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>

1 files changed, 2 insertions, 0 deletions

diff --git a/include/linux/moduleparam.h b/include/linux/moduleparam.h
index 02e5090ce32f..9f51568f51c8 100644
--- a/include/linux/moduleparam.h
+++ b/include/linux/moduleparam.h
@@ -36,6 +36,8 @@ struct kernel_param_ops {
         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 */