Re: [Qemu-devel] [RFC PATCH] cputlb: use uint64_t for interim values for unaligned load

[Philippe Mathieu-Daudé]

On 6/3/19 5:01 PM, Alex Bennée wrote:
> When running on 32 bit TCG backends a wide unaligned load ends up
> truncating data before returning to the guest. We specifically have
> the return type as uint64_t to avoid any premature truncation so we
> should use the same for the interim types.
> 
> Hopefully fixes #1830872

Maybe clearer as:

Fixes: https://bugs.launchpad.net/qemu/+bug/1830872
Fixes: eed5664238e

> 
> Signed-off-by: Alex Bennée <address@hidden>
> ---
>  accel/tcg/cputlb.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/accel/tcg/cputlb.c b/accel/tcg/cputlb.c
> index cdcc3771020..b796ab1cbea 100644
> --- a/accel/tcg/cputlb.c
> +++ b/accel/tcg/cputlb.c
> @@ -1303,7 +1303,7 @@ load_helper(CPUArchState *env, target_ulong addr, 
> TCGMemOpIdx oi,
>          && unlikely((addr & ~TARGET_PAGE_MASK) + size - 1
>                      >= TARGET_PAGE_SIZE)) {
>          target_ulong addr1, addr2;
> -        tcg_target_ulong r1, r2;
> +        uint64_t r1, r2;
>          unsigned shift;
>      do_unaligned_access:
>          addr1 = addr & ~(size - 1);
> 

Reviewed-by: Philippe Mathieu-Daudé <address@hidden>