Patchwork PCI: endpoint: functions: Use kmemdup instead of duplicating its function

login
register
mail settings
Submitter Wen Yang
Date Dec. 6, 2018, 10:21 a.m.
Message ID <20181206102105.53098-1-wen.yang99@zte.com.cn>
Download mbox | patch
Permalink /patch/673915/
State New
Headers show

Comments

Wen Yang - Dec. 6, 2018, 10:21 a.m.
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: Bob Copeland <me@bobcopeland.com>

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(-)
Alan Douglas - Dec. 6, 2018, noon
Hi,

On 06 December 2018 10:21, 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: Bob Copeland <me@bobcopeland.com>

> 

> 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(-)

> 

> diff --git a/drivers/pci/endpoint/functions/pci-epf-test.c b/drivers/pci/endpoint/functions/pci-epf-test.c

> index 3e86fa3c7da3..6e42daa2a651 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 = kzalloc(src_addr, reg->size, GFP_KERNEL);

Looks like a typo - kmemdup instead of kzalloc?

>  	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


Regards,
Alan
David Laight - Dec. 11, 2018, 2:22 p.m.
From: Alan Douglas

> Sent: 06 December 2018 12:01

> Hi,

> 

> On 06 December 2018 10:21, Wen Yang wrote:

> > kmemdup has implemented the function that kmalloc() + memcpy().

> > We prefer to kmemdup rather than code opened implementation.

...
> > diff --git a/drivers/pci/endpoint/functions/pci-epf-test.c b/drivers/pci/endpoint/functions/pci-epf-

> test.c

> > index 3e86fa3c7da3..6e42daa2a651 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 = kzalloc(src_addr, reg->size, GFP_KERNEL);

> Looks like a typo - kmemdup instead of kzalloc?


Which is why making butter (churning) like this is mostly pointless.
It is very easy to make silly mistakes.

	David

-
Registered Address Lakeside, Bramley Road, Mount Farm, Milton Keynes, MK1 1PT, UK
Registration No: 1397386 (Wales)

Patch

diff --git a/drivers/pci/endpoint/functions/pci-epf-test.c b/drivers/pci/endpoint/functions/pci-epf-test.c
index 3e86fa3c7da3..6e42daa2a651 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 = kzalloc(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;