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>

1 files changed, 24 insertions, 0 deletions

diff --git a/arch/arm/mach-qcom/Kconfig b/arch/arm/mach-qcom/Kconfig
new file mode 100644
index 000000000..f4765be1b
--- /dev/null
+++ b/arch/arm/mach-qcom/Kconfig
@@ -0,0 +1,24 @@
+# SPDX-License-Identifier: GPL-2.0-only
+menuconfig ARCH_QCOM
+	bool "Qualcomm Support"
+	depends on ARCH_MULTI_V7
+	select ARM_GIC
+	select ARM_AMBA
+	select CLKSRC_QCOM
+	select HAVE_ARM_ARCH_TIMER
+	select PINCTRL
+	select QCOM_SCM if SMP
+	help
+	  Support for Qualcomm's devicetree based systems.
+	  This includes support for a few devices with ARM64 SoC, that have
+	  ARM32 signed firmware that does not allow booting ARM64 kernels.
+
+if ARCH_QCOM
+
+config ARCH_QCOM_RESERVE_SMEM
+	bool "Reserve SMEM at the beginning of RAM"
+	help
+	  Reserve 2MB at the beginning of the System RAM for shared mem.
+	  This is required on IPQ40xx, MSM8x60 and MSM8960 platforms.
+
+endif