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Date:   Wed, 11 Dec 2019 19:52:02 +0200
From:   Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
To:     Tadeusz Struk <tadeusz.struk@intel.com>
Cc:     peterz@infradead.org, linux-kernel@vger.kernel.org,
        stable@vger.kernel.org, jgg@ziepe.ca, mingo@redhat.com,
        jeffrin@rajagiritech.edu.in, linux-integrity@vger.kernel.org,
        will@kernel.org, peterhuewe@gmx.de
Subject: Re: [PATCH] tpm: fix WARNING: lock held when returning to user space
Message-ID: <20191211175119.GI4516@linux.intel.com>
References: <34e5340f-de75-f20e-7898-6142eac45c13@intel.com>
 <157601267151.12904.7408818232910113434.stgit@tstruk-mobl1>
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On Tue, Dec 10, 2019 at 01:17:51PM -0800, Tadeusz Struk wrote:
> When an application sends TPM commands in NONBLOCKING mode
> the driver holds chip->tpm_mutex returning from write(),
> which triggers WARNING: lock held when returning to user space!
> To silence this warning the driver needs to release the mutex
> and acquire it again in tpm_dev_async_work() before sending
> the command.

This commit message is nonsense ATM. The code leaves locks held,
which is unacceptable.

Silencing warnings is worst possible rationale for a code change
that I can think of starting from the fact that is straight out
wrong and malicious.

/Jarkko