Commit Graph

4 Commits

Author SHA1 Message Date
Greg Kroah-Hartman f76d25275c driver core: devcoredump: convert to use class_groups
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>
2016-11-29 21:12:12 +01:00
Aviya Erenfeld 522566376a devcoredump: add scatterlist support
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>
2016-04-15 11:20:32 -07:00
Johannes Berg d45333294d devcoredump: provide a one-way disable function
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>
2014-11-26 19:40:12 -08:00
Johannes Berg 833c95456a device coredump: add new device coredump class
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>
2014-09-23 22:53:15 -07:00