On Tue, Apr 20, 2021 at 07:56:31PM +0200, David Hildenbrand wrote: > We have a fairly specific alpha binary loader in Linux: running x86 > (i386, i486) binaries via the em86 [1] emulator. As noted in the Kconfig > option, the same behavior can be achieved via binfmt_misc, for example, > more nowadays used for running qemu-user. > > An example on how to get binfmt_misc running with em86 can be found in > Documentation/admin-guide/binfmt-misc.rst > > The defconfig does not have CONFIG_BINFMT_EM86=y set. And doing a > make defconfig && make olddefconfig > results in > # CONFIG_BINFMT_EM86 is not set > > ... as we don't seem to have any supported Linux distirbution for alpha > anymore, there isn't really any "default" user of that feature anymore. > > Searching for "CONFIG_BINFMT_EM86=y" reveals mostly discussions from > around 20 years ago, like [2] describing how to get netscape via em86 > running via em86, or [3] discussing that running wine or installing > Win 3.11 through em86 would be a nice feature. > > The latest binaries available for em86 are from 2000, version 2.2.1 [4] -- > which translates to "unsupported"; further, em86 doesn't even work with > glibc-2.x but only with glibc-2.0 [4, 5]. These are clear signs that > there might not be too many em86 users out there, especially users > relying on modern Linux kernels. > > Even though the code footprint is relatively small, let's just get rid > of this blast from the past that's effectively unused. > > [1] http://ftp.dreamtime.org/pub/linux/Linux-Alpha/em86/v0.4/docs/em86.html > [2] https://static.lwn.net/1998/1119/a/alpha-netscape.html > [3] https://groups.google.com/g/linux.debian.alpha/c/AkGuQHeCe0Y > [4] http://zeniv.linux.org.uk/pub/linux/alpha/em86/v2.2-1/relnotes.2.2.1.html > [5] https://forum.teamspeak.com/archive/index.php/t-1477.html > > Cc: Alexander Viro <viro@xxxxxxxxxxxxxxxxxx> > Cc: Richard Henderson <rth@xxxxxxxxxxx> > Cc: Ivan Kokshaysky <ink@xxxxxxxxxxxxxxxxxxxx> > Cc: Matt Turner <mattst88@xxxxxxxxx> > Cc: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx> > Cc: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> > Cc: Jonathan Corbet <corbet@xxxxxxx> > Cc: linux-fsdevel@xxxxxxxxxxxxxxx > Cc: linux-api@xxxxxxxxxxxxxxx > Cc: linux-alpha@xxxxxxxxxxxxxxx > Signed-off-by: David Hildenbrand <david@xxxxxxxxxx> > --- The only Alpha machines in active use I know of are here in Berlin at the FU so adding Adrian in case they care but I don't think so and this seems like a good cleanup: Acked-by: Christian Brauner <christian.brauner@xxxxxxxxxx> > fs/Kconfig.binfmt | 15 ------- > fs/Makefile | 1 - > fs/binfmt_em86.c | 110 ---------------------------------------------- > 3 files changed, 126 deletions(-) > delete mode 100644 fs/binfmt_em86.c > > diff --git a/fs/Kconfig.binfmt b/fs/Kconfig.binfmt > index c6f1c8c1934e..8720e0a30005 100644 > --- a/fs/Kconfig.binfmt > +++ b/fs/Kconfig.binfmt > @@ -165,21 +165,6 @@ config OSF4_COMPAT > with v4 shared libraries freely available from Compaq. If you're > going to use shared libraries from Tru64 version 5.0 or later, say N. > > -config BINFMT_EM86 > - tristate "Kernel support for Linux/Intel ELF binaries" > - depends on ALPHA > - help > - Say Y here if you want to be able to execute Linux/Intel ELF > - binaries just like native Alpha binaries on your Alpha machine. For > - this to work, you need to have the emulator /usr/bin/em86 in place. > - > - You can get the same functionality by saying N here and saying Y to > - "Kernel support for MISC binaries". > - > - You may answer M to compile the emulation support as a module and > - later load the module when you want to use a Linux/Intel binary. The > - module will be called binfmt_em86. If unsure, say Y. > - > config