On Wed, Mar 18, 2015 at 11:20:08AM -0700, Andy Lutomirski wrote: > > > > Basically the initial registers values are fetched with ptrace > > when program is been dumped, then on restore we copy them back > > into sigcontext. That said we don't mangle fs/gs anyhow simply > > restore the values back from dump. > > Wouldn't it be a little safer to have the kernel make you a sane > sigcontext by raising a signal and catching it rather than writing a > new one from scratch? Grr, maybe the kernel should version its > sigcontext structures.
I think it would, thanks for the point! I'll tune up our code. > Getting fs from ptrace and restoring it to sigcontext is useless -- > ptrace handles fs correctly, but that sigcontext field is just > padding. > > Is CRIU at least reliably putting zero in the ss field? If so, we > could add a special case to translate zero to __USER_DS on restore. > (And then I'll update my test case, and we'll have to document it, > etc.) Well, it should but need to check (we are tryin to not zeroify things until really needed in a sake of speed). -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
