From:   ebiederm@xmission.com (Eric W. Biederman)
To:     Linus Torvalds <torvalds@linux-foundation.org>
Cc:     <linux-kernel@vger.kernel.org>, <linux-arch@vger.kernel.org>,
        Kees Cook <keescook@chromium.org>,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        Christoph Hellwig <hch@infradead.org>,
        Andy Lutomirski <luto@amacapital.net>
References: <87tugkm3gc.fsf@disp2133>
Date:   Wed, 10 Nov 2021 12:14:02 -0600
In-Reply-To: <87tugkm3gc.fsf@disp2133> (Eric W. Biederman's message of "Wed,
        10 Nov 2021 09:32:19 -0600")
Message-ID: <874k8j3ml1.fsf@email.froward.int.ebiederm.org>
User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/26.1 (gnu/linux)
MIME-Version: 1.0
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Subject: Re: [GIT PULL] exit cleanups for v5.16
Precedence: bulk

ebiederm@xmission.com (Eric W. Biederman) writes:

> Linus,
>
> Please pull the exit-cleanups-for-v5.16 branch from the git tree:
>
>   git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace.git exit-cleanups-for-v5.16
>
>   HEAD: f91140e4553408cacd326624cd50fc367725e04a Arnd Bergmann <arnd@arndb.de>
>
>
> While looking at some issues related to the exit path in the kernel I
> found several instances where the code is not using the existing
> abstractions properly.
>
> This set of changes introduces force_fatal_sig a way of sending
> a signal and not allowing it to be caught, and corrects the
> misuse of the existing abstractions that I found.
>
> A lot of the misuse of the existing abstractions are silly things such
> as doing something after calling a no return function, rolling BUG by
> hand, doing more work than necessary to terminate a kernel thread, or
> calling do_exit(SIGKILL) instead of calling force_sig(SIGKILL).
>
> In the review a deficiency in force_fatal_sig and force_sig_seccomp
> where ptrace or sigaction could prevent the delivery of the signal was
> found.  I have added a change that adds SA_IMMUTABLE to change that
> makes it impossible to interrupt the delivery of those signals, and
> allows backporting to fix force_sig_seccomp.
>
> Arnd found an issue where a function passed to kthread_run had the wrong
> prototype, and after my cleanup was failing to build.

I forgot to mention there is a minor conflict with the staging tree.
One of the functions that I cleaned up was in a file that was completely
removed from staging.  The result is that when you encounter the
conflict that file can simply be removed.

Eric