> On 03.06.2015, at 13:53, Mark Brown <[email protected]> wrote: > >> On Wed, Jun 03, 2015 at 01:25:58PM +0200, Lars-Peter Clausen wrote: >> >> Having those kinds of stats in world readable files has serious security >> implications as they can be used to implement side-channel attacks. They >> should probably only be available in debugfs for root. > > We do get to control the permissions on sysfs files, though it's a bit > more unusual to make things root only (and there is the histogram).
I left histogram as a single file because I remember having seen a file in /sys with similar semantics using multiple values (but I can not remember which one). I can remove it when I get back near my development box in a little more than a week. As for side channel attacks: the information is there already. E.g the number of Interrupts for the spi device in /proc/interrupts This could also be used as an indicator for the number of spi transfers handled, so I do not see a huge difference... If you want it as root only - we can do it, but I wonder if it is making a real difference... -- To unsubscribe from this list: send the line "unsubscribe linux-spi" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
