Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]


Groups > linux.kernel > #1325388

[PATCH v4 05/43] usb: gadget: composite: fix recursive spinlock locking

From Robert Baldyga <r.baldyga@samsung.com>
Newsgroups linux.kernel
Subject [PATCH v4 05/43] usb: gadget: composite: fix recursive spinlock locking
Date 2016-02-03 14:00 +0100
Message-ID <qY5co-24p-37@gated-at.bofh.it> (permalink)
References <qY52F-212-5@gated-at.bofh.it>
Organization linux.* mail to news gateway

Show all headers | View raw


Avoid recursive spinlock locking, which could occur during
usb_gadget_deactivate() call. At it's execution path it could call
composite_disconnect() function which locks cdev->lock, previously
locked in usb_function_deactivate() to protect deactivation counter.

To fix this we introduce additional spinlock protecting deactivation
counter.

Signed-off-by: Robert Baldyga <r.baldyga@samsung.com>
---
 drivers/usb/gadget/composite.c | 9 +++++----
 include/linux/usb/composite.h  | 1 +
 2 files changed, 6 insertions(+), 4 deletions(-)

diff --git a/drivers/usb/gadget/composite.c b/drivers/usb/gadget/composite.c
index 8b14c2a..65abc24 100644
--- a/drivers/usb/gadget/composite.c
+++ b/drivers/usb/gadget/composite.c
@@ -283,14 +283,14 @@ int usb_function_deactivate(struct usb_function *function)
 	unsigned long			flags;
 	int				status = 0;
 
-	spin_lock_irqsave(&cdev->lock, flags);
+	spin_lock_irqsave(&cdev->deactivation_lock, flags);
 
 	if (cdev->deactivations == 0)
 		status = usb_gadget_deactivate(cdev->gadget);
 	if (status == 0)
 		cdev->deactivations++;
 
-	spin_unlock_irqrestore(&cdev->lock, flags);
+	spin_unlock_irqrestore(&cdev->deactivation_lock, flags);
 	return status;
 }
 EXPORT_SYMBOL_GPL(usb_function_deactivate);
@@ -311,7 +311,7 @@ int usb_function_activate(struct usb_function *function)
 	unsigned long			flags;
 	int				status = 0;
 
-	spin_lock_irqsave(&cdev->lock, flags);
+	spin_lock_irqsave(&cdev->deactivation_lock, flags);
 
 	if (WARN_ON(cdev->deactivations == 0))
 		status = -EINVAL;
@@ -321,7 +321,7 @@ int usb_function_activate(struct usb_function *function)
 			status = usb_gadget_activate(cdev->gadget);
 	}
 
-	spin_unlock_irqrestore(&cdev->lock, flags);
+	spin_unlock_irqrestore(&cdev->deactivation_lock, flags);
 	return status;
 }
 EXPORT_SYMBOL_GPL(usb_function_activate);
@@ -2072,6 +2072,7 @@ static int composite_bind(struct usb_gadget *gadget,
 		return status;
 
 	spin_lock_init(&cdev->lock);
+	spin_lock_init(&cdev->deactivation_lock);
 	cdev->gadget = gadget;
 	set_gadget_data(gadget, cdev);
 	INIT_LIST_HEAD(&cdev->configs);
diff --git a/include/linux/usb/composite.h b/include/linux/usb/composite.h
index 1074b89..9911c29 100644
--- a/include/linux/usb/composite.h
+++ b/include/linux/usb/composite.h
@@ -487,6 +487,7 @@ struct usb_composite_dev {
 	 * while the deactivation count is nonzero.
 	 */
 	unsigned			deactivations;
+	spinlock_t			deactivation_lock;
 
 	/* the composite driver won't complete the control transfer's
 	 * data/status stages till delayed_status is zero.
-- 
1.9.1

Back to linux.kernel | Previous | NextPrevious in thread | Next in thread | Find similar | Unroll thread


