/** Copyright (c) 1995, 2008, Oracle and/or its affiliates. All rights reserved.* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.** This code is free software; you can redistribute it and/or modify it* under the terms of the GNU General Public License version 2 only, as* published by the Free Software Foundation.  Oracle designates this* particular file as subject to the "Classpath" exception as provided* by Oracle in the LICENSE file that accompanied this code.** This code is distributed in the hope that it will be useful, but WITHOUT* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or* FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License* version 2 for more details (a copy is included in the LICENSE file that* accompanied this code).** You should have received a copy of the GNU General Public License version* 2 along with this work; if not, write to the Free Software Foundation,* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.** Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA* or visit www.oracle.com if you need additional information or have any* questions.*/#undef  _LARGEFILE64_SOURCE
#define _LARGEFILE64_SOURCE 1#include "jni.h"
#include "jvm.h"
#include "jvm_md.h"
#include "jni_util.h"
#include "io_util.h"/** Platform-specific support for java.lang.Process*/
#include <assert.h>
#include <stddef.h>
#include <stdlib.h>
#include <sys/types.h>
#include <ctype.h>
#ifdef _ALLBSD_SOURCE
#include <sys/wait.h>
#else
#include <wait.h>
#endif
#include <signal.h>
#include <string.h>
#include <errno.h>
#include <dirent.h>
#include <unistd.h>
#include <fcntl.h>
#include <limits.h>#ifdef __APPLE__
#include <crt_externs.h>
#define environ (*_NSGetEnviron())
#endif/** There are 3 possible strategies we might use to "fork":** - fork(2).  Very portable and reliable but subject to*   failure due to overcommit (see the documentation on*   /proc/sys/vm/overcommit_memory in Linux proc(5)).*   This is the ancient problem of spurious failure whenever a large*   process starts a small subprocess.** - vfork().  Using this is scary because all relevant man pages*   contain dire warnings, e.g. Linux vfork(2).  But at least it's*   documented in the glibc docs and is standardized by XPG4.*   http://www.opengroup.org/onlinepubs/000095399/functions/vfork.html*   On Linux, one might think that vfork() would be implemented using*   the clone system call with flag CLONE_VFORK, but in fact vfork is*   a separate system call (which is a good sign, suggesting that*   vfork will continue to be supported at least on Linux).*   Another good sign is that glibc implements posix_spawn using*   vfork whenever possible.  Note that we cannot use posix_spawn*   ourselves because there's no reliable way to close all inherited*   file descriptors.** - clone() with flags CLONE_VM but not CLONE_THREAD.  clone() is*   Linux-specific, but this ought to work - at least the glibc*   sources contain code to handle different combinations of CLONE_VM*   and CLONE_THREAD.  However, when this was implemented, it*   appeared to fail on 32-bit i386 (but not 64-bit x86_64) Linux with*   the simple program*     Runtime.getRuntime().exec("/bin/true").waitFor();*   with:*     #  Internal Error (os_linux_x86.cpp:683), pid=19940, tid=2934639536*     #  Error: pthread_getattr_np failed with errno = 3 (ESRCH)*   We believe this is a glibc bug, reported here:*     http://sources.redhat.com/bugzilla/show_bug.cgi?id=10311*   but the glibc maintainers closed it as WONTFIX.** Based on the above analysis, we are currently using vfork() on* Linux and fork() on other Unix systems, but the code to use clone()* remains.*/#define START_CHILD_USE_CLONE 0  /* clone() currently disabled; see above. */#ifndef START_CHILD_USE_CLONE#ifdef __linux__#define START_CHILD_USE_CLONE 1#else#define START_CHILD_USE_CLONE 0#endif
