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\ > > | ^~~~~~~~~~~~ > > ./include/linux/rcupdate.h:1047:29: note: in expansion of macro > > 'kvfree_rcu_arg_2' > > 1047 | #define kfree_rcu(ptr, rhf) kvfree_rcu_arg_2(ptr, rhf) > > | ^~~~~~~~~~~~~~~~ > > net/sunrpc/xprt.c:1856:9: note: in expansion of macro 'kfree_rcu' > > 1856 | kfree_rcu(xprt, rcu); > > | ^~~~~~~~~ > > CC net/kcm/kcmproc.o > > make[4]: *** [scripts/Makefile.build:203: net/sunrpc/xprt.o] Error 1 > > > > Since kfree_rcu() assumes 'offset of struct rcu_head in a rcu-managed > > struct < 4096', the offest of struct rcu_head in struct rpc_xprt should > > not exceed 4096 but does, due to the debug information added by DEPT. > > > > Relocate struct rcu_head to the first field of struct rpc_xprt from an > > arbitrary location to avoid the issue and meet the assumption. > > > > Reported-by: Yunseong Kim > > Signed-off-by: Byungchul Park > > --- > > include/linux/sunrpc/xprt.h | 9 ++++++++- > > 1 file changed, 8 insertions(+), 1 deletion(-) > > > > diff --git a/include/linux/sunrpc/xprt.h b/include/linux/sunrpc/xprt.h > > index f46d1fb8f71a..666e42a17a31 100644 > > --- a/include/linux/sunrpc/xprt.h > > +++ b/include/linux/sunrpc/xprt.h > > @@ -211,6 +211,14 @@ enum xprt_transports { > > > > struct rpc_sysfs_xprt; > > struct rpc_xprt { > > + /* > > + * Place struct rcu_head within the first 4096 bytes of struct > > + * rpc_xprt if sizeof(struct rpc_xprt) > 4096, so that > > + * kfree_rcu() can simply work assuming that. See the comment > > + * in kfree_rcu(). > > + */ > > + struct rcu_head rcu; > > + > > struct kref kref; /* Reference count */ > > const struct rpc_xprt_ops *ops; /* transport methods */ > > unsigned int id; /* transport id */ > > @@ -317,7 +325,6 @@ struct rpc_xprt { > > #if IS_ENABLED(CONFIG_SUNRPC_DEBUG) > > struct dentry *debugfs; /* debugfs directory */ > > #endif > > - struct rcu_head rcu; > > const struct xprt_class *xprt_class; > > struct rpc_sysfs_xprt *xprt_sysfs; > > bool main; /*mark if this is the 1st transport */ > > Seems fine to me. > > Reviewed-by: Jeff Layton Thank you, Jeff. Byungchul