Re: [PATCH] kexec: unmap reserved pages for each error-return way
From: Michael Holzheu
Date: Thu Jan 28 2016 - 05:32:37 EST
On Wed, 27 Jan 2016 11:15:46 -0800
Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> wrote:
> On Wed, 27 Jan 2016 14:48:31 +0300 Dmitry Safonov <dsafonov@xxxxxxxxxxxxx> wrote:
> > For allocation of kimage failure or kexec_prepare or load segments
> > errors there is no need to keep crashkernel memory mapped.
> > It will affect only s390 as map/unmap hook defined only for it.
> > As on unmap s390 also changes os_info structure let's check return code
> > and add info only on success.
> This conflicts (both mechanically and somewhat conceptually) with
> Xunlei Pang's "kexec: Introduce a protection mechanism for the
> crashkernel reserved memory" and "kexec: provide
Hmm, It looks to me that arch_kexec_(un)protect_crashkres() has exactly
the same semantics as crash_(un)map_reserved_pages().
On s390 we don't have the crashkernel memory mapped and therefore need
crash_map_reserved_pages() before loading something into crashkernel
Perhaps I missed something?