1 /*
   2  * Copyright (c) 1998, 2020, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.  Oracle designates this
   8  * particular file as subject to the "Classpath" exception as provided
   9  * by Oracle in the LICENSE file that accompanied this code.
  10  *
  11  * This code is distributed in the hope that it will be useful, but WITHOUT
  12  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  13  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  14  * version 2 for more details (a copy is included in the LICENSE file that
  15  * accompanied this code).
  16  *
  17  * You should have received a copy of the GNU General Public License version
  18  * 2 along with this work; if not, write to the Free Software Foundation,
  19  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  20  *
  21  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  22  * or visit www.oracle.com if you need additional information or have any
  23  * questions.
  24  */
  25 
  26 #include "java.h"
  27 #include "jvm_md.h"
  28 #include <dirent.h>
  29 #include <dlfcn.h>
  30 #include <fcntl.h>
  31 #include <inttypes.h>
  32 #include <stdio.h>
  33 #include <string.h>
  34 #include <stdlib.h>
  35 #include <sys/stat.h>
  36 #include <unistd.h>
  37 #include <sys/types.h>
  38 #include "manifest_info.h"
  39 
  40 
  41 #define JVM_DLL "libjvm.so"
  42 #define JAVA_DLL "libjava.so"
  43 #ifdef AIX
  44 #define LD_LIBRARY_PATH "LIBPATH"
  45 #else
  46 #define LD_LIBRARY_PATH "LD_LIBRARY_PATH"
  47 #endif
  48 
  49 /* help jettison the LD_LIBRARY_PATH settings in the future */
  50 #ifndef SETENV_REQUIRED
  51 #define SETENV_REQUIRED
  52 #endif
  53 
  54 #ifdef __solaris__
  55 #  include <sys/systeminfo.h>
  56 #  include <sys/elf.h>
  57 #  include <stdio.h>
  58 #endif
  59 
  60 /*
  61  * Flowchart of launcher execs and options processing on unix
  62  *
  63  * The selection of the proper vm shared library to open depends on
  64  * several classes of command line options, including vm "flavor"
  65  * options (-client, -server).
  66  * The vm selection options are not passed to the running
  67  * virtual machine; they must be screened out by the launcher.
  68  *
  69  * The version specification (if any) is processed first by the
  70  * platform independent routine SelectVersion.  This may result in
  71  * the exec of the specified launcher version.
  72  *
  73  * Previously the launcher modified the LD_LIBRARY_PATH appropriately for the
  74  * desired data model path, regardless if data models matched or not. The
  75  * launcher subsequently exec'ed the desired executable, in order to make the
  76  * LD_LIBRARY_PATH path available, for the runtime linker.
  77  *
  78  * Now, in most cases,the launcher will dlopen the target libjvm.so. All
  79  * required libraries are loaded by the runtime linker, using the
  80  * $RPATH/$ORIGIN baked into the shared libraries at compile time. Therefore,
  81  * in most cases, the launcher will only exec, if the data models are
  82  * mismatched, and will not set any environment variables, regardless of the
  83  * data models.
  84  *
  85  * However, if the environment contains a LD_LIBRARY_PATH, this will cause the
  86  * launcher to inspect the LD_LIBRARY_PATH. The launcher will check
  87  *  a. if the LD_LIBRARY_PATH's first component is the path to the desired
  88  *     libjvm.so
  89  *  b. if any other libjvm.so is found in any of the paths.
  90  * If case b is true, then the launcher will set the LD_LIBRARY_PATH to the
  91  * desired JRE and reexec, in order to propagate the environment.
  92  *
  93  *  Main
  94  *  (incoming argv)
  95  *  |
  96  * \|/
  97  * CreateExecutionEnvironment
  98  * (determines desired data model)
  99  *  |
 100  *  |
 101  * \|/
 102  *  Have Desired Model ? --> NO --> Exit(with error)
 103  *  |
 104  *  |
 105  * \|/
 106  * YES
 107  *  |
 108  *  |
 109  * \|/
 110  * CheckJvmType
 111  * (removes -client, -server, etc.)
 112  *  |
 113  *  |
 114  * \|/
 115  * TranslateDashJArgs...
