On Thu, Jan 17, 2013 at 11:19:21AM +0000, James Bottomley wrote: > On Thu, 2013-01-17 at 11:04 +0000, Russell King - ARM Linux wrote: > > On Thu, Jan 17, 2013 at 11:01:47AM +0000, James Bottomley wrote: > > > On Thu, 2013-01-17 at 10:47 +0000, Russell King - ARM Linux wrote: > > > > Also, couldn't the addition of the scatterlist offset to the page also > > > > be buggy too? > > > > > > No, fortunately, offset must be within the first page from the point of > > > view of block generated sg lists. As long as nothing within arm > > > violates this, it should be a safe assumption ... although the code > > > seems to assume otherwise. > > > > Are you absolutely sure about that? I believe I have seen cases where > > that has been violated in the past, though it was many years ago. > > >From the point of view of the block layer, absolutely: the scatterlist > is generated from an array of bio_vecs. Each bio_vec is a page, offset > and length element and obeys the rule that offset must be within the > page and offset + length cannot stray over the page. Well, I found it when working on the mmc stuff initially, long before it got complex. The scatterlists were unmodified from the block layer, and I'm positive I saw occasions where the offset in the scatter lists were larger than PAGE_SIZE. > >From the point of view of other arm stuff, I don't know. I'm not talking about anything ARM specific here. -- To unsubscribe from this list: send the line "unsubscribe linux-mmc" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
