On 11/02/2019 05:48, Kishon Vijay Abraham I wrote:
> Hi Lorenzo,
>
> On 08/02/19 5:50 PM, Lorenzo Pieralisi wrote:
>> On Thu, Dec 06, 2018 at 08:52:25PM +0800, Wen Yang wrote:
>>> kmemdup has implemented the function that kmalloc() + memcpy().
>>> We prefer to kmemdup rather than code opened implementation.
>>>
>>> This issue was detected with the help of coccinelle.
>>>
>>> Signed-off-by: Wen Yang <wen.yang99@xxxxxxxxxx>
>>> CC: Kishon Vijay Abraham I <kishon@xxxxxx>
>>> CC: Lorenzo Pieralisi <lorenzo.pieralisi@xxxxxxx>
>>> CC: Bjorn Helgaas <bhelgaas@xxxxxxxxxx>
>>> CC: Gustavo Pimentel <gustavo.pimentel@xxxxxxxxxxxx>
>>> CC: Niklas Cassel <niklas.cassel@xxxxxxxx>
>>> CC: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
>>> CC: Cyrille Pitchen <cyrille.pitchen@xxxxxxxxxxxxxxxxxx>
>>> CC: linux-pci@xxxxxxxxxxxxxxx (open list:PCI ENDPOINT SUBSYSTEM)
>>> CC: linux-kernel@xxxxxxxxxxxxxxx (open list)
>>> ---
>>> drivers/pci/endpoint/functions/pci-epf-test.c | 4 +---
>>> 1 file changed, 1 insertion(+), 3 deletions(-)
>>
>> Kishon,
>>
>> this looks OK to me, anything I am missing ?
>
> For the existing code this might seem the right thing to do but ideally the
> memcpy here should be changed to memcpy_fromio/memcpy_toio.
>
> Also later when we plan to use DMA (on the endpoint) for data transfer, we have
> to use kzalloc and dma_map_single APIs.
Are you considering to use the eDMA driver that I'm developing?
>
> So maybe the right thing would be to just fix it to use memcpy_fromio here.
>
> Thanks
> Kishon
>>
>> Lorenzo
>>
>>> diff --git a/drivers/pci/endpoint/functions/pci-epf-test.c b/drivers/pci/endpoint/functions/pci-epf-test.c
>>> index 3e86fa3c7da3..8df6c019f8a2 100644
>>> --- a/drivers/pci/endpoint/functions/pci-epf-test.c
>>> +++ b/drivers/pci/endpoint/functions/pci-epf-test.c
>>> @@ -169,14 +169,12 @@ static int pci_epf_test_read(struct pci_epf_test *epf_test)
>>> goto err_addr;
>>> }
>>>
>>> - buf = kzalloc(reg->size, GFP_KERNEL);
>>> + buf = kmemdup(src_addr, reg->size, GFP_KERNEL);
>>> if (!buf) {
>>> ret = -ENOMEM;
>>> goto err_map_addr;
>>> }
>>>
>>> - memcpy(buf, src_addr, reg->size);
>>> -
>>> crc32 = crc32_le(~0, buf, reg->size);
>>> if (crc32 != reg->checksum)
>>> ret = -EIO;
>>> --
>>> 2.19.1
>>>
