
 136
 137
 138 static const char *
 139 library_suffix(void)
 140 {
 141    return ".so";
 142 }
 143
 144
 145 #endif
 146
 147
 148 /**
 149  * Open the named driver and find its bootstrap function: _eglMain().
 150  */
 151 static _EGLMain_t
 152 _eglOpenLibrary(const char *driverPath, lib_handle *handle)
 153 {
 154 #if !defined(_EGL_OS_AROS)
 155    lib_handle lib;
 156    _EGLMain_t mainFunc = NULL;
 157    const char *error = "unknown error";
 158
 159    assert(driverPath);
 160
 161    _eglLog(_EGL_DEBUG, "dlopen(%s)", driverPath);
 162    lib = open_library(driverPath);
 163
 164 #if defined(_EGL_OS_WINDOWS)
 165    /* XXX untested */
 166    if (lib)
 167       mainFunc = (_EGLMain_t) GetProcAddress(lib, "_eglMain");
 168 #elif defined(_EGL_OS_UNIX)
 169    if (lib) {
 170       union {
 171          _EGLMain_t func;
 172          void *ptr;
 173       } tmp = { NULL };
 174       /* direct cast gives a warning when compiled with -pedantic */
 175       tmp.ptr = dlsym(lib, "_eglMain");
 176       mainFunc = tmp.func;
 177       if (!mainFunc)
 178          error = dlerror();
 179    }
 180    else {
 181       error = dlerror();
 182    }
 183 #endif
 184
 185    if (!lib) {
 186       _eglLog(_EGL_WARNING, "Could not open driver %s (%s)",
 187               driverPath, error);
 188       return NULL;
 189    }
 190
 191    if (!mainFunc) {
 192       _eglLog(_EGL_WARNING, "_eglMain not found in %s (%s)",
 193               driverPath, error);
 194       if (lib)
 195          close_library(lib);
 196       return NULL;
 197    }
 198
 199    *handle = lib;
 200    return mainFunc;
 201 #else
 202    return NULL;
 203 #endif
 204 }
 205
 206
 207 /**
 208  * Load a module and create the driver object.
 209  */
 210 static EGLBoolean
 211 _eglLoadModule(_EGLModule *mod)
 212 {
 213    _EGLMain_t mainFunc;
 214    lib_handle lib;
 215    _EGLDriver *drv;
 216
 217    if (mod->Driver)
 218       return EGL_TRUE;
 219
 220    if (mod->BuiltIn) {
 221       lib = (lib_handle) NULL;
 222       mainFunc = mod->BuiltIn;
 223    }
 224    else {
 225       mainFunc = _eglOpenLibrary(mod->Path, &lib);
 226       if (!mainFunc)
 227          return EGL_FALSE;
 228    }
 229
 230    drv = mainFunc(NULL);
 231    if (!drv) {
 232       if (lib)
 233          close_library(lib);
 234       return EGL_FALSE;
 235    }
 236
 237    if (!drv->Name) {
 238       _eglLog(_EGL_WARNING, "Driver loaded from %s has no name", mod->Path);
 239       drv->Name = "UNNAMED";
 240    }
 241
 242    mod->Handle = (void *) lib;
 243    mod->Driver = drv;
 244
 245    return EGL_TRUE;
 246 }
 247
 248
 249 /**
 250  * Unload a module.
 251  */
 252 static void
 253 _eglUnloadModule(_EGLModule *mod)
 254 {
 255 #if defined(_EGL_OS_UNIX)
 256    /* destroy the driver */
 257    if (mod->Driver && mod->Driver->Unload)
 258       mod->Driver->Unload(mod->Driver);
 259
 260    /*
 261     * XXX At this point (atexit), the module might be the last reference to
 262     * libEGL.  Closing the module might unmap libEGL and give problems.
 263     */
 264 #if 0
 265    if (mod->Handle)
 266       close_library(mod->Handle);
 267 #endif
 268 #elif defined(_EGL_OS_WINDOWS)
 269    /* XXX Windows unloads DLLs before atexit */
 270 #endif
 271
 272    mod->Driver = NULL;
 273    mod->Handle = NULL;
 274 }
 275
 276
 277 /**
 278  * Add a module to the module array.