 116  * (Prepare to pass args to vm)
 117  *  |
 118  *  |
 119  * \|/
 120  * ParseArguments
 121  *   |
 122  *   |
 123  *  \|/
 124  * RequiresSetenv
 125  * Is LD_LIBRARY_PATH
 126  * and friends set ? --> NO --> Continue
 127  *  YES
 128  *   |
 129  *   |
 130  *  \|/
 131  * Path is desired JRE ? YES --> Continue
 132  *  NO
 133  *   |
 134  *   |
 135  *  \|/
 136  * Paths have well known
 137  * jvm paths ?       --> NO --> Error/Exit
 138  *  YES
 139  *   |
 140  *   |
 141  *  \|/
 142  *  Does libjvm.so exist
 143  *  in any of them ? --> NO  --> Continue
 144  *   YES
 145  *   |
 146  *   |
 147  *  \|/
 148  *  Set the LD_LIBRARY_PATH
 149  *   |
 150  *   |
 151  *  \|/
 152  * Re-exec
 153  *   |
 154  *   |
 155  *  \|/
 156  * Main
 157  */
 158 
 159 /* Store the name of the executable once computed */
 160 static char *execname = NULL;
 161 
 162 /*
 163  * execname accessor from other parts of platform dependent logic
 164  */
 165 const char *
 166 GetExecName() {
 167     return execname;
 168 }
 169 
 170 #ifdef SETENV_REQUIRED
 171 static jboolean
 172 JvmExists(const char *path) {
 173     char tmp[PATH_MAX + 1];
 174     struct stat statbuf;
 175     JLI_Snprintf(tmp, PATH_MAX, "%s/%s", path, JVM_DLL);
 176     if (stat(tmp, &statbuf) == 0) {
 177         return JNI_TRUE;
 178     }
 179     return JNI_FALSE;
 180 }
 181 /*
 182  * contains a lib/{server,client}/libjvm.so ?
 183  */
 184 static jboolean
 185 ContainsLibJVM(const char *env) {
 186     /* the usual suspects */
 187     char clientPattern[] = "lib/client";
 188     char serverPattern[] = "lib/server";
 189     char *envpath;
 190     char *path;
 191     char* save_ptr = NULL;
 192     jboolean clientPatternFound;
 193     jboolean serverPatternFound;
 194 
 195     /* fastest path */
 196     if (env == NULL) {
 197         return JNI_FALSE;
 198     }
 199 
 200     /* to optimize for time, test if any of our usual suspects are present. */
 201     clientPatternFound = JLI_StrStr(env, clientPattern) != NULL;
 202     serverPatternFound = JLI_StrStr(env, serverPattern) != NULL;
 203     if (clientPatternFound == JNI_FALSE && serverPatternFound == JNI_FALSE) {
 204         return JNI_FALSE;
 205     }
 206 
 207     /*
 208      * we have a suspicious path component, check if it contains a libjvm.so
 209      */
 210     envpath = JLI_StringDup(env);
 211     for (path = strtok_r(envpath, ":", &save_ptr); path != NULL; path = strtok_r(NULL, ":", &save_ptr)) {
 212         if (clientPatternFound && JLI_StrStr(path, clientPattern) != NULL) {
 213             if (JvmExists(path)) {
 214                 JLI_MemFree(envpath);
 215                 return JNI_TRUE;
 216             }
 217         }
 218         if (serverPatternFound && JLI_StrStr(path, serverPattern)  != NULL) {
 219             if (JvmExists(path)) {
 220                 JLI_MemFree(envpath);
 221                 return JNI_TRUE;
 222             }
 223         }
 224     }
 225     JLI_MemFree(envpath);
 226     return JNI_FALSE;
 227 }
 228 
 229 /*
 230  * Test whether the environment variable needs to be set, see flowchart.
