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Date:   Thu, 21 Feb 2019 07:18:54 -0800
From:   Luis Chamberlain <mcgrof@kernel.org>
To:     Eric Sandeen <sandeen@sandeen.net>,
        Andrew Morton <akpm@linux-foundation.org>
Cc:     Eric Sandeen <sandeen@redhat.com>,
        Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
        fsdevel <linux-fsdevel@vger.kernel.org>, netdev@vger.kernel.org,
        Kees Cook <keescook@chromium.org>
Subject: Re: [PATCH] sysctl: Fix proc_do_large_bitmap for large input buffers
Message-ID: <20190221151854.GJ11489@garbanzo.do-not-panic.com>
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On Wed, Feb 20, 2019 at 05:35:04PM -0600, Eric Sandeen wrote:
> Here's a pretty hacky test script to test this code via
> ip_local_reserved_ports

Thanks Eric!

So /proc/sys/net/ipv4/ip_local_reserved_ports is a production knob, and
if we wanted to stress test it with a selftest it could break other self
tests or change the system behaviour. Because of this we have now have
lib/test_sysctl.c, and we test this with the script:

tools/testing/selftests/sysctl/sysctl.sh

Any chance you can extend lib/test_sysctl.c with a new respective bitmap
knob, and add a respective test? This will ensure we don't regress
later. 0-day runs sysctl.sh so it should catch any regressions in the
future.

If you can think of other ways to test the knob that would be great too.

  Luis