From 2b97956af60810cd382b86b9ce9aea421b889861 Mon Sep 17 00:00:00 2001 From: Nuoqi Gui Date: Fri, 4 Sep 2026 12:41:55 +0200 Subject: selftests/bpf: Test rhtab kptr cancellation semantics Resizable hash-map updates and deletions must not perform full special-field destruction in their caller context. In particular, a referenced kptr must remain attached to the allocation until the memory allocator destructor can release it safely. Add separate coverage for both affected paths. The update test stores a task kptr, replaces the ordinary value bytes with BPF_EXIST, and verifies that the kptr survived. The delete test removes an element and exchanges its kptr through the still-valid map-value pointer before the allocation is reclaimed. Both cases observe a NULL kptr when rhtab uses bpf_obj_free_fields(). They recover and release the reference after rhtab switches to cancellation semantics. Signed-off-by: Nuoqi Gui [ kkd: Split update and delete coverage and rewrote the commit log ] Signed-off-by: Kumar Kartikeya Dwivedi Link: https://lore.kernel.org/r/20260904104203.345917-5-memxor@gmail.com Signed-off-by: Alexei Starovoitov --- tools/testing/radix-tree/xarray.c | 30 ++++++++++++++++++++++++++++++ 1 file changed, 30 insertions(+) create mode 100644 tools/testing/radix-tree/xarray.c (limited to 'tools/testing/radix-tree/xarray.c') diff --git a/tools/testing/radix-tree/xarray.c b/tools/testing/radix-tree/xarray.c new file mode 100644 index 000000000..253208a85 --- /dev/null +++ b/tools/testing/radix-tree/xarray.c @@ -0,0 +1,30 @@ +// SPDX-License-Identifier: GPL-2.0+ +/* + * xarray.c: Userspace shim for XArray test-suite + * Copyright (c) 2018 Matthew Wilcox + */ + +#include "xarray-shared.h" +#include "test.h" + +#undef XA_DEBUG +#include "../../../lib/test_xarray.c" + +void xarray_tests(void) +{ + xarray_checks(); + xarray_exit(); +} + +int __weak main(void) +{ + rcu_register_thread(); + radix_tree_init(); + xarray_tests(); + radix_tree_cpu_dead(1); + rcu_barrier(); + if (nr_allocated) + printf("nr_allocated = %d\n", nr_allocated); + rcu_unregister_thread(); + return 0; +} -- cgit v1.3.1