 231  */
 232 static jboolean
 233 RequiresSetenv(const char *jvmpath) {
 234     char jpath[PATH_MAX + 1];
 235     char *llp;
 236     char *dmllp = NULL;
 237     char *p; /* a utility pointer */
 238 
 239 #ifdef AIX
 240     /* We always have to set the LIBPATH on AIX because ld doesn't support $ORIGIN. */
 241     return JNI_TRUE;
 242 #endif
 243 
 244     llp = getenv("LD_LIBRARY_PATH");
 245 #ifdef __solaris__
 246     dmllp = getenv("LD_LIBRARY_PATH_64");
 247 #endif /* __solaris__ */
 248     /* no environment variable is a good environment variable */
 249     if (llp == NULL && dmllp == NULL) {
 250         return JNI_FALSE;
 251     }
 252 #ifdef __linux
 253     /*
 254      * On linux, if a binary is running as sgid or suid, glibc sets
 255      * LD_LIBRARY_PATH to the empty string for security purposes. (In contrast,
 256      * on Solaris the LD_LIBRARY_PATH variable for a privileged binary does not
 257      * lose its settings; but the dynamic linker does apply more scrutiny to the
 258      * path.) The launcher uses the value of LD_LIBRARY_PATH to prevent an exec
 259      * loop, here and further downstream. Therefore, if we are running sgid or
 260      * suid, this function's setting of LD_LIBRARY_PATH will be ineffective and
 261      * we should case a return from the calling function.  Getting the right
 262      * libraries will be handled by the RPATH. In reality, this check is
 263      * redundant, as the previous check for a non-null LD_LIBRARY_PATH will
 264      * return back to the calling function forthwith, it is left here to safe
 265      * guard against any changes, in the glibc's existing security policy.
 266      */
 267     if ((getgid() != getegid()) || (getuid() != geteuid())) {
 268         return JNI_FALSE;
 269     }
 270 #endif /* __linux */
 271 
 272     /*
 273      * Prevent recursions. Since LD_LIBRARY_PATH is the one which will be set by
 274      * previous versions of the JRE, thus it is the only path that matters here.
 275      * So we check to see if the desired JRE is set.
 276      */
 277     JLI_StrNCpy(jpath, jvmpath, PATH_MAX);
 278     p = JLI_StrRChr(jpath, '/');
 279     *p = '\0';
 280     if (llp != NULL && JLI_StrNCmp(llp, jpath, JLI_StrLen(jpath)) == 0) {
 281         return JNI_FALSE;
 282     }
 283 
 284     /* scrutinize all the paths further */
 285     if (llp != NULL &&  ContainsLibJVM(llp)) {
 286         return JNI_TRUE;
 287     }
 288     if (dmllp != NULL && ContainsLibJVM(dmllp)) {
 289         return JNI_TRUE;
 290     }
 291     return JNI_FALSE;
 292 }
 293 #endif /* SETENV_REQUIRED */
 294 
 295 void
 296 CreateExecutionEnvironment(int *pargc, char ***pargv,
 297                            char jrepath[], jint so_jrepath,
 298                            char jvmpath[], jint so_jvmpath,
 299                            char jvmcfg[],  jint so_jvmcfg) {
 300 
 301     char * jvmtype = NULL;
 302     int argc = *pargc;
 303     char **argv = *pargv;
 304 
 305 #ifdef SETENV_REQUIRED
 306     jboolean mustsetenv = JNI_FALSE;
 307 #ifdef __solaris__
 308     char *llp64 = NULL; /* existing LD_LIBRARY_PATH_64 setting */
 309 #endif // __solaris__
 310     char *runpath = NULL; /* existing effective LD_LIBRARY_PATH setting */
 311     char* new_runpath = NULL; /* desired new LD_LIBRARY_PATH string */
 312     char* newpath = NULL; /* path on new LD_LIBRARY_PATH */
 313     char* lastslash = NULL;
 314     char** newenvp = NULL; /* current environment */
 315     size_t new_runpath_size;
 316 #endif  /* SETENV_REQUIRED */
 317 
 318     /* Compute/set the name of the executable */
 319     SetExecname(*pargv);
 320 
 321     /* Check to see if the jvmpath exists */
 322     /* Find out where the JRE is that we will be using. */
 323     if (!GetJREPath(jrepath, so_jrepath, JNI_FALSE)) {
 324         JLI_ReportErrorMessage(JRE_ERROR1);
 325         exit(2);
 326     }
 327     JLI_Snprintf(jvmcfg, so_jvmcfg, "%s%slib%sjvm.cfg",
 328             jrepath, FILESEP, FILESEP);
 329     /* Find the specified JVM type */
 330     if (ReadKnownVMs(jvmcfg, JNI_FALSE) < 1) {
 331         JLI_ReportErrorMessage(CFG_ERROR7);
 332         exit(1);
 333     }
 334 
 335     jvmpath[0] = '\0';
 336     jvmtype = CheckJvmType(pargc, pargv, JNI_FALSE);
 337     if (JLI_StrCmp(jvmtype, "ERROR") == 0) {
 338         JLI_ReportErrorMessage(CFG_ERROR9);
 339         exit(4);
 340     }
 341 
 342     if (!GetJVMPath(jrepath, jvmtype, jvmpath, so_jvmpath)) {
 343         JLI_ReportErrorMessage(CFG_ERROR8, jvmtype, jvmpath);
 344         exit(4);
 345     }
 346     /*
 347      * we seem to have everything we need, so without further ado
 348      * we return back, otherwise proceed to set the environment.
