lkml.org 
[lkml]   [2007]   [Mar]   [2]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: + fully-honor-vdso_enabled.patch added to -mm tree
John Reiser wrote:
> The value of ->sysenter_return is interpreted in user space by the
> sysexit instruction; nobody else cares what the value is. The kernel
> is not required to provide a good value when vdso_enabled is zero,
> because the kernel has not told the process that sysenter is valid
> (by setting AT_SYSINFO.)

Doesn't matter because a malicious user can still execute sysenter.
We do have to deal with that somehow, so we have to put something
safe in there.

> Correct. Changing vdso_enabled from 0 to non-zero must be prepared
> to lose this race if it is not prevented. Ordinarily it won't matter
> because the administrator will perform such changes at a "quiet" time.
>

We have to deal with all the possibilities here, too.
-
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: 2007-03-02 23:23    [W:0.111 / U:0.504 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site