 279  */
 280 static _EGLModule *
 281 _eglAddModule(const char *path)
 282 {
 283    _EGLModule *mod;
 284    EGLint i;
 285
 286    if (!_eglModules) {
 287       _eglModules = _eglCreateArray("Module", 8);
 288       if (!_eglModules)
 289          return NULL;
 290    }
 291
 292    /* find duplicates */
 293    for (i = 0; i < _eglModules->Size; i++) {
 294       mod = _eglModules->Elements[i];
 295       if (strcmp(mod->Path, path) == 0)
 296          return mod;
 297    }
 298
 299    /* allocate a new one */
 300    mod = calloc(1, sizeof(*mod));
 301    if (mod) {
 302       mod->Path = _eglstrdup(path);
 303       if (!mod->Path) {
 304          free(mod);
 305          mod = NULL;
 306       }
 307    }
 308    if (mod) {
 309       _eglAppendArray(_eglModules, (void *) mod);
 310       _eglLog(_EGL_DEBUG, "added %s to module array", mod->Path);
 311    }
 312
 313    return mod;
 314 }
 315
 316
 317 /**
 318  * Free a module.
 319  */
 320 static void
 321 _eglFreeModule(void *module)
 322 {
 323    _EGLModule *mod = (_EGLModule *) module;
 324
 325    _eglUnloadModule(mod);
 326    free(mod->Path);
 327    free(mod);
 328 }
 329
 330
 331 #if !defined(_EGL_OS_AROS)
 332 /**
 333  * A loader function for use with _eglPreloadForEach.  The loader data is the
 334  * filename of the driver.   This function stops on the first valid driver.
 335  */
 336 static EGLBoolean
 337 _eglLoaderFile(const char *dir, size_t len, void *loader_data)
 338 {
 339    char path[1024];
 340    const char *filename = (const char *) loader_data;
 341    size_t flen = strlen(filename);
 342
 343    /* make a full path */
 344    if (len + flen + 2 > sizeof(path))
 345       return EGL_TRUE;
 346    if (len) {
 347       memcpy(path, dir, len);
 348       path[len++] = '/';
 349    }
 350    memcpy(path + len, filename, flen);
 351    len += flen;
 352    path[len] = '\0';
 353
 354    if (library_suffix()) {
 355       const char *suffix = library_suffix();
 356       size_t slen = strlen(suffix);
 357       const char *p;
 358       EGLBoolean need_suffix;
 359
 360       p = filename + flen - slen;
 361       need_suffix = (p < filename || strcmp(p, suffix) != 0);
 362       if (need_suffix) {
 363          /* overflow */
 364          if (len + slen + 1 > sizeof(path))
 365             return EGL_TRUE;
 366          strcpy(path + len, suffix);
 367       }
 368    }
 369
 370 #if defined(_EGL_OS_UNIX)
 371    /* check if the file exists */
 372    if (access(path, F_OK))
 373       return EGL_TRUE;
 374 #endif
 375
 376    _eglAddModule(path);
 377
 378    return EGL_TRUE;
 379 }
 380
 381
 382 /**
 383  * Run the callback function on each driver directory.
 384  *
 385  * The process may end prematurely if the callback function returns false.
 386  */
 387 static void
 388 _eglPreloadForEach(const char *search_path,
 389                    EGLBoolean (*loader)(const char *, size_t, void *),
 390                    void *loader_data)
 391 {
 392    const char *cur, *next;
 393    size_t len;
 394
 395    cur = search_path;
 396    while (cur) {
 397       next = strchr(cur, ':');
 398       len = (next) ? next - cur : strlen(cur);
 399
 400       if (!loader(cur, len, loader_data))
 401          break;
 402
 403       cur = (next) ? next + 1 : NULL;
 404    }
 405 }
 406
 407
 408 /**
 409  * Return a list of colon-separated driver directories.
 410  */
 411 static const char *
 412 _eglGetSearchPath(void)
 413 {
 414    static char search_path[1024];
 415
 416 #if defined(_EGL_OS_UNIX) || defined(_EGL_OS_WINDOWS)
 417    if (search_path[0] == '\0') {
 418       char *buf = search_path;
 419       size_t len = sizeof(search_path);
 420       EGLBoolean use_env;
 421       char dir_sep;
 422       int ret;
 423
 424 #if defined(_EGL_OS_UNIX)
 425       use_env = (geteuid() == getuid() && getegid() == getgid());
 426       dir_sep = '/';
 427 #else
 428       use_env = EGL_TRUE;
 429       dir_sep = '\\';
 430 #endif
 431
 432       if (use_env) {
 433          char *p;
 434
 435          /* extract the dirname from EGL_DRIVER */
 436          p = getenv("EGL_DRIVER");
 437          if (p && strchr(p, dir_sep)) {
 438             ret = _eglsnprintf(buf, len, "%s", p);
 439             if (ret > 0 && ret < len) {
 440                p = strrchr(buf, dir_sep);
 441                *p++ = ':';
 442
 443                len -= p - buf;
 444                buf = p;
 445             }
 446          }
 447
 448          /* append EGL_DRIVERS_PATH */
 449          p = getenv("EGL_DRIVERS_PATH");
 450          if (p) {
 451             ret = _eglsnprintf(buf, len, "%s:", p);
 452             if (ret > 0 && ret < len) {
 453                buf += ret;
 454                len -= ret;
 455             }
 456          }
 457       }
 458       else {
 459          _eglLog(_EGL_DEBUG,
 460                "ignore EGL_DRIVERS_PATH for setuid/setgid binaries");
 461       }
 462
 463       ret = _eglsnprintf(buf, len, "%s", _EGL_DRIVER_SEARCH_DIR);
 464       if (ret < 0 || ret >= len)
 465          search_path[0] = '\0';
 466
 467       _eglLog(_EGL_DEBUG, "EGL search path is %s", search_path);
 468    }
 469 #endif /* defined(_EGL_OS_UNIX) || defined(_EGL_OS_WINDOWS) */
 470
 471    return search_path;
 472 }
 473
 474
 475 /**
 476  * Add the user driver to the module array.
