Re: [PATCH V9 2/2] powerpc/nodes: Ensure enough nodes avail for operations

[kbuild test robot]

Hi Michael,

[auto build test ERROR on powerpc/next]
[also build test ERROR on v4.13-rc6 next-20170823]
[if your patch is applied to the wrong git tree, please drop us a note to help improve the system]

url:    https://github.com/0day-ci/linux/commits/Michael-Bringmann/powerpc-numa-Update-CPU-topology-when-VPHN-enabled/20170823-173526
base:   https://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux.git next
config: powerpc-defconfig (attached as .config)
compiler: powerpc64-linux-gnu-gcc (Debian 6.1.1-9) 6.1.1 20160705
reproduce:
        wget https://raw.githubusercontent.com/01org/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
        chmod +x ~/bin/make.cross
        # save the attached .config to linux build tree
        make.cross ARCH=powerpc 

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 errors (new ones prefixed by >>):

   arch/powerpc/mm/numa.c: In function 'initmem_init':
>> arch/powerpc/mm/numa.c:923:3: error: 'levelval' may be used uninitialized in this function [-Werror=maybe-uninitialized]
      printk(KERN_INFO "Numa nodes avail: %d (%d) \n", (int) levelval, (int) entries);
      ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   arch/powerpc/mm/numa.c:904:21: note: 'levelval' was declared here
      u32 len, entries, levelval, i;
                        ^~~~~~~~
   cc1: all warnings being treated as errors

vim +/levelval +923 arch/powerpc/mm/numa.c

   895	
   896	static void __init node_associativity_setup(void)
   897	{
   898		struct device_node *rtas;
   899		printk(KERN_INFO "%s:%d\n", __FUNCTION__, __LINE__);
   900	
   901		rtas = of_find_node_by_path("/rtas");
   902		if (rtas) {
   903			const __be32 *prop;
   904			u32 len, entries, levelval, i;
   905		printk(KERN_INFO "%s:%d\n", __FUNCTION__, __LINE__);
   906	
   907			prop = of_get_property(rtas, "ibm,max-associativity-domains", &len);
   908			if (!prop || len < sizeof(unsigned int)) {
   909		printk(KERN_INFO "%s:%d\n", __FUNCTION__, __LINE__);
   910				goto endit;
   911			}
   912	
   913			entries = of_read_number(prop++, 1);
   914	
   915			if (len < (entries * sizeof(unsigned int))) {
   916		printk(KERN_INFO "%s:%d\n", __FUNCTION__, __LINE__);
   917				goto endit;
   918			}
   919	
   920			for (i = 0; i < entries; i++)
   921				levelval = of_read_number(prop++, 1);
   922	
 > 923			printk(KERN_INFO "Numa nodes avail: %d (%d) \n", (int) levelval, (int) entries);
   924	
   925			for (i = 0; i < levelval; i++) {
   926				if (!node_possible(i)) {
   927					setup_node_data(i, 0, 0);
   928					node_set(i, node_possible_map);
   929				}
   930			}
   931		}
   932	
   933	endit:
   934		if (rtas)
   935			of_node_put(rtas);
   936	}
   937	

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0-DAY kernel test infrastructure                Open Source Technology Center
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