kernel/linux.git/drivers/usb/core/file.c, branch v6.6.132

USB: make usb class a const structure

2023-07-25T15:49:30+00:00

Now that the driver core allows for struct class to be in read-only memory, remove the usb_class structure and create the usbmisc_class const class structure declared at build time which places it into read-only memory, instead of having it to be dynamically allocated at load time. Additionally, now we register usb class at startup and unregister it when shutting down, so we don't have to count uses of the class. Therefore we don't need the 'usb_class' structure anymore. Due to this fact, remove all static functions related to class initialization and deinitialization. We can't use them in 'usb.c' since they are static and we don't really need them anymore. Since we have to register the class in usb_init function in 'usb.c' and use it in 'file.c' as well, declare the usbmisc_class structure as 'export' in the 'usb.h' file. Debatable moment: the class registration and unregistration functions could be extracted to the 'file.c'. I think we don't want to do this since it would be one-line functions. They would make the code paths more confusing and add calling overhead. Suggested-by: Greg Kroah-Hartman Signed-off-by: Ivan Orlov Link: https://lore.kernel.org/r/20230621202514.1223670-1-ivan.orlov0322@gmail.com Signed-off-by: Greg Kroah-Hartman

driver core: class: remove module * from class_create()

2023-03-17T14:16:33+00:00

The module pointer in class_create() never actually did anything, and it shouldn't have been requred to be set as a parameter even if it did something. So just remove it and fix up all callers of the function in the kernel tree at the same time. Cc: "Rafael J. Wysocki" Acked-by: Benjamin Tissoires Link: https://lore.kernel.org/r/20230313181843.1207845-4-gregkh@linuxfoundation.org Signed-off-by: Greg Kroah-Hartman

driver core: make struct class.devnode() take a const *

2022-11-24T16:12:27+00:00

The devnode() in struct class should not be modifying the device that is passed into it, so mark it as a const * and propagate the function signature changes out into all relevant subsystems that use this callback. Cc: Fenghua Yu Cc: Reinette Chatre Cc: Thomas Gleixner Cc: Ingo Molnar Cc: Borislav Petkov Cc: Dave Hansen Cc: x86@kernel.org Cc: "H. Peter Anvin" Cc: FUJITA Tomonori Cc: Jens Axboe Cc: Justin Sanders Cc: Arnd Bergmann Cc: Sumit Semwal Cc: Benjamin Gaignard Cc: Liam Mark Cc: Laura Abbott Cc: Brian Starkey Cc: John Stultz Cc: "Christian König" Cc: Maarten Lankhorst Cc: Maxime Ripard Cc: Thomas Zimmermann Cc: David Airlie Cc: Daniel Vetter Cc: Jason Gunthorpe Cc: Leon Romanovsky Cc: Dennis Dalessandro Cc: Dmitry Torokhov Cc: Mauro Carvalho Chehab Cc: Sean Young Cc: Frank Haverkamp Cc: Jiri Slaby Cc: "Michael S. Tsirkin" Cc: Jason Wang Cc: Alex Williamson Cc: Cornelia Huck Cc: Kees Cook Cc: Anton Vorontsov Cc: Colin Cross Cc: Tony Luck Cc: Jaroslav Kysela Cc: Takashi Iwai Cc: Hans Verkuil Cc: Christophe JAILLET Cc: Xie Yongji Cc: Gautam Dawar Cc: Dan Carpenter Cc: Eli Cohen Cc: Parav Pandit Cc: Maxime Coquelin Cc: alsa-devel@alsa-project.org Cc: dri-devel@lists.freedesktop.org Cc: kvm@vger.kernel.org Cc: linaro-mm-sig@lists.linaro.org Cc: linux-block@vger.kernel.org Cc: linux-input@vger.kernel.org Cc: linux-kernel@vger.kernel.org Cc: linux-media@vger.kernel.org Cc: linux-rdma@vger.kernel.org Cc: linux-scsi@vger.kernel.org Cc: linux-usb@vger.kernel.org Cc: virtualization@lists.linux-foundation.org Link: https://lore.kernel.org/r/20221123122523.1332370-2-gregkh@linuxfoundation.org Signed-off-by: Greg Kroah-Hartman

