drivers/virtio/virtio_mem.c:1031 virtio_mem_mb_plug_any_sb() error: uninitialized symbol 'rc'.

From: kernel test robot <lkp@intel.com>
To: David Hildenbrand <david@redhat.com>
Cc: kbuild-all@lists.01.org, linux-kernel@vger.kernel.org,
	"Michael S. Tsirkin" <mst@redhat.com>,
	Pankaj Gupta <pankaj.gupta.linux@gmail.com>
Subject: drivers/virtio/virtio_mem.c:1031 virtio_mem_mb_plug_any_sb() error: uninitialized symbol 'rc'.
Date: Sat, 8 Aug 2020 19:39:22 +0800	[thread overview]
Message-ID: <202008081921.lHEnQxg2%lkp@intel.com> (raw)

[-- Attachment #1: Type: text/plain, Size: 2756 bytes --]

tree:   https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master
head:   449dc8c97089a6e09fb2dac4d92b1b7ac0eb7c1e
commit: 5f1f79bbc9e26fa9412fa9522f957bb8f030c442 virtio-mem: Paravirtualized memory hotplug
date:   9 weeks ago
config: x86_64-randconfig-m001-20200808 (attached as .config)
compiler: gcc-9 (Debian 9.3.0-15) 9.3.0

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

New smatch warnings:
drivers/virtio/virtio_mem.c:1031 virtio_mem_mb_plug_any_sb() error: uninitialized symbol 'rc'.
drivers/gpu/drm/amd/amdgpu/../display/dc/calcs/dce_calcs.c:1607 calculate_bandwidth() warn: Function too hairy.  No more merges.

Old smatch warnings:
drivers/gpu/drm/amd/amdgpu/../display/dc/calcs/dce_calcs.c:3387 bw_calcs() warn: inconsistent indenting

vim +/rc +1031 drivers/virtio/virtio_mem.c

   978	
   979	/*
   980	 * Try to plug the desired number of subblocks of a memory block that
   981	 * is already added to Linux.
   982	 *
   983	 * Will modify the state of the memory block.
   984	 *
   985	 * Note: Can fail after some subblocks were successfully plugged.
   986	 */
   987	static int virtio_mem_mb_plug_any_sb(struct virtio_mem *vm, unsigned long mb_id,
   988					     uint64_t *nb_sb, bool online)
   989	{
   990		unsigned long pfn, nr_pages;
   991		int sb_id, count;
   992		int rc;
   993	
   994		if (WARN_ON_ONCE(!*nb_sb))
   995			return -EINVAL;
   996	
   997		while (*nb_sb) {
   998			sb_id = virtio_mem_mb_first_unplugged_sb(vm, mb_id);
   999			if (sb_id >= vm->nb_sb_per_mb)
  1000				break;
  1001			count = 1;
  1002			while (count < *nb_sb &&
  1003			       sb_id + count < vm->nb_sb_per_mb &&
  1004			       !virtio_mem_mb_test_sb_plugged(vm, mb_id, sb_id + count,
  1005							      1))
  1006				count++;
  1007	
  1008			rc = virtio_mem_mb_plug_sb(vm, mb_id, sb_id, count);
  1009			if (rc)
  1010				return rc;
  1011			*nb_sb -= count;
  1012			if (!online)
  1013				continue;
  1014	
  1015			/* fake-online the pages if the memory block is online */
  1016			pfn = PFN_DOWN(virtio_mem_mb_id_to_phys(mb_id) +
  1017				       sb_id * vm->subblock_size);
  1018			nr_pages = PFN_DOWN(count * vm->subblock_size);
  1019			virtio_mem_fake_online(pfn, nr_pages);
  1020		}
  1021	
  1022		if (virtio_mem_mb_test_sb_plugged(vm, mb_id, 0, vm->nb_sb_per_mb)) {
  1023			if (online)
  1024				virtio_mem_mb_set_state(vm, mb_id,
  1025							VIRTIO_MEM_MB_STATE_ONLINE);
  1026			else
  1027				virtio_mem_mb_set_state(vm, mb_id,
  1028							VIRTIO_MEM_MB_STATE_OFFLINE);
  1029		}
  1030	
> 1031		return rc;
  1032	}
  1033	

---
0-DAY CI Kernel Test Service, Intel Corporation
https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org

[-- Attachment #2: .config.gz --]
[-- Type: application/gzip, Size: 49578 bytes --]