linux-kernel - [PATCH v3 0/2] mm: only mark/clear KHO scratch memory when needed

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [thread-next>] [day] [month] [year] [list]

Message-ID: <20251128173257.969322-1-usamaarif642@gmail.com>
Date: Fri, 28 Nov 2025 17:29:32 +0000
From: Usama Arif <usamaarif642@...il.com>
To: rppt@...nel.org,
	Andrew Morton <akpm@...ux-foundation.org>
Cc: kas@...nel.org,
	changyuanl@...gle.com,
	graf@...zon.com,
	leitao@...ian.org,
	thevlad@...a.com,
	pratyush@...nel.org,
	dave.hansen@...ux.intel.com,
	linux-mm@...ck.org,
	linux-kernel@...r.kernel.org,
	kernel-team@...a.com,
	Usama Arif <usamaarif642@...il.com>
Subject: [PATCH v3 0/2] mm: only mark/clear KHO scratch memory when needed

The scratch memory for kexec handover is used to bootstrap the
kexec'ed kernel. Only the 1st 1MB is used as scratch, and its a
hack to get around limitations with KHO. It is only needed when
CONFIG_KEXEC_HANDOVER is enabled and only if it is a KHO boot
(both checked by is_kho_boot). Add check to prevent marking a KHO
scratch region unless needed.

CONFIG_MEMBLOCK_KHO_SCRATCH is also removed as its only selected
by KEXEC_HANDOVER.

v2 -> v3:
- is_kho_boot already has stubs when CONFIG_KEXEC_HANDOVER=n,
  no need to move the functions under CONFIG_KEXEC_HANDOVER (Pratyush
  Yadav)
- Commit messsage improvements

v1 -> v2:
- Remove CONFIG_MEMBLOCK_KHO_SCRATCH (Kiryl Shutsemau)
- Move memblock_mark/clear_kho_scratch under alread existing
  CONFIG_KEXEC_HANDOVER in memblock.c.


Usama Arif (2):
  mm/memblock: remove CONFIG_MEMBLOCK_KHO_SCRATCH option
  mm/memblock: only mark/clear KHO scratch memory when needed

 include/linux/memblock.h |  2 +-
 kernel/Kconfig.kexec     |  1 -
 mm/Kconfig               |  4 ----
 mm/memblock.c            | 18 +++++++++++-------
 4 files changed, 12 insertions(+), 13 deletions(-)

-- 
2.47.3