#endif/* By default, use vfork() on Linux. */
#ifndef START_CHILD_USE_VFORK#ifdef __linux__#define START_CHILD_USE_VFORK 1#else#define START_CHILD_USE_VFORK 0#endif
#endif#if START_CHILD_USE_CLONE
#include <sched.h>
#define START_CHILD_SYSTEM_CALL "clone"
#elif START_CHILD_USE_VFORK
#define START_CHILD_SYSTEM_CALL "vfork"
#else
#define START_CHILD_SYSTEM_CALL "fork"
#endif#ifndef STDIN_FILENO
#define STDIN_FILENO 0
#endif#ifndef STDOUT_FILENO
#define STDOUT_FILENO 1
#endif#ifndef STDERR_FILENO
#define STDERR_FILENO 2
#endif#ifndef SA_NOCLDSTOP
#define SA_NOCLDSTOP 0
#endif#ifndef SA_RESTART
#define SA_RESTART 0
#endif#define FAIL_FILENO (STDERR_FILENO + 1)/* TODO: Refactor. */
#define RESTARTABLE(_cmd, _result) do { \do { \_result = _cmd; \} while((_result == -1) && (errno == EINTR)); \
} while(0)/* This is one of the rare times it's more portable to declare an* external symbol explicitly, rather than via a system header.* The declaration is standardized as part of UNIX98, but there is* no standard (not even de-facto) header file where the* declaration is to be found.  See:* http://www.opengroup.org/onlinepubs/009695399/functions/environ.html* http://www.opengroup.org/onlinepubs/009695399/functions/xsh_chap02_02.html** "All identifiers in this volume of IEEE Std 1003.1-2001, except* environ, are defined in at least one of the headers" (!)*/
extern char **environ;static void
setSIGCHLDHandler(JNIEnv *env)
{/* There is a subtle difference between having the signal handler* for SIGCHLD be SIG_DFL and SIG_IGN.  We cannot obtain process* termination information for child processes if the signal* handler is SIG_IGN.  It must be SIG_DFL.** We used to set the SIGCHLD handler only on Linux, but it's* safest to set it unconditionally.** Consider what happens if java's parent process sets the SIGCHLD* handler to SIG_IGN.  Normally signal handlers are inherited by* children, but SIGCHLD is a controversial case.  Solaris appears* to always reset it to SIG_DFL, but this behavior may be* non-standard-compliant, and we shouldn't rely on it.** References:* http://www.opengroup.org/onlinepubs/7908799/xsh/exec.html* http://www.pasc.org/interps/unofficial/db/p1003.1/pasc-1003.1-132.html*/struct sigaction sa;sa.sa_handler = SIG_DFL;sigemptyset(&sa.sa_mask);sa.sa_flags = SA_NOCLDSTOP | SA_RESTART;if (sigaction(SIGCHLD, &sa, NULL) < 0)JNU_ThrowInternalError(env, "Can't set SIGCHLD handler");
}static void*
xmalloc(JNIEnv *env, size_t size)
{void *p = malloc(size);if (p == NULL)JNU_ThrowOutOfMemoryError(env, NULL);return p;
}#define NEW(type, n) ((type *) xmalloc(env, (n) * sizeof(type)))/*** If PATH is not defined, the OS provides some default value.* Unfortunately, there's no portable way to get this value.* Fortunately, it's only needed if the child has PATH while we do not.*/
static const char*
defaultPath(void)
{
#ifdef __solaris__/* These really are the Solaris defaults! */return (geteuid() == 0 || getuid() == 0) ?"/usr/xpg4/bin:/usr/ccs/bin:/usr/bin:/opt/SUNWspro/bin:/usr/sbin" :"/usr/xpg4/bin:/usr/ccs/bin:/usr/bin:/opt/SUNWspro/bin:";
#elsereturn ":/bin:/usr/bin";    /* glibc */
#endif
}static const char*
effectivePath(void)
