linux-next: build failure after merge of the rcu tree

Stephen Rothwell
2016-05-02T04:37:41Z

Hi Paul,

After merging the rcu tree, today's linux-next build (x86_64 allmodconfig)
failed like this:

arch/x86/kvm/vmx.c: In function 'vmx_init':
arch/x86/kvm/vmx.c:11026:2: error: function '_r_a_p__v' is initialized like a variable
rcu_assign_pointer(crash_vmclear_loaded_vmcss,
^
In file included from include/linux/rbtree.h:34:0,
from include/linux/mm_types.h:9,
from arch/x86/kvm/irq.h:25,
from arch/x86/kvm/vmx.c:19:
include/linux/rcupdate.h:657:45: warning: the comparison will always evaluate as 'false' for the address of '_r_a_p__v' will never be NULL [-Waddress]
if (__builtin_constant_p(v) && (_r_a_p__v) == NULL) \
^
arch/x86/kvm/vmx.c:11026:2: note: in expansion of macro 'rcu_assign_pointer'
rcu_assign_pointer(crash_vmclear_loaded_vmcss,
^
include/linux/rcupdate.h:655:12: error: nested function '_r_a_p__v' declared but never defined
typeof(v) _r_a_p__v = (v); \
^
arch/x86/kvm/vmx.c:11026:2: note: in expansion of macro 'rcu_assign_pointer'
rcu_assign_pointer(crash_vmclear_loaded_vmcss,
^

Caused by commit

16d7afcaa530 ("rcu: No ordering for rcu_assign_pointer() of NULL")

I have reverted that commit for today.

--
Cheers,
Stephen Rothwell