Fix kenv behavior when there is no static environment

In case where there are no static kernel environment entries, the
function init_dynamic_kenv() adds an incorrect entry at position 0 of
the dynamic kernel environment. This in turn causes kenv(1) to print
and empty list even though there are dynamic entries added later.

Fix this by checking env_pos in init_dynamic_kenv() and adding dynamic
entries only if there are static entries.

1 files changed, 16 insertions, 13 deletions

diff --git a/sys/kern/kern_environment.c b/sys/kern/kern_environment.c
index d60299b..3b04cb7 100644
--- a/sys/kern/kern_environment.c
+++ b/sys/kern/kern_environment.c
@@ -231,20 +231,23 @@ init_dynamic_kenv(void *data __unused)
 	kenvp = malloc((KENV_SIZE + 1) * sizeof(char *), M_KENV,
 		M_WAITOK | M_ZERO);
 	i = 0;
-	for (cp = kern_envp; cp != NULL; cp = kernenv_next(cp)) {
-		len = strlen(cp) + 1;
-		if (len > KENV_MNAMELEN + 1 + KENV_MVALLEN + 1) {
-			printf("WARNING: too long kenv string, ignoring %s\n",
-			    cp);
-			continue;
+	if (env_pos > 0) {
+		for (cp = kern_envp; cp != NULL; cp = kernenv_next(cp)) {
+			len = strlen(cp) + 1;
+			if (len > KENV_MNAMELEN + 1 + KENV_MVALLEN + 1) {
+				printf(
+				"WARNING: too long kenv string, ignoring %s\n",
+				    cp);
+				continue;
+			}
+			if (i < KENV_SIZE) {
+				kenvp[i] = malloc(len, M_KENV, M_WAITOK);
+				strcpy(kenvp[i++], cp);
+			} else
+				printf(
+				"WARNING: too many kenv strings, ignoring %s\n",
+				    cp);
 		}
-		if (i < KENV_SIZE) {
-			kenvp[i] = malloc(len, M_KENV, M_WAITOK);
-			strcpy(kenvp[i++], cp);
-		} else
-			printf(
-			    "WARNING: too many kenv strings, ignoring %s\n",
-			    cp);
 	}
 	kenvp[i] = NULL;