lkml.org 
[lkml]   [2011]   [May]   [31]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
From
Date
SubjectRe: [PATCH v4 09/10] x86-64: Randomize int 0xcc magic al values at boot
On Tue, May 31, 2011 at 11:56 AM, Andrew Lutomirski <luto@mit.edu> wrote:
> We could scrap int 0xcc entirely and emulate on page fault, but that
> is slower and has other problems (like breaking anything that thinks
> it can look at a call target in a binary and dereference that
> address).
>
> Here's a possibly dumb/evil idea:
>
> Put real syscalls in the vsyscall page but mark the page NX.  Then
> emulate the vsyscalls on the PF_INSTR fault when userspace jumps to
> the correct address but send SIGSEGV for the wrong address.
>
> Down side: it's even more complexity for the same silly case.

Scratch that. It's incompatible with keeping time() fast for now.

>
> --Andy
>
>>
>> Thanks,
>>
>>        Ingo
>>
>
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/

\
 
 \ /
  Last update: 2011-05-31 18:13    [W:0.091 / U:0.392 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site