xen/char: console: Use const whenever we point to literal strings

Literal strings are not meant to be modified. So we should use const
char * rather than char * when we want to store a pointer to them.

The array should also not be modified at all and is only used by
xenlog_update_val(). So take the opportunity to add an extra const and
move the definition in the function.

Signed-off-by: Julien Grall <jgrall@amazon.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Luca Fancellu <luca.fancellu@arm.com>

diff --git a/xen/drivers/char/console.c b/xen/drivers/char/console.c
index 23583751709c6ff7c842846b91cb1a320e5852d7..7d0a603d031183e0209a87fdca981a98009573c3 100644 (file)
--- a/xen/drivers/char/console.c
+++ b/xen/drivers/char/console.c
@@ -168,10 +168,11 @@ static int parse_guest_loglvl(const char *s);
 static char xenlog_val[LOGLVL_VAL_SZ];
 static char xenlog_guest_val[LOGLVL_VAL_SZ];
 
-static char *lvl2opt[] = { "none", "error", "warning", "info", "all" };
-
 static void xenlog_update_val(int lower, int upper, char *val)
 {
+    static const char * const lvl2opt[] =
+        { "none", "error", "warning", "info", "all" };
+
     snprintf(val, LOGLVL_VAL_SZ, "%s/%s", lvl2opt[lower], lvl2opt[upper]);
 }
 
@@ -262,7 +263,7 @@ static int parse_guest_loglvl(const char *s)
     return ret;
 }
 
-static char *loglvl_str(int lvl)
+static const char *loglvl_str(int lvl)
 {
     switch ( lvl )
     {