{const char *s = getenv("PATH");return (s != NULL) ? s : defaultPath();
}static int
countOccurrences(const char *s, char c)
{int count;for (count = 0; *s != '\0'; s++)count += (*s == c);return count;
}static const char * const *
splitPath(JNIEnv *env, const char *path)
{const char *p, *q;char **pathv;int i;int count = countOccurrences(path, ':') + 1;pathv = NEW(char*, count+1);pathv[count] = NULL;for (p = path, i = 0; i < count; i++, p = q + 1) {for (q = p; (*q != ':') && (*q != '\0'); q++);if (q == p)             /* empty PATH component => "." */pathv[i] = "./";else {int addSlash = ((*(q - 1)) != '/');pathv[i] = NEW(char, q - p + addSlash + 1);memcpy(pathv[i], p, q - p);if (addSlash)pathv[i][q - p] = '/';pathv[i][q - p + addSlash] = '\0';}}return (const char * const *) pathv;
}/*** Cached value of JVM's effective PATH.* (We don't support putenv("PATH=...") in native code)*/
static const char *parentPath;/*** Split, canonicalized version of parentPath*/
static const char * const *parentPathv;static jfieldID field_exitcode;JNIEXPORT void JNICALL
Java_java_lang_UNIXProcess_initIDs(JNIEnv *env, jclass clazz)
{field_exitcode = (*env)->GetFieldID(env, clazz, "exitcode", "I");parentPath  = effectivePath();parentPathv = splitPath(env, parentPath);setSIGCHLDHandler(env);
}#ifndef WIFEXITED
#define WIFEXITED(status) (((status)&0xFF) == 0)
#endif#ifndef WEXITSTATUS
#define WEXITSTATUS(status) (((status)>>8)&0xFF)
#endif#ifndef WIFSIGNALED
#define WIFSIGNALED(status) (((status)&0xFF) > 0 && ((status)&0xFF00) == 0)
#endif#ifndef WTERMSIG
#define WTERMSIG(status) ((status)&0x7F)
#endif/* Block until a child process exits and return its exit code.Note, can only be called once for any given pid. */
JNIEXPORT jint JNICALL
Java_java_lang_UNIXProcess_waitForProcessExit(JNIEnv* env,jobject junk,jint pid)
{/* We used to use waitid() on Solaris, waitpid() on Linux, but* waitpid() is more standard, so use it on all POSIX platforms. */int status;/* Wait for the child process to exit.  This returns immediately ifthe child has already exited. */while (waitpid(pid, &status, 0) < 0) {switch (errno) {case ECHILD: return 0;case EINTR: break;default: return -1;}}if (WIFEXITED(status)) {/** The child exited normally; get its exit code.*/return WEXITSTATUS(status);} else if (WIFSIGNALED(status)) {/* The child exited because of a signal.* The best value to return is 0x80 + signal number,* because that is what all Unix shells do, and because* it allows callers to distinguish between process exit and* process death by signal.* Unfortunately, the historical behavior on Solaris is to return* the signal number, and we preserve this for compatibility. */
#ifdef __solaris__return WTERMSIG(status);
#elsereturn 0x80 + WTERMSIG(status);
#endif} else {/** Unknown exit code; pass it through.*/return status;}
}static ssize_t
restartableWrite(int fd, const void *buf, size_t count)
{ssize_t result;RESTARTABLE(write(fd, buf, count), result);return result;
}static int
restartableDup2(int fd_from, int fd_to)
{int err;RESTARTABLE(dup2(fd_from, fd_to), err);return err;
}static int
restartableClose(int fd)
{int err;RESTARTABLE(close(fd), err);return err;
}static int
closeSafely(int fd)
{return (fd == -1) ? 0 : restartableClose(fd);
}static int
isAsciiDigit(char c)
{return c >= '0' && c <= '9';
}#ifdef _ALLBSD_SOURCE
#define FD_DIR "/dev/fd"
#define dirent64 dirent
#define readdir64 readdir
#else
#define FD_DIR "/proc/self/fd"
#endifstatic int
closeDescriptors(void)
