rmmod: fix bad error message

    Before:

    ># busybox_old rmmod gtrhfhdfghdf
    rmmod: can't unload 'gtrhfhdfghdf': unknown symbol in module, or unknown parameter

    After:

    ># busybox rmmod gtrhfhdfghdf
    rmmod: can't unload module 'gtrhfhdfghdf': No such file or directory

function                                             old     new   delta
modprobe_main                                        726     721      -5
do_modprobe                                          599     590      -9
rmmod_main                                           187     169     -18
------------------------------------------------------------------------------
(add/remove: 0/0 grow/shrink: 0/3 up/down: 0/-32)             Total: -32 bytes

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>

3 files changed, 15 insertions, 9 deletions

diff --git a/modutils/modprobe.c b/modutils/modprobe.c
index 314a7a1..952ba03 100644
--- a/modutils/modprobe.c
+++ b/modutils/modprobe.c
@@ -461,9 +461,8 @@ static int do_modprobe(struct module_entry *m)
 				rc = bb_delete_module(m2->modname, O_EXCL);
 				if (rc) {
 					if (first) {
-						bb_error_msg("can't unload module %s: %s",
-							humanly_readable_name(m2),
-							moderror(rc));
+						bb_perror_msg("can't unload module %s",
+							humanly_readable_name(m2));
 						break;
 					}
 				} else {
@@ -622,7 +621,7 @@ int modprobe_main(int argc UNUSED_PARAM, char **argv)
 			 * autoclean will be removed".
 			 */
 			if (bb_delete_module(NULL, O_NONBLOCK | O_EXCL) != 0)
-				bb_perror_msg_and_die("rmmod");
+				bb_perror_nomsg_and_die();
 		}
 		return EXIT_SUCCESS;
 	}
diff --git a/modutils/modutils.c b/modutils/modutils.c
index 84300d9..ef4134a 100644
--- a/modutils/modutils.c
+++ b/modutils/modutils.c
@@ -190,6 +190,11 @@ int FAST_FUNC bb_delete_module(const char *module, unsigned int flags)
 	return errno;
 }
 
+/* Note: not suitable for delete_module() errnos.
+ * For them, probably only EWOULDBLOCK needs explaining:
+ * "Other modules depend on us". So far we don't do such
+ * translation and don't use moderror() for removal errors.
+ */
 const char* FAST_FUNC moderror(int err)
 {
 	switch (err) {
diff --git a/modutils/rmmod.c b/modutils/rmmod.c
index f13ff9e..5c353ef 100644
--- a/modutils/rmmod.c
+++ b/modutils/rmmod.c
@@ -28,7 +28,7 @@
 int rmmod_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
 int rmmod_main(int argc UNUSED_PARAM, char **argv)
 {
-	int n;
+	int n, err;
 	unsigned flags = O_NONBLOCK | O_EXCL;
 
 	/* Parse command line. */
@@ -40,7 +40,8 @@ int rmmod_main(int argc UNUSED_PARAM, char **argv)
 		flags |= O_TRUNC;
 	if (n & 4) {
 		/* Unload _all_ unused modules via NULL delete_module() call */
-		if (bb_delete_module(NULL, flags) != 0 && errno != EFAULT)
+		err = bb_delete_module(NULL, flags);
+		if (err && err != EFAULT)
 			bb_perror_msg_and_die("rmmod");
 		return EXIT_SUCCESS;
 	}
@@ -58,9 +59,10 @@ int rmmod_main(int argc UNUSED_PARAM, char **argv)
 			safe_strncpy(modname, bname, MODULE_NAME_LEN);
 		else
 			filename2modname(bname, modname);
-		if (bb_delete_module(modname, flags))
-			bb_error_msg_and_die("can't unload '%s': %s",
-					modname, moderror(errno));
+		err = bb_delete_module(modname, flags);
+		if (err)
+			bb_perror_msg_and_die("can't unload module '%s'",
+					modname);
 	}
 
 	return EXIT_SUCCESS;