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/gcc-plugins/Makefile | 72 ++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 72 insertions(+) create mode 100644 scripts/gcc-plugins/Makefile (limited to 'scripts/gcc-plugins/Makefile') diff --git a/scripts/gcc-plugins/Makefile b/scripts/gcc-plugins/Makefile new file mode 100644 index 000000000..05b14aba4 --- /dev/null +++ b/scripts/gcc-plugins/Makefile @@ -0,0 +1,72 @@ +# SPDX-License-Identifier: GPL-2.0 + +$(obj)/randomize_layout_plugin.so: $(obj)/randomize_layout_seed.h +quiet_cmd_create_randomize_layout_seed = SEEDHDR $@ +cmd_create_randomize_layout_seed = \ + SEED=$$(cat $(filter-out FORCE,$^) $@; \ + echo ' * This file is automatically generated. Keep it private.' >> $@; \ + echo ' * Exposing this value will expose the layout of randomized structures.' >> $@; \ + echo ' */' >> $@; \ + echo "const char *randstruct_seed = \"$$SEED\";" >> $@ +$(obj)/randomize_layout_seed.h: $(objtree)/scripts/basic/randstruct.seed FORCE + $(call if_changed,create_randomize_layout_seed) +targets += randomize_layout_seed.h + +# Build rules for plugins +# +# No extra code is needed for single-file plugins. +# For multi-file plugins, use *-objs syntax to list the objects. +# +# If the plugin foo.so is compiled from foo.c and foo2.c, you can do: +# +# foo-objs := foo.o foo2.o + +always-y += $(GCC_PLUGIN) + +GCC_PLUGINS_DIR = $(shell $(CC) -print-file-name=plugin) + +plugin_cxxflags = -Wp,-MMD,$(depfile) $(KBUILD_HOSTCXXFLAGS) -fPIC \ + -include $(srctree)/include/linux/compiler-version.h \ + -DPLUGIN_VERSION=$(call stringify,$(KERNELVERSION)) \ + -I $(GCC_PLUGINS_DIR)/include -I $(obj) \ + -fno-rtti -fno-exceptions -fasynchronous-unwind-tables \ + -ggdb -Wno-narrowing -Wno-unused-variable \ + -Wno-format-diag + +plugin_ldflags = -shared + +plugin-single := $(foreach m, $(GCC_PLUGIN), $(if $($(m:%.so=%-objs)),,$(m))) +plugin-multi := $(filter-out $(plugin-single), $(GCC_PLUGIN)) +plugin-objs := $(sort $(foreach m, $(plugin-multi), $($(m:%.so=%-objs)))) + +targets += $(plugin-single) $(plugin-multi) $(plugin-objs) +clean-files += *.so + +plugin-single := $(addprefix $(obj)/, $(plugin-single)) +plugin-multi := $(addprefix $(obj)/, $(plugin-multi)) +plugin-objs := $(addprefix $(obj)/, $(plugin-objs)) + +quiet_cmd_plugin_cxx_so_c = HOSTCXX $@ + cmd_plugin_cxx_so_c = $(HOSTCXX) $(plugin_cxxflags) $(plugin_ldflags) -o $@ $< + +$(plugin-single): $(obj)/%.so: $(src)/%.c FORCE + $(call if_changed_dep,plugin_cxx_so_c) + +quiet_cmd_plugin_ld_so_o = HOSTLD $@ + cmd_plugin_ld_so_o = $(HOSTCXX) $(plugin_ldflags) -o $@ \ + $(addprefix $(obj)/, $($(target-stem)-objs)) + +$(plugin-multi): FORCE + $(call if_changed,plugin_ld_so_o) +$(foreach m, $(notdir $(plugin-multi)), $(eval $(obj)/$m: $(addprefix $(obj)/, $($(m:%.so=%-objs))))) + +quiet_cmd_plugin_cxx_o_c = HOSTCXX $@ + cmd_plugin_cxx_o_c = $(HOSTCXX) $(plugin_cxxflags) -c -o $@ $< + +$(plugin-objs): $(obj)/%.o: $(src)/%.c FORCE + $(call if_changed_dep,plugin_cxx_o_c) + +$(obj)/../../include/generated/gcc-plugins.h: $(plugin-single) $(plugin-multi) FORCE + $(call if_changed,touch) +always-y += ../../include/generated/gcc-plugins.h -- cgit v1.3.1