page_owner silently truncates stack traces deeper than PAGE_OWNER_STACK_DEPTH (16), which hides root caller information during memory debugging. Add a ratelimited warning to notify developers when this truncation occurs. Signed-off-by: Jiayuan Liang --- mm/page_owner.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/mm/page_owner.c b/mm/page_owner.c index 8178e0be5..962a4f694 100644 --- a/mm/page_owner.c +++ b/mm/page_owner.c @@ -163,6 +163,9 @@ static noinline depot_stack_handle_t save_stack(gfp_t flags) set_current_in_page_owner(); nr_entries = stack_trace_save(entries, ARRAY_SIZE(entries), 2); + if (nr_entries >= PAGE_OWNER_STACK_DEPTH) + pr_warn_ratelimited("page_owner: stack depth %u exceeds limit %u\n", + nr_entries, PAGE_OWNER_STACK_DEPTH); handle = stack_depot_save(entries, nr_entries, flags); if (!handle) handle = failure_handle; -- 2.43.0