On Tue, Apr 23, 2019 at 06:33:33PM +0800, kbuild test robot wrote:
> tree: https://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu.git
> dev.2019.04.16a
> head: ca8714f549be5a186d086a223184095759eb7094
> commit: 9a1a31194644dfc6b8f19755ea44ecf84f37cf40 [38/72] rcu: Enable
> elimination of Tree-RCU softirq processing
> reproduce:
> # apt-get install sparse
> git checkout 9a1a31194644dfc6b8f19755ea44ecf84f37cf40
> make ARCH=x86_64 allmodconfig
> make C=1 CF='-fdiagnostic-prefix -D__CHECK_ENDIAN__'
>
> If you fix the issue, kindly add following tag
> Reported-by: kbuild test robot <[email protected]>
>
>
>
> sparse warnings: (new ones prefixed by >>)
>
> >> kernel/rcu/tree.c:2408:36: sparse: sparse: incorrect type in initializer
> >> (different address spaces) @@ expected struct task_struct [noderef]
> >> <asn:3> **store @@ got struct task_struct [noderef] <asn:3> **store @@
Line 2408 of kernel/rcu/tree.c for commit 9a1a31194644 ("rcu: Enable
elimination of Tree-RCU softirq processing") is this:
.store = &rcu_data.rcu_cpu_kthread_task,
So I am having some difficulty understanding this sparse diagnostic.
Help?
Thanx, Paul
> >> kernel/rcu/tree.c:2408:36: sparse: expected struct task_struct
> >> [noderef] <asn:3> **store
> >> kernel/rcu/tree.c:2408:36: sparse: got struct task_struct *[noderef]
> >> <asn:3> *
> kernel/rcu/tree.c:3234:13: sparse: sparse: incorrect type in argument 1
> (different modifiers) @@ expected int ( *threadfn )( ... ) @@ got int (
> [noreint ( *threadfn )( ... ) @@
> kernel/rcu/tree.c:3234:13: sparse: expected int ( *threadfn )( ... )
> kernel/rcu/tree.c:3234:13: sparse: got int ( [noreturn] * )( ... )
> kernel/rcu/tree.c:1110:13: sparse: sparse: context imbalance in
> 'rcu_start_this_gp' - different lock contexts for basic block
> kernel/rcu/tree.c:1502:9: sparse: sparse: context imbalance in
> 'rcu_gp_init' - different lock contexts for basic block
> kernel/rcu/tree.c:2190:9: sparse: sparse: context imbalance in
> 'force_qs_rnp' - different lock contexts for basic block
> kernel/rcu/tree.c:2243:25: sparse: sparse: context imbalance in
> 'rcu_force_quiescent_state' - unexpected unlock
> kernel/rcu/tree_stall.h:640:9: sparse: sparse: context imbalance in
> 'rcu_check_gp_start_stall' - different lock contexts for basic block
> kernel/rcu/tree_exp.h:193:9: sparse: sparse: context imbalance in
> '__rcu_report_exp_rnp' - different lock contexts for basic block
>
> vim +2408 kernel/rcu/tree.c
>
> 2406
> 2407 static struct smp_hotplug_thread rcu_cpu_thread_spec = {
> > 2408 .store =
> > &rcu_data.rcu_cpu_kthread_task,
> 2409 .thread_should_run = rcu_cpu_kthread_should_run,
> 2410 .thread_fn = rcu_cpu_kthread,
> 2411 .thread_comm = "rcuc/%u",
> 2412 .setup = rcu_cpu_kthread_setup,
> 2413 .park = rcu_cpu_kthread_park,
> 2414 };
> 2415
>
> ---
> 0-DAY kernel test infrastructure Open Source Technology Center
> https://lists.01.org/pipermail/kbuild-all Intel Corporation
>
