1 files changed, 116 insertions, 0 deletions

diff --git a/fs/binfmt_script.c b/fs/binfmt_script.c
new file mode 100644
index 000000000000..1edbcca25a73
--- /dev/null
+++ b/fs/binfmt_script.c
@@ -0,0 +1,116 @@
+/*
+ *  linux/fs/binfmt_script.c
+ *
+ *  Copyright (C) 1996  Martin von Löwis
+ *  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>
+#include <linux/err.h>
+#include <linux/fs.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] = '\0';
+        if ((cp = strchr(bprm->buf, '\n')) == NULL)
+                cp = bprm->buf+BINPRM_BUF_SIZE-1;
+        *cp = '\0';
+        while (cp > bprm->buf) {
+                cp--;
+                if ((*cp == ' ') || (*cp == '\t'))
+                        *cp = '\0';
+                else
+                        break;
+        }
+        for (cp = bprm->buf+2; (*cp == ' ') || (*cp == '\t'); cp++);
+        if (*cp == '\0') 
+                return -ENOEXEC; /* No interpreter name found */
+        i_name = cp;
+        i_arg = NULL;
+        for ( ; *cp && (*cp != ' ') && (*cp != '\t'); cp++)
+                /* nothing */ ;
+        while ((*cp == ' ') || (*cp == '\t'))
+                *cp++ = '\0';
+        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->interp, 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++;
+        bprm->interp = interp;
+
+        /*
+         * 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);
+}
+
+static struct linux_binfmt script_format = {
+        .module         = THIS_MODULE,
+        .load_binary    = load_script,
+};
+
+static int __init init_script_binfmt(void)
+{
+        return register_binfmt(&script_format);
+}
+
+static void __exit exit_script_binfmt(void)
+{
+        unregister_binfmt(&script_format);
+}
+
+core_initcall(init_script_binfmt);
+module_exit(exit_script_binfmt);
+MODULE_LICENSE("GPL");