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path: root/drivers/base/devcoredump.c
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2023-11-28devcoredump: Send uevent once devcd is readyMukesh Ojha1-0/+3
dev_coredumpm() creates a devcoredump device and adds it to the core kernel framework which eventually end up sending uevent to the user space and later creates a symbolic link to the failed device. An application running in userspace may be interested in this symbolic link to get the name of the failed device. In a issue scenario, once uevent sent to the user space it start reading '/sys/class/devcoredump/devcdX/failing_device' to get the actual name of the device which might not been created and it is in its path of creation. To fix this, suppress sending uevent till the failing device symbolic link gets created and send uevent once symbolic link is created successfully. Fixes: 833c95456a70 ("device coredump: add new device coredump class") Signed-off-by: Mukesh Ojha <quic_mojha@quicinc.com> Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/1700232572-25823-1-git-send-email-quic_mojha@quicinc.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-03-29driver core: class: mark the struct class for sysfs callbacks as constantGreg Kroah-Hartman1-2/+2
struct class should never be modified in a sysfs callback as there is nothing in the structure to modify, and frankly, the structure is almost never used in a sysfs callback, so mark it as constant to allow struct class to be moved to read-only memory. While we are touching all class sysfs callbacks also mark the attribute as constant as it can not be modified. The bonding code still uses this structure so it can not be removed from the function callbacks. Cc: "David S. Miller" <davem@davemloft.net> Cc: "Rafael J. Wysocki" <rafael@kernel.org> Cc: Bartosz Golaszewski <brgl@bgdev.pl> Cc: Eric Dumazet <edumazet@google.com> Cc: Jakub Kicinski <kuba@kernel.org> Cc: Jens Axboe <axboe@kernel.dk> Cc: Johannes Berg <johannes@sipsolutions.net> Cc: Linus Walleij <linus.walleij@linaro.org> Cc: Minchan Kim <minchan@kernel.org> Cc: Miquel Raynal <miquel.raynal@bootlin.com> Cc: Namjae Jeon <linkinjeon@kernel.org> Cc: Paolo Abeni <pabeni@redhat.com> Cc: Russ Weight <russell.h.weight@intel.com> Cc: Sergey Senozhatsky <senozhatsky@chromium.org> Cc: Steve French <sfrench@samba.org> Cc: Vignesh Raghavendra <vigneshr@ti.com> Cc: linux-cifs@vger.kernel.org Cc: linux-gpio@vger.kernel.org Cc: linux-mtd@lists.infradead.org Cc: linux-rdma@vger.kernel.org Cc: linux-s390@vger.kernel.org Cc: linuxppc-dev@lists.ozlabs.org Cc: netdev@vger.kernel.org Reviewed-by: Luis Chamberlain <mcgrof@kernel.org> Link: https://lore.kernel.org/r/20230325084537.3622280-1-gregkh@linuxfoundation.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-03-17drivers: remove struct module * setting from struct classGreg Kroah-Hartman1-1/+0
There is no need to manually set the owner of a struct class, as the registering function does it automatically, so remove all of the explicit settings from various drivers that did so as it is unneeded. This allows us to remove this pointer entirely from this structure going forward. Cc: "Rafael J. Wysocki" <rafael@kernel.org> Link: https://lore.kernel.org/r/20230313181843.1207845-2-gregkh@linuxfoundation.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-09-24devcoredump : Serialize devcd_del workMukesh Ojha1-2/+81
In following scenario(diagram), when one thread X running dev_coredumpm() adds devcd device to the framework which sends uevent notification to userspace and another thread Y reads this uevent and call to devcd_data_write() which eventually try to delete the queued timer that is not initialized/queued yet. So, debug object reports some warning and in the meantime, timer is initialized and queued from X path. and from Y path, it gets reinitialized again and timer->entry.pprev=NULL and try_to_grab_pending() stucks. To fix this, introduce mutex and a boolean flag to serialize the behaviour. cpu0(X) cpu1(Y) dev_coredump() uevent sent to user space device_add() ======================> user space process Y reads the uevents writes to devcd fd which results into writes to devcd_data_write() mod_delayed_work() try_to_grab_pending() del_timer() debug_assert_init() INIT_DELAYED_WORK() schedule_delayed_work() debug_object_fixup() timer_fixup_assert_init() timer_setup() do_init_timer() /* Above call reinitializes the timer to timer->entry.pprev=NULL and this will be checked later in timer_pending() call. */ timer_pending() !hlist_unhashed_lockless(&timer->entry) !h->pprev /* del_timer() checks h->pprev and finds it to be NULL due to which try_to_grab_pending() stucks. */ Link: https://lore.kernel.org/lkml/2e1f81e2-428c-f11f-ce92-eb11048cb271@quicinc.com/ Signed-off-by: Mukesh Ojha <quic_mojha@quicinc.com> Link: https://lore.kernel.org/r/1663073424-13663-1-git-send-email-quic_mojha@quicinc.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-06-04devcoredump: remove contact informationJohannes Berg1-4/+0
