Re: [PATCH-for-5.2] hw/arm/smmuv3: Fix potential integer overflow (CID 1432363)

[Auger Eric <eric.auger@redhat.com>]

Hi Philippe,

On 10/30/20 3:46 PM, Philippe Mathieu-Daudé wrote:
> Use the BIT_ULL() macro to ensure we use 64-bit arithmetic.
> This fixes the following Coverity issue (OVERFLOW_BEFORE_WIDEN):
> 
>   CID 1432363 (#1 of 1): Unintentional integer overflow:
> 
>   overflow_before_widen:
>     Potentially overflowing expression 1 << scale with type int
>     (32 bits, signed) is evaluated using 32-bit arithmetic, and
>     then used in a context that expects an expression of type
>     hwaddr (64 bits, unsigned).
> 
> Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Acked-by: Eric Auger <eric.auger@redhat.com>

Thanks!

Eric
> ---
>  hw/arm/smmuv3.c | 3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)
> 
> diff --git a/hw/arm/smmuv3.c b/hw/arm/smmuv3.c
> index 2017ba7a5a7..22607c37841 100644
> --- a/hw/arm/smmuv3.c
> +++ b/hw/arm/smmuv3.c
> @@ -17,6 +17,7 @@
>   */
>  
>  #include "qemu/osdep.h"
> +#include "qemu/bitops.h"
>  #include "hw/irq.h"
>  #include "hw/sysbus.h"
>  #include "migration/vmstate.h"
> @@ -864,7 +865,7 @@ static void smmuv3_s1_range_inval(SMMUState *s, Cmd *cmd)
>          scale = CMD_SCALE(cmd);
>          num = CMD_NUM(cmd);
>          ttl = CMD_TTL(cmd);
> -        num_pages = (num + 1) * (1 << (scale));
> +        num_pages = (num + 1) * BIT_ULL(scale);
>      }
>  
>      if (type == SMMU_CMD_TLBI_NH_VA) {
>