 477  *
 478  * The user driver is specified by EGL_DRIVER.
 479  */
 480 static EGLBoolean
 481 _eglAddUserDriver(void)
 482 {
 483    const char *search_path = _eglGetSearchPath();
 484    char *env;
 485    size_t name_len = 0;
 486
 487    env = getenv("EGL_DRIVER");
 488 #if defined(_EGL_OS_UNIX)
 489    if (env && strchr(env, '/')) {
 490       search_path = "";
 491       if ((geteuid() != getuid() || getegid() != getgid())) {
 492          _eglLog(_EGL_DEBUG,
 493                "ignore EGL_DRIVER for setuid/setgid binaries");
 494          env = NULL;
 495       }
 496    }
 497    else if (env) {
 498       char *suffix = strchr(env, '.');
 499       name_len = (suffix) ? suffix - env : strlen(env);
 500    }
 501 #else
 502    if (env)
 503       name_len = strlen(env);
 504 #endif /* _EGL_OS_UNIX */
 505
 506    /*
 507     * Try built-in drivers first if we know the driver name.  This makes sure
 508     * we do not load the outdated external driver that is still on the
 509     * filesystem.
 510     */
 511    if (name_len) {
 512       _EGLModule *mod;
 513       EGLint i;
 514
 515       for (i = 0; _eglBuiltInDrivers[i].name; i++) {
 516          if (strlen(_eglBuiltInDrivers[i].name) == name_len &&
 517              !strncmp(_eglBuiltInDrivers[i].name, env, name_len)) {
 518             mod = _eglAddModule(env);
 519             if (mod)
 520                mod->BuiltIn = _eglBuiltInDrivers[i].main;
 521
 522             return EGL_TRUE;
 523          }
 524       }
 525    }
 526
 527    /* otherwise, treat env as a path */
 528    if (env) {
 529       _eglPreloadForEach(search_path, _eglLoaderFile, (void *) env);
 530
 531       return EGL_TRUE;
 532    }
 533
 534    return EGL_FALSE;
 535 }
 536
 537
 538 /**
 539  * Add egl_gallium to the module array.
 540  */
 541 static void
 542 _eglAddGalliumDriver(void)
 543 {
 544 #ifndef _EGL_BUILT_IN_DRIVER_GALLIUM
 545    void *external = (void *) "egl_gallium";
 546    _eglPreloadForEach(_eglGetSearchPath(), _eglLoaderFile, external);
 547 #endif
 548 }
 549 #endif /* !defined(_EGL_OS_AROS) */
 550
 551 /**
 552  * Add built-in drivers to the module array.
 553  */
 554 static void
 555 _eglAddBuiltInDrivers(void)
 556 {
 557    _EGLModule *mod;
 558    EGLint i;
 559
 560    for (i = 0; _eglBuiltInDrivers[i].name; i++) {
 561       mod = _eglAddModule(_eglBuiltInDrivers[i].name);
 562       if (mod)
 563          mod->BuiltIn = _eglBuiltInDrivers[i].main;
 564    }
 565 }
 566
 567
 568 /**
 569  * Add drivers to the module array.  Drivers will be loaded as they are matched
 570  * to displays.
 571  */
 572 static EGLBoolean
 573 _eglAddDrivers(void)
 574 {
 575    if (_eglModules)
 576       return EGL_TRUE;
 577
 578 #if !defined(_EGL_OS_AROS)
 579    if (!_eglAddUserDriver()) {
 580       /*
 581        * Add other drivers only when EGL_DRIVER is not set.  The order here
 582        * decides the priorities.
