constify string/array kparam tracking structures

.. in an effort to make read-only whatever can be made, so that
CONFIG_DEBUG_RODATA can catch as many issues as possible.

Signed-off-by: Jan Beulich <jbeulich@novell.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 11 insertions, 7 deletions

diff --git a/include/linux/moduleparam.h b/include/linux/moduleparam.h
index c83588c8d08..13410b20600 100644
--- a/include/linux/moduleparam.h
+++ b/include/linux/moduleparam.h
@@ -38,7 +38,11 @@ struct kernel_param {
         unsigned int perm;
         param_set_fn set;
         param_get_fn get;
-        void *arg;
+        union {
+                void *arg;
+                const struct kparam_string *str;
+                const struct kparam_array *arr;
+        };
 };
 
 /* Special one for strings we want to copy into */
@@ -66,11 +70,11 @@ struct kparam_array
         /* Default value instead of permissions? */                     \
         static int __param_perm_check_##name __attribute__((unused)) =  \
         BUILD_BUG_ON_ZERO((perm) < 0 || (perm) > 0777 || ((perm) & 2)); \
-        static char __param_str_##name[] = prefix #name;                \
+        static const char __param_str_##name[] = prefix #name;          \
         static struct kernel_param const __param_##name                 \
         __attribute_used__                                              \
     __attribute__ ((unused,__section__ ("__param"),aligned(sizeof(void *)))) \
-        = { __param_str_##name, perm, set, get, arg }
+        = { __param_str_##name, perm, set, get, { arg } }
 
 #define module_param_call(name, set, get, arg, perm)                          \
         __module_param_call(MODULE_PARAM_PREFIX, name, set, get, arg, perm)
@@ -88,10 +92,10 @@ struct kparam_array
 
 /* Actually copy string: maxlen param is usually sizeof(string). */
 #define module_param_string(name, string, len, perm)                    \
-        static struct kparam_string __param_string_##name               \
+        static const struct kparam_string __param_string_##name         \
                 = { len, string };                                      \
         module_param_call(name, param_set_copystring, param_get_string, \
-                   &__param_string_##name, perm);                       \
+                          .str = &__param_string_##name, perm);         \
         __MODULE_PARM_TYPE(name, "string")
 
 /* Called on module insert or kernel boot */
@@ -149,11 +153,11 @@ extern int param_get_invbool(char *buffer, struct kernel_param *kp);
 
 /* Comma-separated array: *nump is set to number they actually specified. */
 #define module_param_array_named(name, array, type, nump, perm)         \
-        static struct kparam_array __param_arr_##name                   \
+        static const struct kparam_array __param_arr_##name             \
         = { ARRAY_SIZE(array), nump, param_set_##type, param_get_##type,\
             sizeof(array[0]), array };                                  \
         module_param_call(name, param_array_set, param_array_get,       \
-                          &__param_arr_##name, perm);                   \
+                          .arr = &__param_arr_##name, perm);            \
         __MODULE_PARM_TYPE(name, "array of " #type)
 
 #define module_param_array(name, type, nump, perm)              \