On 08/11/15 at 02:33pm, Baoquan He wrote: > Hi Andrew, > > On 08/03/15 at 03:04pm, Andrew Morton wrote: > > On Mon, 3 Aug 2015 20:50:43 +0800 Baoquan He <bhe at redhat.com> wrote: > > And I think the WARN_ON can be replaced with a > > BUILD_BUG_ON(sizeof>PAGE_SIZE)? That would avoid adding runtime > > overhead. > > Rethink about this, you are right. Using BUILD_BUG_ON is better. > Anyone who found this compiling break should check if his/her code > changes increase the crash_notes size. If possible that increase need be > avoidable. Otherwise he should report this to upstream why it's > unavoidable to increase crash_notes size, then let's consider the > redesign the crash_notes data structure. > > So I will use BUILD_BUG_ON and repost. Baoquan. If the size of notes never be exceeded to PAGE_SIZE, I think we can revert below patch, since the situation which describes in patch does not happen. commit 38dfac843cb6d7be1874888839817404a15a6b3c Author: Greg Pearson <greg.pearson at hp.com> Date: Mon Feb 10 14:25:36 2014 -0800 vmcore: prevent PT_NOTE p_memsz overflow during header update What do you think about this? Thanks Minfei