{DIR *dp;struct dirent64 *dirp;int from_fd = FAIL_FILENO + 1;/* We're trying to close all file descriptors, but opendir() might* itself be implemented using a file descriptor, and we certainly* don't want to close that while it's in use.  We assume that if* opendir() is implemented using a file descriptor, then it uses* the lowest numbered file descriptor, just like open().  So we* close a couple explicitly.  */restartableClose(from_fd);          /* for possible use by opendir() */restartableClose(from_fd + 1);      /* another one for good luck */if ((dp = opendir(FD_DIR)) == NULL)return 0;/* We use readdir64 instead of readdir to work around Solaris bug* 6395699: /proc/self/fd fails to report file descriptors >= 1024 on Solaris 9*/while ((dirp = readdir64(dp)) != NULL) {int fd;if (isAsciiDigit(dirp->d_name[0]) &&(fd = strtol(dirp->d_name, NULL, 10)) >= from_fd + 2)restartableClose(fd);}closedir(dp);return 1;
}static int
moveDescriptor(int fd_from, int fd_to)
{if (fd_from != fd_to) {if ((restartableDup2(fd_from, fd_to) == -1) ||(restartableClose(fd_from) == -1))return -1;}return 0;
}static const char *
getBytes(JNIEnv *env, jbyteArray arr)
{return arr == NULL ? NULL :(const char*) (*env)->GetByteArrayElements(env, arr, NULL);
}static void
releaseBytes(JNIEnv *env, jbyteArray arr, const char* parr)
{if (parr != NULL)(*env)->ReleaseByteArrayElements(env, arr, (jbyte*) parr, JNI_ABORT);
}static void
initVectorFromBlock(const char**vector, const char* block, int count)
{int i;const char *p;for (i = 0, p = block; i < count; i++) {/* Invariant: p always points to the start of a C string. */vector[i] = p;while (*(p++));}vector[count] = NULL;
}static void
throwIOException(JNIEnv *env, int errnum, const char *defaultDetail)
{static const char * const format = "error=%d, %s";const char *detail = defaultDetail;char *errmsg;jstring s;if (errnum != 0) {const char *s = strerror(errnum);if (strcmp(s, "Unknown error") != 0)detail = s;}/* ASCII Decimal representation uses 2.4 times as many bits as binary. */errmsg = NEW(char, strlen(format) + strlen(detail) + 3 * sizeof(errnum));sprintf(errmsg, format, errnum, detail);s = JNU_NewStringPlatform(env, errmsg);if (s != NULL) {jobject x = JNU_NewObjectByName(env, "java/io/IOException","(Ljava/lang/String;)V", s);if (x != NULL)(*env)->Throw(env, x);}free(errmsg);
}#ifdef DEBUG_PROCESS
/* Debugging process code is difficult; where to write debug output? */
static void
debugPrint(char *format, ...)
{FILE *tty = fopen("/dev/tty", "w");va_list ap;va_start(ap, format);vfprintf(tty, format, ap);va_end(ap);fclose(tty);
}
#endif /* DEBUG_PROCESS *//*** Exec FILE as a traditional Bourne shell script (i.e. one without #!).* If we could do it over again, we would probably not support such an ancient* misfeature, but compatibility wins over sanity.  The original support for* this was imported accidentally from execvp().*/
static void
execve_as_traditional_shell_script(const char *file,const char *argv[],const char *const envp[])
{/* Use the extra word of space provided for us in argv by caller. */const char *argv0 = argv[0];const char *const *end = argv;while (*end != NULL)++end;memmove(argv+2, argv+1, (end-argv) * sizeof (*end));argv[0] = "/bin/sh";argv[1] = file;execve(argv[0], (char **) argv, (char **) envp);/* Can't even exec /bin/sh?  Big trouble, but let's soldier on... */memmove(argv+1, argv+2, (end-argv) * sizeof (*end));argv[0] = argv0;
}/*** Like execve(2), except that in case of ENOEXEC, FILE is assumed to* be a shell script and the system default shell is invoked to run it.*/
static void
