lkml.org 
[lkml]   [2005]   [Jun]   [2]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [Patch] x86_64: TASK_SIZE fixes for compatibility mode processes
On Thu, Jun 02, 2005 at 01:50:13PM -0700, Andrew Morton wrote:
> "Siddha, Suresh B" <suresh.b.siddha@intel.com> wrote:
> >
> > +#define TASK_SIZE_OF(child) ((test_tsk_thread_flag(child, TIF_IA32)) ? IA32_PAGE_OFFSET : TASK_SIZE64)
>
> The task size is an attribute of the task's mm_struct, not of the task.

ia64, ppc64 and s390 seems be getting this info from thread_info or
thread_struct in the task struct.

> The place where this tends to come unstuck is when a 32-bit task holds a
> reference on a 64-bit tasks's task_struct via a read of a /proc file. If
> the 64-bit task exits then it is the 32-bit task who does the final freeing
> of the 64-bit tasks's task_struct and mm_struct. (and all vice-versa, of
> course). Will your patch handle this race scenario correctly?

In recent kernels, instead of TASK_SIZE, "-1" is getting passed to unmap_vmas()
from exit_mmap. Same case with ceiling (set to "0") for free_pgtables().
It shouldn't be a problem with this, right?

thanks,
suresh
-
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: 2005-06-03 00:25    [W:0.038 / U:1.988 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site