On Wed, Feb 29, 2012 at 05:23:10PM -0800, Eugene Surovegin wrote: > On Wed, Feb 29, 2012 at 5:18 PM, Simon Horman <horms at verge.net.au> wrote: > > > On Wed, Feb 29, 2012 at 09:21:23AM -0800, Eugene Surovegin wrote: > > > Per-CPU allocations are not guaranteed to be physically contiguous. > > > However, kdump kernel and user-space code assumes that per-CPU > > > memory, used for saving CPU registers on crash, is. > > > This can cause corrupted /proc/vmcore in some cases - the main > > > symptom being huge ELF note section. > > > > > > Force page alignment for note_buf_t to ensure that this assumption holds. > > > > Ouch. I'm surprised there is an allocation on crash, perhaps > > it could at least be done earlier? And am I right in thinking > > that this change increases the likely hood that the allocation > > could fail? > > > > I'm not following. This allocation is done on start-up, not on crash. > If you cannot allocate this much memory on system boot, I'm not sure what > else you can do on this system.... Sorry, my eyes deceived me. You are correct and I agree. Is it the case that note_buf_t is never larger than PAGE_SIZE? If so I your patch looks good to me.
