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SubjectRe: [PATCH v2] PCI: endpoint: functions: Use kmemdup instead of duplicating its function
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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@zte.com.cn>
>> CC: Kishon Vijay Abraham I <kishon@ti.com>
>> CC: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
>> CC: Bjorn Helgaas <bhelgaas@google.com>
>> CC: Gustavo Pimentel <gustavo.pimentel@synopsys.com>
>> CC: Niklas Cassel <niklas.cassel@axis.com>
>> CC: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
>> CC: Cyrille Pitchen <cyrille.pitchen@free-electrons.com>
>> CC: linux-pci@vger.kernel.org (open list:PCI ENDPOINT SUBSYSTEM)
>> CC: linux-kernel@vger.kernel.org (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.

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
>>

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