 583        */
 584       _eglAddGalliumDriver();
 585       _eglAddBuiltInDrivers();
 586    }
 587 #else
 588    _eglAddBuiltInDrivers();
 589 #endif
 590
 591    return (_eglModules != NULL);
 592 }
 593
 594
 595 /**
 596  * A helper function for _eglMatchDriver.  It finds the first driver that can
 597  * initialize the display and return.
 598  */
 599 static _EGLDriver *
 600 _eglMatchAndInitialize(_EGLDisplay *dpy)
 601 {
 602    _EGLDriver *drv = NULL;
 603    EGLint i = 0;
 604
 605    if (!_eglAddDrivers()) {
 606       _eglLog(_EGL_WARNING, "failed to find any driver");
 607       return NULL;
 608    }
 609
 610    if (dpy->Driver) {
 611       drv = dpy->Driver;
 612       /* no re-matching? */
 613       if (!drv->API.Initialize(drv, dpy))
 614          drv = NULL;
 615       return drv;
 616    }
 617
 618    while (i < _eglModules->Size) {
 619       _EGLModule *mod = (_EGLModule *) _eglModules->Elements[i];
 620
 621       if (!_eglLoadModule(mod)) {
 622          /* remove invalid modules */
 623          _eglEraseArray(_eglModules, i, _eglFreeModule);
 624          continue;
 625       }
 626
 627       if (mod->Driver->API.Initialize(mod->Driver, dpy)) {
 628          drv = mod->Driver;
 629          break;
 630       }
 631       else {
 632          i++;
 633       }
 634    }
 635
 636    return drv;
 637 }
 638
 639
 640 /**
 641  * Match a display to a driver.  The display is initialized unless test_only is
 642  * true.  The matching is done by finding the first driver that can initialize
 643  * the display.
 644  */
 645 _EGLDriver *
 646 _eglMatchDriver(_EGLDisplay *dpy, EGLBoolean test_only)
 647 {
 648    _EGLDriver *best_drv;
 649
 650    assert(!dpy->Initialized);
 651
 652    _eglLockMutex(&_eglModuleMutex);
 653
 654    /* set options */
 655    dpy->Options.TestOnly = test_only;
 656    dpy->Options.UseFallback = EGL_FALSE;
 657
 658    best_drv = _eglMatchAndInitialize(dpy);
 659    if (!best_drv) {
 660       dpy->Options.UseFallback = EGL_TRUE;
 661       best_drv = _eglMatchAndInitialize(dpy);
 662    }
 663
 664    _eglUnlockMutex(&_eglModuleMutex);
 665
 666    if (best_drv) {
 667       _eglLog(_EGL_DEBUG, "the best driver is %s%s",
 668             best_drv->Name, (test_only) ? " (test only) " : "");
 669       if (!test_only) {
 670          dpy->Driver = best_drv;
 671          dpy->Initialized = EGL_TRUE;
 672       }
 673    }
 674
 675    return best_drv;
 676 }
 677
 678
 679 __eglMustCastToProperFunctionPointerType
 680 _eglGetDriverProc(const char *procname)
 681 {
 682    EGLint i;
 683    _EGLProc proc = NULL;
 684
 685    if (!_eglModules) {
 686       /* load the driver for the default display */
 687       EGLDisplay egldpy = eglGetDisplay(EGL_DEFAULT_DISPLAY);
 688       _EGLDisplay *dpy = _eglLookupDisplay(egldpy);
 689       if (!dpy || !_eglMatchDriver(dpy, EGL_TRUE))
 690          return NULL;
 691    }
 692
 693    for (i = 0; i < _eglModules->Size; i++) {
 694       _EGLModule *mod = (_EGLModule *) _eglModules->Elements[i];
 695
 696       if (!mod->Driver)
 697          break;
 698       proc = mod->Driver->API.GetProcAddress(mod->Driver, procname);
 699       if (proc)
 700          break;
 701    }
 702
 703    return proc;
 704 }
 705
 706
 707 /**
 708  * Unload all drivers.
 709  */
 710 void
 711 _eglUnloadDrivers(void)
 712 {
 713    /* this is called at atexit time */
 714    if (_eglModules) {
 715       _eglDestroyArray(_eglModules, _eglFreeModule);
 716       _eglModules = NULL;
 717    }
 718 }
 719
 720 #if !defined(_EGL_OS_AROS)
 721 /**
 722  * Invoke a callback function on each EGL search path.
 723  *
 724  * The first argument of the callback function is the name of the search path.
 725  * The second argument is the length of the name.
 726  */
 727 void
 728 _eglSearchPathForEach(EGLBoolean (*callback)(const char *, size_t, void *),
 729                       void *callback_data)
 730 {
 731    const char *search_path = _eglGetSearchPath();
 732    _eglPreloadForEach(search_path, callback, callback_data);
 733 }
 734 #endif