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| author | Ilya Maximets <i.maximets@ovn.org> | 2023-10-09 12:43:21 +0200 |
|---|---|---|
| committer | Michael S. Tsirkin <mst@redhat.com> | 2023-10-22 05:18:16 -0400 |
| commit | b15c18c51910ec5ef8c506f641f487507e42c79b (patch) | |
| tree | 95fb0e05650cf7694d96d10a721c294190a48cc6 | |
| parent | d7dc0682f5cb549ea9afdc418f95412e83cc5e8c (diff) | |
| download | qemu-b15c18c51910ec5ef8c506f641f487507e42c79b.zip qemu-b15c18c51910ec5ef8c506f641f487507e42c79b.tar.gz qemu-b15c18c51910ec5ef8c506f641f487507e42c79b.tar.bz2 | |
memory: initialize 'fv' in MemoryRegionCache to make Coverity happy
Coverity scan reports multiple false-positive "defects" for the
following series of actions in virtio.c:
MemoryRegionCache indirect_desc_cache;
address_space_cache_init_empty(&indirect_desc_cache);
address_space_cache_destroy(&indirect_desc_cache);
For some reason it's unable to recognize the dependency between 'mrs.mr'
and 'fv' and insists that '!mrs.mr' check in address_space_cache_destroy
may take a 'false' branch, even though it is explicitly initialized to
NULL in the address_space_cache_init_empty():
*** CID 1522371: Memory - illegal accesses (UNINIT)
/qemu/hw/virtio/virtio.c: 1627 in virtqueue_split_pop()
1621 }
1622
1623 vq->inuse++;
1624
1625 trace_virtqueue_pop(vq, elem, elem->in_num, elem->out_num);
1626 done:
>>> CID 1522371: Memory - illegal accesses (UNINIT)
>>> Using uninitialized value "indirect_desc_cache.fv" when
>>> calling "address_space_cache_destroy".
1627 address_space_cache_destroy(&indirect_desc_cache);
1628
1629 return elem;
1630
1631 err_undo_map:
1632 virtqueue_undo_map_desc(out_num, in_num, iov);
** CID 1522370: Memory - illegal accesses (UNINIT)
Instead of trying to silence these false positive reports in 4
different places, initializing 'fv' as well, as this doesn't result
in any noticeable performance impact.
Signed-off-by: Ilya Maximets <i.maximets@ovn.org>
Message-Id: <20231009104322.3085887-1-i.maximets@ovn.org>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
| -rw-r--r-- | include/exec/memory.h | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/include/exec/memory.h b/include/exec/memory.h index 653a32e..9087d02 100644 --- a/include/exec/memory.h +++ b/include/exec/memory.h @@ -2793,6 +2793,8 @@ int64_t address_space_cache_init(MemoryRegionCache *cache, static inline void address_space_cache_init_empty(MemoryRegionCache *cache) { cache->mrs.mr = NULL; + /* There is no real need to initialize fv, but it makes Coverity happy. */ + cache->fv = NULL; } /** |