execve_with_shell_fallback(const char *file,const char *argv[],const char *const envp[])
{
#if START_CHILD_USE_CLONE || START_CHILD_USE_VFORK/* shared address space; be very careful. */execve(file, (char **) argv, (char **) envp);if (errno == ENOEXEC)execve_as_traditional_shell_script(file, argv, envp);
#else/* unshared address space; we can mutate environ. */environ = (char **) envp;execvp(file, (char **) argv);
#endif
}/*** 'execvpe' should have been included in the Unix standards,* and is a GNU extension in glibc 2.10.** JDK_execvpe is identical to execvp, except that the child environment is* specified via the 3rd argument instead of being inherited from environ.*/
static void
JDK_execvpe(const char *file,const char *argv[],const char *const envp[])
{if (envp == NULL || (char **) envp == environ) {execvp(file, (char **) argv);return;}if (*file == '\0') {errno = ENOENT;return;}if (strchr(file, '/') != NULL) {execve_with_shell_fallback(file, argv, envp);} else {/* We must search PATH (parent's, not child's) */char expanded_file[PATH_MAX];int filelen = strlen(file);int sticky_errno = 0;const char * const * dirs;for (dirs = parentPathv; *dirs; dirs++) {const char * dir = *dirs;int dirlen = strlen(dir);if (filelen + dirlen + 1 >= PATH_MAX) {errno = ENAMETOOLONG;continue;}memcpy(expanded_file, dir, dirlen);memcpy(expanded_file + dirlen, file, filelen);expanded_file[dirlen + filelen] = '\0';execve_with_shell_fallback(expanded_file, argv, envp);/* There are 3 responses to various classes of errno:* return immediately, continue (especially for ENOENT),* or continue with "sticky" errno.** From exec(3):** If permission is denied for a file (the attempted* execve returned EACCES), these functions will continue* searching the rest of the search path.  If no other* file is found, however, they will return with the* global variable errno set to EACCES.*/switch (errno) {case EACCES:sticky_errno = errno;/* FALLTHRU */case ENOENT:case ENOTDIR:
#ifdef ELOOPcase ELOOP:
#endif
#ifdef ESTALEcase ESTALE:
#endif
#ifdef ENODEVcase ENODEV:
#endif
#ifdef ETIMEDOUTcase ETIMEDOUT:
#endifbreak; /* Try other directories in PATH */default:return;}}if (sticky_errno != 0)errno = sticky_errno;}
}/** Reads nbyte bytes from file descriptor fd into buf,* The read operation is retried in case of EINTR or partial reads.** Returns number of bytes read (normally nbyte, but may be less in* case of EOF).  In case of read errors, returns -1 and sets errno.*/
static ssize_t
readFully(int fd, void *buf, size_t nbyte)
{ssize_t remaining = nbyte;for (;;) {ssize_t n = read(fd, buf, remaining);if (n == 0) {return nbyte - remaining;} else if (n > 0) {remaining -= n;if (remaining <= 0)return nbyte;/* We were interrupted in the middle of reading the bytes.* Unlikely, but possible. */buf = (void *) (((char *)buf) + n);} else if (errno == EINTR) {/* Strange signals like SIGJVM1 are possible at any time.* See http://www.dreamsongs.com/WorseIsBetter.html */} else {return -1;}}
}typedef struct _ChildStuff
{int in[2];int out[2];int err[2];int fail[2];int fds[3];const char **argv;const char **envv;const char *pdir;jboolean redirectErrorStream;
#if START_CHILD_USE_CLONEvoid *clone_stack;
#endif
} ChildStuff;static void
copyPipe(int from[2], int to[2])
{to[0] = from[0];to[1] = from[1];
}/*** Child process after a successful fork() or clone().* This function must not return, and must be prepared for either all* of its address space to be shared with its parent, or to be a copy.* It must not modify global variables such as "environ".*/
