Re: [PATCH v2] ARM: mm: fix location of _etext
From: Kees Cook
Date: Thu Jun 16 2016 - 13:08:12 EST
On Thu, Jun 16, 2016 at 5:04 AM, Ard Biesheuvel
<ard.biesheuvel@xxxxxxxxxx> wrote:
> On 15 June 2016 at 22:24, Kees Cook <keescook@xxxxxxxxxxxx> wrote:
>> The _etext position is defined to be the end of the kernel text code,
>> and should not include any part of the data segments. This interferes
>> with things that might check memory ranges and expect executable code
>> up to _etext. Just to be conservative, leave the kernel resource as
>> it was, using __init_begin instead of _etext as the end mark.
>>
>> Signed-off-by: Kees Cook <keescook@xxxxxxxxxxxx>
>> ---
>> v2:
>> - Switched resource tracker to using __init_begin, rmk
>
> Actually, Linus removed the x86 /proc/iomem resources for kernel segments in
>
> c4004b02f8e5 ("x86: remove the kernel code/data/bss resources from /proc/iomem")
>
> so I wonder if we should not just do the same for ARM and arm64?
Nope, that got reverted. Removing it breaks things.
4046d6e81f33b7ef50d6668b78076d54c5e066b6
-Kees
--
Kees Cook
Chrome OS & Brillo Security