modprobe: revert checking for /, stop doing basename() on modprobe args

function                                             old     new   delta
process_module                                       726     719      -7
filename2modname                                      81      67     -14
------------------------------------------------------------------------------
(add/remove: 0/0 grow/shrink: 0/2 up/down: 0/-21)             Total: -21 bytes

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
diff --git a/modutils/modprobe-small.c b/modutils/modprobe-small.c
index b7990bf..dafe91e 100644
--- a/modutils/modprobe-small.c
+++ b/modutils/modprobe-small.c
@@ -149,9 +149,13 @@
 static char *filename2modname(const char *filename, char *modname)
 {
 	int i;
-	char *from;
+	const char *from;
 
-	from = bb_get_last_path_component_nostrip(filename);
+	// Disabled since otherwise "modprobe dir/name" would work
+	// as if it is "modprobe name". It is unclear why
+	// 'basenamization' was here in the first place.
+	//from = bb_get_last_path_component_nostrip(filename);
+	from = filename;
 	for (i = 0; i < (MODULE_NAME_LEN-1) && from[i] != '\0' && from[i] != '.'; i++)
 		modname[i] = (from[i] == '-') ? '_' : from[i];
 	modname[i] = '\0';
diff --git a/modutils/modprobe.c b/modutils/modprobe.c
index f090428..f08f085 100644
--- a/modutils/modprobe.c
+++ b/modutils/modprobe.c
@@ -238,17 +238,6 @@
 {
 	struct module_entry *m;
 
-	/*
-	 * get_or_add_modentry() strips path from name and works
-	 * on remaining basename.
-	 * This would make "rmmod dir/name" and "modprobe dir/name"
-	 * to work like "rmmod name" and "modprobe name",
-	 * which is wrong, and can be abused via implicit modprobing:
-	 * "ifconfig /usbserial up" tries to modprobe netdev-/usbserial.
-	 */
-	if (strchr(name, '/'))
-		bb_error_msg_and_die("malformed module name '%s'", name);
-
 	m = get_or_add_modentry(name);
 	if (!(option_mask32 & (OPT_REMOVE | OPT_SHOW_DEPS))
 	 && (m->flags & MODULE_FLAG_LOADED)
diff --git a/modutils/modutils.c b/modutils/modutils.c
index 6187ca7..ff79d3f 100644
--- a/modutils/modutils.c
+++ b/modutils/modutils.c
@@ -48,13 +48,17 @@
 char* FAST_FUNC filename2modname(const char *filename, char *modname)
 {
 	int i;
-	char *from;
+	const char *from;
 
 	if (filename == NULL)
 		return NULL;
 	if (modname == NULL)
 		modname = xmalloc(MODULE_NAME_LEN);
-	from = bb_get_last_path_component_nostrip(filename);
+	// Disabled since otherwise "modprobe dir/name" would work
+	// as if it is "modprobe name". It is unclear why
+	// 'basenamization' was here in the first place.
+	//from = bb_get_last_path_component_nostrip(filename);
+	from = filename;
 	for (i = 0; i < (MODULE_NAME_LEN-1) && from[i] != '\0' && from[i] != '.'; i++)
 		modname[i] = (from[i] == '-') ? '_' : from[i];
 	modname[i] = '\0';