binfmt_script.c
上传用户:lgb322
上传日期:2013-02-24
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文件大小:3k
- /*
- * linux/fs/binfmt_script.c
- *
- * Copyright (C) 1996 Martin von L鰓is
- * original #!-checking implemented by tytso.
- */
- #include <linux/module.h>
- #include <linux/string.h>
- #include <linux/stat.h>
- #include <linux/slab.h>
- #include <linux/binfmts.h>
- #include <linux/init.h>
- #include <linux/file.h>
- #include <linux/smp_lock.h>
- static int load_script(struct linux_binprm *bprm,struct pt_regs *regs)
- {
- char *cp, *i_name, *i_arg;
- struct file *file;
- char interp[BINPRM_BUF_SIZE];
- int retval;
- if ((bprm->buf[0] != '#') || (bprm->buf[1] != '!') || (bprm->sh_bang))
- return -ENOEXEC;
- /*
- * This section does the #! interpretation.
- * Sorta complicated, but hopefully it will work. -TYT
- */
- bprm->sh_bang++;
- allow_write_access(bprm->file);
- fput(bprm->file);
- bprm->file = NULL;
- bprm->buf[BINPRM_BUF_SIZE - 1] = ' ';
- if ((cp = strchr(bprm->buf, 'n')) == NULL)
- cp = bprm->buf+BINPRM_BUF_SIZE-1;
- *cp = ' ';
- while (cp > bprm->buf) {
- cp--;
- if ((*cp == ' ') || (*cp == 't'))
- *cp = ' ';
- else
- break;
- }
- for (cp = bprm->buf+2; (*cp == ' ') || (*cp == 't'); cp++);
- if (*cp == ' ')
- return -ENOEXEC; /* No interpreter name found */
- i_name = cp;
- i_arg = 0;
- for ( ; *cp && (*cp != ' ') && (*cp != 't'); cp++)
- /* nothing */ ;
- while ((*cp == ' ') || (*cp == 't'))
- *cp++ = ' ';
- if (*cp)
- i_arg = cp;
- strcpy (interp, i_name);
- /*
- * OK, we've parsed out the interpreter name and
- * (optional) argument.
- * Splice in (1) the interpreter's name for argv[0]
- * (2) (optional) argument to interpreter
- * (3) filename of shell script (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) return retval;
- bprm->argc++;
- /*
- * OK, now restart the process with the interpreter's dentry.
- */
- 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,regs);
- }
- struct linux_binfmt script_format = {
- NULL, THIS_MODULE, load_script, NULL, NULL, 0
- };
- static int __init init_script_binfmt(void)
- {
- return register_binfmt(&script_format);
- }
- static void __exit exit_script_binfmt(void)
- {
- unregister_binfmt(&script_format);
- }
- module_init(init_script_binfmt)
- module_exit(exit_script_binfmt)