Thread

[PATCH v4 00/43] usb: gadget: composite: introduce new function API Robert Baldyga <r.baldyga@samsung.com> - 2016-02-03 13:50 +0100
  [PATCH v4 10/43] usb: gadget: composite: handle vendor descs Robert Baldyga <r.baldyga@samsung.com> - 2016-02-03 13:50 +0100
  [PATCH v4 16/43] usb: gadget: composite: add usb_function_get_ep()  function Robert Baldyga <r.baldyga@samsung.com> - 2016-02-03 13:50 +0100
  [PATCH v4 24/43] usb: gadget: f_rndis: conversion to new API Robert Baldyga <r.baldyga@samsung.com> - 2016-02-03 13:50 +0100
  [PATCH v4 18/43] usb: gadget: composite: usb_get_endpoint_address()  function Robert Baldyga <r.baldyga@samsung.com> - 2016-02-03 13:50 +0100
  [PATCH v4 06/43] usb: gadget: composite: introduce new descriptors  format Robert Baldyga <r.baldyga@samsung.com> - 2016-02-03 13:50 +0100
    Re: [PATCH v4 06/43] usb: gadget: composite: introduce new  descriptors format kbuild test robot <lkp@intel.com> - 2016-02-04 06:20 +0100
  [PATCH v4 15/43] usb: gadget: composite: handle get_alt() automatically Robert Baldyga <r.baldyga@samsung.com> - 2016-02-03 13:50 +0100
  [PATCH v4 04/43] usb: gadget: configfs: fix error path Robert Baldyga <r.baldyga@samsung.com> - 2016-02-03 13:50 +0100
  [PATCH v4 37/43] usb: gadget: f_mass_storage: conversion to new API Robert Baldyga <r.baldyga@samsung.com> - 2016-02-03 13:50 +0100
  [PATCH v4 23/43] usb: gadget: f_ecm: conversion to new API Robert Baldyga <r.baldyga@samsung.com> - 2016-02-03 13:50 +0100
  [PATCH v4 02/43] usb: gadget: f_sourcesink: free requests in  sourcesink_disable() Robert Baldyga <r.baldyga@samsung.com> - 2016-02-03 13:50 +0100
  [PATCH v4 13/43] usb: gadget: composite: enable eps before calling  set_alt() callback Robert Baldyga <r.baldyga@samsung.com> - 2016-02-03 13:50 +0100
  [PATCH v4 32/43] usb: gadget: f_obex: conversion to new API Robert Baldyga <r.baldyga@samsung.com> - 2016-02-03 13:50 +0100
  [PATCH v4 20/43] usb: gadget: configfs: add new composite API support Robert Baldyga <r.baldyga@samsung.com> - 2016-02-03 13:50 +0100
  [PATCH v4 27/43] usb: gadget: f_acm: conversion to new API Robert Baldyga <r.baldyga@samsung.com> - 2016-02-03 13:50 +0100
  [PATCH v4 26/43] usb: gadget: f_hid: conversion to new API Robert Baldyga <r.baldyga@samsung.com> - 2016-02-03 13:50 +0100
  [PATCH v4 30/43] usb: gadget: f_printer: conversion to new API Robert Baldyga <r.baldyga@samsung.com> - 2016-02-03 13:50 +0100
  [PATCH v4 08/43] usb: gadget: composite: introduce new USB function ops Robert Baldyga <r.baldyga@samsung.com> - 2016-02-03 13:50 +0100
  [PATCH v4 35/43] usb: gadget: f_uac1: conversion to new API Robert Baldyga <r.baldyga@samsung.com> - 2016-02-03 13:50 +0100
  [PATCH v4 31/43] usb: gadget: f_serial: conversion to new API Robert Baldyga <r.baldyga@samsung.com> - 2016-02-03 13:50 +0100
  [PATCH v4 42/43] Documentation: update uvc configfs interface  description Robert Baldyga <r.baldyga@samsung.com> - 2016-02-03 13:50 +0100
