Messages in this thread | | | Subject | Re: [PATCH v9 29/51] mm/mprotect, powerpc/mm/pkeys, x86/mm/pkeys: Add sysfs interface | From | Benjamin Herrenschmidt <> | Date | Wed, 20 Dec 2017 08:34:56 +1100 |
| |
On Mon, 2017-12-18 at 14:28 -0800, Dave Hansen wrote: > > We do not have generic support for something like that on ppc. > > The kernel looks at the device tree to determine what hardware features > > are available. But does not have mechanism to tell the hardware to track > > which of its features are currently enabled/used by the kernel; atleast > > not for the memory-key feature. > > Bummer. You're missing out. > > But, you could still do this with a syscall. "Hey, kernel, do you > support this feature?"
I'm not sure I understand Ram's original (quoted) point, but informing userspace of CPU features is what AT_HWCAP's are about.
Ben.
| |