Adding upstream version 4.19.249.upstream/4.19.249

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 423 insertions, 0 deletions

diff --git a/Documentation/admin-guide/java.rst b/Documentation/admin-guide/java.rst
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+Java(tm) Binary Kernel Support for Linux v1.03
+----------------------------------------------
+
+Linux beats them ALL! While all other OS's are TALKING about direct
+support of Java Binaries in the OS, Linux is doing it!
+
+You can execute Java applications and Java Applets just like any
+other program after you have done the following:
+
+1) You MUST FIRST install the Java Developers Kit for Linux.
+   The Java on Linux HOWTO gives the details on getting and
+   installing this. This HOWTO can be found at:
+
+	ftp://sunsite.unc.edu/pub/Linux/docs/HOWTO/Java-HOWTO
+
+   You should also set up a reasonable CLASSPATH environment
+   variable to use Java applications that make use of any
+   nonstandard classes (not included in the same directory
+   as the application itself).
+
+2) You have to compile BINFMT_MISC either as a module or into
+   the kernel (``CONFIG_BINFMT_MISC``) and set it up properly.
+   If you choose to compile it as a module, you will have
+   to insert it manually with modprobe/insmod, as kmod
+   cannot easily be supported with binfmt_misc.
+   Read the file 'binfmt_misc.txt' in this directory to know
+   more about the configuration process.
+
+3) Add the following configuration items to binfmt_misc
+   (you should really have read ``binfmt_misc.txt`` now):
+   support for Java applications::
+
+     ':Java:M::\xca\xfe\xba\xbe::/usr/local/bin/javawrapper:'
+
+   support for executable Jar files::
+
+     ':ExecutableJAR:E::jar::/usr/local/bin/jarwrapper:'
+
+   support for Java Applets::
+
+     ':Applet:E::html::/usr/bin/appletviewer:'
+
+   or the following, if you want to be more selective::
+
+     ':Applet:M::<!--applet::/usr/bin/appletviewer:'
+
+   Of course you have to fix the path names. The path/file names given in this
+   document match the Debian 2.1 system. (i.e. jdk installed in ``/usr``,
+   custom wrappers from this document in ``/usr/local``)
+
+   Note, that for the more selective applet support you have to modify
+   existing html-files to contain ``<!--applet-->`` in the first line
+   (``<`` has to be the first character!) to let this work!
+
+   For the compiled Java programs you need a wrapper script like the
+   following (this is because Java is broken in case of the filename
+   handling), again fix the path names, both in the script and in the
+   above given configuration string.
+
+   You, too, need the little program after the script. Compile like::
+
+	gcc -O2 -o javaclassname javaclassname.c
+
+   and stick it to ``/usr/local/bin``.
+
+   Both the javawrapper shellscript and the javaclassname program
+   were supplied by Colin J. Watson <cjw44@cam.ac.uk>.
+
+Javawrapper shell script:
+
+.. code-block:: sh
+
+  #!/bin/bash
+  # /usr/local/bin/javawrapper - the wrapper for binfmt_misc/java
+
+  if [ -z "$1" ]; then
+	exec 1>&2
+	echo Usage: $0 class-file
+	exit 1
+  fi
+
+  CLASS=$1
+  FQCLASS=`/usr/local/bin/javaclassname $1`
+  FQCLASSN=`echo $FQCLASS | sed -e 's/^.*\.\([^.]*\)$/\1/'`
+  FQCLASSP=`echo $FQCLASS | sed -e 's-\.-/-g' -e 's-^[^/]*$--' -e 's-/[^/]*$--'`
+
+  # for example:
+  # CLASS=Test.class
+  # FQCLASS=foo.bar.Test
+  # FQCLASSN=Test
+  # FQCLASSP=foo/bar
+
+  unset CLASSBASE
+
+  declare -i LINKLEVEL=0
+
+  while :; do
+	if [ "`basename $CLASS .class`" == "$FQCLASSN" ]; then
+		# See if this directory works straight off
+		cd -L `dirname $CLASS`
+		CLASSDIR=$PWD
+		cd $OLDPWD
+		if echo $CLASSDIR | grep -q "$FQCLASSP$"; then
+			CLASSBASE=`echo $CLASSDIR | sed -e "s.$FQCLASSP$.."`
+			break;
+		fi
+		# Try dereferencing the directory name
+		cd -P `dirname $CLASS`
+		CLASSDIR=$PWD
+		cd $OLDPWD
+		if echo $CLASSDIR | grep -q "$FQCLASSP$"; then
+			CLASSBASE=`echo $CLASSDIR | sed -e "s.$FQCLASSP$.."`
+			break;
+		fi
+		# If no other possible filename exists
+		if [ ! -L $CLASS ]; then
+			exec 1>&2
+			echo $0:
+			echo "  $CLASS should be in a" \
+			     "directory tree called $FQCLASSP"
