lkml.org 
[lkml]   [2005]   [Sep]   [16]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH 2.6.13.1] Patch for invisible threads
On Thu, Sep 15, 2005 at 07:54:56PM -0500, Sripathi Kodi wrote:
> proc_root_link and proc_task_root_link still have some duplicated code. I
> could have split these functions further to avoid duplication completely,
> but that would move incrementing and decrementing fs->lock to two different
> functions, which I think will be confusing.
>
> The other way of implementing this that I could think of was to have a flag
> to indicate that the call is from ->permission path and pass it all along.
> This will avoid having to change many existing functions, but it will
> defeat the purpose of limiting this kludge code to ->permission path.
>
> Please let me know how it is looking now.

Ugh... Considering that all of that is _only_ for /proc/<pid>/task and
that proc_permission() is a couple of function calls, why bother with
proc_task_check_root() instead of just adding proc_task_permission() with

{
struct dentry *root;
struct vfsmount *vfsmnt;

if (generic_permission(inode, mask, NULL) != 0)
return -EACCES;

/* or just open-code it here, for that matter */
if (proc_task_root_link(inode, &root, &vfsmnt))
return -ENOENT;

return proc_check_chroot(root, vfsmnt);
}

for a body and leaving proc_permission() without any changes at all?

> Further, about actual permission checks that we are doing, can we say: "A
> process should be able to see /proc/<pid>/task/* of another process only if
> they both belong to same uid or reader is root"? But any such change will
> change the behavior of commands like 'ps', right?

Right. The real question is whether the current behaviour makes any sense.
I've no objections to your patch + modification above, but I really wonder
if we should keep current rules in that area.
-
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: 2005-09-16 09:49    [W:0.115 / U:0.064 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site