From: Mimi Zohar <zohar@linux.ibm.com>
To: Lakshmi Ramasubramanian <nramas@linux.microsoft.com>,
James.Bottomley@HansenPartnership.com,
linux-integrity@vger.kernel.org
Cc: eric.snowberg@oracle.com, dhowells@redhat.com,
mathew.j.martineau@linux.intel.com, matthewgarrett@google.com,
sashal@kernel.org, jamorris@linux.microsoft.com,
linux-kernel@vger.kernel.org, keyrings@vger.kernel.org
Subject: Re: [PATCH v5 1/2] IMA: Define workqueue for early boot "key" measurements
Date: Fri, 20 Dec 2019 07:53:06 -0500 [thread overview]
Message-ID: <1576846386.5241.13.camel@linux.ibm.com> (raw)
In-Reply-To: <503845c9-beeb-b520-ec3f-af5fa7d2b91f@linux.microsoft.com>
On Thu, 2019-12-19 at 08:55 -0800, Lakshmi Ramasubramanian wrote:
> I am not sure if the mutex can be removed.
>
> In ima_queue_key() we need to test the flag and add the key to the list
> as an atomic operation:
>
> if (!test_bit())
> insert_key_to_list
>
> Suppose the if condition is true, but before we could insert the key to
> the list, ima_process_queued_keys() runs and processes queued keys we'll
> add the key to the list and never process it.
>
> Is there an API in the kernel to test and add an entry to a list
> atomically?
Ok, using test_and_set_bit() and test_bit() only helps, if we can get
rid of the mutex. I'll queue these patches.
thanks,
Mimi
next prev parent reply other threads:[~2019-12-20 12:53 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-12-18 16:44 [PATCH v5 0/2] IMA: Deferred measurement of keys Lakshmi Ramasubramanian
2019-12-18 16:44 ` [PATCH v5 1/2] IMA: Define workqueue for early boot "key" measurements Lakshmi Ramasubramanian
2019-12-19 13:11 ` Mimi Zohar
2019-12-19 16:55 ` Lakshmi Ramasubramanian
2019-12-20 12:53 ` Mimi Zohar [this message]
2019-12-18 16:44 ` [PATCH v5 2/2] IMA: Call workqueue functions to measure queued keys Lakshmi Ramasubramanian
2019-12-20 19:01 ` [PATCH v5 0/2] IMA: Deferred measurement of keys Mimi Zohar
2019-12-20 19:25 ` Lakshmi Ramasubramanian
2019-12-20 19:36 ` Mimi Zohar
2019-12-20 20:50 ` Lakshmi Ramasubramanian
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