 349      */
 350 #ifdef SETENV_REQUIRED
 351     mustsetenv = RequiresSetenv(jvmpath);
 352     JLI_TraceLauncher("mustsetenv: %s\n", mustsetenv ? "TRUE" : "FALSE");
 353 
 354     if (mustsetenv == JNI_FALSE) {
 355         return;
 356     }
 357 #else
 358     return;
 359 #endif /* SETENV_REQUIRED */
 360 
 361 #ifdef SETENV_REQUIRED
 362     if (mustsetenv) {
 363         /*
 364          * We will set the LD_LIBRARY_PATH as follows:
 365          *
 366          *     o          $JVMPATH (directory portion only)
 367          *     o          $JRE/lib
 368          *     o          $JRE/../lib
 369          *
 370          * followed by the user's previous effective LD_LIBRARY_PATH, if
 371          * any.
 372          */
 373 
 374 #ifdef __solaris__
 375         llp64 = getenv("LD_LIBRARY_PATH_64");
 376         runpath = (llp64 == NULL) ? getenv(LD_LIBRARY_PATH) : llp64;
 377 #else
 378         runpath = getenv(LD_LIBRARY_PATH);
 379 #endif /* __solaris__ */
 380 
 381         /* runpath contains current effective LD_LIBRARY_PATH setting */
 382         { /* New scope to declare local variable */
 383             char *new_jvmpath = JLI_StringDup(jvmpath);
 384             new_runpath_size = ((runpath != NULL) ? JLI_StrLen(runpath) : 0) +
 385                     2 * JLI_StrLen(jrepath) +
 386                     JLI_StrLen(new_jvmpath) + 52;
 387             new_runpath = JLI_MemAlloc(new_runpath_size);
 388             newpath = new_runpath + JLI_StrLen(LD_LIBRARY_PATH "=");
 389 
 390 
 391             /*
 392              * Create desired LD_LIBRARY_PATH value for target data model.
 393              */
 394             {
 395                 /* remove the name of the .so from the JVM path */
 396                 lastslash = JLI_StrRChr(new_jvmpath, '/');
 397                 if (lastslash)
 398                     *lastslash = '\0';
 399 
 400                 sprintf(new_runpath, LD_LIBRARY_PATH "="
 401                         "%s:"
 402                         "%s/lib:"
 403                         "%s/../lib",
 404                         new_jvmpath,
 405                         jrepath,
 406                         jrepath
 407                         );
 408 
 409                 JLI_MemFree(new_jvmpath);
 410 
 411                 /*
 412                  * Check to make sure that the prefix of the current path is the
 413                  * desired environment variable setting, though the RequiresSetenv
 414                  * checks if the desired runpath exists, this logic does a more
 415                  * comprehensive check.
