Re: [Qemu-devel] [PATCH v2] strongarm: mask off high[32:28] bits from dir and state registers

[Philippe Mathieu-Daudé]

On 30/10/18 12:49, P J P wrote:
> +-- On Mon, 29 Oct 2018, Peter Maydell wrote --+
> | >      switch (offset) {
> | >      case GPDR:        /* GPIO Pin-Direction registers */
> | > -        s->dir = value;
> | > +        s->dir = value & 0x3fffff;
> |
> | The commit message says it's masking [31:28], but the
> | code is masking [31:22]. The SA1110 spec suggests the
> | commit message is correct and the code is not.
>
> Ouch, sorry! Sent revised patch v3.

That's where the extract32() is more convenient and less bug prone:

               s->dir = extract32(value, 0, 28); /* mask off [31:28] */
> Thank you.
> --
> Prasad J Pandit / Red Hat Product Security Team
> 47AF CE69 3A90 54AA 9045 1053 DD13 3D32 FE5B 041F