On Mon, Aug 31, 2015 at 2:23 PM, Andy Lutomirski <l...@amacapital.net> wrote: > On Aug 31, 2015 1:13 PM, "Kees Cook" <keesc...@chromium.org> wrote: >> >> On Wed, Aug 12, 2015 at 7:23 PM, Josh Triplett <j...@joshtriplett.org> wrote: >> > On Wed, Aug 12, 2015 at 05:55:19PM -0700, Kees Cook wrote: >> >> Most modern systems can run with vsyscall=none. In an effort to provide >> >> a way for build-time defaults to lack legacy settings, this adds a new >> >> CONFIG to select the type of vsyscall mapping to use, similar to the >> >> existing "vsyscall" command line parameter. >> >> >> >> Signed-off-by: Kees Cook <keesc...@chromium.org> >> > >> > Seems reasonable to me. One question, though: is there *any* reason to >> > choose "native" over "emulate"? (Does "emulate" have a sufficient >> > performance penalty to matter, and do people running old glibc really >> > care about that performance while still not wanting to upgrade?) >> > If there is a reason, could you please document it in the >> > descriptions of the "native" and "emulate" options (as an upside and a >> > downside, respectively)? If there isn't, you might consider a patch to >> > remove "native". >> >> I think "native" is available out of an abundance of caution. Andy >> left it available, though I'm not sure if he had plans to remove >> "native" entirely. > > Native adds almost no code and almost no maintenance burden -- it's > really just a PTE bit. > >> >> Can someone from the x86 tree take this patch, or are there other >> things to improve? > > It looks good to me.
tglx, hpa, ingo? Can this go into -tip? Thanks! -Kees -- Kees Cook Chrome OS Security -- 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/
