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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-05-06 01:02:30 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-05-06 01:02:30 +0000 |
commit | 76cb841cb886eef6b3bee341a2266c76578724ad (patch) | |
tree | f5892e5ba6cc11949952a6ce4ecbe6d516d6ce58 /fs/binfmt_em86.c | |
parent | Initial commit. (diff) | |
download | linux-upstream/4.19.249.tar.xz linux-upstream/4.19.249.zip |
Adding upstream version 4.19.249.upstream/4.19.249upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'fs/binfmt_em86.c')
-rw-r--r-- | fs/binfmt_em86.c | 118 |
1 files changed, 118 insertions, 0 deletions
diff --git a/fs/binfmt_em86.c b/fs/binfmt_em86.c new file mode 100644 index 000000000..dd2d3f0cd --- /dev/null +++ b/fs/binfmt_em86.c @@ -0,0 +1,118 @@ +/* + * 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; + + allow_write_access(bprm->file); + fput(bprm->file); + bprm->file = NULL; + + /* 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_strings_kernel(1, &bprm->filename, bprm); + if (retval < 0) return retval; + bprm->argc++; + if (i_arg) { + retval = copy_strings_kernel(1, &i_arg, bprm); + if (retval < 0) return retval; + bprm->argc++; + } + retval = copy_strings_kernel(1, &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->file = file; + + retval = prepare_binprm(bprm); + if (retval < 0) + return retval; + + return search_binary_handler(bprm); +} + +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"); |