From mboxrd@z Thu Jan 1 00:00:00 1970 From: Thomas Gleixner Subject: Re: [PATCH 28/34] x86: wire up mprotect_key() system call Date: Tue, 8 Dec 2015 19:44:59 +0100 (CET) Message-ID: References: <20151204011424.8A36E365@viggo.jf.intel.com> <20151204011503.2A095839@viggo.jf.intel.com> Mime-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Return-path: In-Reply-To: <20151204011503.2A095839-LXbPSdftPKxrdx17CPfAsdBPR1lH4CV8@public.gmane.org> Sender: linux-api-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Dave Hansen Cc: linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-mm-Bw31MaZKKs3YtjvyW6yDsg@public.gmane.org, x86-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org, dave.hansen-VuQAYsv1563Yd54FQh9/CA@public.gmane.org, linux-api-u79uwXL29TY76Z2rM5mHXA@public.gmane.org List-Id: linux-api@vger.kernel.org On Thu, 3 Dec 2015, Dave Hansen wrote: > #include > diff -puN mm/Kconfig~pkeys-16-x86-mprotect_key mm/Kconfig > --- a/mm/Kconfig~pkeys-16-x86-mprotect_key 2015-12-03 16:21:31.114920208 -0800 > +++ b/mm/Kconfig 2015-12-03 16:21:31.119920435 -0800 > @@ -679,4 +679,5 @@ config NR_PROTECTION_KEYS > # Everything supports a _single_ key, so allow folks to > # at least call APIs that take keys, but require that the > # key be 0. > + default 16 if X86_INTEL_MEMORY_PROTECTION_KEYS > default 1 What happens if I set that to 42? I think we want to make this a runtime evaluated thingy. If pkeys are compiled in, but the machine does not support it then we don't support 16 keys, or do we? Thanks, tglx