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authorKumar Kartikeya Dwivedi <memxor@gmail.com>2026-09-04 10:43:19 +0200
committerAlexei Starovoitov <ast@kernel.org>2026-09-04 07:58:36 -0700
commit6668ed271eaefaa63e686bdfbedaeb7b8e492722 (patch)
tree58e8288fead484f6755ad0815fc74c3742663761 /scripts/Makefile.clang
downloadlinux-stable-6668ed271eaefaa63e686bdfbedaeb7b8e492722.tar.gz
linux-stable-6668ed271eaefaa63e686bdfbedaeb7b8e492722.zip
selftests/bpf: Reject graph kptr use after RCU unlockgrafted
Add a sleepable verifier test that loads a graph-node local kptr in an explicit RCU read-side critical section, then passes its node to bpf_rbtree_remove() after the section ends. Before the verifier fix, the stale NON_OWN_REF flag makes the node look like a live borrowed reference and the program is accepted. After the fix, the pointer is demoted without NON_OWN_REF and the graph kfunc argument is rejected. Also exercise a graph kptr loaded while a spin lock provides implicit RCU protection. The pointer must be invalidated when the lock is released, which guards the required ordering between non-owning-reference invalidation and RCU demotion. Update the existing fault-protected load test state description. The post-unlock pointer no longer carries NON_OWN_REF, but remains readable because the load is rewritten to use BPF_PROBE_MEM. Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com> Link: https://lore.kernel.org/r/20260904084325.52250-7-memxor@gmail.com Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Diffstat (limited to 'scripts/Makefile.clang')
-rw-r--r--scripts/Makefile.clang42
1 files changed, 42 insertions, 0 deletions
diff --git a/scripts/Makefile.clang b/scripts/Makefile.clang
new file mode 100644
index 000000000..b67636b28
--- /dev/null
+++ b/scripts/Makefile.clang
@@ -0,0 +1,42 @@
+# Individual arch/{arch}/Makefiles should use -EL/-EB to set intended
+# endianness and -m32/-m64 to set word size based on Kconfigs instead of
+# relying on the target triple.
+CLANG_TARGET_FLAGS_arm := arm-linux-gnueabi
+CLANG_TARGET_FLAGS_arm64 := aarch64-linux-gnu
+CLANG_TARGET_FLAGS_hexagon := hexagon-linux-musl
+CLANG_TARGET_FLAGS_loongarch := loongarch64-linux-gnusf
+CLANG_TARGET_FLAGS_m68k := m68k-linux-gnu
+CLANG_TARGET_FLAGS_mips := mipsel-linux-gnu
+CLANG_TARGET_FLAGS_powerpc := powerpc64le-linux-gnu
+CLANG_TARGET_FLAGS_riscv := riscv64-linux-gnu
+CLANG_TARGET_FLAGS_s390 := s390x-linux-gnu
+CLANG_TARGET_FLAGS_sparc := sparc64-linux-gnu
+CLANG_TARGET_FLAGS_x86 := x86_64-linux-gnu
+# This is only for i386 UM builds, which need the 32-bit target not -m32
+CLANG_TARGET_FLAGS_i386 := i386-linux-gnu
+CLANG_TARGET_FLAGS_um := $(CLANG_TARGET_FLAGS_$(SUBARCH))
+CLANG_TARGET_FLAGS := $(CLANG_TARGET_FLAGS_$(SRCARCH))
+
+ifeq ($(CLANG_TARGET_FLAGS),)
+$(error add '--target=' option to scripts/Makefile.clang)
+else
+CLANG_FLAGS += --target=$(CLANG_TARGET_FLAGS)
+endif
+
+ifeq ($(LLVM_IAS),0)
+CLANG_FLAGS += -fno-integrated-as
+GCC_TOOLCHAIN_DIR := $(dir $(shell which $(CROSS_COMPILE)elfedit))
+CLANG_FLAGS += --prefix=$(GCC_TOOLCHAIN_DIR)$(notdir $(CROSS_COMPILE))
+else
+CLANG_FLAGS += -fintegrated-as
+endif
+# By default, clang only warns when it encounters an unknown warning flag or
+# certain optimization flags it knows it has not implemented.
+# Make it behave more like gcc by erroring when these flags are encountered
+# so they can be implemented or wrapped in cc-option.
+CLANG_FLAGS += -Werror=unknown-warning-option
+CLANG_FLAGS += -Werror=ignored-optimization-argument
+CLANG_FLAGS += -Werror=option-ignored
+CLANG_FLAGS += -Werror=unused-command-line-argument
+KBUILD_CPPFLAGS += $(CLANG_FLAGS)
+export CLANG_FLAGS