static int
childProcess(void *arg)
{const ChildStuff* p = (const ChildStuff*) arg;/* Close the parent sides of the pipes.Closing pipe fds here is redundant, since closeDescriptors()would do it anyways, but a little paranoia is a good thing. */if ((closeSafely(p->in[1])   == -1) ||(closeSafely(p->out[0])  == -1) ||(closeSafely(p->err[0])  == -1) ||(closeSafely(p->fail[0]) == -1))goto WhyCantJohnnyExec;/* Give the child sides of the pipes the right fileno's. *//* Note: it is possible for in[0] == 0 */if ((moveDescriptor(p->in[0] != -1 ?  p->in[0] : p->fds[0],STDIN_FILENO) == -1) ||(moveDescriptor(p->out[1]!= -1 ? p->out[1] : p->fds[1],STDOUT_FILENO) == -1))goto WhyCantJohnnyExec;if (p->redirectErrorStream) {if ((closeSafely(p->err[1]) == -1) ||(restartableDup2(STDOUT_FILENO, STDERR_FILENO) == -1))goto WhyCantJohnnyExec;} else {if (moveDescriptor(p->err[1] != -1 ? p->err[1] : p->fds[2],STDERR_FILENO) == -1)goto WhyCantJohnnyExec;}if (moveDescriptor(p->fail[1], FAIL_FILENO) == -1)goto WhyCantJohnnyExec;/* close everything */if (closeDescriptors() == 0) { /* failed,  close the old way */int max_fd = (int)sysconf(_SC_OPEN_MAX);int fd;for (fd = FAIL_FILENO + 1; fd < max_fd; fd++)if (restartableClose(fd) == -1 && errno != EBADF)goto WhyCantJohnnyExec;}/* change to the new working directory */if (p->pdir != NULL && chdir(p->pdir) < 0)goto WhyCantJohnnyExec;if (fcntl(FAIL_FILENO, F_SETFD, FD_CLOEXEC) == -1)goto WhyCantJohnnyExec;JDK_execvpe(p->argv[0], p->argv, p->envv);WhyCantJohnnyExec:/* We used to go to an awful lot of trouble to predict whether the* child would fail, but there is no reliable way to predict the* success of an operation without *trying* it, and there's no way* to try a chdir or exec in the parent.  Instead, all we need is a* way to communicate any failure back to the parent.  Easy; we just* send the errno back to the parent over a pipe in case of failure.* The tricky thing is, how do we communicate the *success* of exec?* We use FD_CLOEXEC together with the fact that a read() on a pipe* yields EOF when the write ends (we have two of them!) are closed.*/{int errnum = errno;restartableWrite(FAIL_FILENO, &errnum, sizeof(errnum));}restartableClose(FAIL_FILENO);_exit(-1);return 0;  /* Suppress warning "no return value from function" */
}/*** Start a child process running function childProcess.* This function only returns in the parent.* We are unusually paranoid; use of clone/vfork is* especially likely to tickle gcc/glibc bugs.*/
#ifdef __attribute_noinline__  /* See: sys/cdefs.h */
__attribute_noinline__
#endif
static pid_t
startChild(ChildStuff *c) {
#if START_CHILD_USE_CLONE
#define START_CHILD_CLONE_STACK_SIZE (64 * 1024)/** See clone(2).* Instead of worrying about which direction the stack grows, just* allocate twice as much and start the stack in the middle.*/if ((c->clone_stack = malloc(2 * START_CHILD_CLONE_STACK_SIZE)) == NULL)/* errno will be set to ENOMEM */return -1;return clone(childProcess,c->clone_stack + START_CHILD_CLONE_STACK_SIZE,CLONE_VFORK | CLONE_VM | SIGCHLD, c);
#else#if START_CHILD_USE_VFORK/** We separate the call to vfork into a separate function to make* very sure to keep stack of child from corrupting stack of parent,* as suggested by the scary gcc warning:*  warning: variable 'foo' might be clobbered by 'longjmp' or 'vfork'*/volatile pid_t resultPid = vfork();#else/** From Solaris fork(2): In Solaris 10, a call to fork() is* identical to a call to fork1(); only the calling thread is* replicated in the child process. This is the POSIX-specified* behavior for fork().*/pid_t resultPid = fork();#endifif (resultPid == 0)childProcess(c);assert(resultPid != 0);  /* childProcess never returns */return resultPid;
