On 16.01.20 09:06, David Hildenbrand wrote: > On 16.01.20 04:01, Pingfan Liu wrote: >> When fully deactivated, it is meaningless to keep the value of a section's >> mem_map. And its mem_map will be reassigned during re-added. >> >> Beside this, it breaks the user space tool "makedumpfile", which makes >> assumption that a hot-removed section having mem_map as NULL. >> >> The bug can be reproduced on IBM POWERVM by "drmgr -c mem -r -q 5" , >> trigger a crash, and save vmcore by makedumpfile > > Are you using an up-to-date makedumfile and did kdump.service properly > get reloaded on the udev events? I remember that this works. > > makedumpfile will not dump memory sections that a) are not marked > offline (SECTION_IS_ONLINE) - after offlining b) are not part of an > iomem resource - after memory unplug. > > > The current code makes sure that sparse_decode_mem_map() will return NULL. > ... but it's only used at this very place. I think we should add a Fixes: tag, although this might be fixed as well in makedumpfile (so people are aware that patch broke something) Reviewed-by: David Hildenbrand <david@xxxxxxxxxx> -- Thanks, David / dhildenb
