Re: [PATCH v2 1/2] remoteproc: qcom_q6v5_mss: Add modem debug policy support

[Sibi Sankar <sibis@codeaurora.org>]

On 2020-07-22 09:24, Bjorn Andersson wrote:
> On Tue 21 Jul 04:29 PDT 2020, Sibi Sankar wrote:
> 
>> Add modem debug policy support which will enable coredumps and live
>> debug support when the msadp firmware is present on secure devices.
>> 
>> Signed-off-by: Sibi Sankar <sibis@codeaurora.org>
>> ---
>> 
>> v2:
>>  * Use request_firmware_direct [Bjorn]
>>  * Use Bjorn's template to show if debug policy is present
>>  * Add size check to prevent memcpy out of bounds [Bjorn]
>> 
>>  drivers/remoteproc/qcom_q6v5_mss.c | 16 +++++++++++++++-
>>  1 file changed, 15 insertions(+), 1 deletion(-)
>> 
>> diff --git a/drivers/remoteproc/qcom_q6v5_mss.c 
>> b/drivers/remoteproc/qcom_q6v5_mss.c
>> index 0b6f260eb5349..49cd16e050533 100644
>> --- a/drivers/remoteproc/qcom_q6v5_mss.c
>> +++ b/drivers/remoteproc/qcom_q6v5_mss.c
>> @@ -189,6 +189,7 @@ struct q6v5 {
>>  	phys_addr_t mba_phys;
>>  	void *mba_region;
>>  	size_t mba_size;
>> +	size_t dp_size;
>> 
>>  	phys_addr_t mpss_phys;
>>  	phys_addr_t mpss_reloc;
>> @@ -408,6 +409,14 @@ static int q6v5_xfer_mem_ownership(struct q6v5 
>> *qproc, int *current_perm,
>>  static int q6v5_load(struct rproc *rproc, const struct firmware *fw)
>>  {
>>  	struct q6v5 *qproc = rproc->priv;
>> +	const struct firmware *dp_fw;
>> +
>> +	if (!request_firmware_direct(&dp_fw, "msadp", qproc->dev) && 
>> fw->size <= SZ_1M &&
>> +	    (SZ_1M + dp_fw->size) <= qproc->mba_size) {
>> +		memcpy(qproc->mba_region + SZ_1M, dp_fw->data, dp_fw->size);
>> +		qproc->dp_size = dp_fw->size;
>> +		release_firmware(dp_fw);
> 
> If request_firmware_direct() succeeds, but return a firmware blob 
> bigger
> than mba_size - SZ_1M you won't get here and will end up leaking dp_fw.
> 
> Additionally, there really isn't a need for requesting the firmware in
> the first place if fw->size > SZ_1M.
> 
> So I think it's better if you break this out in it's own function where
> you don't need to squeeze everything into one or two conditionals.

I'll fix dp_fw leak and move it
to a new func. Thanks for the
review.

> 
> Regards,
> Bjorn
> 
>> +	}
>> 
>>  	memcpy(qproc->mba_region, fw->data, fw->size);
>> 
>> @@ -896,6 +905,10 @@ static int q6v5_mba_load(struct q6v5 *qproc)
>>  	}
>> 
>>  	writel(qproc->mba_phys, qproc->rmb_base + RMB_MBA_IMAGE_REG);
>> +	if (qproc->dp_size) {
>> +		writel(qproc->mba_phys + SZ_1M, qproc->rmb_base + 
>> RMB_PMI_CODE_START_REG);
>> +		writel(qproc->dp_size, qproc->rmb_base + RMB_PMI_CODE_LENGTH_REG);
>> +	}
>> 
>>  	ret = q6v5proc_reset(qproc);
>>  	if (ret)
>> @@ -1257,7 +1270,8 @@ static int q6v5_start(struct rproc *rproc)
>>  	if (ret)
>>  		return ret;
>> 
>> -	dev_info(qproc->dev, "MBA booted, loading mpss\n");
>> +	dev_info(qproc->dev, "MBA booted with%s debug policy, loading 
>> mpss\n",
>> +		 qproc->dp_size ? "" : "out");
>> 
>>  	ret = q6v5_mpss_load(qproc);
>>  	if (ret)
>> --
>> The Qualcomm Innovation Center, Inc. is a member of the Code Aurora 
>> Forum,
>> a Linux Foundation Collaborative Project
>> 

-- 
Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum,
a Linux Foundation Collaborative Project.