linux-toradex.git/drivers/base/devcoredump.c, branch v6.16-rc1

treewide: Switch/rename to timer_delete[_sync]()

2025-04-05T08:30:12+00:00

timer_delete[_sync]() replaces del_timer[_sync](). Convert the whole tree
over and remove the historical wrapper inlines.

Conversion was done with coccinelle plus manual fixups where necessary.

Signed-off-by: Thomas Gleixner 
Signed-off-by: Ingo Molnar

devcoredump: Constify 'struct bin_attribute'

2025-01-15T17:30:58+00:00

The sysfs core now allows instances of 'struct bin_attribute' to be
moved into read-only memory. Make use of that to protect them against
accidental or malicious modifications.

Signed-off-by: Thomas Weißschuh 
Link: https://lore.kernel.org/r/20250114-sysfs-const-bin_attr-devcoredump-v1-2-fa93be30efae@weissschuh.net
Signed-off-by: Greg Kroah-Hartman

devcoredump: Define 'struct bin_attribute' through macro

2025-01-15T17:30:57+00:00

The macro saves some lines of code and simplifies the constification of
the attribute.

Signed-off-by: Thomas Weißschuh 
Link: https://lore.kernel.org/r/20250114-sysfs-const-bin_attr-devcoredump-v1-1-fa93be30efae@weissschuh.net
Signed-off-by: Greg Kroah-Hartman

devcoredump: cleanup some comments

2025-01-10T09:15:08+00:00

Correct a spello, remove an extra space between words, and fix
one kernel-doc warning:

drivers/base/devcoredump.c:292: warning: No description found for return value of 'devcd_read_from_sgtable'

Fixes: 522566376a3f ("devcoredump: add scatterlist support")
Fixes: 01daccf74832 ("devcoredump : Serialize devcd_del work")
Signed-off-by: Randy Dunlap 
Cc: Johannes Berg 
Cc: Greg Kroah-Hartman 
Cc: Rafael J. Wysocki 
Cc: Aviya Erenfeld 
Cc: Mukesh Ojha 
Link: https://lore.kernel.org/r/20241130023554.538820-1-rdunlap@infradead.org
Signed-off-by: Greg Kroah-Hartman

devcoredump: Add dev_coredumpm_timeout()

2024-06-12T15:29:36+00:00

Add function to set a custom coredump timeout.

For Xe driver usage, current 5 minutes timeout may be too short for
users to search and understand what needs to be done to capture
coredump to report bugs.

We have plans to automate(distribute a udev script) it but at the end
will be up to distros and users to pack it so having a option to
increase the timeout is a safer option.

v2:
- replace dev_coredump_timeout_set() by dev_coredumpm_timeout() (Mukesh)

v3:
- make dev_coredumpm() static inline (Johannes)

v5:
- rename DEVCOREDUMP_TIMEOUT -> DEVCD_TIMEOUT to avoid redefinition
in include/net/bluetooth/coredump.h

v6:
- fix definition of dev_coredumpm_timeout() when CONFIG_DEV_COREDUMP
is disabled

Cc: Rodrigo Vivi 
Cc: Mukesh Ojha 
Cc: Johannes Berg 
Cc: Jonathan Cavitt 
Reviewed-by: Rodrigo Vivi 
Reviewed-by: Jonathan Cavitt 
Signed-off-by: José Roberto de Souza 
Acked-by: Greg Kroah-Hartman 
Acked-by: Johannes Berg 
Link: https://patchwork.freedesktop.org/patch/msgid/20240611174716.72660-1-jose.souza@intel.com
Signed-off-by: Rodrigo Vivi

devcoredump: Add dev_coredump_put()

2024-04-11T13:39:48+00:00

It is useful for modules that do not want to keep coredump available
after its unload.
Otherwise, the coredump would only be removed after DEVCD_TIMEOUT
seconds.

v2:
- dev_coredump_put() documentation updated (Mukesh)

Cc: Rodrigo Vivi 
Cc: Mukesh Ojha 
Cc: Johannes Berg 
Cc: Jonathan Cavitt 
Reviewed-by: Johannes Berg 
Acked-by: Jonathan Cavitt 
Signed-off-by: José Roberto de Souza 
Acked-by: Greg Kroah-Hartman 
Link: https://patchwork.freedesktop.org/patch/msgid/20240409200206.108452-1-jose.souza@intel.com
Signed-off-by: Rodrigo Vivi

devcoredump: Send uevent once devcd is ready

2023-11-28T19:39:18+00:00

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 
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

driver core: class: mark the struct class for sysfs callbacks as constant

2023-03-29T05:54:58+00:00

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" 
Cc: "Rafael J. Wysocki" 
Cc: Bartosz Golaszewski 
Cc: Eric Dumazet 
Cc: Jakub Kicinski 
Cc: Jens Axboe 
Cc: Johannes Berg 
Cc: Linus Walleij 
Cc: Minchan Kim 
Cc: Miquel Raynal 
Cc: Namjae Jeon 
Cc: Paolo Abeni 
Cc: Russ Weight 
Cc: Sergey Senozhatsky 
Cc: Steve French 
Cc: Vignesh Raghavendra 
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 
Link: https://lore.kernel.org/r/20230325084537.3622280-1-gregkh@linuxfoundation.org
Signed-off-by: Greg Kroah-Hartman

drivers: remove struct module * setting from struct class

2023-03-17T14:16:27+00:00

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" 
Link: https://lore.kernel.org/r/20230313181843.1207845-2-gregkh@linuxfoundation.org
Signed-off-by: Greg Kroah-Hartman

devcoredump : Serialize devcd_del work

2022-09-24T12:01:40+00:00

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 
Link: https://lore.kernel.org/r/1663073424-13663-1-git-send-email-quic_mojha@quicinc.com
Signed-off-by: Greg Kroah-Hartman