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8187443: Forest Consolidation: Move files to unified layout

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Reviewed-by: darcy, ihse
This commit is contained in:
Erik Joelsson 2017-09-12 19:03:39 +02:00
parent 270fe13182
commit 3789983e89
56923 changed files with 3 additions and 15727 deletions
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src/java.base/unix/native/libjava/ProcessImpl_md.c Normal file
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/*
* Copyright (c) 1995, 2015, 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>
#include <sys/wait.h>
#include <signal.h>
#include <string.h>
#if defined(__solaris__) || defined(_ALLBSD_SOURCE) || defined(_AIX)
#include <spawn.h>
#endif
#include "childproc.h"
/*
* There are 4 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.
*
* - posix_spawn(). While posix_spawn() is a fairly elaborate and
* complicated system call, it can't quite do everything that the old
* fork()/exec() combination can do, so the only feasible way to do
* this, is to use posix_spawn to launch a new helper executable
* "jprochelper", which in turn execs the target (after cleaning
* up file-descriptors etc.) The end result is the same as before,
* a child process linked to the parent in the same way, but it
* avoids the problem of duplicating the parent (VM) process
* address space temporarily, before launching the target command.
*
* Based on the above analysis, we are currently using vfork() on
* Linux and posix_spawn() on other Unix systems.
*/
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/bin:/opt/SUNWspro/bin:/usr/sbin" :
"/usr/xpg4/bin:/usr/bin:/opt/SUNWspro/bin:";
#else
return ":/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 *
effectivePathv(JNIEnv *env)
{
char *p;
int i;
const char *path = effectivePath();
int count = countOccurrences(path, ':') + 1;
size_t pathvsize = sizeof(const char *) * (count+1);
size_t pathsize = strlen(path) + 1;
const char **pathv = (const char **) xmalloc(env, pathvsize + pathsize);
if (pathv == NULL)
return NULL;
p = (char *) pathv + pathvsize;
memcpy(p, path, pathsize);
/* split PATH by replacing ':' with NULs; empty components => "." */
for (i = 0; i < count; i++) {
char *q = p + strcspn(p, ":");
pathv[i] = (p == q) ? "." : p;
*q = '\0';
p = q + 1;
}
pathv[count] = NULL;
return pathv;
}
JNIEXPORT void JNICALL
Java_java_lang_ProcessImpl_init(JNIEnv *env, jclass clazz)
{
parentPathv = effectivePathv(env);
CHECK_NULL(parentPathv);
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
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);
}
#define IOE_FORMAT "error=%d, %s"
static void
throwIOException(JNIEnv *env, int errnum, const char *defaultDetail)
{
const char *detail = defaultDetail;
char *errmsg;
size_t fmtsize;
char tmpbuf[1024];
jstring s;
if (errnum != 0) {
int ret = getErrorString(errnum, tmpbuf, sizeof(tmpbuf));
if (ret != EINVAL)
detail = tmpbuf;
}
/* ASCII Decimal representation uses 2.4 times as many bits as binary. */
fmtsize = sizeof(IOE_FORMAT) + strlen(detail) + 3 * sizeof(errnum);
errmsg = NEW(char, fmtsize);
if (errmsg == NULL)
return;
snprintf(errmsg, fmtsize, IOE_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 */
static void
copyPipe(int from[2], int to[2])
{
to[0] = from[0];
to[1] = from[1];
}
/* arg is an array of pointers to 0 terminated strings. array is terminated
* by a null element.
*
* *nelems and *nbytes receive the number of elements of array (incl 0)
* and total number of bytes (incl. 0)
* Note. An empty array will have one null element
* But if arg is null, then *nelems set to 0, and *nbytes to 0
*/
static void arraysize(const char * const *arg, int *nelems, int *nbytes)
{
int i, bytes, count;
const char * const *a = arg;
char *p;
int *q;
if (arg == 0) {
*nelems = 0;
*nbytes = 0;
return;
}
/* count the array elements and number of bytes */
for (count=0, bytes=0; *a != 0; count++, a++) {
bytes += strlen(*a)+1;
}
*nbytes = bytes;
*nelems = count+1;
}
/* copy the strings from arg[] into buf, starting at given offset
* return new offset to next free byte
*/
static int copystrings(char *buf, int offset, const char * const *arg) {
char *p;
const char * const *a;
int count=0;
if (arg == 0) {
return offset;
}
for (p=buf+offset, a=arg; *a != 0; a++) {
int len = strlen(*a) +1;
memcpy(p, *a, len);
p += len;
count += len;
}
return offset+count;
}
/**
* We are unusually paranoid; use of vfork is
* especially likely to tickle gcc/glibc bugs.
*/
#ifdef __attribute_noinline__ /* See: sys/cdefs.h */
__attribute_noinline__
#endif
/* vfork(2) is deprecated on Solaris */
#ifndef __solaris__
static pid_t
vforkChild(ChildStuff *c) {
volatile pid_t resultPid;
/*
* 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'
*/
resultPid = vfork();
if (resultPid == 0) {
childProcess(c);
}
assert(resultPid != 0); /* childProcess never returns */
return resultPid;
}
#endif
static pid_t
forkChild(ChildStuff *c) {
pid_t resultPid;
/*
* 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().
