Stefano Brivio <sbrivio@xxxxxxxxxx> wrote: > > In new code, k+4 is the perfect "already-aligned" address where we would > > 'no-op' the address on a ARCH_KMALLOC_MINALIGN == 4 system. > > Isn't the already aligned-address k - 4, that is, k + 28? With k + 4, > we would have &scratch->map[0] at k + 8. But anyway: Yes, k-4 (k+28). [..] > > Maybe thats what you were saying. I could try to add/expand the > > comments here for the alignment calculations. > > ...yes, the rest is exactly what I meant. I'm not really satisfied of > the paragraph below but maybe something on the lines of: > > /* Align &scratch->map (not the struct itself): the extra > * %NFT_PIPAPO_ALIGN_HEADROOM bytes passed to kzalloc_node() above > * guarantee we can waste up to those bytes in order to align the map > * field regardless of its offset within the struct. > */ Thanks, thats good, I'll use that. I think I'll also add a BUILD_BUG_ON to assert map offset <= NFT_PIPAPO_ALIGN_HEADROOM, just in case.
