From 9cc63f8bcd560c760d0b12e15bba8f81c86237cf Mon Sep 17 00:00:00 2001 From: "Paul E. McKenney" Date: Fri, 14 Aug 2026 15:43:51 -0700 Subject: Merge branches 'expcb.2026.07.24a', 'misc.2026.07.30a', 'rcu-tasks.2026.07.30a', 'srcu.2026.08.11a' and 'torture.2026.08.14a' into HEAD Changes: Make expedited grace periods expedite normal RCU callbacks Miscellaneous fixes: * Improve diagnostic output with character task states. * Mark accesses to inform KCSAN of concurrency design. * Move from kmalloc() to kmalloc_obj(). * Documentation updates. * Improve handling of RCU deferred quiescent states. * Clean up unused function arguments and structure fields. * Reduce show_rcu_gp_kthreads() stack space. Tasks RCU updates: * Clean up after SRCU re-implementation of Tasks Trace RCU. * Mark accesses to inform KCSAN of concurrency design. * Add ->lazy_timer status to diagnostic output. * Remove an unnecessary memory barrier. * Fix a data race, courtesy of KCSAN. * Documentation updates. * Convert cond_resched_tasks_rcu_qs() from macro to static inline function. SRCU updates: * Add Rust helpers for SRCU. * Avoid losing queued work at cleanup_srcu_struct() time. Torture-test updates: * Preparation work for immediate RCU priority deboosting. * Test RCU readers from real interrupt handlers (as opposed to softirq). * Simplify code through use of cpumask_next_wrap(). * Improve diagnostic output with character task states. * Add rcutorture.nwriters parameter to allow lightweight stall testing, and rcutorture.stall_only to make doing so easier. * Test an RCU Tasks Trace grace period implying an RCU grace period. * Make RCU Tasks Trace torturing track reader batches. * Fix a data race, courtesy of KCSAN. * Plug a shuffle_tmp_mask memory leak on kthread spawn failure. --- tools/testing/radix-tree/regression3.c | 95 ++++++++++++++++++++++++++++++++++ 1 file changed, 95 insertions(+) create mode 100644 tools/testing/radix-tree/regression3.c (limited to 'tools/testing/radix-tree/regression3.c') diff --git a/tools/testing/radix-tree/regression3.c b/tools/testing/radix-tree/regression3.c new file mode 100644 index 000000000..9f9a3b280 --- /dev/null +++ b/tools/testing/radix-tree/regression3.c @@ -0,0 +1,95 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Regression3 + * Description: + * Helper radix_tree_iter_retry resets next_index to the current index. + * In following radix_tree_next_slot current chunk size becomes zero. + * This isn't checked and it tries to dereference null pointer in slot. + * + * Helper radix_tree_iter_resume reset slot to NULL and next_index to index + 1, + * for tagger iteraction it also must reset cached tags in iterator to abort + * next radix_tree_next_slot and go to slow-path into radix_tree_next_chunk. + * + * Running: + * This test should run to completion immediately. The above bug would + * cause it to segfault. + * + * Upstream commit: + * Not yet + */ +#include +#include +#include +#include +#include +#include + +#include "regression.h" + +void regression3_test(void) +{ + RADIX_TREE(root, GFP_KERNEL); + void *ptr0 = (void *)4ul; + void *ptr = (void *)8ul; + struct radix_tree_iter iter; + void **slot; + bool first; + + printv(1, "running regression test 3 (should take milliseconds)\n"); + + radix_tree_insert(&root, 0, ptr0); + radix_tree_tag_set(&root, 0, 0); + + first = true; + radix_tree_for_each_tagged(slot, &root, &iter, 0, 0) { + printv(2, "tagged %ld %p\n", iter.index, *slot); + if (first) { + radix_tree_insert(&root, 1, ptr); + radix_tree_tag_set(&root, 1, 0); + first = false; + } + if (radix_tree_deref_retry(*slot)) { + printv(2, "retry at %ld\n", iter.index); + slot = radix_tree_iter_retry(&iter); + continue; + } + } + radix_tree_delete(&root, 1); + + first = true; + radix_tree_for_each_slot(slot, &root, &iter, 0) { + printv(2, "slot %ld %p\n", iter.index, *slot); + if (first) { + radix_tree_insert(&root, 1, ptr); + first = false; + } + if (radix_tree_deref_retry(*slot)) { + printv(2, "retry at %ld\n", iter.index); + slot = radix_tree_iter_retry(&iter); + continue; + } + } + + radix_tree_for_each_slot(slot, &root, &iter, 0) { + printv(2, "slot %ld %p\n", iter.index, *slot); + if (!iter.index) { + printv(2, "next at %ld\n", iter.index); + slot = radix_tree_iter_resume(slot, &iter); + } + } + + radix_tree_tag_set(&root, 0, 0); + radix_tree_tag_set(&root, 1, 0); + radix_tree_for_each_tagged(slot, &root, &iter, 0, 0) { + printv(2, "tagged %ld %p\n", iter.index, *slot); + if (!iter.index) { + printv(2, "next at %ld\n", iter.index); + slot = radix_tree_iter_resume(slot, &iter); + } + } + + radix_tree_delete(&root, 0); + radix_tree_delete(&root, 1); + + printv(1, "regression test 3 passed\n"); +} -- cgit v1.3.1