#endif /* ! START_CHILD_USE_CLONE */
}JNIEXPORT jint JNICALL
Java_java_lang_UNIXProcess_forkAndExec(JNIEnv *env,jobject process,jbyteArray prog,jbyteArray argBlock, jint argc,jbyteArray envBlock, jint envc,jbyteArray dir,jintArray std_fds,jboolean redirectErrorStream)
{int errnum;int resultPid = -1;int in[2], out[2], err[2], fail[2];jint *fds = NULL;const char *pprog = NULL;const char *pargBlock = NULL;const char *penvBlock = NULL;ChildStuff *c;in[0] = in[1] = out[0] = out[1] = err[0] = err[1] = fail[0] = fail[1] = -1;if ((c = NEW(ChildStuff, 1)) == NULL) return -1;c->argv = NULL;c->envv = NULL;c->pdir = NULL;
#if START_CHILD_USE_CLONEc->clone_stack = NULL;
#endif/* Convert prog + argBlock into a char ** argv.* Add one word room for expansion of argv for use by* execve_as_traditional_shell_script.*/assert(prog != NULL && argBlock != NULL);if ((pprog     = getBytes(env, prog))       == NULL) goto Catch;if ((pargBlock = getBytes(env, argBlock))   == NULL) goto Catch;if ((c->argv = NEW(const char *, argc + 3)) == NULL) goto Catch;c->argv[0] = pprog;initVectorFromBlock(c->argv+1, pargBlock, argc);if (envBlock != NULL) {/* Convert envBlock into a char ** envv */if ((penvBlock = getBytes(env, envBlock))   == NULL) goto Catch;if ((c->envv = NEW(const char *, envc + 1)) == NULL) goto Catch;initVectorFromBlock(c->envv, penvBlock, envc);}if (dir != NULL) {if ((c->pdir = getBytes(env, dir)) == NULL) goto Catch;}assert(std_fds != NULL);fds = (*env)->GetIntArrayElements(env, std_fds, NULL);if (fds == NULL) goto Catch;if ((fds[0] == -1 && pipe(in)  < 0) ||(fds[1] == -1 && pipe(out) < 0) ||(fds[2] == -1 && pipe(err) < 0) ||(pipe(fail) < 0)) {throwIOException(env, errno, "Bad file descriptor");goto Catch;}c->fds[0] = fds[0];c->fds[1] = fds[1];c->fds[2] = fds[2];copyPipe(in,   c->in);copyPipe(out,  c->out);copyPipe(err,  c->err);copyPipe(fail, c->fail);c->redirectErrorStream = redirectErrorStream;resultPid = startChild(c);assert(resultPid != 0);if (resultPid < 0) {throwIOException(env, errno, START_CHILD_SYSTEM_CALL " failed");goto Catch;}restartableClose(fail[1]); fail[1] = -1; /* See: WhyCantJohnnyExec */switch (readFully(fail[0], &errnum, sizeof(errnum))) {case 0: break; /* Exec succeeded */case sizeof(errnum):waitpid(resultPid, NULL, 0);throwIOException(env, errnum, "Exec failed");goto Catch;default:throwIOException(env, errno, "Read failed");goto Catch;}fds[0] = (in [1] != -1) ? in [1] : -1;fds[1] = (out[0] != -1) ? out[0] : -1;fds[2] = (err[0] != -1) ? err[0] : -1;Finally:
#if START_CHILD_USE_CLONEfree(c->clone_stack);
#endif/* Always clean up the child's side of the pipes */closeSafely(in [0]);closeSafely(out[1]);closeSafely(err[1]);/* Always clean up fail descriptors */closeSafely(fail[0]);closeSafely(fail[1]);releaseBytes(env, prog,     pprog);releaseBytes(env, argBlock, pargBlock);releaseBytes(env, envBlock, penvBlock);releaseBytes(env, dir,      c->pdir);free(c->argv);free(c->envv);free(c);if (fds != NULL)(*env)->ReleaseIntArrayElements(env, std_fds, fds, 0);return resultPid;Catch:/* Clean up the parent's side of the pipes in case of failure only */closeSafely(in [1]);closeSafely(out[0]);closeSafely(err[0]);goto Finally;
}JNIEXPORT void JNICALL
Java_java_lang_UNIXProcess_destroyProcess(JNIEnv *env, jobject junk, jint pid)
{kill(pid, SIGTERM);
}