On Tue, Jan 20, 2009 at 09:15:51AM -0500, Vivek Goyal wrote: > On Mon, Jan 19, 2009 at 04:21:27PM -0500, Neil Horman wrote: > > Hey all- > > It would be nice to be able to extract the dmesg log from a vmcore file > > without needing to keep the debug symbols for the running kernel handy all the > > time. We have a facility to do this in /proc/vmcore. This patch adds the > > log_buf and log_end symbols to the vmcoreinfo area so that tools (like > > makedumpfile) can easily extract the dmesg logs from a vmcore image. > > > > It would be nice to get dmesg log if debug symbols are not around. Can't > we use System.map for getting symbol addresses? vmcoreinfo had started > small and seems to be growing now. I am thinking down the line will making > use of System.map for such cases make sense? > System.map only include exported and public symbols. log_buf and log_end are static, and not reported in the System.map. Its a nice idea, but not comprehensive for everything in the kernel. ><snip> > > Will it be an issue if we make log_buf and log_end non static and directly > access these in kexec.c? > I had considered that, but was a bit hesitant to do so, since it exposes the internal implementation of the dmesg buffer. In the event someone disables CONFIG_PRINTK, thats just more code we need to ifdef. With this implementation we just stub out the log_buf_setup function, and let that be that. It seems more consice to me this way. Regards Neil > Thanks > Vivek >
