[PATCH 0/3] execute PROCMAP_QUERY ioctl under per-vma lock

From: Suren Baghdasaryan
Date: Thu Jul 31 2025 - 18:00:59 EST


With /proc/pid/maps now being read under per-vma lock protection we can
reuse parts of that code to execute PROCMAP_QUERY ioctl also without
taking mmap_lock. The change is designed to reduce mmap_lock contention
and prevent PROCMAP_QUERY ioctl calls from blocking address space updates.

This patchset was split out of the original patchset [1] that introduced
per-vma lock usage for /proc/pid/maps reading. It contains PROCMAP_QUERY
tests, code refactoring patch to simplify the main change and the actual
transition to per-vma lock.

[1] https://lore.kernel.org/all/20250704060727.724817-1-surenb@xxxxxxxxxx/

Suren Baghdasaryan (3):
selftests/proc: test PROCMAP_QUERY ioctl while vma is concurrently
modified
fs/proc/task_mmu: factor out proc_maps_private fields used by
PROCMAP_QUERY
fs/proc/task_mmu: execute PROCMAP_QUERY ioctl under per-vma locks

fs/proc/internal.h | 15 +-
fs/proc/task_mmu.c | 149 ++++++++++++------
tools/testing/selftests/proc/proc-maps-race.c | 65 ++++++++
3 files changed, 174 insertions(+), 55 deletions(-)


base-commit: 01da54f10fddf3b01c5a3b80f6b16bbad390c302
--
2.50.1.565.gc32cd1483b-goog