34 # define USE_DEBUG 1
40 	VERBOSE_STATUS = 1 /* make it zero to save 400 bytes kernel memory */
44 #define MISC_FMT_PRESERVE_ARGV0 (1UL << 31)
45 #define MISC_FMT_OPEN_BINARY (1UL << 30)
46 #define MISC_FMT_CREDENTIALS (1UL << 29)
47 #define MISC_FMT_OPEN_FILE (1UL << 28)
69  *  - type:   1 byte
94 	Node *e;  in search_binfmt_handler()  local
97 	list_for_each_entry(e, &misc->entries, list) {  in search_binfmt_handler()
102 		if (!test_bit(Enabled, &e->flags))  in search_binfmt_handler()
106 		if (!test_bit(Magic, &e->flags)) {  in search_binfmt_handler()
107 			if (p && !strcmp(e->magic, p + 1))  in search_binfmt_handler()
108 				return e;  in search_binfmt_handler()
113 		s = bprm->buf + e->offset;  in search_binfmt_handler()
114 		if (e->mask) {  in search_binfmt_handler()
115 			for (j = 0; j < e->size; j++)  in search_binfmt_handler()
116 				if ((*s++ ^ e->magic[j]) & e->mask[j])  in search_binfmt_handler()
119 			for (j = 0; j < e->size; j++)  in search_binfmt_handler()
120 				if ((*s++ ^ e->magic[j]))  in search_binfmt_handler()
123 		if (j == e->size)  in search_binfmt_handler()
124 			return e;  in search_binfmt_handler()
143 	Node *e;  in get_binfmt_handler()  local
146 	e = search_binfmt_handler(misc, bprm);  in get_binfmt_handler()
147 	if (e)  in get_binfmt_handler()
148 		refcount_inc(&e->users);  in get_binfmt_handler()
150 	return e;  in get_binfmt_handler()
155  * @e: node to put
161 static void put_binfmt_handler(Node *e)  in put_binfmt_handler()  argument
163 	if (refcount_dec_and_test(&e->users)) {  in put_binfmt_handler()
164 		if (e->flags & MISC_FMT_OPEN_FILE)  in put_binfmt_handler()
165 			filp_close(e->interp_file, NULL);  in put_binfmt_handler()
166 		kfree(e);  in put_binfmt_handler()
231 		bprm->have_execfd = 1;  in load_misc_binary()
233 	/* make argv[1] be the path to the binary */  in load_misc_binary()
263 		bprm->execfd_creds = 1;  in load_misc_binary()
301 	s[-1] ='\0';  in scanarg()
305 static char *check_special_flags(char *sfs, Node *e)  in check_special_flags()  argument
308 	int cont = 1;  in check_special_flags()
316 			e->flags |= MISC_FMT_PRESERVE_ARGV0;  in check_special_flags()
321 			e->flags |= MISC_FMT_OPEN_BINARY;  in check_special_flags()
328 			e->flags |= (MISC_FMT_CREDENTIALS |  in check_special_flags()
334 			e->flags |= MISC_FMT_OPEN_FILE;  in check_special_flags()
351 	Node *e;  in create_entry()  local
365 	e = kmalloc(memsize, GFP_KERNEL_ACCOUNT);  in create_entry()
366 	if (!e)  in create_entry()
369 	p = buf = (char *)e + sizeof(Node);  in create_entry()
371 	memset(e, 0, sizeof(Node));  in create_entry()
383 	e->name = p;  in create_entry()
388 	if (!e->name[0] ||  in create_entry()
389 	    !strcmp(e->name, ".") ||  in create_entry()
390 	    !strcmp(e->name, "..") ||  in create_entry()
391 	    strchr(e->name, '/'))  in create_entry()
394 	pr_debug("register: name: {%s}\n", e->name);  in create_entry()
398 	case 'E':  in create_entry()
399 		pr_debug("register: type: E (extension)\n");  in create_entry()
400 		e->flags = 1 << Enabled;  in create_entry()
404 		e->flags = (1 << Enabled) | (1 << Magic);  in create_entry()
412 	if (test_bit(Magic, &e->flags)) {  in create_entry()
422 			int r = kstrtoint(p, 10, &e->offset);  in create_entry()
423 			if (r != 0 || e->offset < 0)  in create_entry()
429 		pr_debug("register: offset: %#x\n", e->offset);  in create_entry()
432 		e->magic = p;  in create_entry()
436 		if (!e->magic[0])  in create_entry()
441 				DUMP_PREFIX_NONE, e->magic, p - e->magic);  in create_entry()
444 		e->mask = p;  in create_entry()
448 		if (!e->mask[0]) {  in create_entry()
449 			e->mask = NULL;  in create_entry()
454 				DUMP_PREFIX_NONE, e->mask, p - e->mask);  in create_entry()
462 		e->size = string_unescape_inplace(e->magic, UNESCAPE_HEX);  in create_entry()
463 		if (e->mask &&  in create_entry()
464 		    string_unescape_inplace(e->mask, UNESCAPE_HEX) != e->size)  in create_entry()
466 		if (e->size > BINPRM_BUF_SIZE ||  in create_entry()
467 		    BINPRM_BUF_SIZE - e->size < e->offset)  in create_entry()
469 		pr_debug("register: magic/mask length: %i\n", e->size);  in create_entry()
473 				DUMP_PREFIX_NONE, e->magic, e->size);  in create_entry()
475 			if (e->mask) {  in create_entry()
