From: Johannes Berg Date: Fri, 12 Sep 2014 07:01:56 +0000 (+0200) Subject: device coredump: add new device coredump class X-Git-Tag: fixes-for-v3.18-merge-window~13^2~10 X-Git-Url: http://git.openpandora.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=833c95456a70826d1384883b73fd23aff24d366f;p=pandora-kernel.git 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 Signed-off-by: Greg Kroah-Hartman --- Reading git-diff-tree failed