That email address hasn't existed for a long time, and the mailing address is pretty useless; remove all of this. Signed-off-by: Johannes Berg <johannes.berg@intel.com> Link: https://lore.kernel.org/r/20210528100314.d419f6e8e2d2.Ica8076036c755d6f782becd62d04c41361323130@changeid Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-04-02devcoredump: fix kernel-doc warningPierre-Louis Bossart1-2/+2
remove make W=1 warnings drivers/base/devcoredump.c:208: warning: Function parameter or member 'data' not described in 'devcd_free_sgtable' drivers/base/devcoredump.c:208: warning: Excess function parameter 'table' description in 'devcd_free_sgtable' drivers/base/devcoredump.c:225: warning: expecting prototype for devcd_read_from_table(). Prototype was for devcd_read_from_sgtable() instead Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com> Link: https://lore.kernel.org/r/20210331232614.304591-8-pierre-louis.bossart@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-03-23devcoredump: avoid -Wempty-body warningsArnd Bergmann1-6/+9
Cleaning out the last -Wempty-body warnings found some interesting cases with empty macros, along with harmless warnings like this one: drivers/base/devcoredump.c: In function 'dev_coredumpm': drivers/base/devcoredump.c:297:56: error: suggest braces around empty body in an 'if' statement [-Werror=empty-body] 297 | /* nothing - symlink will be missing */; | ^ drivers/base/devcoredump.c:301:56: error: suggest braces around empty body in an 'if' statement [-Werror=empty-body] 301 | /* nothing - symlink will be missing */; | ^ Randy tried addressing this one before, and there were multiple other ideas in that thread. Add a runtime warning and code comment here. Link: https://lore.kernel.org/lkml/20200418184111.13401-8-rdunlap@infradead.org/ Cc: Randy Dunlap <rdunlap@infradead.org> Cc: Matthew Wilcox <willy@infradead.org> Signed-off-by: Arnd Bergmann <arnd@arndb.de> Link: https://lore.kernel.org/r/20210322114258.3420937-1-arnd@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-10-02drivers core: Miscellaneous changes for sysfs_emitJoe Perches1-1/+1
Change additional instances that could use sysfs_emit and sysfs_emit_at that the coccinelle script could not convert. o macros creating show functions with ## concatenation o unbound sprintf uses with buf+len for start of output to sysfs_emit_at o returns with ?: tests and sprintf to sysfs_emit o sysfs output with struct class * not struct device * arguments Miscellanea: o remove unnecessary initializations around these changes o consistently use int len for return length of show functions o use octal permissions and not S_<FOO> o rename a few show function names so DEVICE_ATTR_<FOO> can be used o use DEVICE_ATTR_ADMIN_RO where appropriate o consistently use const char *output for strings o checkpatch/style neatening Signed-off-by: Joe Perches <joe@perches.com> Link: https://lore.kernel.org/r/8bc24444fe2049a9b2de6127389b57edfdfe324d.1600285923.git.joe@perches.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-08-15devcoredump: fix typo in commentAkinobu Mita1-1/+1
s/dev_coredumpmsg/dev_coredumpsg/ in the kernel-doc Reviewed-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com> Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com> Link: https://lore.kernel.org/r/1564243146-5681-3-git-send-email-akinobu.mita@gmail.com Signed-off-by: Johannes Berg <johannes.berg@intel.com> Link: https://lore.kernel.org/r/20190731100007.32684-2-johannes@sipsolutions.net Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-08-15devcoredump: use memory_read_from_bufferAkinobu Mita1-10/+1
Use memory_read_from_buffer() to simplify devcd_readv(). Reviewed-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com> Reviewed-by: Johannes Berg <johannes@sipsolutions.net> Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com> Link: https://lore.kernel.org/r/1564243146-5681-2-git-send-email-akinobu.mita@gmail.com Signed-off-by: Johannes Berg <johannes.berg@intel.com> Link: https://lore.kernel.org/r/20190731100007.32684-1-johannes@sipsolutions.net Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-12-07driver core: Remove redundant license textGreg Kroah-Hartman1-16/+0
