On Tue Mar 7, 2023 at 3:37 PM AEST, Benjamin Gray wrote: > On Tue, 2023-03-07 at 15:05 +1000, Nicholas Piggin wrote: > > I think it is not quite per-process? I don't actually know how the > > user > > toolchain side is put together, but I'm thinking we can not give it a > > new > > salt on fork(), but we could on exec(). I think we could actually > > give > > each thread their own salt within a process too, right? > > Yeah, the error case is we return further than we called in a given > execution context. A forked child may return after the fork, meaning it > needs the same key as the parent for the hashchk to work. Exec can get > a new key because we can't return with any existing hashes. I haven't > seen enough of kernel thread support to know if/how we can give threads > their own key. I believe they go through the fork() call that copies > the parent key currently.
Could look at possibly doing per-thread keys afterward but what you're doing makes sense so no problem. Thanks, Nick
