diff mbox series

[v3] usb: prevent duplicate bEndpointAddress by usb_ep_autoconfig_ss (bitmap).

Message ID 20230429144516.2848-1-wlodzimierz.lipert@gmail.com (mailing list archive)
State Superseded
Headers show
Series [v3] usb: prevent duplicate bEndpointAddress by usb_ep_autoconfig_ss (bitmap). | expand

Commit Message

Wlodzimierz Lipert April 29, 2023, 2:45 p.m. UTC
usb_ep_autoconfig_ss tries to use endpoint name or internal counters to generate
bEndpointAddress - this leads to duplicate addresses. Fix changes the
way in/out_epnum is used, now as bitmap which represents unavailable ep numbers.
Refined autoconf logic.

Signed-off-by: Wlodzimierz Lipert <wlodzimierz.lipert@gmail.com>
---
 drivers/usb/gadget/epautoconf.c | 25 ++++++++++++++++---------
 include/linux/usb/gadget.h      |  4 ++--
 2 files changed, 18 insertions(+), 11 deletions(-)

Comments

Alan Stern April 29, 2023, 3:33 p.m. UTC | #1
On Sat, Apr 29, 2023 at 04:45:16PM +0200, Wlodzimierz Lipert wrote:
> usb_ep_autoconfig_ss tries to use endpoint name or internal counters to generate
> bEndpointAddress - this leads to duplicate addresses. Fix changes the
> way in/out_epnum is used, now as bitmap which represents unavailable ep numbers.
> Refined autoconf logic.
> 
> Signed-off-by: Wlodzimierz Lipert <wlodzimierz.lipert@gmail.com>
> ---

You didn't describe here the difference from the previous version.

>  drivers/usb/gadget/epautoconf.c | 25 ++++++++++++++++---------
>  include/linux/usb/gadget.h      |  4 ++--
>  2 files changed, 18 insertions(+), 11 deletions(-)
> 
> diff --git a/drivers/usb/gadget/epautoconf.c b/drivers/usb/gadget/epautoconf.c
> index 1eb4fa2e623f..74430807b803 100644
> --- a/drivers/usb/gadget/epautoconf.c
> +++ b/drivers/usb/gadget/epautoconf.c
> @@ -67,6 +67,8 @@ struct usb_ep *usb_ep_autoconfig_ss(
>  )
>  {
>  	struct usb_ep	*ep;
> +	unsigned *epmap;
> +	u8 num;

Please copy the indentation style of the surrounding code.

>  
>  	if (gadget->ops->match_ep) {
>  		ep = gadget->ops->match_ep(gadget, desc, ep_comp);
> @@ -93,19 +95,23 @@ struct usb_ep *usb_ep_autoconfig_ss(
>  
>  	/* report address */
>  	desc->bEndpointAddress &= USB_DIR_IN;
> +	epmap = usb_endpoint_dir_in(desc) ?
> +		&gadget->in_epnum : &gadget->out_epnum;

A continuation line should be indented by something other than one tab 
stop, to make it look different from a nested statement.

Other than these minor stylistic issues, the patch looks fine.

Acked-by: Alan Stern <stern@rowland.harvard.edu>

Alan Stern

> +
>  	if (isdigit(ep->name[2])) {
> -		u8 num = simple_strtoul(&ep->name[2], NULL, 10);
> -		desc->bEndpointAddress |= num;
> -	} else if (desc->bEndpointAddress & USB_DIR_IN) {
> -		if (++gadget->in_epnum > 15)
> +		num = simple_strtoul(&ep->name[2], NULL, 10);
> +		WARN_ON(num == 0 || num > 15);
> +		if (*epmap & (1U << num))
>  			return NULL;
> -		desc->bEndpointAddress = USB_DIR_IN | gadget->in_epnum;
>  	} else {
> -		if (++gadget->out_epnum > 15)
> +		/* find first available ep number (not encoded in ep name) */
> +		num = ffz(*epmap);
> +		if (num > 15)
>  			return NULL;
> -		desc->bEndpointAddress |= gadget->out_epnum;
>  	}
>  
> +	*epmap |= 1U << num;
> +	desc->bEndpointAddress |= num;
>  	ep->address = desc->bEndpointAddress;
>  	ep->desc = NULL;
>  	ep->comp_desc = NULL;
> @@ -208,7 +214,8 @@ void usb_ep_autoconfig_reset (struct usb_gadget *gadget)
>  		ep->claimed = false;
>  		ep->driver_data = NULL;
>  	}
> -	gadget->in_epnum = 0;
> -	gadget->out_epnum = 0;
> +	/* ep num 0 is reserved: not available for auto configuration */
> +	gadget->in_epnum = 1U;
> +	gadget->out_epnum = 1U;
>  }
>  EXPORT_SYMBOL_GPL(usb_ep_autoconfig_reset);
> diff --git a/include/linux/usb/gadget.h b/include/linux/usb/gadget.h
> index 6a178177e4c9..1e00e22202bc 100644
> --- a/include/linux/usb/gadget.h
> +++ b/include/linux/usb/gadget.h
> @@ -343,8 +343,8 @@ struct usb_gadget_ops {
>   *	and sometimes configuration.
>   * @dev: Driver model state for this abstract device.
>   * @isoch_delay: value from Set Isoch Delay request. Only valid on SS/SSP
> - * @out_epnum: last used out ep number
> - * @in_epnum: last used in ep number
> + * @out_epnum: bitmap of allocated out ep numbers
> + * @in_epnum: bitmap of allocated in ep numbers
>   * @mA: last set mA value
>   * @otg_caps: OTG capabilities of this gadget.
>   * @sg_supported: true if we can handle scatter-gather
> -- 
> 2.39.2
>
diff mbox series

