commit da2654b78ce3af083e42c2f7512d09082b872676
Author: Yannick Le Pennec <yannick.lepennec@live.fr>
Date:   Mon Mar 24 18:35:53 2025 +0100

    tools/rmmod: fix garbled error message
    
    a6f9cd0 ("tools/rmmod: consistently use ERR logging facility") fixed
    the split between syslog and stderr of various error message substrings
    by calling the ERR macro instead of writing directly to stderr, but in
    doing so also completely mangled the output because the ERR macro
    decorates its arguments:
    
        $ rmmod iwlwifi
        rmmod: ERROR: Module iwlwifi is in use by:rmmod: ERROR:  iwlmvmrmmod: ERROR:
    
    And in syslog:
    
        $ rmmod -s iwlwifi
        2025-03-24T17:22:34.878318+01:00 mangolassi rmmod: ERROR: Module iwlwifi is in use by:
        2025-03-24T17:22:34.889145+01:00 mangolassi rmmod: ERROR:  iwlmvm
        2025-03-24T17:22:34.889224+01:00 mangolassi rmmod: ERROR:
    
    This commit fixes that by building the holder names list with a strbuf
    and then passes the whole thing at once to ERR.
    
    Fixes: a6f9cd0 ("tools/rmmod: consistently use ERR logging facility")
    Signed-off-by: Yannick Le Pennec <yannick.lepennec@live.fr>
    Link: https://lore.kernel.org/r/VI1PR02MB48291E3BDB7E764ED67154949BA42@VI1PR02MB4829.eurprd02.prod.outlook.com
    Signed-off-by: Lucas De Marchi <lucas.de.marchi@gmail.com>
    Link: https://github.com/kmod-project/kmod/pull/328

diff --git a/tools/rmmod.c b/tools/rmmod.c
index 962d850..61f2e00 100644
--- a/tools/rmmod.c
+++ b/tools/rmmod.c
@@ -15,6 +15,7 @@
 #include <sys/types.h>
 
 #include <shared/macro.h>
+#include <shared/strbuf.h>
 
 #include <libkmod/libkmod.h>
 
@@ -63,16 +64,18 @@ static int check_module_inuse(struct kmod_module *mod)
 
 	holders = kmod_module_get_holders(mod);
 	if (holders != NULL) {
+		DECLARE_STRBUF_WITH_STACK(buf, 128);
 		struct kmod_list *itr;
 
-		ERR("Module %s is in use by:", kmod_module_get_name(mod));
-
 		kmod_list_foreach(itr, holders) {
 			struct kmod_module *hm = kmod_module_get_module(itr);
-			ERR(" %s", kmod_module_get_name(hm));
+			strbuf_pushchar(&buf, ' ');
+			strbuf_pushchars(&buf, kmod_module_get_name(hm));
 			kmod_module_unref(hm);
 		}
-		ERR("\n");
+
+		ERR("Module %s is in use by:%s\n", kmod_module_get_name(mod),
+		    strbuf_str(&buf));
 
 		kmod_module_unref_list(holders);
 		return -EBUSY;