USB: core: Fix races in character device registration and deregistraion

2019-08-12T20:47:24+00:00

The syzbot fuzzer has found two (!) races in the USB character device registration and deregistration routines. This patch fixes the races. The first race results from the fact that usb_deregister_dev() sets usb_minors[intf->minor] to NULL before calling device_destroy() on the class device. This leaves a window during which another thread can allocate the same minor number but will encounter a duplicate name error when it tries to register its own class device. A typical error message in the system log would look like: sysfs: cannot create duplicate filename '/class/usbmisc/ldusb0' The patch fixes this race by destroying the class device first. The second race is in usb_register_dev(). When that routine runs, it first allocates a minor number, then drops minor_rwsem, and then creates the class device. If the device creation fails, the minor number is deallocated and the whole routine returns an error. But during the time while minor_rwsem was dropped, there is a window in which the minor number is allocated and so another thread can successfully open the device file. Typically this results in use-after-free errors or invalid accesses when the other thread closes its open file reference, because the kernel then tries to release resources that were already deallocated when usb_register_dev() failed. The patch fixes this race by keeping minor_rwsem locked throughout the entire routine. Reported-and-tested-by: syzbot+30cf45ebfe0b0c4847a1@syzkaller.appspotmail.com Signed-off-by: Alan Stern CC: Link: https://lore.kernel.org/r/Pine.LNX.4.44L0.1908121607590.1659-100000@iolanthe.rowland.org Signed-off-by: Greg Kroah-Hartman

USB: core: move existing SPDX tags to top of the file

2017-11-03T09:12:26+00:00

To match the rest of the kernel, the SPDX tags for the drivers/usb/core/ files are moved to the first line of the file. This makes it more obvious the tag is present as well as making it match the other 12k files in the tree with this location. It also uses // to match the "expected style" as well. Signed-off-by: Greg Kroah-Hartman

USB: Proper handling of Race Condition when two USB class drivers try to call init_usb_class simultaneously

2017-03-29T09:55:25+00:00

There is race condition when two USB class drivers try to call init_usb_class at the same time and leads to crash. code path: probe->usb_register_dev->init_usb_class To solve this, mutex locking has been added in init_usb_class() and destroy_usb_class(). As pointed by Alan, removed "if (usb_class)" test from destroy_usb_class() because usb_class can never be NULL there. Signed-off-by: Ajay Kaher Acked-by: Alan Stern Cc: stable Signed-off-by: Greg Kroah-Hartman

USB: core: add missing license information to some files

2016-10-29T16:51:56+00:00

Some of the USB core files were missing explicit license information. As all files in the kernel tree are implicitly licensed under the GPLv2-only, be explicit in case someone get confused looking at individual files by using the SPDX nomenclature. Signed-off-by: Greg Kroah-Hartman

usb: core: use kbasename() instead of open-coded variant

2016-01-25T04:37:47+00:00

kbasename() helper is dedicated to find a last part of the filename or pathname. USB core uses open-coded variant of that helper. Replace some lines of code by kbasename() call. The current users do not have trailing slash and we are on the safe side to make such change. I dig a history of the code under question up and found the patch [1] that brought it along with the same to tty layer. The check for trailing slash looks like copy'n'paste thing and I consider it as redundant. [1] http://www.kernel.org/pub/linux/kernel//people/akpm/patches/2.5/2.5.69/2.5.69-mm3/broken-out/linus.patch Signed-off-by: Andy Shevchenko Cc: Greg Kroah-Hartman Cc: Rasmus Villemoes Signed-off-by: Greg Kroah-Hartman

Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs

2013-11-13T06:34:18+00:00

Pull vfs updates from Al Viro: "All kinds of stuff this time around; some more notable parts: - RCU'd vfsmounts handling - new primitives for coredump handling - files_lock is gone - Bruce's delegations handling series - exportfs fixes plus misc stuff all over the place" * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (101 commits) ecryptfs: ->f_op is never NULL locks: break delegations on any attribute modification locks: break delegations on link locks: break delegations on rename locks: helper functions for delegation breaking locks: break delegations on unlink namei: minor vfs_unlink cleanup locks: implement delegations locks: introduce new FL_DELEG lock flag vfs: take i_mutex on renamed file vfs: rename I_MUTEX_QUOTA now that it's not used for quotas vfs: don't use PARENT/CHILD lock classes for non-directories vfs: pull ext4's double-i_mutex-locking into common code exportfs: fix quadratic behavior in filehandle lookup exportfs: better variable name exportfs: move most of reconnect_path to helper function exportfs: eliminate unused "noprogress" counter exportfs: stop retrying once we race with rename/remove exportfs: clear DISCONNECTED on all parents sooner exportfs: more detailed comment for path_reconnect ...

consolidate the reassignments of ->f_op in ->open() instances

2013-10-25T03:34:53+00:00

Signed-off-by: Al Viro