On Tue, Oct 28, 2014 at 08:22:16AM -0400, Prarit Bhargava wrote: > > > On 10/28/2014 08:16 AM, Andi Kleen wrote: > > On Fri, Oct 24, 2014 at 08:53:27AM -0400, Prarit Bhargava wrote: > >> There have been several times where I have had to rebuild a kernel to > >> cause a panic when hitting a WARN() in the code in order to get a crash > >> dump from a system. Sometimes this is easy to do, other times (such as > >> in the case of a remote admin) it is not trivial to send new images to the > >> user. > >> > >> A much easier method would be a switch to change the WARN() over to a > >> BUG(). This makes debugging easier in that I can now test the actual > >> image the WARN() was seen on and I do not have to engage in remote > >> debugging. > > > > IMHO this would be better and far more generically done with kdb. > > You would need two things: > > > > - Extend the break point command to run another command on a break point. > > - Add a command line (or possibly /proc) option to execute some kdb commands at > > kernel boot. > > I suppose ... but that would mean I would have to explain to an end user the > elaborate process of enabling kdb, inserting a break point, etc. The whole > purpose of this is to let an end user panic on WARN() easily. > > Asking an end user to enable kdb is magnitudes worse than asking them to > recompile a kernel. Agreed. Asking a customer to setup and run kdb and put breakpoints is much more pain than simply asking to reboot kernel with a command line option. Thanks Vivek
