[PATCH 5.12 158/178] cfg80211: make certificate generation more robust

Greg Kroah-Hartman
2021-06-21T16:52:34Z

From: Johannes Berg <johannes.berg@intel.com>

commit b5642479b0f7168fe16d156913533fe65ab4f8d5 upstream.

If all net/wireless/certs/*.hex files are deleted, the build
will hang at this point since the 'cat' command will have no
arguments. Do "echo | cat - ..." so that even if the "..."
part is empty, the whole thing won't hang.

Cc: stable@vger.kernel.org
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Luca Coelho <luciano.coelho@intel.com>
Link: https://lore.kernel.org/r/iwlwifi.20210618133832.c989056c3664.Ic3b77531d00b30b26dcd69c64e55ae2f60c3f31e@changeid
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
net/wireless/Makefile | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

--- a/net/wireless/Makefile
+++ b/net/wireless/Makefile
@@ -28,7 +28,7 @@ $(obj)/shipped-certs.c: $(wildcard $(src
@$(kecho) " GEN $@"
@(echo '#include "reg.h"'; \
echo 'const u8 shipped_regdb_certs[] = {'; \
- cat $^ ; \
+ echo | cat - $^ ; \
echo '};'; \
echo 'unsigned int shipped_regdb_certs_len = sizeof(shipped_regdb_certs);'; \