RE: [PATCH 17/30] pci: Use kmemdup rather than duplicating its implementation

[David Laight <David.Laight@ACULAB.COM>]

From: Fuqian Huang
> Sent: 03 July 2019 14:16
> 
> kmemdup is introduced to duplicate a region of memory in a neat way.
> Rather than kmalloc/kzalloc + memset, which the programmer needs to
> write the size twice (sometimes lead to mistakes), kmemdup improves
> readability, leads to smaller code and also reduce the chances of mistakes.
> Suggestion to use kmemdup rather than using kmalloc/kzalloc + memset.
> 
> Signed-off-by: Fuqian Huang <huangfq.daxian@gmail.com>
> ---
>  drivers/pci/hotplug/ibmphp_core.c | 13 ++++++-------
>  1 file changed, 6 insertions(+), 7 deletions(-)
> 
> diff --git a/drivers/pci/hotplug/ibmphp_core.c b/drivers/pci/hotplug/ibmphp_core.c
> index 17124254d897..0e340e105c3b 100644
> --- a/drivers/pci/hotplug/ibmphp_core.c
> +++ b/drivers/pci/hotplug/ibmphp_core.c
> @@ -1261,19 +1261,18 @@ static int __init ibmphp_init(void)
> 
>  	info(DRIVER_DESC " version: " DRIVER_VERSION "\n");
> 
> -	ibmphp_pci_bus = kmalloc(sizeof(*ibmphp_pci_bus), GFP_KERNEL);
> -	if (!ibmphp_pci_bus) {
> -		rc = -ENOMEM;
> -		goto exit;
> -	}
> -
>  	bus = pci_find_bus(0, 0);
>  	if (!bus) {
>  		err("Can't find the root pci bus, can not continue\n");
>  		rc = -ENODEV;
>  		goto error;
>  	}
> -	memcpy(ibmphp_pci_bus, bus, sizeof(*ibmphp_pci_bus));
> +
> +	ibmphp_pci_bus = kmemdup(bus, sizeof(*ibmphp_pci_bus), GFP_KERNEL);
> +	if (!ibmphp_pci_bus) {
> +		rc = -ENOMEM;
> +		goto exit;
> +	}

Not sure why I even looked as this...

But the error path if pci_find_bus() fails is now wrong.

	David

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