linux-kernel - [PATCH 0/3 v2] fs/proc: extend the PAGEMAP

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 for Android: free password hash cracker in your pocket

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

Message-ID: <20250324065328.107678-1-avagin@google.com>
Date: Mon, 24 Mar 2025 06:53:25 +0000
From: Andrei Vagin <avagin@...gle.com>
To: Lorenzo Stoakes <lorenzo.stoakes@...cle.com>, Andrew Morton <akpm@...ux-foundation.org>
Cc: linux-kernel@...r.kernel.org, linux-mm@...ck.org, 
	linux-fsdevel@...r.kernel.org, linux-doc@...r.kernel.org, 
	David Hildenbrand <david@...hat.com>, Shuah Khan <shuah@...nel.org>, Jonathan Corbet <corbet@....net>, 
	criu@...ts.linux.dev, Andrei Vagin <avagin@...gle.com>
Subject: [PATCH 0/3 v2] fs/proc: extend the PAGEMAP_SCAN ioctl to report guard regions

Introduce the PAGE_IS_GUARD flag in the PAGEMAP_SCAN ioctl to expose
information about guard regions. This allows userspace tools, such as
CRIU, to detect and handle guard regions.

Currently, CRIU utilizes PAGEMAP_SCAN as a more efficient alternative to
parsing /proc/pid/pagemap. Without this change, guard regions are
incorrectly reported as swap-anon regions, leading CRIU to attempt
dumping them and subsequently failing.

This series should be applied on top of "[PATCH 0/2] fs/proc/task_mmu:
add guard region bit to pagemap":
https://lore.kernel.org/all/2025031926-engraved-footer-3e9b@gregkh/T/

The series includes updates to the documentation and selftests to
reflect the new functionality.

v2:
- sync linux/fs.h with the kernel sources
- address comments from Lorenzo and David.

Andrei Vagin (3):
  fs/proc: extend the PAGEMAP_SCAN ioctl to report guard regions
  tools headers UAPI: Sync linux/fs.h with the kernel sources
  selftests/mm: add PAGEMAP_SCAN guard region test

 Documentation/admin-guide/mm/pagemap.rst   |  1 +
 fs/proc/task_mmu.c                         | 17 ++++---
 include/uapi/linux/fs.h                    |  1 +
 tools/include/uapi/linux/fs.h              | 19 +++++++-
 tools/testing/selftests/mm/guard-regions.c | 57 ++++++++++++++++++++++
 5 files changed, 87 insertions(+), 8 deletions(-)

-- 
2.49.0.rc1.451.g8f38331e32-goog