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 --- scripts/Makefile.randstruct | 17 +++++++++++++++++ 1 file changed, 17 insertions(+) create mode 100644 scripts/Makefile.randstruct (limited to 'scripts/Makefile.randstruct') diff --git a/scripts/Makefile.randstruct b/scripts/Makefile.randstruct new file mode 100644 index 000000000..24e283e89 --- /dev/null +++ b/scripts/Makefile.randstruct @@ -0,0 +1,17 @@ +# SPDX-License-Identifier: GPL-2.0 + +randstruct-cflags-y += -DRANDSTRUCT + +ifdef CONFIG_GCC_PLUGIN_RANDSTRUCT +randstruct-cflags-y \ + += -fplugin=$(objtree)/scripts/gcc-plugins/randomize_layout_plugin.so +randstruct-cflags-$(CONFIG_RANDSTRUCT_PERFORMANCE) \ + += -fplugin-arg-randomize_layout_plugin-performance-mode +else +randstruct-cflags-y \ + += -frandomize-layout-seed-file=$(objtree)/scripts/basic/randstruct.seed +endif + +export RANDSTRUCT_CFLAGS := $(randstruct-cflags-y) + +KBUILD_CFLAGS += $(RANDSTRUCT_CFLAGS) -- cgit v1.3.1