BINFMT_MISC > tristate "Kernel support for MISC binaries" > help > diff --git a/fs/Makefile b/fs/Makefile > index 3215fe205256..c92e403c53f8 100644 > --- a/fs/Makefile > +++ b/fs/Makefile > @@ -39,7 +39,6 @@ obj-$(CONFIG_FS_ENCRYPTION) += crypto/ > obj-$(CONFIG_FS_VERITY) += verity/ > obj-$(CONFIG_FILE_LOCKING) += locks.o > obj-$(CONFIG_BINFMT_AOUT) += binfmt_aout.o > -obj-$(CONFIG_BINFMT_EM86) += binfmt_em86.o > obj-$(CONFIG_BINFMT_MISC) += binfmt_misc.o > obj-$(CONFIG_BINFMT_SCRIPT) += binfmt_script.o > obj-$(CONFIG_BINFMT_ELF) += binfmt_elf.o > diff --git a/fs/binfmt_em86.c b/fs/binfmt_em86.c > deleted file mode 100644 > index 06b9b9fddf70..000000000000 > --- a/fs/binfmt_em86.c > +++ /dev/null > @@ -1,110 +0,0 @@ > -// SPDX-License-Identifier: GPL-2.0-only > -/* > - * linux/fs/binfmt_em86.c > - * > - * Based on linux/fs/binfmt_script.c > - * Copyright (C) 1996 Martin von Löwis > - * original #!-checking implemented by tytso. > - * > - * em86 changes Copyright (C) 1997 Jim Paradis > - */ > - > -#include <linux/module.h> > -#include <linux/string.h> > -#include <linux/stat.h> > -#include <linux/binfmts.h> > -#include <linux/elf.h> > -#include <linux/init.h> > -#include <linux/fs.h> > -#include <linux/file.h> > -#include <linux/errno.h> > - > - > -#define EM86_INTERP "/usr/bin/em86" > -#define EM86_I_NAME "em86" > - > -static int load_em86(struct linux_binprm *bprm) > -{ > - const char *i_name, *i_arg; > - char *interp; > - struct file * file; > - int retval; > - struct elfhdr elf_ex; > - > - /* Make sure this is a Linux/Intel ELF executable... */ > - elf_ex = *((struct elfhdr *)bprm->buf); > - > - if (memcmp(elf_ex.e_ident, ELFMAG, SELFMAG) != 0) > - return -ENOEXEC; > - > - /* First of all, some simple consistency checks */ > - if ((elf_ex.e_type != ET_EXEC && elf_ex.e_type != ET_DYN) || > - (!((elf_ex.e_machine == EM_386) || (elf_ex.e_machine == EM_486))) || > - !bprm->file->f_op->mmap) { > - return -ENOEXEC; > - } > - > - /* Need to be able to load the file after exec */ > - if (bprm->interp_flags & BINPRM_FLAGS_PATH_INACCESSIBLE) > - return -ENOENT; > - > - /* Unlike in the script case, we don't have to do any hairy > - * parsing to find our interpreter... it's hardcoded! > - */ > - interp = EM86_INTERP; > - i_name = EM86_I_NAME; > - i_arg = NULL; /* We reserve the right to add an arg later */ > - > - /* > - * Splice in (1) the interpreter's name for argv[0] > - * (2) (optional) argument to interpreter > - * (3) filename of emulated file (replace argv[0]) > - * > - * This is done in reverse order, because of how the > - * user environment and arguments are stored. > - */ > - remove_arg_zero(bprm); > - retval = copy_string_kernel(bprm->filename, bprm); > - if (retval < 0) return retval; > - bprm->argc++; > - if (i_arg) { > - retval = copy_string_kernel(i_arg, bprm); > - if (retval < 0) return retval; > - bprm->argc++; > - } > - retval = copy_string_kernel(i_name, bprm); > - if (retval < 0) return retval; > - bprm->argc++; > - > - /* > - * OK, now restart the process with the interpreter's inode. > - * Note that we use open_exec() as the name is now in kernel > - * space, and we don't need to copy it. > - */ > - file = open_exec(interp); > - if (IS_ERR(file)) > - return PTR_ERR(file); > - > - bprm->interpreter = file; > - return 0; > -} > - > -static struct linux_binfmt em86_format = { > - .module = THIS_MODULE, > - .load_binary = load_em86, > -}; > - > -static int __init init_em86_binfmt(void) > -{ > - register_binfmt(&em86_format); > - return 0; > -} > - > -static void __exit exit_em86_binfmt(void) > -{ > - unregister_binfmt(&em86_format); > -} > - > -core_initcall(init_em86_binfmt); > -module_exit(exit_em86_binfmt); > -MODULE_LICENSE("GPL"); > -- > 2.30.2 >
