Re: [PATCH net-next 15/24] net: Use nested-BH locking for XDP redirect.

[kernel test robot <lkp@intel.com>]

Hi Sebastian,

kernel test robot noticed the following build warnings:

[auto build test WARNING on net-next/main]

url:    https://github.com/intel-lab-lkp/linux/commits/Sebastian-Andrzej-Siewior/locking-local_lock-Introduce-guard-definition-for-local_lock/20231216-011911
base:   net-next/main
patch link:    https://lore.kernel.org/r/20231215171020.687342-16-bigeasy%40linutronix.de
patch subject: [PATCH net-next 15/24] net: Use nested-BH locking for XDP redirect.
config: x86_64-randconfig-122-20231216 (https://download.01.org/0day-ci/archive/20231216/202312161103.iKeGoacH-lkp@intel.com/config)
compiler: clang version 16.0.4 (https://github.com/llvm/llvm-project.git ae42196bc493ffe877a7e3dff8be32035dea4d07)
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20231216/202312161103.iKeGoacH-lkp@intel.com/reproduce)

If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202312161103.iKeGoacH-lkp@intel.com/

sparse warnings: (new ones prefixed by >>)
   net/sched/cls_api.c:391:22: sparse: sparse: incorrect type in assignment (different base types) @@     expected restricted __be16 [usertype] protocol @@     got unsigned int [usertype] protocol @@
   net/sched/cls_api.c:391:22: sparse:     expected restricted __be16 [usertype] protocol
   net/sched/cls_api.c:391:22: sparse:     got unsigned int [usertype] protocol
   net/sched/cls_api.c:1862:16: sparse: sparse: incompatible types in comparison expression (different address spaces):
   net/sched/cls_api.c:1862:16: sparse:    struct tcf_proto *
   net/sched/cls_api.c:1862:16: sparse:    struct tcf_proto [noderef] __rcu *
   net/sched/cls_api.c:1962:20: sparse: sparse: incompatible types in comparison expression (different address spaces):
   net/sched/cls_api.c:1962:20: sparse:    struct tcf_proto [noderef] __rcu *
   net/sched/cls_api.c:1962:20: sparse:    struct tcf_proto *
   net/sched/cls_api.c:1924:25: sparse: sparse: incompatible types in comparison expression (different address spaces):
   net/sched/cls_api.c:1924:25: sparse:    struct tcf_proto [noderef] __rcu *
   net/sched/cls_api.c:1924:25: sparse:    struct tcf_proto *
   net/sched/cls_api.c:1944:16: sparse: sparse: incompatible types in comparison expression (different address spaces):
   net/sched/cls_api.c:1944:16: sparse:    struct tcf_proto *
   net/sched/cls_api.c:1944:16: sparse:    struct tcf_proto [noderef] __rcu *
   net/sched/cls_api.c:2010:25: sparse: sparse: restricted __be16 degrades to integer
   net/sched/cls_api.c:2697:50: sparse: sparse: restricted __be16 degrades to integer
>> net/sched/cls_api.c:3933:38: sparse: sparse: incorrect type in argument 1 (different address spaces) @@     expected struct local_lock_t [usertype] *l @@     got struct local_lock_t [noderef] __percpu * @@
   net/sched/cls_api.c:3933:38: sparse:     expected struct local_lock_t [usertype] *l
   net/sched/cls_api.c:3933:38: sparse:     got struct local_lock_t [noderef] __percpu *
   net/sched/cls_api.c: note: in included file (through include/linux/mmzone.h, include/linux/gfp.h, include/linux/umh.h, include/linux/kmod.h, ...):
   include/linux/local_lock.h:71:1: sparse: sparse: incorrect type in initializer (different address spaces) @@     expected void const [noderef] __percpu *__vpp_verify @@     got struct local_lock_t [usertype] * @@
   include/linux/local_lock.h:71:1: sparse:     expected void const [noderef] __percpu *__vpp_verify
   include/linux/local_lock.h:71:1: sparse:     got struct local_lock_t [usertype] *

vim +3933 net/sched/cls_api.c

  3921	
  3922	struct sk_buff *tcf_qevent_handle(struct tcf_qevent *qe, struct Qdisc *sch, struct sk_buff *skb,
  3923					  struct sk_buff **to_free, int *ret)
  3924	{
  3925		struct tcf_result cl_res;
  3926		struct tcf_proto *fl;
  3927	
  3928		if (!qe->info.block_index)
  3929			return skb;
  3930	
  3931		fl = rcu_dereference_bh(qe->filter_chain);
  3932	
> 3933		guard(local_lock_nested_bh)(&bpf_run_lock.redirect_lock);
  3934		switch (tcf_classify(skb, NULL, fl, &cl_res, false)) {
  3935		case TC_ACT_SHOT:
  3936			qdisc_qstats_drop(sch);
  3937			__qdisc_drop(skb, to_free);
  3938			*ret = __NET_XMIT_BYPASS;
  3939			return NULL;
  3940		case TC_ACT_STOLEN:
  3941		case TC_ACT_QUEUED:
  3942		case TC_ACT_TRAP:
  3943			__qdisc_drop(skb, to_free);
  3944			*ret = __NET_XMIT_STOLEN;
  3945			return NULL;
  3946		case TC_ACT_REDIRECT:
  3947			skb_do_redirect(skb);
  3948			*ret = __NET_XMIT_STOLEN;
  3949			return NULL;
  3950		}
  3951	
  3952		return skb;
  3953	}
  3954	EXPORT_SYMBOL(tcf_qevent_handle);
  3955	

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