On 30.09.20 18:36, Fam Zheng wrote:
> On Wed, 2020-09-30 at 17:58 +0200, Christian Borntraeger wrote:
>> Fedora 32 gcc 10 seems to give false positives:
>>
>> Compiling C object libblock.fa.p/block_vmdk.c.o
>> ../block/vmdk.c: In function ‘vmdk_parse_extents’:
>> ../block/vmdk.c:587:5: error: ‘extent’ may be used uninitialized in
>> this function [-Werror=maybe-uninitialized]
>> 587 | g_free(extent->l1_table);
>> | ^~~~~~~~~~~~~~~~~~~~~~~~
>> ../block/vmdk.c:754:17: note: ‘extent’ was declared here
>> 754 | VmdkExtent *extent;
>> | ^~~~~~
>> ../block/vmdk.c:620:11: error: ‘extent’ may be used uninitialized in
>> this function [-Werror=maybe-uninitialized]
>> 620 | ret = vmdk_init_tables(bs, extent, errp);
>> | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>> ../block/vmdk.c:598:17: note: ‘extent’ was declared here
>> 598 | VmdkExtent *extent;
>> | ^~~~~~
>> ../block/vmdk.c:1178:39: error: ‘extent’ may be used uninitialized in
>> this function [-Werror=maybe-uninitialized]
>> 1178 | extent->flat_start_offset = flat_offset << 9;
>> | ~~~~~~~~~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~
>> ../block/vmdk.c: In function ‘vmdk_open_vmdk4’:
>> ../block/vmdk.c:581:22: error: ‘extent’ may be used uninitialized in
>> this function [-Werror=maybe-uninitialized]
>> 581 | extent->l2_cache =
>> | ~~~~~~~~~~~~~~~~~^
>> 582 | g_malloc(extent->entry_size * extent->l2_size *
>> L2_CACHE_SIZE);
>> | ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>> ~~~~~~~~~
>> ../block/vmdk.c:872:17: note: ‘extent’ was declared here
>> 872 | VmdkExtent *extent;
>> | ^~~~~~
>> ../block/vmdk.c: In function ‘vmdk_open’:
>> ../block/vmdk.c:620:11: error: ‘extent’ may be used uninitialized in
>> this function [-Werror=maybe-uninitialized]
>> 620 | ret = vmdk_init_tables(bs, extent, errp);
>> | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>> ../block/vmdk.c:598:17: note: ‘extent’ was declared here
>> 598 | VmdkExtent *extent;
>> | ^~~~~~
>> cc1: all warnings being treated as errors
>> make: *** [Makefile.ninja:884: libblock.fa.p/block_vmdk.c.o] Error 1
>>
>> fix them by assigning a default value.
>>
>> Signed-off-by: Christian Borntraeger <borntrae...@de.ibm.com>
>> ---
>> block/vmdk.c | 8 ++++----
>> 1 file changed, 4 insertions(+), 4 deletions(-)
>>
>> diff --git a/block/vmdk.c b/block/vmdk.c
>> index 8ec62c7ab798..a00dc00eb47a 100644
>> --- a/block/vmdk.c
>> +++ b/block/vmdk.c
>> @@ -595,7 +595,7 @@ static int vmdk_open_vmfs_sparse(BlockDriverState
>> *bs,
>> int ret;
>> uint32_t magic;
>> VMDK3Header header;
>> - VmdkExtent *extent;
>> + VmdkExtent *extent = NULL;
>>
>> ret = bdrv_pread(file, sizeof(magic), &header, sizeof(header));
>> if (ret < 0) {
>> @@ -751,7 +751,7 @@ static int vmdk_open_se_sparse(BlockDriverState
>> *bs,
>> int ret;
>> VMDKSESparseConstHeader const_header;
>> VMDKSESparseVolatileHeader volatile_header;
>> - VmdkExtent *extent;
>> + VmdkExtent *extent = NULL;
>>
>> ret = bdrv_apply_auto_read_only(bs,
>> "No write support for seSparse images available", errp);
>> @@ -869,7 +869,7 @@ static int vmdk_open_vmdk4(BlockDriverState *bs,
>> uint32_t magic;
>> uint32_t l1_size, l1_entry_sectors;
>> VMDK4Header header;
>> - VmdkExtent *extent;
>> + VmdkExtent *extent = NULL;
>> BDRVVmdkState *s = bs->opaque;
>> int64_t l1_backup_offset = 0;
>> bool compressed;
>> @@ -1088,7 +1088,7 @@ static int vmdk_parse_extents(const char *desc,
>> BlockDriverState *bs,
>> BdrvChild *extent_file;
>> BdrvChildRole extent_role;
>> BDRVVmdkState *s = bs->opaque;
>> - VmdkExtent *extent;
>> + VmdkExtent *extent = NULL;
>> char extent_opt_prefix[32];
>> Error *local_err = NULL;
>>
>
> Looks trivial, and correct.
>
> Reviewed-by: Fam Zheng <f...@euphon.net>
Will this go via the block or trivial tree (cced).
