Re: [PATCH 4/5] target/loongarch/tlb_helper: Fix coverity integer overflow error

[Richard Henderson]

On 7/12/22 13:31, Xiaojuan Yang wrote:
> Replace '1' with '1UL' to fix unintentional integer overflow errors
> in tlb_helper file.
>
> Fix coverity CID: 1489759 1489762
>
> Signed-off-by: Xiaojuan Yang <yangxiaojuan@loongson.cn>
> ---
>   target/loongarch/tlb_helper.c | 4 ++--
>   1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/target/loongarch/tlb_helper.c b/target/loongarch/tlb_helper.c
> index bab19c7e05..b300230588 100644
> --- a/target/loongarch/tlb_helper.c
> +++ b/target/loongarch/tlb_helper.c
> @@ -298,7 +298,7 @@ static void invalidate_tlb_entry(CPULoongArchState *env, 
> int index)
>       } else {
>           tlb_ps = FIELD_EX64(env->CSR_STLBPS, CSR_STLBPS, PS);
>       }
> -    pagesize = 1 << tlb_ps;
> +    pagesize = 1UL << tlb_ps;
>       mask = MAKE_64BIT_MASK(0, tlb_ps + 1);

This is incorrect, because 1ul is still 32 bits on some hosts, including 
windows64.
More generally, 'ul' is *always* incorrect for qemu.

Much better here to use

    pagesize = MAKE_64BIT_MASK(tlb_ps, 1);

> -            tmp0 += (1 << ps);
> +            tmp0 += (1UL << ps);

Likewise.


r~