Re: [PATCH resend] gpu: host1x: fix error return code in host1x_memory_context_list_init()

[Yang Yingliang <yangyingliang@huawei.com>]

On 2022/11/26 0:00, Mikko Perttunen wrote:
> On 11/24/22 10:05, Yang Yingliang wrote:
>> If context device has no IOMMU, the 'cdl->devs' is freed in error path,
>> but host1x_memory_context_list_init() doesn't return an error code, so
>> the module can be loaded successfully, when it's unloading, the
>> host1x_memory_context_list_free() is called in host1x_remove(), it will
>> cause double free. Return an error code to fix this.
>>
>> Fixes: 8aa5bcb61612 ("gpu: host1x: Add context device management code")
>> Signed-off-by: Yang Yingliang <yangyingliang@huawei.com>
>> ---
>> The previous patch link:
>> https://lore.kernel.org/lkml/20220714031123.2154506-1-yangyingliang@huawei.com/ 
>>
>> ---
>>   drivers/gpu/host1x/context.c | 1 +
>>   1 file changed, 1 insertion(+)
>>
>> diff --git a/drivers/gpu/host1x/context.c b/drivers/gpu/host1x/context.c
>> index b08cf11f9a66..5cf9b98bedd0 100644
>> --- a/drivers/gpu/host1x/context.c
>> +++ b/drivers/gpu/host1x/context.c
>> @@ -74,6 +74,7 @@ int host1x_memory_context_list_init(struct host1x 
>> *host1x)
>>           if (!fwspec || !device_iommu_mapped(&ctx->dev)) {
>>               dev_err(host1x->dev, "Context device %d has no 
>> IOMMU!\n", i);
>>               device_del(&ctx->dev);
>> +            err = -EOPNOTSUPP;
>>               goto del_devices;
>>           }
>
> One side effect of this patch would be that if IOMMU is disabled on a 
> system with context devices defined, Host1x won't work at all 
> (currently probe continues and it works though without context 
> isolation).
>
> I'm not sure if that's something anyone is likely to run into, but it 
> might be better to get rid of one of the frees instead.
>
> If you can update with that that'd be great, or I can put it onto the 
> TODO list.
I can send a v2 later.

Thanks,
Yang
>
> Thanks,
> Mikko
> .