Message	SHA1
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> Johannes Berg   authored and   Greg Kroah-Hartman   commited 2014-09-23 22:53:15 -07:00	833c95456a