  [PATCH v4 43/43] usb: gadget: f_uvc: conversion to new API Robert Baldyga <r.baldyga@samsung.com> - 2016-02-03 13:50 +0100
  [PATCH v4 25/43] usb: gadget: f_hid: handle requests lifetime properly Robert Baldyga <r.baldyga@samsung.com> - 2016-02-03 13:50 +0100
  [PATCH v4 03/43] usb: gadget: f_loopback: free requests in  loopback_disable() Robert Baldyga <r.baldyga@samsung.com> - 2016-02-03 13:50 +0100
  [PATCH v4 38/43] usb: gadget: u_serial: remove  usb_ep_enable()/usb_ep_disable() Robert Baldyga <r.baldyga@samsung.com> - 2016-02-03 13:50 +0100
  [PATCH v4 34/43] usb: gadget: f_subset: conversion to new API Robert Baldyga <r.baldyga@samsung.com> - 2016-02-03 13:50 +0100
  [PATCH v4 29/43] usb: gadget: f_ncm: conversion to new API Robert Baldyga <r.baldyga@samsung.com> - 2016-02-03 13:50 +0100
  [PATCH v4 22/43] usb: gadget: f_sourcesink: convert to new API Robert Baldyga <r.baldyga@samsung.com> - 2016-02-03 13:50 +0100
  [PATCH v4 39/43] usb: gadget: u_ether: remove  usb_ep_enable()/usb_ep_disable() Robert Baldyga <r.baldyga@samsung.com> - 2016-02-03 13:50 +0100
  [PATCH v4 40/43] usb: gadget: uvc: fix typo in UVCG_OPTS_ATTR() macro Robert Baldyga <r.baldyga@samsung.com> - 2016-02-03 13:50 +0100
  [PATCH v4 36/43] usb: gadget: f_uac2: conversion to new API Robert Baldyga <r.baldyga@samsung.com> - 2016-02-03 13:50 +0100
  [PATCH v4 41/43] usb: gadget: uvc: simplify descriptors generation Robert Baldyga <r.baldyga@samsung.com> - 2016-02-03 13:50 +0100
  [PATCH v4 09/43] usb: gadget: composite: handle function bind Robert Baldyga <r.baldyga@samsung.com> - 2016-02-03 14:00 +0100
    Re: [PATCH v4 09/43] usb: gadget: composite: handle function bind kbuild test robot <lkp@intel.com> - 2016-02-04 06:50 +0100
  [PATCH v4 01/43] usb: gadget: f_sourcesink: make ISO altset  user-selectable Robert Baldyga <r.baldyga@samsung.com> - 2016-02-03 14:00 +0100
  [PATCH v4 12/43] usb: gadget: composite: disable eps before calling  disable() callback Robert Baldyga <r.baldyga@samsung.com> - 2016-02-03 14:00 +0100
  [PATCH v4 17/43] usb: gadget: composite: add usb_get_interface_id()  function Robert Baldyga <r.baldyga@samsung.com> - 2016-02-03 14:00 +0100
  [PATCH v4 19/43] usb: gadget: composite: enable adding USB functions  using new API Robert Baldyga <r.baldyga@samsung.com> - 2016-02-03 14:00 +0100
  [PATCH v4 05/43] usb: gadget: composite: fix recursive spinlock locking Robert Baldyga <r.baldyga@samsung.com> - 2016-02-03 14:00 +0100
  [PATCH v4 21/43] usb: gadget: f_loopback: convert to new API Robert Baldyga <r.baldyga@samsung.com> - 2016-02-03 14:00 +0100
  [PATCH v4 14/43] usb: gadget: composite: introduce clear_alt()  operation Robert Baldyga <r.baldyga@samsung.com> - 2016-02-03 14:00 +0100
  [PATCH v4 11/43] usb: gadget: composite: generate old descs for  compatibility Robert Baldyga <r.baldyga@samsung.com> - 2016-02-03 14:00 +0100
  [PATCH v4 07/43] usb: gadget: composite: add functions for descriptors  handling Robert Baldyga <r.baldyga@samsung.com> - 2016-02-03 14:00 +0100

csiph-web