On 12/10/2014 06:14 PM, Eric W. Biederman wrote: > Thomas Gleixner <t...@linutronix.de> writes: >> please pull the latest x86-mpx-for-linus git tree from: >> >> git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git >> x86-mpx-for-linus >> >> This enables support for x86 MPX: >> >> MPX is a new debug feature for bound checking in user space. It >> requires kernel support to handle the bound tables and decode the >> bound violating instruction in the trap handler. > > I some really dumb questions. > > Given that mpx is both architecture and cpu specific why use prctl? > I would think arch_prctl would be a much more appropriate place to > expose this logic.
I actually never considered arch_prctl(). It doesn't seem a bad fit for any reason, just that I never thought of it and no one suggested it up to this point. Is there any *real* advantage to arch_prctl()? We have some gcc code that's going to be using these prctls and if we need to change the interface, we've got to get that code changed too... fast. > Why don't you have a call to let an application query to see if mpx > management is enabled? I am trying to imagine how checkpoint/restart is > going to be supported for mpx applications. If I can't even query if > mpx is enabled I don't have a clue how we could save this state and > duplicate it in another process on another machine. You probably need to actually save off the contents of mm->bd_addr itself. I guess you can do it along with all the other internals of the mm that get saved off currently. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
