lkml.org 
[lkml]   [2007]   [Mar]   [8]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH] Fix atomicity of TIF update in flush_thread() for x86_64
* David Miller (davem@davemloft.net) wrote:
> From: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
> Date: Thu, 8 Mar 2007 21:15:53 -0500
>
> > Fix atomicity of TIF update in flush_thread() for x86_64
> >
> > Race :
> >
> > parent process executing :
> > sys_ptrace()
> > (lock_kernel())
> > (ptrace_get_task_struct(pid))
> > arch_ptrace()
> > ptrace_detach()
> > ptrace_disable(child);
> > clear_singlestep(child);
> > clear_tsk_thread_flag(child, TIF_SINGLESTEP);
> > (which clears the TIF_SINGLESTEP flag atomically from a different
> > process)
> > (put_task_struct(child))
> > (unlock_kernel())
> >
> > And at the same time, in the child process :
> > sys_execve()
> > do_execve()
> > search_binary_handler()
> > load_elf_binary()
> > flush_old_exec()
> > flush_thread()
> > doing a non-atomic thread flag update
> >
> > It applies on 2.6.20.
> >
> > Signed-off-by: Rebecca Schultz <rschultz@google.com>
> > Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
>
> Please fix all platforms, not just your favorite one, kthx.
> :-)

Please be comprehensive of the speed at which fingers can type on my
keyboard. Your quickness at replying to email is impressive though ;)

I am working on it, it won't take long.

Regards,

Mathieu

--
Mathieu Desnoyers
Computer Engineering Ph.D. Student, Ecole Polytechnique de Montreal
OpenPGP key fingerprint: 8CD5 52C3 8E3C 4140 715F BA06 3F25 A8FE 3BAE 9A68
-
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: 2007-03-09 03:25    [W:0.038 / U:2.136 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site