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.
Changes since v1 [2] - Added Tested-by and Acked-by, per SeongJae Park - Fixed NOMMU case, per Vlastimil Babka - Renamed proc_maps_query_data to proc_maps_locking_ctx, per Vlastimil Babka
[1] https://lore.kernel.org/all/20250704060727.724817-1-surenb@google.com/ [2] https://lore.kernel.org/all/20250731220024.702621-1-surenb@google.com/
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 ++++++++++++------ fs/proc/task_nommu.c | 14 +- tools/testing/selftests/proc/proc-maps-race.c | 65 ++++++++ 4 files changed, 181 insertions(+), 62 deletions(-)
base-commit: 01da54f10fddf3b01c5a3b80f6b16bbad390c302