Re: [PATCH] coredump_filter: enable to change the default filter

From: Andrew Morton
Date: Thu Dec 11 2008 - 18:11:05 EST


On Thu, 11 Dec 2008 15:46:49 +0900 (JST)
KOSAKI Motohiro <kosaki.motohiro@xxxxxxxxxxxxxx> wrote:

> Hi
>
> > This patch introduces new kernel parameter `coredump_filter'.
> > Setting a value to this parameter causes the default bitmask
> > of coredump_filter to be changed.
> >
> > It is useful for users to change coredump_filter settings for
> > the whole system at boot time. Without this parameter, users
> > have to change coredump_filter settings for each /proc/<pid>/
> > in an initializing script.
>
> I think this patch only useful on following situation, right?
>
> - Administrator can't change rc script.
> - Administrator can change boot parameter.
>
>
> When happen above situation?
> or, you intent to init process debugging?

Yes, this can be implemented in userspace by setting init's filter
before init forks any other processes.

I can understand the practical problems with that form of implementation
however :(


Or does the patch change other behaviour? Say, when mm_init() is
called by a kernel thread (current->mm==NULL)? call_usermodehelper(),
for example?

If so, then setting init's filter doesn't cover that case.
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/