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Date:   Mon, 2 Mar 2020 10:38:51 -0800
From:   Kees Cook <keescook@chromium.org>
To:     Arvind Sankar <nivedita@alum.mit.edu>
Cc:     dave.hansen@linux.intel.com, kernel-hardening@lists.openwall.com,
        linux-kernel@vger.kernel.org, luto@kernel.org, me@tobin.cc,
        peterz@infradead.org, tycho@tycho.ws, x86@kernel.org
Subject: Re: [PATCH] x86/mm/init_32: Don't print out kernel memory layout if
 KASLR
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 <20200301001123.GA1278373@rani.riverdale.lan>
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On Sat, Feb 29, 2020 at 07:11:23PM -0500, Arvind Sankar wrote:
> On Sat, Feb 29, 2020 at 03:51:45PM -0800, Kees Cook wrote:
> > Arvind Sankar said:
> > > For security, only show the virtual kernel memory layout if KASLR is
> > > disabled.
> > 
> > These have been entirely removed on other architectures, so let's
> > just do the same for ia32 and remove it unconditionally.
> > 
> > 071929dbdd86 ("arm64: Stop printing the virtual memory layout")
> > 1c31d4e96b8c ("ARM: 8820/1: mm: Stop printing the virtual memory layout")
> > 31833332f798 ("m68k/mm: Stop printing the virtual memory layout")
> > fd8d0ca25631 ("parisc: Hide virtual kernel memory layout")
> > adb1fe9ae2ee ("mm/page_alloc: Remove kernel address exposure in free_reserved_area()")
> > 
> > -Kees
> > 
> > -- 
> > Kees Cook
> 
> microblaze (arch/microblaze/mm/init.c) and PPC32 (arch/powerpc/mm/mem.c)
> appear to still print it out. I can't test those, but will resubmit
> x86-32 with it removed.

Might as well fix those up too. :)

-- 
Kees Cook