Re: [PATCH v2] rxrpc: Fix using alignmask being zero for __page_frag_alloc_align()

[Paolo Abeni]

On Sun, 2024-04-28 at 19:16 +0800, Yunsheng Lin wrote:
> rxrpc_alloc_data_txbuf() may be called with data_align being
> zero in none_alloc_txbuf() and rxkad_alloc_txbuf(), data_align
> is supposed to be an order-based alignment value, but zero is
> not a valid order-based alignment value, and '~(data_align - 1)'
> doesn't result in a valid mask-based alignment value for
> __page_frag_alloc_align().
> 
> Fix it by passing a valid order-based alignment value in
> none_alloc_txbuf() and rxkad_alloc_txbuf().
> 
> Also use page_frag_alloc_align() expecting an order-based
> alignment value in rxrpc_alloc_data_txbuf() to avoid doing the
> alignment converting operation and to catch possible invalid
> alignment value in the future. Remove the 'if (data_align)'
> checking too, as it is always true for a valid order-based
> alignment value.
> 
> Fixes: 6b2536462fd4 ("rxrpc: Fix use of changed alignment param to page_frag_alloc_align()")
> Fixes: 49489bb03a50 ("rxrpc: Do zerocopy using MSG_SPLICE_PAGES and page frags")
> CC: David Howells <dhowells@xxxxxxxxxx>
> CC: Alexander Duyck <alexander.duyck@xxxxxxxxx>
> Signed-off-by: Yunsheng Lin <linyunsheng@xxxxxxxxxx>
> Acked-by: David Howells <dhowells@xxxxxxxxxx>

Double checking before doing dumb mistakes...

@David: I assume from your ack you are fine with this patch being
merged via the net tree, am I correct?

Thanks,

Paolo