Now that the SPDX tag is in all driver core files, that identifies the license in a specific and legally-defined manner. So the extra GPL text wording can be removed as it is no longer needed at all. This is done on a quest to remove the 700+ different ways that files in the kernel describe the GPL license text. And there's unneeded stuff like the address (sometimes incorrect) for the FSF which is never needed. No copyright headers or other non-license-description text was removed. Cc: Johannes Berg <johannes@sipsolutions.net> Cc: "Luis R. Rodriguez" <mcgrof@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-12-07driver core: add SPDX identifiers to all driver core filesGreg Kroah-Hartman1-0/+1
It's good to have SPDX identifiers in all files to make it easier to audit the kernel tree for correct licenses. Update the driver core files files with the correct SPDX license identifier based on the license text in the file itself. The SPDX identifier is a legally binding shorthand, which can be used instead of the full boiler plate text. This work is based on a script and data from Thomas Gleixner, Philippe Ombredanne, and Kate Stewart. Cc: Johannes Berg <johannes@sipsolutions.net> Cc: "Luis R. Rodriguez" <mcgrof@kernel.org> Cc: William Breathitt Gray <vilhelm.gray@gmail.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Kate Stewart <kstewart@linuxfoundation.org> Cc: Philippe Ombredanne <pombredanne@nexb.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-11-29driver core: devcoredump: convert to use class_groupsGreg Kroah-Hartman1-4/+6
Convert devcoredump to use class_groups instead of class_attrs as that's the correct way to handle lists of class attribute files. Acked-by: Johannes Berg <johannes@sipsolutions.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-04-15devcoredump: add scatterlist supportAviya Erenfeld1-9/+74
Add scatterlist support (dev_coredumpsg) to allow drivers to avoid vmalloc() like dev_coredumpm(), while also avoiding the module reference that the latter function requires. This internally uses dev_coredumpm() with function inside the devcoredump module, requiring removing the const (which touches the driver using it.) Signed-off-by: Aviya Erenfeld <aviya.erenfeld@intel.com> Signed-off-by: Johannes Berg <johannes.berg@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-11-26devcoredump: provide a one-way disable functionJohannes Berg1-8/+48
Since device/firmware coredumps can contain private data, it can be desirable to turn them off unconditionally to be certain that no such data will be collected by the system. To achieve this, provide a "disabled" sysfs class attribute that can only be changed from 0 to 1 and not back. Upon disabling, discard existing coredumps and stop storing new ones. Signed-off-by: Johannes Berg <johannes.berg@intel.com> Reviewed-by: Kees Cook <keescook@chromium.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-09-23device coredump: add new device coredump classJohannes Berg1-0/+265
Many devices run firmware and/or complex hardware, and most of that can have bugs. When it misbehaves, however, it is often much harder to debug than software running on the host. Introduce a "device coredump" mechanism to allow dumping internal device/firmware state through a generalized mechanism. As devices are different and information needed can vary accordingly, this doesn't prescribe a file format - it just provides mechanism to get data to be able to capture it in a generalized way (e.g. in distributions.) The dumped data will be readable in sysfs in the virtual device's data file under /sys/class/devcoredump/devcd*/. Writing to it will free the data and remove the device, as does a 5-minute timeout. Note that generalized capturing of such data may result in privacy issues, so users generally need to be involved. In order to allow certain users/system integrators/... to disable the feature at all, introduce a Kconfig option to override the drivers that would like to have the feature. For now, this provides two ways of dumping data: 1) with a vmalloc'ed area, that is then given to the subsystem and freed after retrieval or timeout 2) with a generalized reader/free function method We could/should add more options, e.g. a list of pages, since the vmalloc area is very limited on some architectures. Signed-off-by: Johannes Berg <johannes.berg@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>