mirror of
https://github.com/edk2-porting/linux-next.git
synced 2024-12-21 11:44:01 +08:00
0ea6e61122
Below you will find an updated version from the original series bunching all patches into one big patch updating broken web addresses that are located in Documentation/* Some of the addresses date as far far back as 1995 etc... so searching became a bit difficult, the best way to deal with these is to use web.archive.org to locate these addresses that are outdated. Now there are also some addresses pointing to .spec files some are located, but some(after searching on the companies site)where still no where to be found. In this case I just changed the address to the company site this way the users can contact the company and they can locate them for the users. Signed-off-by: Justin P. Mattock <justinmattock@gmail.com> Signed-off-by: Thomas Weber <weber@corscience.de> Signed-off-by: Mike Frysinger <vapier.adi@gmail.com> Cc: Paulo Marques <pmarques@grupopie.com> Cc: Randy Dunlap <rdunlap@xenotime.net> Cc: Michael Neuling <mikey@neuling.org> Signed-off-by: Jiri Kosina <jkosina@suse.cz>
117 lines
5.9 KiB
Plaintext
117 lines
5.9 KiB
Plaintext
Kernel Support for miscellaneous (your favourite) Binary Formats v1.1
|
|
=====================================================================
|
|
|
|
This Kernel feature allows you to invoke almost (for restrictions see below)
|
|
every program by simply typing its name in the shell.
|
|
This includes for example compiled Java(TM), Python or Emacs programs.
|
|
|
|
To achieve this you must tell binfmt_misc which interpreter has to be invoked
|
|
with which binary. Binfmt_misc recognises the binary-type by matching some bytes
|
|
at the beginning of the file with a magic byte sequence (masking out specified
|
|
bits) you have supplied. Binfmt_misc can also recognise a filename extension
|
|
aka '.com' or '.exe'.
|
|
|
|
First you must mount binfmt_misc:
|
|
mount binfmt_misc -t binfmt_misc /proc/sys/fs/binfmt_misc
|
|
|
|
To actually register a new binary type, you have to set up a string looking like
|
|
:name:type:offset:magic:mask:interpreter:flags (where you can choose the ':' upon
|
|
your needs) and echo it to /proc/sys/fs/binfmt_misc/register.
|
|
Here is what the fields mean:
|
|
- 'name' is an identifier string. A new /proc file will be created with this
|
|
name below /proc/sys/fs/binfmt_misc
|
|
- 'type' is the type of recognition. Give 'M' for magic and 'E' for extension.
|
|
- 'offset' is the offset of the magic/mask in the file, counted in bytes. This
|
|
defaults to 0 if you omit it (i.e. you write ':name:type::magic...')
|
|
- 'magic' is the byte sequence binfmt_misc is matching for. The magic string
|
|
may contain hex-encoded characters like \x0a or \xA4. In a shell environment
|
|
you will have to write \\x0a to prevent the shell from eating your \.
|
|
If you chose filename extension matching, this is the extension to be
|
|
recognised (without the '.', the \x0a specials are not allowed). Extension
|
|
matching is case sensitive!
|
|
- 'mask' is an (optional, defaults to all 0xff) mask. You can mask out some
|
|
bits from matching by supplying a string like magic and as long as magic.
|
|
The mask is anded with the byte sequence of the file.
|
|
- 'interpreter' is the program that should be invoked with the binary as first
|
|
argument (specify the full path)
|
|
- 'flags' is an optional field that controls several aspects of the invocation
|
|
of the interpreter. It is a string of capital letters, each controls a certain
|
|
aspect. The following flags are supported -
|
|
'P' - preserve-argv[0]. Legacy behavior of binfmt_misc is to overwrite the
|
|
original argv[0] with the full path to the binary. When this flag is
|
|
included, binfmt_misc will add an argument to the argument vector for
|
|
this purpose, thus preserving the original argv[0].
