From: Luis Chamberlain <mcgrof@kernel.org>
To: Rafael Aquini <aquini@redhat.com>
Cc: linux-kernel@vger.kernel.org, linux-doc@vger.kernel.org,
kexec@lists.infradead.org, linux-fsdevel@vger.kernel.org,
dyoung@redhat.com, bhe@redhat.com, corbet@lwn.net,
keescook@chromium.org, akpm@linux-foundation.org, cai@lca.pw,
rdunlap@infradead.org, tytso@mit.edu, bunk@kernel.org,
torvalds@linux-foundation.org, gregkh@linuxfoundation.org,
labbott@redhat.com, jeffm@suse.com, jikos@kernel.org,
jeyu@suse.de, tiwai@suse.de, AnDavis@suse.com,
rpalethorpe@suse.de
Subject: Re: [PATCH v5] kernel: add panic_on_taint
Date: Fri, 15 May 2020 20:26:56 +0000 [thread overview]
Message-ID: <20200515202656.GZ11244@42.do-not-panic.com> (raw)
In-Reply-To: <20200515175502.146720-1-aquini@redhat.com>
On Fri, May 15, 2020 at 01:55:02PM -0400, Rafael Aquini wrote:
> Analogously to the introduction of panic_on_warn, this patch introduces a kernel
> option named panic_on_taint in order to provide a simple and generic way to stop
> execution and catch a coredump when the kernel gets tainted by any given flag.
>
> This is useful for debugging sessions as it avoids having to rebuild the kernel
> to explicitly add calls to panic() into the code sites that introduce the taint
> flags of interest. For instance, if one is interested in proceeding with a
> post-mortem analysis at the point a given code path is hitting a bad page
> (i.e. unaccount_page_cache_page(), or slab_bug()), a coredump can be collected
> by rebooting the kernel with 'panic_on_taint=0x20' amended to the command line.
>
> Another, perhaps less frequent, use for this option would be as a mean for
> assuring a security policy case where only a subset of taints, or no single
> taint (in paranoid mode), is allowed for the running system.
> The optional switch 'nousertaint' is handy in this particular scenario,
> as it will avoid userspace induced crashes by writes to sysctl interface
> /proc/sys/kernel/tainted causing false positive hits for such policies.
>
> Suggested-by: Qian Cai <cai@lca.pw>
> Signed-off-by: Rafael Aquini <aquini@redhat.com>
Reviewed-by: Luis Chamberlain <mcgrof@kernel.org>
Luis
prev parent reply other threads:[~2020-05-15 20:27 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-05-15 17:55 [PATCH v5] kernel: add panic_on_taint Rafael Aquini
2020-05-15 20:26 ` Luis Chamberlain [this message]
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