Re: [PATCH v2] usbip: dynamically allocate idev by nports found in sysfs

[Shuah Khan]

On 05/22/2018 11:04 AM, Michael Grzeschik wrote:
> As the amount of available ports varies by the kernels build
> configuration. To remove the limitation of the fixed 128 ports
> we allocate the amount of idevs by using the number we get
> from the kernel.
> 
> Signed-off-by: Michael Grzeschik <m.grzeschik@xxxxxxxxxxxxxx>
> ---
> v1 -> v2: - reworked memory allocation into one calloc call
>           - added error path on allocation failure
> 
>  tools/usb/usbip/libsrc/vhci_driver.c | 14 +++++++++-----
>  tools/usb/usbip/libsrc/vhci_driver.h |  3 +--
>  2 files changed, 10 insertions(+), 7 deletions(-)
> 
> diff --git a/tools/usb/usbip/libsrc/vhci_driver.c b/tools/usb/usbip/libsrc/vhci_driver.c
> index c9c81614a66ad..6e2a9edfd1f0d 100644
> --- a/tools/usb/usbip/libsrc/vhci_driver.c
> +++ b/tools/usb/usbip/libsrc/vhci_driver.c
> @@ -242,13 +242,20 @@ static int read_record(int rhport, char *host, unsigned long host_len,
>  
>  int usbip_vhci_driver_open(void)
>  {
> +	int nports = get_nports();
> 

I missed this error leg in my previous comments. get_nports() could return
errorwhich is -1.

>  	udev_context = udev_new();
>  	if (!udev_context) {
>  		err("udev_new failed");
>  		return -1;
>  	}
>  
> -	vhci_driver = calloc(1, sizeof(struct usbip_vhci_driver));
> +	vhci_driver = calloc(1, sizeof(struct usbip_vhci_driver) +
> +			nports * sizeof(struct usbip_imported_device));

nports could be -1 at this point.

> +	if (!vhci_driver) {
> +		err("vhci_driver allocation failed");
> +		return -1;
> +	}
>  
>  	/* will be freed in usbip_driver_close() */
>  	vhci_driver->hc_device =
> @@ -260,15 +267,12 @@ int usbip_vhci_driver_open(void)
>  		goto err;
>  	}
>  
> -	vhci_driver->nports = get_nports();
> +	vhci_driver->nports = nports;
>  	dbg("available ports: %d", vhci_driver->nports);
>  
>  	if (vhci_driver->nports <= 0) {
>  		err("no available ports");
>  		goto err;
This check should move up along with the get_nports() call.

> -	} else if (vhci_driver->nports > MAXNPORT) {
> -		err("port number exceeds %d", MAXNPORT);
> -		goto err;
>  	}
>  
>  	vhci_driver->ncontrollers = get_ncontrollers();
> diff --git a/tools/usb/usbip/libsrc/vhci_driver.h b/tools/usb/usbip/libsrc/vhci_driver.h
> index 418b404d51210..6c9aca2167051 100644
> --- a/tools/usb/usbip/libsrc/vhci_driver.h
> +++ b/tools/usb/usbip/libsrc/vhci_driver.h
> @@ -13,7 +13,6 @@
>  
>  #define USBIP_VHCI_BUS_TYPE "platform"
>  #define USBIP_VHCI_DEVICE_NAME "vhci_hcd.0"
> -#define MAXNPORT 128
>  
>  enum hub_speed {
>  	HUB_SPEED_HIGH = 0,
> @@ -41,7 +40,7 @@ struct usbip_vhci_driver {
>  
>  	int ncontrollers;
>  	int nports;
> -	struct usbip_imported_device idev[MAXNPORT];
> +	struct usbip_imported_device idev[];
>  };
>  
>  
> 

thanks,
-- Shuah