orangefs: add usercopy whitelist to orangefs_op_cache

orangefs_op_cache is created with kmem_cache_create(), which provides
no usercopy whitelist. orangefs_devreq_read() copies the tag and upcall
fields directly from slab objects to userspace via copy_to_user(). With
CONFIG_HARDENED_USERCOPY enabled, this triggers usercopy_abort().

Switch to kmem_cache_create_usercopy() with a whitelist covering the
tag and upcall fields, matching the pattern already used by
orangefs_inode_cache in super.c.

Signed-off-by: Ziyi Guo <n7l8m4@u.northwestern.edu>
Signed-off-by: Mike Marshall <hubcap@omnibond.com>

Author: haruki3hhh

fs/orangefs/orangefs-cache.c

@@ -19,10 +19,14 @@ static struct kmem_cache *op_cache;
 
 int op_cache_initialize(void)
 {
-	op_cache = kmem_cache_create("orangefs_op_cache",
+	op_cache = kmem_cache_create_usercopy("orangefs_op_cache",
 				     sizeof(struct orangefs_kernel_op_s),
 				     0,
 				     0,
+					 offsetof(struct orangefs_kernel_op_s, tag),
+					 offsetof(struct orangefs_kernel_op_s, upcall) +
+					     sizeof(struct orangefs_upcall_s) -
+						 offsetof(struct orangefs_kernel_op_s, tag),
 				     NULL);
 
 	if (!op_cache) {