RE: [Xen-devel] [PATCH] xen/arm: Return correct code error for xen_swiotlb_map_page

[Frediano Ziglio]

> On Thu, 6 Nov 2014, Frediano Ziglio wrote:
> > 2014-11-06 17:30 GMT+00:00 Stefano Stabellini
> <stefano.stabellini@xxxxxxxxxxxxx>:
> >       On Thu, 6 Nov 2014, Frediano Ziglio wrote:
> >       > On ARM error code is not 0 so avoid to return it as error.
> >       >
> >       > Signed-off-by: Frediano Ziglio <frediano.ziglio@xxxxxxxxxx>
> >
> >       Acked-by: Stefano Stabellini <stefano.stabellini@xxxxxxxxxxxxx>
> >
> >
> >       Could you please fix the same error in lib/swiotlb.c too please?
> >
> >
> > Same patch or another ?
> >
> 
> Another
> 

lib/swiotlb.c is not affected at a physical address to io_tlb_overflow_buffer is returned in case of error.
Looks like a way to transform silently an allocation error to a more serious memory corruption.

Frediano

> >
> >       >Â drivers/xen/swiotlb-xen.c | 2 +-
> >       >Â 1 file changed, 1 insertion(+), 1 deletion(-)
> >       >
> >       > diff --git a/drivers/xen/swiotlb-xen.c b/drivers/xen/swiotlb-
> xen.c
> >       > index ebd8f21..3b8d628 100644
> >       > --- a/drivers/xen/swiotlb-xen.c
> >       > +++ b/drivers/xen/swiotlb-xen.c
> >       > @@ -425,7 +425,7 @@ dma_addr_t xen_swiotlb_map_page(struct
> device *dev, struct page *page,
> >       >Â Â Â Â */
> >       >Â Â Â Âif (!dma_capable(dev, dev_addr, size)) {
> >       >Â Â Â Â Â Â Â Âswiotlb_tbl_unmap_single(dev, map, size, dir);
> >       > -Â Â Â Â Â Â Âdev_addr = 0;
> >       > +Â Â Â Â Â Â Âdev_addr = DMA_ERROR_CODE;
> >       >Â Â Â Â}
> >       >Â Â Â Âreturn dev_addr;
> >       >Â }
> >       > --
> >       > 1.9.1
> >       >
> >       >
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