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. Can someone from the x86 tree take this patch, or are there other things to improve? 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/