*/
resultPid = fork();
if (resultPid == 0) {
childProcess(c);
}
assert(resultPid != 0); /* childProcess never returns */
return resultPid;
}
#if defined(__solaris__) || defined(_ALLBSD_SOURCE) || defined(_AIX)
static pid_t
spawnChild(JNIEnv *env, jobject process, ChildStuff *c, const char *helperpath) {
pid_t resultPid;
jboolean isCopy;
int i, offset, rval, bufsize, magic;
char *buf, buf1[16];
char *hlpargs[2];
SpawnInfo sp;
/* need to tell helper which fd is for receiving the childstuff
* and which fd to send response back on
*/
snprintf(buf1, sizeof(buf1), "%d:%d", c->childenv[0], c->fail[1]);
/* put the fd string as argument to the helper cmd */
hlpargs[0] = buf1;
hlpargs[1] = 0;
/* Following items are sent down the pipe to the helper
* after it is spawned.
* All strings are null terminated. All arrays of strings
* have an empty string for termination.
* - the ChildStuff struct
* - the SpawnInfo struct
* - the argv strings array
* - the envv strings array
* - the home directory string
* - the parentPath string
* - the parentPathv array
*/
/* First calculate the sizes */
arraysize(c->argv, &sp.nargv, &sp.argvBytes);
bufsize = sp.argvBytes;
arraysize(c->envv, &sp.nenvv, &sp.envvBytes);
bufsize += sp.envvBytes;
sp.dirlen = c->pdir == 0 ? 0 : strlen(c->pdir)+1;
bufsize += sp.dirlen;
arraysize(parentPathv, &sp.nparentPathv, &sp.parentPathvBytes);
bufsize += sp.parentPathvBytes;
/* We need to clear FD_CLOEXEC if set in the fds[].
* Files are created FD_CLOEXEC in Java.
* Otherwise, they will be closed when the target gets exec'd */
for (i=0; i<3; i++) {
if (c->fds[i] != -1) {
int flags = fcntl(c->fds[i], F_GETFD);
if (flags & FD_CLOEXEC) {
fcntl(c->fds[i], F_SETFD, flags & (~1));
}
}
}
rval = posix_spawn(&resultPid, helperpath, 0, 0, (char * const *) hlpargs, environ);
if (rval != 0) {
return -1;
}
/* now the lengths are known, copy the data */
buf = NEW(char, bufsize);
if (buf == 0) {
return -1;
}
offset = copystrings(buf, 0, &c->argv[0]);
offset = copystrings(buf, offset, &c->envv[0]);
memcpy(buf+offset, c->pdir, sp.dirlen);
offset += sp.dirlen;
offset = copystrings(buf, offset, parentPathv);
assert(offset == bufsize);
magic = magicNumber();
/* write the two structs and the data buffer */
write(c->childenv[1], (char *)&magic, sizeof(magic)); // magic number first
write(c->childenv[1], (char *)c, sizeof(*c));
write(c->childenv[1], (char *)&sp, sizeof(sp));
write(c->childenv[1], buf, bufsize);
free(buf);
/* In this mode an external main() in invoked which calls back into
* childProcess() in this file, rather than directly
* via the statement below */
return resultPid;
}
#endif
/*
* Start a child process running function childProcess.
* This function only returns in the parent.
*/
static pid_t
startChild(JNIEnv *env, jobject process, ChildStuff *c, const char *helperpath) {
switch (c->mode) {
/* vfork(2) is deprecated on Solaris */
#ifndef __solaris__
case MODE_VFORK:
return vforkChild(c);
#endif
case MODE_FORK:
return forkChild(c);
#if defined(__solaris__) || defined(_ALLBSD_SOURCE) || defined(_AIX)
case MODE_POSIX_SPAWN:
return spawnChild(env, process, c, helperpath);
#endif
default:
return -1;
}
}
JNIEXPORT jint JNICALL
Java_java_lang_ProcessImpl_forkAndExec(JNIEnv *env,
jobject process,
jint mode,
jbyteArray helperpath,
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], childenv[2];
jint *fds = NULL;
const char *phelperpath = 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;
childenv[0] = childenv[1] = -1;
if ((c = NEW(ChildStuff, 1)) == NULL) return -1;
c->argv = NULL;
c->envv = NULL;
c->pdir = NULL;
/* Convert prog + argBlock into a char ** argv.
* Add one word room for expansion of argv for use by
* execve_as_traditional_shell_script.
* This word is also used when using posix_spawn mode
*/
assert(prog != NULL && argBlock != NULL);
if ((phelperpath = getBytes(env, helperpath)) == NULL) goto Catch;
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;
c->argc = argc + 2;
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(childenv) < 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);
copyPipe(childenv, c->childenv);
c->redirectErrorStream = redirectErrorStream;
c->mode = mode;
resultPid = startChild(env, process, c, phelperpath);
assert(resultPid != 0);
if (resultPid < 0) {
switch (c->mode) {
case MODE_VFORK:
throwIOException(env, errno, "vfork failed");
break;
case MODE_FORK:
throwIOException(env, errno, "fork failed");
break;
case MODE_POSIX_SPAWN:
throwIOException(env, errno, "posix_spawn failed");
break;
}
goto Catch;
}
close(fail[1]); fail[1] = -1; /* See: WhyCantJohnnyExec (childproc.c) */
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:
/* Always clean up the child's side of the pipes */
closeSafely(in [0]);
closeSafely(out[1]);
closeSafely(err[1]);
/* Always clean up fail and childEnv descriptors */
closeSafely(fail[0]);
closeSafely(fail[1]);
closeSafely(childenv[0]);
closeSafely(childenv[1]);
releaseBytes(env, helperpath, phelperpath);
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]); in[1] = -1;
closeSafely(out[0]); out[0] = -1;
closeSafely(err[0]); err[0] = -1;
goto Finally;
}