 416                  */
 417                 if (runpath != NULL &&
 418                         JLI_StrNCmp(newpath, runpath, JLI_StrLen(newpath)) == 0 &&
 419                         (runpath[JLI_StrLen(newpath)] == 0 ||
 420                         runpath[JLI_StrLen(newpath)] == ':')) {
 421                     JLI_MemFree(new_runpath);
 422                     return;
 423                 }
 424             }
 425         }
 426 
 427         /*
 428          * Place the desired environment setting onto the prefix of
 429          * LD_LIBRARY_PATH.  Note that this prevents any possible infinite
 430          * loop of execv() because we test for the prefix, above.
 431          */
 432         if (runpath != 0) {
 433             /* ensure storage for runpath + colon + NULL */
 434             if ((JLI_StrLen(runpath) + 1 + 1) > new_runpath_size) {
 435                 JLI_ReportErrorMessageSys(JRE_ERROR11);
 436                 exit(1);
 437             }
 438             JLI_StrCat(new_runpath, ":");
 439             JLI_StrCat(new_runpath, runpath);
 440         }
 441 
 442         if (putenv(new_runpath) != 0) {
 443             /* problem allocating memory; LD_LIBRARY_PATH not set properly */
 444             exit(1);
 445         }
 446 
 447         /*
 448          * Unix systems document that they look at LD_LIBRARY_PATH only
 449          * once at startup, so we have to re-exec the current executable
 450          * to get the changed environment variable to have an effect.
 451          */
 452 #ifdef __solaris__
 453         /*
 454          * new LD_LIBRARY_PATH took over for LD_LIBRARY_PATH_64
 455          */
 456         if (llp64 != NULL) {
 457             UnsetEnv("LD_LIBRARY_PATH_64");
 458         }
 459 #endif // __solaris__
 460 
 461         newenvp = environ;
 462     }
 463 #endif /* SETENV_REQUIRED */
 464     {
 465         char *newexec = execname;
 466         JLI_TraceLauncher("TRACER_MARKER:About to EXEC\n");
 467         (void) fflush(stdout);
 468         (void) fflush(stderr);
 469 #ifdef SETENV_REQUIRED
 470         if (mustsetenv) {
 471             execve(newexec, argv, newenvp);
 472         } else {
 473             execv(newexec, argv);
 474         }
 475 #else /* !SETENV_REQUIRED */
 476         execv(newexec, argv);
 477 #endif /* SETENV_REQUIRED */
 478         JLI_ReportErrorMessageSys(JRE_ERROR4, newexec);
 479     }
 480     exit(1);
 481 }
 482 
 483 
 484 static jboolean
 485 GetJVMPath(const char *jrepath, const char *jvmtype,
 486            char *jvmpath, jint jvmpathsize)
 487 {
 488     struct stat s;
 489 
 490     if (JLI_StrChr(jvmtype, '/')) {
 491         JLI_Snprintf(jvmpath, jvmpathsize, "%s/" JVM_DLL, jvmtype);
 492     } else {
 493         JLI_Snprintf(jvmpath, jvmpathsize, "%s/lib/%s/" JVM_DLL, jrepath, jvmtype);
 494     }
 495 
 496     JLI_TraceLauncher("Does `%s' exist ... ", jvmpath);
 497 
 498     if (stat(jvmpath, &s) == 0) {
 499         JLI_TraceLauncher("yes.\n");
 500         return JNI_TRUE;
 501     } else {
 502         JLI_TraceLauncher("no.\n");
 503         return JNI_FALSE;
 504     }
 505 }
 506 
 507 /*
 508  * Find path to JRE based on .exe's location or registry settings.