|
|
'O' - open-binary. Legacy behavior of binfmt_misc is to pass the full path
|
|
of the binary to the interpreter as an argument. When this flag is
|
|
included, binfmt_misc will open the file for reading and pass its
|
|
descriptor as an argument, instead of the full path, thus allowing
|
|
the interpreter to execute non-readable binaries. This feature should
|
|
be used with care - the interpreter has to be trusted not to emit
|
|
the contents of the non-readable binary.
|
|
'C' - credentials. Currently, the behavior of binfmt_misc is to calculate
|
|
the credentials and security token of the new process according to
|
|
the interpreter. When this flag is included, these attributes are
|
|
calculated according to the binary. It also implies the 'O' flag.
|
|
This feature should be used with care as the interpreter
|
|
will run with root permissions when a setuid binary owned by root
|
|
is run with binfmt_misc.
|
|
|
|
|
|
There are some restrictions:
|
|
- the whole register string may not exceed 255 characters
|
|
- the magic must reside in the first 128 bytes of the file, i.e.
|
|
offset+size(magic) has to be less than 128
|
|
- the interpreter string may not exceed 127 characters
|
|
|
|
To use binfmt_misc you have to mount it first. You can mount it with
|
|
"mount -t binfmt_misc none /proc/sys/fs/binfmt_misc" command, or you can add
|
|
a line "none /proc/sys/fs/binfmt_misc binfmt_misc defaults 0 0" to your
|
|
/etc/fstab so it auto mounts on boot.
|
|
|
|
You may want to add the binary formats in one of your /etc/rc scripts during
|
|
boot-up. Read the manual of your init program to figure out how to do this
|
|
right.
|
|
|
|
Think about the order of adding entries! Later added entries are matched first!
|
|
|
|
|
|
A few examples (assumed you are in /proc/sys/fs/binfmt_misc):
|
|
|
|
- enable support for em86 (like binfmt_em86, for Alpha AXP only):
|
|
echo ':i386:M::\x7fELF\x01\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x02\x00\x03:\xff\xff\xff\xff\xff\xfe\xfe\xff\xff\xff\xff\xff\xff\xff\xff\xff\xfb\xff\xff:/bin/em86:' > register
|
|
echo ':i486:M::\x7fELF\x01\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x02\x00\x06:\xff\xff\xff\xff\xff\xfe\xfe\xff\xff\xff\xff\xff\xff\xff\xff\xff\xfb\xff\xff:/bin/em86:' > register
|
|
|
|
- enable support for packed DOS applications (pre-configured dosemu hdimages):
|
|
echo ':DEXE:M::\x0eDEX::/usr/bin/dosexec:' > register
|
|
|
|
- enable support for Windows executables using wine:
|
|
echo ':DOSWin:M::MZ::/usr/local/bin/wine:' > register
|
|
|
|
For java support see Documentation/java.txt
|
|
|
|
|
|
You can enable/disable binfmt_misc or one binary type by echoing 0 (to disable)
|
|
or 1 (to enable) to /proc/sys/fs/binfmt_misc/status or /proc/.../the_name.
|
|
Catting the file tells you the current status of binfmt_misc/the entry.
|
|
|
|
You can remove one entry or all entries by echoing -1 to /proc/.../the_name
|
|
or /proc/sys/fs/binfmt_misc/status.
|
|
|
|
|
|
HINTS:
|
|
======
|
|
|
|
If you want to pass special arguments to your interpreter, you can
|
|
write a wrapper script for it. See Documentation/java.txt for an
|
|
example.
|
|
|
|
Your interpreter should NOT look in the PATH for the filename; the kernel
|
|
passes it the full filename (or the file descriptor) to use. Using $PATH can
|
|
cause unexpected behaviour and can be a security hazard.
|
|
|
|
|
|
There is a web page about binfmt_misc at
|
|
http://www.tat.physik.uni-tuebingen.de
|
|
|
|
Richard Günther <rguenth@tat.physik.uni-tuebingen.de>
|