477 				char *masked = kmalloc(e->size, GFP_KERNEL_ACCOUNT);  in create_entry()
481 					DUMP_PREFIX_NONE, e->mask, e->size);  in create_entry()
484 					for (i = 0; i < e->size; ++i)  in create_entry()
485 						masked[i] = e->magic[i] & e->mask[i];  in create_entry()
488 						DUMP_PREFIX_NONE, masked, e->size);  in create_entry()
495 		/* Handle the 'E' (extension) format. */  in create_entry()
504 		e->magic = p;  in create_entry()
509 		if (!e->magic[0] || strchr(e->magic, '/'))  in create_entry()
511 		pr_debug("register: extension: {%s}\n", e->magic);  in create_entry()
521 	e->interpreter = p;  in create_entry()
526 	if (!e->interpreter[0])  in create_entry()
528 	pr_debug("register: interpreter: {%s}\n", e->interpreter);  in create_entry()
531 	p = check_special_flags(p, e);  in create_entry()
537 	return e;  in create_entry()
543 	kfree(e);  in create_entry()
546 	kfree(e);  in create_entry()
552  * '1' enables, '0' disables and '-1' clears entry/binfmt_misc
564 	if (s[count - 1] == '\n')  in parse_command()
566 	if (count == 1 && s[0] == '0')  in parse_command()
567 		return 1;  in parse_command()
568 	if (count == 1 && s[0] == '1')  in parse_command()
570 	if (count == 2 && s[0] == '-' && s[1] == '1')  in parse_command()
577 static void entry_status(Node *e, char *page)  in entry_status()  argument
582 	if (test_bit(Enabled, &e->flags))  in entry_status()
590 	dp += sprintf(dp, "%s\ninterpreter %s\n", status, e->interpreter);  in entry_status()
594 	if (e->flags & MISC_FMT_PRESERVE_ARGV0)  in entry_status()
596 	if (e->flags & MISC_FMT_OPEN_BINARY)  in entry_status()
598 	if (e->flags & MISC_FMT_CREDENTIALS)  in entry_status()
600 	if (e->flags & MISC_FMT_OPEN_FILE)  in entry_status()
604 	if (!test_bit(Magic, &e->flags)) {  in entry_status()
605 		sprintf(dp, "extension .%s\n", e->magic);  in entry_status()
607 		dp += sprintf(dp, "offset %i\nmagic ", e->offset);  in entry_status()
608 		dp = bin2hex(dp, e->magic, e->size);  in entry_status()
609 		if (e->mask) {  in entry_status()
611 			dp = bin2hex(dp, e->mask, e->size);  in entry_status()
661 	Node *e = inode->i_private;  in bm_evict_inode()  local
665 	if (e) {  in bm_evict_inode()
670 		if (!list_empty(&e->list))  in bm_evict_inode()
671 			list_del_init(&e->list);  in bm_evict_inode()
673 		put_binfmt_handler(e);  in bm_evict_inode()
718  * @e: binary type handler to remove
727 static void remove_binfmt_handler(struct binfmt_misc *misc, Node *e)  in remove_binfmt_handler()  argument
730 	list_del_init(&e->list);  in remove_binfmt_handler()
732 	unlink_binfmt_dentry(e->dentry);  in remove_binfmt_handler()
740 	Node *e = file_inode(file)->i_private;  in bm_entry_read()  local
748 	entry_status(e, page);  in bm_entry_read()
760 	Node *e = inode->i_private;  in bm_entry_write()  local
764 	case 1:  in bm_entry_write()
766 		clear_bit(Enabled, &e->flags);  in bm_entry_write()
770 		set_bit(Enabled, &e->flags);  in bm_entry_write()
786 		if (!list_empty(&e->list))  in bm_entry_write()
787 			remove_binfmt_handler(i_binfmt_misc(inode), e);  in bm_entry_write()
809 	Node *e;  in bm_register_write()  local
817 	e = create_entry(buffer, count);  in bm_register_write()
819 	if (IS_ERR(e))  in bm_register_write()
820 		return PTR_ERR(e);  in bm_register_write()
822 	if (e->flags & MISC_FMT_OPEN_FILE) {  in bm_register_write()
833 		f = open_exec(e->interpreter);  in bm_register_write()
837 				 e->interpreter);  in bm_register_write()
838 			kfree(e);  in bm_register_write()
841 		e->interp_file = f;  in bm_register_write()
845 	dentry = lookup_one_len(e->name, root, strlen(e->name));  in bm_register_write()
860 	refcount_set(&e->users, 1);  in bm_register_write()
861 	e->dentry = dget(dentry);  in bm_register_write()
862 	inode->i_private = e;  in bm_register_write()
868 	list_add(&e->list, &misc->entries);  in bm_register_write()
880 		kfree(e);  in bm_register_write()
909 	Node *e, *next;  in bm_status_write()  local
914 	case 1:  in bm_status_write()
936 		list_for_each_entry_safe(e, next, &misc->entries, list)  in bm_status_write()
937 			remove_binfmt_handler(misc, e);  in bm_status_write()
985 	 * Lazily allocate a new binfmt_misc instance for this namespace, i.e.  in bm_fill_super()