Re: linux-kernel-digest V1 #2839 (writable /proc/<pid>/cmdli
Andi Kleen (ak@muc.de)
Tue, 17 Nov 1998 05:48:43 +0100
On Mon, Nov 16, 1998 at 11:39:16PM +0100, Peeter Joot wrote:
> Hi Andy,
>
> The sendmail solution that uses kmem is only for SCO if I read the code right.
> On linux all that is required is coping a new string into argv[0]. This is
> much simpler then messing around with /proc at least in our case (db2) where we
> have a multi-process based system rather than a multi-thread based solution.
>
> But, your point about threads is a good one, because argv[0] would be shared
> for all threads and a writable /proc/<pid>/cmdline could be used to rename the
> ps output for different threads/clones, and overwriting argv[0] wouldn't work
> in this case.
It wouldn't even with your /proc hack.
If the threads share VM (with CLONE_VM) they share
all memory, including the environment. argv[] is stored in the environment.
Changing Linux to support only partly shared memory in CLONE_VM (with threads
private pages like in Windows or OS/2) would be a fairly major redesign
of the kernel threads mechanism.
-Andi
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