From a0f2b65275413b3438e9f55b1427273cd893c3b2 Mon Sep 17 00:00:00 2001 From: Arnd Bergmann Date: Mon, 13 Jun 2016 15:04:56 +0200 Subject: [PATCH] ceph: fix symbol versioning for ceph_monc_do_statfs The genksyms helper in the kernel cannot parse a type definition like "typeof(((type *)0)->keyfld)" that is used in the DEFINE_RB_FUNCS helper, causing the following EXPORT_SYMBOL() statement to be ignored when computing the crcs, and triggering a warning about this: WARNING: "ceph_monc_do_statfs" [fs/ceph/ceph.ko] has no CRC To work around the problem, we can rewrite the type to reference an undefined 'extern' symbol instead of a NULL pointer. This is evidently ok for genksyms, and it no longer complains about the line when calling it with 'genksyms -w'. I've looked briefly into extending genksyms instead, but it seems really hard to do. Jan Beulich introduced basic support for 'typeof' a while ago in dc53324060f3 ("genksyms: fix typeof() handling"), but that is not sufficient for the expression we have here. Signed-off-by: Arnd Bergmann Fixes: fcd00b68bbe2 ("libceph: DEFINE_RB_FUNCS macro") Cc: Jan Beulich Cc: Michal Marek Signed-off-by: Ilya Dryomov --- include/linux/ceph/libceph.h | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/include/linux/ceph/libceph.h b/include/linux/ceph/libceph.h index 6afc5d98fad1..83fc1fff7061 100644 --- a/include/linux/ceph/libceph.h +++ b/include/linux/ceph/libceph.h @@ -215,8 +215,9 @@ static void erase_##name(struct rb_root *root, type *t) \ } #define DEFINE_RB_LOOKUP_FUNC(name, type, keyfld, nodefld) \ +extern type __lookup_##name##_key; \ static type *lookup_##name(struct rb_root *root, \ - typeof(((type *)0)->keyfld) key) \ + typeof(__lookup_##name##_key.keyfld) key) \ { \ struct rb_node *n = root->rb_node; \ \ -- 2.20.1