Date: Thu, 14 Apr 2016 22:34:44 +0200 From: Pavel Machek <pavel@...x.de> To: Kees Cook <keescook@...omium.org> Cc: Linus Torvalds <torvalds@...ux-foundation.org>, "Rafael J. Wysocki" <rafael@...nel.org>, Ingo Molnar <mingo@...nel.org>, James Morse <james.morse@....com>, Ard Biesheuvel <ard.biesheuvel@...aro.org>, Matt Redfearn <matt.redfearn@...tec.com>, Yves-Alexis Perez <corsac@...ian.org>, Emrah Demir <ed@...sec.com>, Jonathan Corbet <corbet@....net>, "x86@...nel.org" <x86@...nel.org>, Len Brown <len.brown@...el.com>, Borislav Petkov <bp@...e.de>, Andy Lutomirski <luto@...nel.org>, "linux-doc@...r.kernel.org" <linux-doc@...r.kernel.org>, Linux PM list <linux-pm@...r.kernel.org>, LKML <linux-kernel@...r.kernel.org>, "kernel-hardening@...ts.openwall.com" <kernel-hardening@...ts.openwall.com> Subject: Re: [PATCH v2] kaslr: allow kASLR to be default over Hibernation On Thu 2016-04-14 13:14:07, Kees Cook wrote: > On Thu, Apr 14, 2016 at 1:01 PM, Pavel Machek <pavel@...x.de> wrote: > > Hi! > > > >> Since kASLR and Hibernation can not currently coexist at runtime > >> on x86, the default behavior was to disable kASLR by default when > >> CONFIG_HIBERNATION was present (to retain original behavior). > >> > >> The behavior of kASLR on arm64 (and soon MIPS) is to be enabled by > >> default when selected at build time. Since arm64 Hibernation does not > >> conflict with kASLR, this fixes the hibernation argument parsing to be > >> x86-specific. Additionally, since end users want to be able to select > >> kASLR on x86 by default at build time, create CONFIG_RANDOMIZE_BASE_ON > >> that is present only on x86. > >> > >> Signed-off-by: Kees Cook <keescook@...omium.org> > > > > I believe this is bad idea. arm64 shows that kaslr and hibernation can > > coexist, and hibernation is still useful when your battery runs out. > > What? I'm confused -- this patch leaves the x86 behavior as-is by > default but allows hibernation to work with arm64. (For example, right > now, if you boot arm64 with "kaslr" kernel argument, hibernation will > get needlessly disabled.) So it is very different from the PATCH v1, still it shares the subject? This is the part I don't like: > >> Since kASLR and Hibernation can not currently coexist at runtime > >> on x86, the default behavior was to disable kASLR by default when > >> CONFIG_HIBERNATION was present (to retain original behavior). Now I notice that it is quite unclear if it actually changes anything... Pavel -- (english) http://www.livejournal.com/~pavelmachek (cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html
Powered by blists - more mailing lists
Confused about mailing lists and their use? Read about mailing lists on Wikipedia and check out these guidelines on proper formatting of your messages.