Messages in this thread | | | Date | Thu, 6 Mar 2008 16:20:57 +0200 (EET) | From | Pekka J Enberg <> | Subject | Re: [PATCH] netfilter: replace horrible hack with ksize() |
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On Thu, 6 Mar 2008, Pekka J Enberg wrote: > > > - if (newlen >= ct->ext->real_len) { > > > + if (newlen >= ksize(ct->ext)) { > > > > This needs to look at the currently allocated size, otherwise > > it will always realloc when adding new extensions after having > > used up ksize(ct->ext) space. > > Lets say you > > p = kmalloc(8, ...); > > Then ksize(p) will return the currently allocated size which is 32 bytes > when page size is 4 KB, and not 8 bytes. So it should be equivalent of > what the current code does. > > What am I missing here?
Ok, it's not equivalent. We have two sizes: object size (8 bytes) and buffer size (32 bytes) here. In netfilter, ->real_len is same as object size, not buffer size as ksize() is.
But now I am officially even more confused, why does the netfilter code decided whether to reallocate based on _object size_ and not _buffer size_ (as krealloc() does, for example)?
Pekka
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