 509  */
 510 static jboolean
 511 GetJREPath(char *path, jint pathsize, jboolean speculative)
 512 {
 513     char libjava[MAXPATHLEN];
 514     struct stat s;
 515 
 516     if (GetApplicationHome(path, pathsize)) {
 517         /* Is JRE co-located with the application? */
 518         JLI_Snprintf(libjava, sizeof(libjava), "%s/lib/" JAVA_DLL, path);
 519         if (access(libjava, F_OK) == 0) {
 520             JLI_TraceLauncher("JRE path is %s\n", path);
 521             return JNI_TRUE;
 522         }
 523         /* ensure storage for path + /jre + NULL */
 524         if ((JLI_StrLen(path) + 4  + 1) > (size_t) pathsize) {
 525             JLI_TraceLauncher("Insufficient space to store JRE path\n");
 526             return JNI_FALSE;
 527         }
 528         /* Does the app ship a private JRE in <apphome>/jre directory? */
 529         JLI_Snprintf(libjava, sizeof(libjava), "%s/jre/lib/" JAVA_DLL, path);
 530         if (access(libjava, F_OK) == 0) {
 531             JLI_StrCat(path, "/jre");
 532             JLI_TraceLauncher("JRE path is %s\n", path);
 533             return JNI_TRUE;
 534         }
 535     }
 536 
 537     if (GetApplicationHomeFromDll(path, pathsize)) {
 538         JLI_Snprintf(libjava, sizeof(libjava), "%s/lib/" JAVA_DLL, path);
 539         if (stat(libjava, &s) == 0) {
 540             JLI_TraceLauncher("JRE path is %s\n", path);
 541             return JNI_TRUE;
 542         }
 543     }
 544 
 545     if (!speculative)
 546       JLI_ReportErrorMessage(JRE_ERROR8 JAVA_DLL);
 547     return JNI_FALSE;
 548 }
 549 
 550 jboolean
 551 LoadJavaVM(const char *jvmpath, InvocationFunctions *ifn)
 552 {
 553     void *libjvm;
 554 
 555     JLI_TraceLauncher("JVM path is %s\n", jvmpath);
 556 
 557     libjvm = dlopen(jvmpath, RTLD_NOW + RTLD_GLOBAL);
 558     if (libjvm == NULL) {
 559 #if defined(__solaris__) && defined(__sparc) && !defined(_LP64) /* i.e. 32-bit sparc */
 560       FILE * fp;
 561       Elf32_Ehdr elf_head;
 562       int count;
 563       int location;
 564 
 565       fp = fopen(jvmpath, "r");
 566       if (fp == NULL) {
 567         JLI_ReportErrorMessage(DLL_ERROR2, jvmpath, dlerror());
 568         return JNI_FALSE;
 569       }
 570 
 571       /* read in elf header */
 572       count = fread((void*)(&elf_head), sizeof(Elf32_Ehdr), 1, fp);
 573       fclose(fp);
 574       if (count < 1) {
 575         JLI_ReportErrorMessage(DLL_ERROR2, jvmpath, dlerror());
 576         return JNI_FALSE;
 577       }
 578 
 579       /*
 580        * Check for running a server vm (compiled with -xarch=v8plus)
 581        * on a stock v8 processor.  In this case, the machine type in
 582        * the elf header would not be included the architecture list
 583        * provided by the isalist command, which is turn is gotten from
 584        * sysinfo.  This case cannot occur on 64-bit hardware and thus
 585        * does not have to be checked for in binaries with an LP64 data
 586        * model.
 587        */
 588       if (elf_head.e_machine == EM_SPARC32PLUS) {
 589         char buf[257];  /* recommended buffer size from sysinfo man
 590                            page */
 591         long length;
 592         char* location;
 593 
 594         length = sysinfo(SI_ISALIST, buf, 257);
 595         if (length > 0) {
 596             location = JLI_StrStr(buf, "sparcv8plus ");
 597           if (location == NULL) {
 598             JLI_ReportErrorMessage(JVM_ERROR3);
 599             return JNI_FALSE;
 600           }
 601         }
 602       }
 603 #endif
 604         JLI_ReportErrorMessage(DLL_ERROR1, __LINE__);
 605         JLI_ReportErrorMessage(DLL_ERROR2, jvmpath, dlerror());
 606         return JNI_FALSE;
 607     }
 608 
 609     ifn->CreateJavaVM = (CreateJavaVM_t)
 610         dlsym(libjvm, "JNI_CreateJavaVM");
 611     if (ifn->CreateJavaVM == NULL) {
 612         JLI_ReportErrorMessage(DLL_ERROR2, jvmpath, dlerror());
 613         return JNI_FALSE;
 614     }
 615 
 616     ifn->GetDefaultJavaVMInitArgs = (GetDefaultJavaVMInitArgs_t)
 617         dlsym(libjvm, "JNI_GetDefaultJavaVMInitArgs");
 618     if (ifn->GetDefaultJavaVMInitArgs == NULL) {
 619         JLI_ReportErrorMessage(DLL_ERROR2, jvmpath, dlerror());
 620         return JNI_FALSE;
 621     }
 622 
 623     ifn->GetCreatedJavaVMs = (GetCreatedJavaVMs_t)
 624         dlsym(libjvm, "JNI_GetCreatedJavaVMs");
 625     if (ifn->GetCreatedJavaVMs == NULL) {
 626         JLI_ReportErrorMessage(DLL_ERROR2, jvmpath, dlerror());
 627         return JNI_FALSE;
 628     }
 629 
 630     return JNI_TRUE;
 631 }
 632 
 633 /*
 634  * Compute the name of the executable
 635  *
 636  * In order to re-exec securely we need the absolute path of the
 637  * executable. On Solaris getexecname(3c) may not return an absolute
 638  * path so we use dladdr to get the filename of the executable and
 639  * then use realpath to derive an absolute path. From Solaris 9
 640  * onwards the filename returned in DL_info structure from dladdr is
 641  * an absolute pathname so technically realpath isn't required.
 642  * On Linux we read the executable name from /proc/self/exe.
 643  * As a fallback, and for platforms other than Solaris and Linux,
 644  * we use FindExecName to compute the executable name.
 645  */
 646 const char*
 647 SetExecname(char **argv)
 648 {
 649     char* exec_path = NULL;
 650 #if defined(__solaris__)
 651     {
 652         Dl_info dlinfo;
 653         int (*fptr)();
 654 
 655         fptr = (int (*)())dlsym(RTLD_DEFAULT, "main");
 656         if (fptr == NULL) {
 657             JLI_ReportErrorMessage(DLL_ERROR3, dlerror());
 658             return JNI_FALSE;
 659         }
 660 
 661         if (dladdr((void*)fptr, &dlinfo)) {
 662             char *resolved = (char*)JLI_MemAlloc(PATH_MAX+1);
 663             if (resolved != NULL) {
 664                 exec_path = realpath(dlinfo.dli_fname, resolved);
 665                 if (exec_path == NULL) {
 666                     JLI_MemFree(resolved);
 667                 }
 668             }
 669         }
 670     }
 671 #elif defined(__linux__)
 672     {
 673         const char* self = "/proc/self/exe";
 674         char buf[PATH_MAX+1];
 675         int len = readlink(self, buf, PATH_MAX);
 676         if (len >= 0) {
 677             buf[len] = '\0';            /* readlink(2) doesn't NUL terminate */
 678             exec_path = JLI_StringDup(buf);
 679         }
 680     }
 681 #else /* !__solaris__ && !__linux__ */
 682     {
 683         /* Not implemented */
 684     }
 685 #endif
 686 
 687     if (exec_path == NULL) {
 688         exec_path = FindExecName(argv[0]);
 689     }
 690     execname = exec_path;
 691     return exec_path;
 692 }
 693 
 694 /* --- Splash Screen shared library support --- */
 695 static const char* SPLASHSCREEN_SO = JNI_LIB_NAME("splashscreen");
 696 static void* hSplashLib = NULL;
 697 
 698 void* SplashProcAddress(const char* name) {
 699     if (!hSplashLib) {
 700         int ret;
 701         char jrePath[MAXPATHLEN];
 702         char splashPath[MAXPATHLEN];
 703 
 704         if (!GetJREPath(jrePath, sizeof(jrePath), JNI_FALSE)) {
 705             JLI_ReportErrorMessage(JRE_ERROR1);
 706             return NULL;
 707         }
 708         ret = JLI_Snprintf(splashPath, sizeof(splashPath), "%s/lib/%s",
 709                      jrePath, SPLASHSCREEN_SO);
 710 
 711         if (ret >= (int) sizeof(splashPath)) {
 712             JLI_ReportErrorMessage(JRE_ERROR11);
 713             return NULL;
 714         }
 715         if (ret < 0) {
 716             JLI_ReportErrorMessage(JRE_ERROR13);
 717             return NULL;
 718         }
 719         hSplashLib = dlopen(splashPath, RTLD_LAZY | RTLD_GLOBAL);
 720         JLI_TraceLauncher("Info: loaded %s\n", splashPath);
 721     }
 722     if (hSplashLib) {
 723         void* sym = dlsym(hSplashLib, name);
 724         return sym;
 725     } else {
 726         return NULL;
 727     }
 728 }
 729 
 730 /*
 731  * Signature adapter for pthread_create() or thr_create().