+			exit 1
+		fi
+	fi
+	if [ ! -L $CLASS ]; then break; fi
+	# Go down one more level of symbolic links
+	let LINKLEVEL+=1
+	if [ $LINKLEVEL -gt 5 ]; then
+		exec 1>&2
+		echo $0:
+		echo "  Too many symbolic links encountered"
+		exit 1
+	fi
+	CLASS=`ls --color=no -l $CLASS | sed -e 's/^.* \([^ ]*\)$/\1/'`
+  done
+
+  if [ -z "$CLASSBASE" ]; then
+	if [ -z "$FQCLASSP" ]; then
+		GOODNAME=$FQCLASSN.class
+	else
+		GOODNAME=$FQCLASSP/$FQCLASSN.class
+	fi
+	exec 1>&2
+	echo $0:
+	echo "  $FQCLASS should be in a file called $GOODNAME"
+	exit 1
+  fi
+
+  if ! echo $CLASSPATH | grep -q "^\(.*:\)*$CLASSBASE\(:.*\)*"; then
+	# class is not in CLASSPATH, so prepend dir of class to CLASSPATH
+	if [ -z "${CLASSPATH}" ] ; then
+		export CLASSPATH=$CLASSBASE
+	else
+		export CLASSPATH=$CLASSBASE:$CLASSPATH
+	fi
+  fi
+
+  shift
+  /usr/bin/java $FQCLASS "$@"
+
+javaclassname.c:
+
+.. code-block:: c
+
+  /* javaclassname.c
+   *
+   * Extracts the class name from a Java class file; intended for use in a Java
+   * wrapper of the type supported by the binfmt_misc option in the Linux kernel.
+   *
+   * Copyright (C) 1999 Colin J. Watson <cjw44@cam.ac.uk>.
+   *
+   * This program is free software; you can redistribute it and/or modify
+   * it under the terms of the GNU General Public License as published by
+   * the Free Software Foundation; either version 2 of the License, or
+   * (at your option) any later version.
+   *
+   * This program 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 for more details.
+   *
+   * You should have received a copy of the GNU General Public License
+   * along with this program; if not, write to the Free Software
+   * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+   */
+
+  #include <stdlib.h>
+  #include <stdio.h>
+  #include <stdarg.h>
+  #include <sys/types.h>
+
+  /* From Sun's Java VM Specification, as tag entries in the constant pool. */
+
+  #define CP_UTF8 1
+  #define CP_INTEGER 3
+  #define CP_FLOAT 4
+  #define CP_LONG 5
+  #define CP_DOUBLE 6
+  #define CP_CLASS 7
+  #define CP_STRING 8
+  #define CP_FIELDREF 9
+  #define CP_METHODREF 10
+  #define CP_INTERFACEMETHODREF 11
+  #define CP_NAMEANDTYPE 12
+  #define CP_METHODHANDLE 15
+  #define CP_METHODTYPE 16
+  #define CP_INVOKEDYNAMIC 18
+
+  /* Define some commonly used error messages */
+
+  #define seek_error() error("%s: Cannot seek\n", program)
+  #define corrupt_error() error("%s: Class file corrupt\n", program)
+  #define eof_error() error("%s: Unexpected end of file\n", program)
+  #define utf8_error() error("%s: Only ASCII 1-255 supported\n", program);
+
+  char *program;
+
+  long *pool;
+
+  u_int8_t read_8(FILE *classfile);
+  u_int16_t read_16(FILE *classfile);
+  void skip_constant(FILE *classfile, u_int16_t *cur);
+  void error(const char *format, ...);
+  int main(int argc, char **argv);
+
+  /* Reads in an unsigned 8-bit integer. */
+  u_int8_t read_8(FILE *classfile)
+  {
+	int b = fgetc(classfile);
+	if(b == EOF)
+		eof_error();
+	return (u_int8_t)b;
+  }
+
+  /* Reads in an unsigned 16-bit integer. */
+  u_int16_t read_16(FILE *classfile)
+  {
+	int b1, b2;
+	b1 = fgetc(classfile);
+	if(b1 == EOF)
+		eof_error();
+	b2 = fgetc(classfile);
+	if(b2 == EOF)
+		eof_error();
+	return (u_int16_t)((b1 << 8) | b2);
+  }
+
+  /* Reads in a value from the constant pool. */
+  void skip_constant(FILE *classfile, u_int16_t *cur)
+  {
+	u_int16_t len;
+	int seekerr = 1;
+	pool[*cur] = ftell(classfile);
+	switch(read_8(classfile))
+	{
+	case CP_UTF8:
+		len = read_16(classfile);
+		seekerr = fseek(classfile, len, SEEK_CUR);
+		break;
+	case CP_CLASS:
+	case CP_STRING:
+	case CP_METHODTYPE:
+		seekerr = fseek(classfile, 2, SEEK_CUR);
+		break;
+	case CP_METHODHANDLE:
+		seekerr = fseek(classfile, 3, SEEK_CUR);
+		break;
+	case CP_INTEGER:
+	case CP_FLOAT:
+	case CP_FIELDREF:
+	case CP_METHODREF:
+	case CP_INTERFACEMETHODREF:
+	case CP_NAMEANDTYPE:
+	case CP_INVOKEDYNAMIC:
+		seekerr = fseek(classfile, 4, SEEK_CUR);
+		break;
+	case CP_LONG:
+	case CP_DOUBLE:
+		seekerr = fseek(classfile, 8, SEEK_CUR);
+		++(*cur);
+		break;
+	default:
+		corrupt_error();
+	}
+	if(seekerr)
+		seek_error();
+  }
+
+  void error(const char *format, ...)
