Am Dienstag, den 09.01.2018, 08:12 +0100 schrieb Thomas Trepl: > Am Montag, den 08.01.2018, 16:14 -0800 schrieb Paul Rogers: > > I've just patched one of my older Core2 "Conroe", LFS-7.7, up to > > 4.4.110. It's an i686 system. With each minor-version patch "make > > oldconfig" was run. I saw no kernel config parameter for > > PAGE_TABLE_ISOLATION when I rebuilt the patched kernel. I can find > > no evidence it has been built into this kernel. I did get some > > hits > > for "kaiser" in the source code, arch/x86/mm/kaiser.c, and the > > mm/Makefile looks for CONFIG_PAGE_TABLE_ISOLATION. The make log I > > kept does not contain the string "kaiser", nor does > > /boot/System.map. > > > > Any ideas? TIA. > > > > You could check dmesg after reboot. If there is a line like > > [ 0.000000] Kernel/User page tables isolation: enabled > > then it should be active. At least on x64_64 such a line comes up > (with 4.14.12). > > Will do a i686 build today...
Did so. Looks like the KPTI stuff is somehow different (if at all) implemented for 32bit kernels. Indeed, the option to select CONFIG_PAGE_TABLE_ISOLATION isn't available and when booting a fresh i686-4.14.12 kernel it does not show the "Kernel/User page tables isolation: enabled" message. Havn't found much info about KPTI on i686 yet. Nevertheless, when running the i686 kernel on a Xeon-E3-1245 /proc/cpuinfo says "bugs : cpu_insecure". So, at least a bit has changed for 32bit-kernels, too. Does anyone have more insights here? -- Thomas -- http://lists.linuxfromscratch.org/listinfo/lfs-support FAQ: http://www.linuxfromscratch.org/blfs/faq.html Unsubscribe: See the above information page Do not top post on this list. A: Because it messes up the order in which people normally read text. Q: Why is top-posting such a bad thing? A: Top-posting. Q: What is the most annoying thing in e-mail? http://en.wikipedia.org/wiki/Posting_style
