linux-kernel - [PATCH v2 0/7] vma count: fixes, test and improvements

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: <20250915163838.631445-1-kaleshsingh@google.com>
Date: Mon, 15 Sep 2025 09:36:31 -0700
From: Kalesh Singh <kaleshsingh@...gle.com>
To: akpm@...ux-foundation.org, minchan@...nel.org, lorenzo.stoakes@...cle.com, 
	david@...hat.com, Liam.Howlett@...cle.com, rppt@...nel.org, pfalcato@...e.de
Cc: kernel-team@...roid.com, android-mm@...gle.com, 
	Kalesh Singh <kaleshsingh@...gle.com>, Alexander Viro <viro@...iv.linux.org.uk>, 
	Christian Brauner <brauner@...nel.org>, Jan Kara <jack@...e.cz>, Kees Cook <kees@...nel.org>, 
	Vlastimil Babka <vbabka@...e.cz>, Suren Baghdasaryan <surenb@...gle.com>, Michal Hocko <mhocko@...e.com>, 
	Steven Rostedt <rostedt@...dmis.org>, Masami Hiramatsu <mhiramat@...nel.org>, 
	Mathieu Desnoyers <mathieu.desnoyers@...icios.com>, Ingo Molnar <mingo@...hat.com>, 
	Peter Zijlstra <peterz@...radead.org>, Juri Lelli <juri.lelli@...hat.com>, 
	Vincent Guittot <vincent.guittot@...aro.org>, Dietmar Eggemann <dietmar.eggemann@....com>, 
	Ben Segall <bsegall@...gle.com>, Mel Gorman <mgorman@...e.de>, 
	Valentin Schneider <vschneid@...hat.com>, Jann Horn <jannh@...gle.com>, Shuah Khan <shuah@...nel.org>, 
	linux-kernel@...r.kernel.org, linux-fsdevel@...r.kernel.org, 
	linux-mm@...ck.org, linux-trace-kernel@...r.kernel.org, 
	linux-kselftest@...r.kernel.org
Subject: [PATCH v2 0/7] vma count: fixes, test and improvements

Hi all,

This is v2 to the VMA count patch I previously posted at:

https://lore.kernel.org/r/20250903232437.1454293-1-kaleshsingh@google.com/


I've split it into multiple patches to address the feedback.

The main changes in v2 are:

- Use a capacity-based check for VMA count limit, per Lorenzo.
- Rename map_count to vma_count, per David.
- Add assertions for exceeding the limit, per Pedro.
- Add tests for max_vma_count, per Liam.
- Emit a trace event for failure due to insufficient capacity for
  observability

Tested on x86_64 and arm64:

- Build test:
    - allyesconfig for rename

- Selftests:
      cd tools/testing/selftests/mm && \
          make && \
          ./run_vmtests.sh -t max_vma_count

       (With trace_max_vma_count_exceeded enabled)

- vma tests:
      cd tools/testing/vma && \
          make && \
	  ./vma

Thanks,
Kalesh

Kalesh Singh (7):
  mm: fix off-by-one error in VMA count limit checks
  mm/selftests: add max_vma_count tests
  mm: introduce vma_count_remaining()
  mm: rename mm_struct::map_count to vma_count
  mm: harden vma_count against direct modification
  mm: add assertion for VMA count limit
  mm/tracing: introduce max_vma_count_exceeded trace event

 fs/binfmt_elf.c                               |   2 +-
 fs/coredump.c                                 |   2 +-
 include/linux/mm.h                            |  35 +-
 include/linux/mm_types.h                      |   5 +-
 include/trace/events/vma.h                    |  32 +
 kernel/fork.c                                 |   2 +-
 mm/debug.c                                    |   2 +-
 mm/internal.h                                 |   1 +
 mm/mmap.c                                     |  28 +-
 mm/mremap.c                                   |  13 +-
 mm/nommu.c                                    |   8 +-
 mm/util.c                                     |   1 -
 mm/vma.c                                      |  88 ++-
 tools/testing/selftests/mm/Makefile           |   1 +
 .../selftests/mm/max_vma_count_tests.c        | 709 ++++++++++++++++++
 tools/testing/selftests/mm/run_vmtests.sh     |   5 +
 tools/testing/vma/vma.c                       |  32 +-
 tools/testing/vma/vma_internal.h              |  44 +-
 18 files changed, 949 insertions(+), 61 deletions(-)
 create mode 100644 include/trace/events/vma.h
 create mode 100644 tools/testing/selftests/mm/max_vma_count_tests.c


base-commit: f83ec76bf285bea5727f478a68b894f5543ca76e
-- 
2.51.0.384.g4c02a37b29-goog