Re: [PATCH v1 4/4] xen/netback: Fix grant copy across page boundary with KASAN

[Paul Durrant]

On Wed, 8 Jan 2020 at 15:21, Sergey Dyasli <sergey.dyasli@xxxxxxxxxx> wrote:
>
> From: Ross Lagerwall <ross.lagerwall@xxxxxxxxxx>
>
> When KASAN (or SLUB_DEBUG) is turned on, the normal expectation that
> allocations are aligned to the next power of 2 of the size does not
> hold. Therefore, handle grant copies that cross page boundaries.
>
> Signed-off-by: Ross Lagerwall <ross.lagerwall@xxxxxxxxxx>
> Signed-off-by: Sergey Dyasli <sergey.dyasli@xxxxxxxxxx>
> ---
> RFC --> v1:
> - Added BUILD_BUG_ON to the netback patch
> - xenvif_idx_release() now located outside the loop
>
> CC: Wei Liu <wei.liu@xxxxxxxxxx>
> CC: Paul Durrant <paul@xxxxxxx>
[snip]
>
> +static void __init __maybe_unused build_assertions(void)
> +{
> +       BUILD_BUG_ON(sizeof(struct xenvif_tx_cb) > 48);

FIELD_SIZEOF(struct sk_buff, cb) rather than a magic '48' I think.

  Paul

> +}
> +
>  MODULE_LICENSE("Dual BSD/GPL");
>  MODULE_ALIAS("xen-backend:vif");
> --
> 2.17.1
>