 732  */
 733 static void* ThreadJavaMain(void* args) {
 734     return (void*)(intptr_t)JavaMain(args);
 735 }
 736 
 737 /*
 738  * Block current thread and continue execution in a new thread.
 739  */
 740 int
 741 CallJavaMainInNewThread(jlong stack_size, void* args) {
 742     int rslt;
 743 #ifndef __solaris__
 744     pthread_t tid;
 745     pthread_attr_t attr;
 746     pthread_attr_init(&attr);
 747     pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_JOINABLE);
 748 
 749     if (stack_size > 0) {
 750         pthread_attr_setstacksize(&attr, stack_size);
 751     }
 752     pthread_attr_setguardsize(&attr, 0); // no pthread guard page on java threads
 753 
 754     if (pthread_create(&tid, &attr, ThreadJavaMain, args) == 0) {
 755         void* tmp;
 756         pthread_join(tid, &tmp);
 757         rslt = (int)(intptr_t)tmp;
 758     } else {
 759        /*
 760         * Continue execution in current thread if for some reason (e.g. out of
 761         * memory/LWP)  a new thread can't be created. This will likely fail
 762         * later in JavaMain as JNI_CreateJavaVM needs to create quite a
 763         * few new threads, anyway, just give it a try..
 764         */
 765         rslt = JavaMain(args);
 766     }
 767 
 768     pthread_attr_destroy(&attr);
 769 #else /* __solaris__ */
 770     thread_t tid;
 771     long flags = 0;
 772     if (thr_create(NULL, stack_size, ThreadJavaMain, args, flags, &tid) == 0) {
 773         void* tmp;
 774         thr_join(tid, NULL, &tmp);
 775         rslt = (int)(intptr_t)tmp;
 776     } else {
 777         /* See above. Continue in current thread if thr_create() failed */
 778         rslt = JavaMain(args);
 779     }
 780 #endif /* !__solaris__ */
 781     return rslt;
 782 }
 783 
 784 /* Coarse estimation of number of digits assuming the worst case is a 64-bit pid. */
 785 #define MAX_PID_STR_SZ   20
 786 
 787 int
 788 JVMInit(InvocationFunctions* ifn, jlong threadStackSize,
 789         int argc, char **argv,
 790         int mode, char *what, int ret)
 791 {
 792     ShowSplashScreen();
 793     return ContinueInNewThread(ifn, threadStackSize, argc, argv, mode, what, ret);
 794 }
 795 
 796 void
 797 PostJVMInit(JNIEnv *env, jclass mainClass, JavaVM *vm)
 798 {
 799     // stubbed out for windows and *nixes.
 800 }
 801 
 802 void
 803 RegisterThread()
 804 {
 805     // stubbed out for windows and *nixes.
 806 }
 807 
 808 /*
 809  * on unix, we return a false to indicate this option is not applicable
 810  */
 811 jboolean
 812 ProcessPlatformOption(const char *arg)
 813 {
 814     return JNI_FALSE;
 815 }
 816 
 817 #ifndef __solaris__
 818 
 819 /*
 820  * Provide a CounterGet() implementation based on gettimeofday() which
 821  * is universally available, even though it may not be 'high resolution'
 822  * compared to platforms that provide gethrtime() (like Solaris). It is
 823  * also subject to time-of-day changes, but alternatives may not be
 824  * known to be available at either build time or run time.
 825  */
 826 uint64_t CounterGet() {
 827     uint64_t result = 0;
 828     struct timeval tv;
 829     if (gettimeofday(&tv, NULL) != -1) {
 830         result = 1000000LL * (uint64_t)tv.tv_sec;
 831         result += (uint64_t)tv.tv_usec;
 832     }
 833     return result;
 834 }
 835 
 836 #endif // !__solaris__