Re: [Qemu-devel] [PATCH v3 18/21] vmdk: Handle failure for potentially large allocations

["Benoît Canet" <benoit.canet@irqsave.net>]

The Tuesday 03 Jun 2014 à 15:10:59 (+0200), Kevin Wolf wrote :
> Some code in the block layer makes potentially huge allocations. Failure
> is not completely unexpected there, so avoid aborting qemu and handle
> out-of-memory situations gracefully.
> 
> This patch addresses the allocations in the vmdk block driver.
> 
> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
> ---
>  block/vmdk.c | 12 ++++++++++--
>  1 file changed, 10 insertions(+), 2 deletions(-)
> 
> diff --git a/block/vmdk.c b/block/vmdk.c
> index 2b38f61..fd81b1f 100644
> --- a/block/vmdk.c
> +++ b/block/vmdk.c
> @@ -448,7 +448,11 @@ static int vmdk_init_tables(BlockDriverState *bs, VmdkExtent *extent,
>  
>      /* read the L1 table */
>      l1_size = extent->l1_size * sizeof(uint32_t);
> -    extent->l1_table = g_malloc(l1_size);
> +    extent->l1_table = g_try_malloc(l1_size);
> +    if (l1_size && extent->l1_table == NULL) {
> +        return -ENOMEM;
> +    }
> +
>      ret = bdrv_pread(extent->file,
>                       extent->l1_table_offset,
>                       extent->l1_table,
> @@ -464,7 +468,11 @@ static int vmdk_init_tables(BlockDriverState *bs, VmdkExtent *extent,
>      }
>  
>      if (extent->l1_backup_table_offset) {
> -        extent->l1_backup_table = g_malloc(l1_size);
> +        extent->l1_backup_table = g_try_malloc(l1_size);
> +        if (l1_size && extent->l1_backup_table == NULL) {
> +            ret = -ENOMEM;
> +            goto fail_l1;
> +        }
>          ret = bdrv_pread(extent->file,
>                           extent->l1_backup_table_offset,
>                           extent->l1_backup_table,
> -- 
> 1.8.3.1
> 
> 
Reviewed-by: Benoit Canet <benoit@irqsave.net>