2:30 a.m.
Well that's embarrassing, I can't believe I didn't catch that in my
testing. I'm sure I built the kernel with lockdep enabled several
times.
Ah well, I can send a fix out for this and the other issue the test bot found.
On Sat, Apr 17, 2021 at 8:20 AM kernel test robot <lkp(a)intel.com> wrote:
>
> tree: https://git.kernel.org/pub/scm/virt/kvm/kvm.git queue
> head: 3afb84581509b8d28979d15b5d727366efb3c8e5
> commit: 078d47ee71d6a53657b5917ce1478f10bc173fa5 [149/154] KVM: x86/mmu: Protect the
tdp_mmu_roots list with RCU
> config: x86_64-allyesconfig (attached as .config)
> compiler: gcc-9 (Debian 9.3.0-22) 9.3.0
> reproduce (this is a W=1 build):
> #
https://git.kernel.org/pub/scm/virt/kvm/kvm.git/commit/?id=078d47ee71d6a5...
> git remote add kvm https://git.kernel.org/pub/scm/virt/kvm/kvm.git
> git fetch --no-tags kvm queue
> git checkout 078d47ee71d6a53657b5917ce1478f10bc173fa5
> # save the attached .config to linux build tree
> make W=1 W=1 ARCH=x86_64
>
> If you fix the issue, kindly add following tag as appropriate
> Reported-by: kernel test robot <lkp(a)intel.com>
>
> All errors (new ones prefixed by >>):
>
> In file included from include/linux/rculist.h:11,
> from include/linux/pid.h:5,
> from include/linux/sched.h:14,
> from include/linux/kvm_host.h:12,
> from arch/x86/kvm/mmu.h:5,
> from arch/x86/kvm/mmu/tdp_mmu.c:3:
> arch/x86/kvm/mmu/tdp_mmu.c: In function 'kvm_tdp_mmu_get_vcpu_root_hpa':
> >> arch/x86/kvm/mmu/tdp_mmu.c:141:5: error: implicit declaration of function
'lockdep_is_help'; did you mean 'lockdep_is_held'?
[-Werror=implicit-function-declaration]
> 141 | lockdep_is_help(&kvm->arch.tdp_mmu_pages_lock)) \
> | ^~~~~~~~~~~~~~~
> include/linux/rcupdate.h:318:52: note: in definition of macro
'RCU_LOCKDEP_WARN'
> 318 | if (debug_lockdep_rcu_enabled() && !__warned && (c)) {
\
> | ^
> include/linux/rculist.h:391:7: note: in expansion of macro
'__list_check_rcu'
> 391 | for (__list_check_rcu(dummy, ## cond, 0), \
> | ^~~~~~~~~~~~~~~~
> arch/x86/kvm/mmu/tdp_mmu.c:139:2: note: in expansion of macro
'list_for_each_entry_rcu'
> 139 | list_for_each_entry_rcu(_root, &_kvm->arch.tdp_mmu_roots, link,
\
> | ^~~~~~~~~~~~~~~~~~~~~~~
> arch/x86/kvm/mmu/tdp_mmu.c:188:2: note: in expansion of macro
'for_each_tdp_mmu_root'
> 188 | for_each_tdp_mmu_root(kvm, root, kvm_mmu_role_as_id(role)) {
> | ^~~~~~~~~~~~~~~~~~~~~
> cc1: some warnings being treated as errors
>
>
> vim +141 arch/x86/kvm/mmu/tdp_mmu.c
>
> 124
> 125 /*
> 126 * Note: this iterator gets and puts references to the roots it iterates
over.
> 127 * This makes it safe to release the MMU lock and yield within the loop, but
> 128 * if exiting the loop early, the caller must drop the reference to the most
> 129 * recent root. (Unless keeping a live reference is desirable.)
> 130 */
> 131 #define for_each_tdp_mmu_root_yield_safe(_kvm, _root, _as_id) \
> 132 for (_root = tdp_mmu_next_root(_kvm, NULL); \
> 133 _root; \
> 134 _root = tdp_mmu_next_root(_kvm, _root)) \
> 135 if (kvm_mmu_page_as_id(_root) != _as_id) { \
> 136 } else
> 137
> 138 #define for_each_tdp_mmu_root(_kvm, _root, _as_id)
\
> 139 list_for_each_entry_rcu(_root, &_kvm->arch.tdp_mmu_roots,
link, \
> 140 lockdep_is_held_type(&kvm->mmu_lock,
0) || \
> > 141
lockdep_is_help(&kvm->arch.tdp_mmu_pages_lock)) \
> 142 if (kvm_mmu_page_as_id(_root) != _as_id) { \
> 143 } else
> 144
>
> ---
> 0-DAY CI Kernel Test Service, Intel Corporation
> https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org