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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.autofdo
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.autofdo')
-rw-r--r--scripts/Makefile.autofdo28
1 files changed, 28 insertions, 0 deletions
diff --git a/scripts/Makefile.autofdo b/scripts/Makefile.autofdo
new file mode 100644
index 000000000..1442043da
--- /dev/null
+++ b/scripts/Makefile.autofdo
@@ -0,0 +1,28 @@
+# SPDX-License-Identifier: GPL-2.0
+
+# Enable available and selected Clang AutoFDO features.
+
+CFLAGS_AUTOFDO_CLANG := -fdebug-info-for-profiling -mllvm -enable-fs-discriminator=true -mllvm -improved-fs-discriminator=true
+RUSTFLAGS_AUTOFDO_CLANG := $(if $(call rustc-min-version,109800),-Zdebuginfo-for-profiling,-Zdebug-info-for-profiling) -Cllvm-args=-enable-fs-discriminator=true -Cllvm-args=-improved-fs-discriminator=true
+
+ifndef CONFIG_DEBUG_INFO
+ CFLAGS_AUTOFDO_CLANG += -gmlt
+ RUSTFLAGS_AUTOFDO_CLANG += -Cdebuginfo=line-tables-only
+endif
+
+ifdef CLANG_AUTOFDO_PROFILE
+ CFLAGS_AUTOFDO_CLANG += -fprofile-sample-use=$(CLANG_AUTOFDO_PROFILE) -ffunction-sections
+ CFLAGS_AUTOFDO_CLANG += -fsplit-machine-functions
+ RUSTFLAGS_AUTOFDO_CLANG += -Zprofile-sample-use=$(CLANG_AUTOFDO_PROFILE) -Zfunction-sections=y
+ RUSTFLAGS_AUTOFDO_CLANG += -Cllvm-args=-split-machine-functions
+endif
+
+ifdef CONFIG_LTO_CLANG_THIN
+ ifdef CLANG_AUTOFDO_PROFILE
+ KBUILD_LDFLAGS += --lto-sample-profile=$(CLANG_AUTOFDO_PROFILE)
+ endif
+ KBUILD_LDFLAGS += --mllvm=-enable-fs-discriminator=true --mllvm=-improved-fs-discriminator=true -plugin-opt=thinlto
+ KBUILD_LDFLAGS += -plugin-opt=-split-machine-functions
+endif
+
+export CFLAGS_AUTOFDO_CLANG RUSTFLAGS_AUTOFDO_CLANG