+  {
+	va_list ap;
+	va_start(ap, format);
+	vfprintf(stderr, format, ap);
+	va_end(ap);
+	exit(1);
+  }
+
+  int main(int argc, char **argv)
+  {
+	FILE *classfile;
+	u_int16_t cp_count, i, this_class, classinfo_ptr;
+	u_int8_t length;
+
+	program = argv[0];
+
+	if(!argv[1])
+		error("%s: Missing input file\n", program);
+	classfile = fopen(argv[1], "rb");
+	if(!classfile)
+		error("%s: Error opening %s\n", program, argv[1]);
+
+	if(fseek(classfile, 8, SEEK_SET))  /* skip magic and version numbers */
+		seek_error();
+	cp_count = read_16(classfile);
+	pool = calloc(cp_count, sizeof(long));
+	if(!pool)
+		error("%s: Out of memory for constant pool\n", program);
+
+	for(i = 1; i < cp_count; ++i)
+		skip_constant(classfile, &i);
+	if(fseek(classfile, 2, SEEK_CUR))	/* skip access flags */
+		seek_error();
+
+	this_class = read_16(classfile);
+	if(this_class < 1 || this_class >= cp_count)
+		corrupt_error();
+	if(!pool[this_class] || pool[this_class] == -1)
+		corrupt_error();
+	if(fseek(classfile, pool[this_class] + 1, SEEK_SET))
+		seek_error();
+
+	classinfo_ptr = read_16(classfile);
+	if(classinfo_ptr < 1 || classinfo_ptr >= cp_count)
+		corrupt_error();
+	if(!pool[classinfo_ptr] || pool[classinfo_ptr] == -1)
+		corrupt_error();
+	if(fseek(classfile, pool[classinfo_ptr] + 1, SEEK_SET))
+		seek_error();
+
+	length = read_16(classfile);
+	for(i = 0; i < length; ++i)
+	{
+		u_int8_t x = read_8(classfile);
+		if((x & 0x80) || !x)
+		{
+			if((x & 0xE0) == 0xC0)
+			{
+				u_int8_t y = read_8(classfile);
+				if((y & 0xC0) == 0x80)
+				{
+					int c = ((x & 0x1f) << 6) + (y & 0x3f);
+					if(c) putchar(c);
+					else utf8_error();
+				}
+				else utf8_error();
+			}
+			else utf8_error();
+		}
+		else if(x == '/') putchar('.');
+		else putchar(x);
+	}
+	putchar('\n');
+	free(pool);
+	fclose(classfile);
+	return 0;
+  }
+
+jarwrapper::
+
+  #!/bin/bash
+  # /usr/local/java/bin/jarwrapper - the wrapper for binfmt_misc/jar
+
+  java -jar $1
+
+
+Now simply ``chmod +x`` the ``.class``, ``.jar`` and/or ``.html`` files you
+want to execute.
+
+To add a Java program to your path best put a symbolic link to the main
+.class file into /usr/bin (or another place you like) omitting the .class
+extension. The directory containing the original .class file will be
+added to your CLASSPATH during execution.
+
+
+To test your new setup, enter in the following simple Java app, and name
+it "HelloWorld.java":
+
+.. code-block:: java
+
+	class HelloWorld {
+		public static void main(String args[]) {
+			System.out.println("Hello World!");
+		}
+	}
+
+Now compile the application with::
+
+	javac HelloWorld.java
+
+Set the executable permissions of the binary file, with::
+
+	chmod 755 HelloWorld.class
+
+And then execute it::
+
+	./HelloWorld.class
+
+
+To execute Java Jar files, simple chmod the ``*.jar`` files to include
+the execution bit, then just do::
+
+       ./Application.jar
+
+
+To execute Java Applets, simple chmod the ``*.html`` files to include
+the execution bit, then just do::
+
+	./Applet.html
+
+
+originally by Brian A. Lantz, brian@lantz.com
+heavily edited for binfmt_misc by Richard Günther
+new scripts by Colin J. Watson <cjw44@cam.ac.uk>
+added executable Jar file support by Kurt Huwig <kurt@iku-netz.de>