Patch

diff --git a/drivers/usb/gadget/epautoconf.c b/drivers/usb/gadget/epautoconf.c
index 1eb4fa2e623f..74430807b803 100644
--- a/drivers/usb/gadget/epautoconf.c
+++ b/drivers/usb/gadget/epautoconf.c
@@ -67,6 +67,8 @@  struct usb_ep *usb_ep_autoconfig_ss(
 )
 {
 	struct usb_ep	*ep;
+	unsigned *epmap;
+	u8 num;
 
 	if (gadget->ops->match_ep) {
 		ep = gadget->ops->match_ep(gadget, desc, ep_comp);
@@ -93,19 +95,23 @@  struct usb_ep *usb_ep_autoconfig_ss(
 
 	/* report address */
 	desc->bEndpointAddress &= USB_DIR_IN;
+	epmap = usb_endpoint_dir_in(desc) ?
+		&gadget->in_epnum : &gadget->out_epnum;
+
 	if (isdigit(ep->name[2])) {
-		u8 num = simple_strtoul(&ep->name[2], NULL, 10);
-		desc->bEndpointAddress |= num;
-	} else if (desc->bEndpointAddress & USB_DIR_IN) {
-		if (++gadget->in_epnum > 15)
+		num = simple_strtoul(&ep->name[2], NULL, 10);
+		WARN_ON(num == 0 || num > 15);
+		if (*epmap & (1U << num))
 			return NULL;
-		desc->bEndpointAddress = USB_DIR_IN | gadget->in_epnum;
 	} else {
-		if (++gadget->out_epnum > 15)
+		/* find first available ep number (not encoded in ep name) */
+		num = ffz(*epmap);
+		if (num > 15)
 			return NULL;
-		desc->bEndpointAddress |= gadget->out_epnum;
 	}
 
+	*epmap |= 1U << num;
+	desc->bEndpointAddress |= num;
 	ep->address = desc->bEndpointAddress;
 	ep->desc = NULL;
 	ep->comp_desc = NULL;
@@ -208,7 +214,8 @@  void usb_ep_autoconfig_reset (struct usb_gadget *gadget)
 		ep->claimed = false;
 		ep->driver_data = NULL;
 	}
-	gadget->in_epnum = 0;
-	gadget->out_epnum = 0;
+	/* ep num 0 is reserved: not available for auto configuration */
+	gadget->in_epnum = 1U;
+	gadget->out_epnum = 1U;
 }
 EXPORT_SYMBOL_GPL(usb_ep_autoconfig_reset);
diff --git a/include/linux/usb/gadget.h b/include/linux/usb/gadget.h
index 6a178177e4c9..1e00e22202bc 100644
--- a/include/linux/usb/gadget.h
+++ b/include/linux/usb/gadget.h
@@ -343,8 +343,8 @@  struct usb_gadget_ops {
  *	and sometimes configuration.
  * @dev: Driver model state for this abstract device.
  * @isoch_delay: value from Set Isoch Delay request. Only valid on SS/SSP
- * @out_epnum: last used out ep number
- * @in_epnum: last used in ep number
+ * @out_epnum: bitmap of allocated out ep numbers
+ * @in_epnum: bitmap of allocated in ep numbers
  * @mA: last set mA value
  * @otg_caps: OTG capabilities of this gadget.
  * @sg_supported: true if we can handle scatter-gather