[bigeasy-staging:arm-locking-v2 3/4] drivers//of/base.c:821:8: warning: 'node' may be used uninitialized in this function

[bigeasy-staging:arm-locking-v2 3/4] drivers//of/base.c:821:8: warning: 'node' may be used uninitialized in this function

[kbuild test robot]

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tree:   https://git.kernel.org/pub/scm/linux/kernel/git/bigeasy/staging.git arm-locking-v2
head:   c6339276cd4a34957bd9ba40e0a415c8755b54aa
commit: ee1a9ea5a47977cc72768b6da279635b9d9b858a [3/4] ARM: Inline locking functions for !PREEMPTION
config: arm-omap2plus_defconfig (attached as .config)
compiler: arm-linux-gnueabi-gcc (GCC) 7.4.0
reproduce:
        wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
        chmod +x ~/bin/make.cross
        git checkout ee1a9ea5a47977cc72768b6da279635b9d9b858a
        # save the attached .config to linux build tree
        GCC_VERSION=7.4.0 make.cross ARCH=arm 

If you fix the issue, kindly add following tag
Reported-by: kbuild test robot <lkp@intel.com>

Note: it may well be a FALSE warning. FWIW you are at least aware of it now.
http://gcc.gnu.org/wiki/Better_Uninitialized_Warnings

All warnings (new ones prefixed by >>):

   drivers//of/base.c: In function 'of_get_next_cpu_node':
>> drivers//of/base.c:821:8: warning: 'node' may be used uninitialized in this function [-Wmaybe-uninitialized]
      next = node->child;
      ~~~~~^~~~~~~~~~~~~

vim +/node +821 drivers//of/base.c

3296193d1421c2 Timur Tabi  2012-08-14  799  
f1f207e43b8a49 Rob Herring 2018-08-22  800  /**
f1f207e43b8a49 Rob Herring 2018-08-22  801   *	of_get_next_cpu_node - Iterate on cpu nodes
f1f207e43b8a49 Rob Herring 2018-08-22  802   *	@prev:	previous child of the /cpus node, or NULL to get first
f1f207e43b8a49 Rob Herring 2018-08-22  803   *
f1f207e43b8a49 Rob Herring 2018-08-22  804   *	Returns a cpu node pointer with refcount incremented, use of_node_put()
f1f207e43b8a49 Rob Herring 2018-08-22  805   *	on it when done. Returns NULL when prev is the last child. Decrements
f1f207e43b8a49 Rob Herring 2018-08-22  806   *	the refcount of prev.
f1f207e43b8a49 Rob Herring 2018-08-22  807   */
f1f207e43b8a49 Rob Herring 2018-08-22  808  struct device_node *of_get_next_cpu_node(struct device_node *prev)
f1f207e43b8a49 Rob Herring 2018-08-22  809  {
f1f207e43b8a49 Rob Herring 2018-08-22  810  	struct device_node *next = NULL;
f1f207e43b8a49 Rob Herring 2018-08-22  811  	unsigned long flags;
f1f207e43b8a49 Rob Herring 2018-08-22  812  	struct device_node *node;
f1f207e43b8a49 Rob Herring 2018-08-22  813  
f1f207e43b8a49 Rob Herring 2018-08-22  814  	if (!prev)
f1f207e43b8a49 Rob Herring 2018-08-22  815  		node = of_find_node_by_path("/cpus");
f1f207e43b8a49 Rob Herring 2018-08-22  816  
f1f207e43b8a49 Rob Herring 2018-08-22  817  	raw_spin_lock_irqsave(&devtree_lock, flags);
f1f207e43b8a49 Rob Herring 2018-08-22  818  	if (prev)
f1f207e43b8a49 Rob Herring 2018-08-22  819  		next = prev->sibling;
f1f207e43b8a49 Rob Herring 2018-08-22  820  	else if (node) {
f1f207e43b8a49 Rob Herring 2018-08-22 @821  		next = node->child;
f1f207e43b8a49 Rob Herring 2018-08-22  822  		of_node_put(node);
f1f207e43b8a49 Rob Herring 2018-08-22  823  	}
f1f207e43b8a49 Rob Herring 2018-08-22  824  	for (; next; next = next->sibling) {
f1f207e43b8a49 Rob Herring 2018-08-22  825  		if (!(of_node_name_eq(next, "cpu") ||
e8b1dee21420f8 Rob Herring 2018-08-29  826  		      __of_node_is_type(next, "cpu")))
f1f207e43b8a49 Rob Herring 2018-08-22  827  			continue;
f1f207e43b8a49 Rob Herring 2018-08-22  828  		if (of_node_get(next))
f1f207e43b8a49 Rob Herring 2018-08-22  829  			break;
f1f207e43b8a49 Rob Herring 2018-08-22  830  	}
f1f207e43b8a49 Rob Herring 2018-08-22  831  	of_node_put(prev);
f1f207e43b8a49 Rob Herring 2018-08-22  832  	raw_spin_unlock_irqrestore(&devtree_lock, flags);
f1f207e43b8a49 Rob Herring 2018-08-22  833  	return next;
f1f207e43b8a49 Rob Herring 2018-08-22  834  }
f1f207e43b8a49 Rob Herring 2018-08-22  835  EXPORT_SYMBOL(of_get_next_cpu_node);
f1f207e43b8a49 Rob Herring 2018-08-22  836  

:::::: The code at line 821 was first introduced by commit
:::::: f1f207e43b8a49ac2ee3c36a64de1f84651c6079 of: Add cpu node iterator for_each_of_cpu_node()

:::::: TO: Rob Herring <robh@kernel.org>
:::::: CC: Rob Herring <robh@kernel.org>

---
0-DAY kernel test infrastructure                Open Source Technology Center
https://lists.01.org/pipermail/kbuild-all                   Intel Corporation

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