Re: [PATCH 2/6] x86/irq: Extend NMI handler registration interface to include source

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

Hi Jacob,

kernel test robot noticed the following build warnings:

[auto build test WARNING on perf-tools-next/perf-tools-next]
[also build test WARNING on perf-tools/perf-tools linus/master v6.10-rc1 next-20240529]
[cannot apply to tip/perf/core tip/x86/core acme/perf/core]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch#_base_tree_information]

url:    https://github.com/intel-lab-lkp/linux/commits/Jacob-Pan/x86-irq-Add-enumeration-of-NMI-source-reporting-CPU-feature/20240530-043112
base:   https://git.kernel.org/pub/scm/linux/kernel/git/perf/perf-tools-next.git perf-tools-next
patch link:    https://lore.kernel.org/r/20240529203325.3039243-3-jacob.jun.pan%40linux.intel.com
patch subject: [PATCH 2/6] x86/irq: Extend NMI handler registration interface to include source
config: x86_64-randconfig-122-20240530 (https://download.01.org/0day-ci/archive/20240530/202405301437.O5puBRHP-lkp@intel.com/config)
compiler: gcc-13 (Ubuntu 13.2.0-4ubuntu3) 13.2.0
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20240530/202405301437.O5puBRHP-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/202405301437.O5puBRHP-lkp@intel.com/

sparse warnings: (new ones prefixed by >>)
>> arch/x86/kernel/nmi.c:189:17: sparse: sparse: incompatible types in comparison expression (different address spaces):
   arch/x86/kernel/nmi.c:189:17: sparse:    struct nmiaction [noderef] __rcu *
   arch/x86/kernel/nmi.c:189:17: sparse:    struct nmiaction *
   arch/x86/kernel/nmi.c:228:33: sparse: sparse: incompatible types in comparison expression (different address spaces):
   arch/x86/kernel/nmi.c:228:33: sparse:    struct nmiaction [noderef] __rcu *
   arch/x86/kernel/nmi.c:228:33: sparse:    struct nmiaction *
   arch/x86/kernel/nmi.c: note: in included file (through include/linux/smp.h, include/linux/lockdep.h, include/linux/spinlock.h):
   include/linux/list.h:83:21: sparse: sparse: self-comparison always evaluates to true
   include/linux/list.h:83:21: sparse: sparse: self-comparison always evaluates to true

vim +189 arch/x86/kernel/nmi.c

   177	
   178	int __register_nmi_handler(unsigned int type, struct nmiaction *action)
   179	{
   180		struct nmi_desc *desc = nmi_to_desc(type);
   181		unsigned long flags;
   182	
   183		if (WARN_ON_ONCE(!action->handler || !list_empty(&action->list)))
   184			return -EINVAL;
   185	
   186		raw_spin_lock_irqsave(&desc->lock, flags);
   187	
   188		if (use_nmi_source(type, action))
 > 189			rcu_assign_pointer(nmiaction_src_table[action->source_vec], action);
   190		/*
   191		 * Indicate if there are multiple registrations on the
   192		 * internal NMI handler call chains (SERR and IO_CHECK).
   193		 */
   194		WARN_ON_ONCE(type == NMI_SERR && !list_empty(&desc->head));
   195		WARN_ON_ONCE(type == NMI_IO_CHECK && !list_empty(&desc->head));
   196	
   197		/*
   198		 * some handlers need to be executed first otherwise a fake
   199		 * event confuses some handlers (kdump uses this flag)
   200		 */
   201		if (action->flags & NMI_FLAG_FIRST)
   202			list_add_rcu(&action->list, &desc->head);
   203		else
   204			list_add_tail_rcu(&action->list, &desc->head);
   205	
   206		raw_spin_unlock_irqrestore(&desc->lock, flags);
   207		return 0;
   208	}
   209	EXPORT_SYMBOL(__register_nmi_handler);
   210	

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