On Mon, Jun 24, 2019 at 08:35:33PM +0300, Imre Deak wrote: > Hi, > > On Thu, Jun 20, 2019 at 02:02:21PM +0800, Herbert Xu wrote: > > On Mon, Jun 17, 2019 at 09:15:02PM +0000, Christophe Leroy wrote: > > > All mapping iterator logic is based on the assumption that sg->offset > > > is always lower than PAGE_SIZE. > > > > > > But there are situations where sg->offset is such that the SG item > > > is on the second page. > > could you explain how sg->offset becomes >= PAGE_SIZE? The network stack can produce SG list elements that are longer than PAGE_SIZE. If you the iterate over it one page at a time then the offset can exceed PAGE_SIZE. Cheers, -- Email: Herbert Xu <herbert@xxxxxxxxxxxxxxxxxxx> Home Page: http://gondor.apana.org.au/~herbert/ PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt
