On Mon, 23 Oct 2023 at 18:22, <andrey.konovalov@xxxxxxxxx> wrote: [...] > --- > > Changes v2->v3: > - Fix null-ptr-deref by using the proper number of entries for > initializing the stack table when alloc_large_system_hash() > auto-calculates the number (see patch #12). > - Keep STACKDEPOT/STACKDEPOT_ALWAYS_INIT Kconfig options not configurable > by users. > - Use lockdep_assert_held_read annotation in depot_fetch_stack. > - WARN_ON invalid flags in stack_depot_save_flags. > - Moved "../slab.h" include in mm/kasan/report_tags.c in the right patch. > - Various comment fixes. > > Changes v1->v2: > - Rework API to stack_depot_save_flags(STACK_DEPOT_FLAG_GET) + > stack_depot_put. > - Add CONFIG_STACKDEPOT_MAX_FRAMES Kconfig option. > - Switch stack depot to using list_head's. > - Assorted minor changes, see the commit message for each path. > > Andrey Konovalov (19): > lib/stackdepot: check disabled flag when fetching > lib/stackdepot: simplify __stack_depot_save > lib/stackdepot: drop valid bit from handles > lib/stackdepot: add depot_fetch_stack helper > lib/stackdepot: use fixed-sized slots for stack records 1. I know fixed-sized slots are need for eviction to work, but have you evaluated if this causes some excessive memory waste now? Or is it negligible? If it turns out to be a problem, one way out would be to partition the freelist into stack size classes; e.g. one for each of stack traces of size 8, 16, 32, 64. > lib/stackdepot: fix and clean-up atomic annotations > lib/stackdepot: rework helpers for depot_alloc_stack > lib/stackdepot: rename next_pool_required to new_pool_required > lib/stackdepot: store next pool pointer in new_pool > lib/stackdepot: store free stack records in a freelist > lib/stackdepot: use read/write lock 2. I still think switching to the percpu_rwsem right away is the right thing, and not actually a downside. I mentioned this before, but you promised a follow-up patch, so I trust that this will happen. ;-) > lib/stackdepot: use list_head for stack record links > kmsan: use stack_depot_save instead of __stack_depot_save > lib/stackdepot, kasan: add flags to __stack_depot_save and rename > lib/stackdepot: add refcount for records > lib/stackdepot: allow users to evict stack traces > kasan: remove atomic accesses to stack ring entries > kasan: check object_size in kasan_complete_mode_report_info > kasan: use stack_depot_put for tag-based modes > > include/linux/stackdepot.h | 59 ++++-- > lib/Kconfig | 10 + > lib/stackdepot.c | 418 ++++++++++++++++++++++++------------- > mm/kasan/common.c | 7 +- > mm/kasan/generic.c | 9 +- > mm/kasan/kasan.h | 2 +- > mm/kasan/report_tags.c | 27 +-- > mm/kasan/tags.c | 24 ++- > mm/kmsan/core.c | 7 +- > 9 files changed, 365 insertions(+), 198 deletions(-) Acked-by: Marco Elver <elver@xxxxxxxxxx> The series looks good in its current state. However, see my 2 higher-level comments above.
