param: add a free hook to kernel_param_ops.
This allows us to generalize the KPARAM_KMALLOCED flag, by calling a function
on every parameter when a module is unloaded.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Reviewed-by: Takashi Iwai <tiwai@suse.de>
Tested-by: Phil Carmody <ext-phil.2.carmody@nokia.com>
diff --git a/include/linux/moduleparam.h b/include/linux/moduleparam.h
index 02e5090..9f51568 100644
--- a/include/linux/moduleparam.h
+++ b/include/linux/moduleparam.h
@@ -36,6 +36,8 @@
int (*set)(const char *val, const struct kernel_param *kp);
/* Returns length written or -errno. Buffer is 4k (ie. be short!) */
int (*get)(char *buffer, const struct kernel_param *kp);
+ /* Optional function to free kp->arg when module unloaded. */
+ void (*free)(void *arg);
};
/* Flag bits for kernel_param.flags */
diff --git a/kernel/params.c b/kernel/params.c
index a550698..458a09b 100644
--- a/kernel/params.c
+++ b/kernel/params.c
@@ -399,9 +399,20 @@
return off;
}
+static void param_array_free(void *arg)
+{
+ unsigned int i;
+ const struct kparam_array *arr = arg;
+
+ if (arr->ops->free)
+ for (i = 0; i < (arr->num ? *arr->num : arr->max); i++)
+ arr->ops->free(arr->elem + arr->elemsize * i);
+}
+
struct kernel_param_ops param_array_ops = {
.set = param_array_set,
.get = param_array_get,
+ .free = param_array_free,
};
EXPORT_SYMBOL(param_array_ops);
@@ -634,7 +645,11 @@
void destroy_params(const struct kernel_param *params, unsigned num)
{
- /* FIXME: This should free kmalloced charp parameters. It doesn't. */
+ unsigned int i;
+
+ for (i = 0; i < num; i++)
+ if (params[i].ops->free)
+ params[i].ops->free(params[i].arg);
}
static void __init kernel_add_sysfs_param(const char *name,