On Fri, Mar 17, 2017 at 11:52:01AM -0700, Michael Davidson wrote: > On Fri, Mar 17, 2017 at 5:44 AM, Peter Zijlstra <peterz@xxxxxxxxxxxxx> wrote: > > > > Be that as it may; what you construct above is disgusting. Surely the > > code can be refactored to not look like dog vomit? > > > > Also; its not immediately obvious conf->copies is 'small' and this > > doesn't blow up the stack; I feel that deserves a comment somewhere. > > > > I agree that the code is horrible. > > It is, in fact, exactly the same solution that was used to remove > variable length arrays in structs from several of the crypto drivers a > few years ago - see the definition of SHASH_DESC_ON_STACK() in > "crypto/hash.h" - I did not, however, hide the horrors in a macro > preferring to leave the implementation visible as a warning to whoever > might touch the code next. > > I believe that the actual stack usage is exactly the same as it was previously. > > I can certainly wrap this up in a macro and add comments with > appropriately dire warnings in it if you feel that is both necessary > and sufficient. We got away with ugly in the past, so we should get to do it again?
