linux-kernel - Re: [PATCH v9 4/7] remoteproc: core: Add TEE interface support for firmware release

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <yvax326sikpqkaygfldunjpziwwlwccfzmi6r5ikaqoyvfvama@w7kifjv5yt47>
Date: Wed, 25 Sep 2024 20:51:57 -0700
From: Bjorn Andersson <andersson@...nel.org>
To: Arnaud Pouliquen <arnaud.pouliquen@...s.st.com>
Cc: Mathieu Poirier <mathieu.poirier@...aro.org>, 
	Jens Wiklander <jens.wiklander@...aro.org>, Rob Herring <robh+dt@...nel.org>, 
	Krzysztof Kozlowski <krzysztof.kozlowski+dt@...aro.org>, Conor Dooley <conor+dt@...nel.org>, 
	linux-stm32@...md-mailman.stormreply.com, linux-arm-kernel@...ts.infradead.org, 
	linux-remoteproc@...r.kernel.org, linux-kernel@...r.kernel.org, op-tee@...ts.trustedfirmware.org, 
	devicetree@...r.kernel.org
Subject: Re: [PATCH v9 4/7] remoteproc: core: Add TEE interface support for
 firmware release

On Fri, Aug 30, 2024 at 11:51:44AM GMT, Arnaud Pouliquen wrote:
> Add support for releasing remote processor firmware through
> the Trusted Execution Environment (TEE) interface.
> 
> The tee_rproc_release_fw() function is called in the following cases:
> 
> - An error occurs in rproc_start() between the loading of the segments and
>   the start of the remote processor.
> - When rproc_release_fw is called on error or after stopping the remote
>   processor.
> 
> Signed-off-by: Arnaud Pouliquen <arnaud.pouliquen@...s.st.com>
> ---
>  drivers/remoteproc/remoteproc_core.c | 10 ++++++++--
>  1 file changed, 8 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/remoteproc/remoteproc_core.c b/drivers/remoteproc/remoteproc_core.c
> index 7694817f25d4..32052dedc149 100644
> --- a/drivers/remoteproc/remoteproc_core.c
> +++ b/drivers/remoteproc/remoteproc_core.c
> @@ -29,6 +29,7 @@
>  #include <linux/debugfs.h>
>  #include <linux/rculist.h>
>  #include <linux/remoteproc.h>
> +#include <linux/remoteproc_tee.h>
>  #include <linux/iommu.h>
>  #include <linux/idr.h>
>  #include <linux/elf.h>
> @@ -1258,6 +1259,9 @@ static int rproc_alloc_registered_carveouts(struct rproc *rproc)
>  
>  static void rproc_release_fw(struct rproc *rproc)
>  {
> +	if (rproc->state == RPROC_OFFLINE && rproc->tee_interface)
> +		tee_rproc_release_fw(rproc);

I don't like the idea of having op-tee specific calls made from the
core. If the problem is that we need to unroll something we did at load,
can we instead come up with a more generic mechanism to unload that? Or
can we perhaps postpone the tee interaction until start() to avoid the
gap?


PS. Most of the Qualcomm drivers are TEE-based...so the "tee_interface"
boolean check here is not very nice.

Regards,
Bjorn

> +
>  	/* Free the copy of the resource table */
>  	kfree(rproc->cached_table);
>  	rproc->cached_table = NULL;
> @@ -1348,7 +1352,7 @@ static int rproc_start(struct rproc *rproc, const struct firmware *fw)
>  	if (ret) {
>  		dev_err(dev, "failed to prepare subdevices for %s: %d\n",
>  			rproc->name, ret);
> -		goto reset_table_ptr;
> +		goto release_fw;
>  	}
>  
>  	/* power up the remote processor */
> @@ -1376,7 +1380,9 @@ static int rproc_start(struct rproc *rproc, const struct firmware *fw)
>  	rproc->ops->stop(rproc);
>  unprepare_subdevices:
>  	rproc_unprepare_subdevices(rproc);
> -reset_table_ptr:
> +release_fw:
> +	if (rproc->tee_interface)
> +		tee_rproc_release_fw(rproc);
>  	rproc->table_ptr = rproc->cached_table;
>  
>  	return ret;
> -- 
> 2.25.1
>