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, 63 insertions, 0 deletions

diff --git a/arch/arm/mach-bcm/Makefile b/arch/arm/mach-bcm/Makefile
new file mode 100644
index 000000000..6baedf4c6
--- /dev/null
+++ b/arch/arm/mach-bcm/Makefile
@@ -0,0 +1,63 @@
+# SPDX-License-Identifier: GPL-2.0-only
+#
+# Copyright (C) 2012-2015 Broadcom Corporation
+#
+
+# Cygnus
+obj-$(CONFIG_ARCH_BCM_CYGNUS) +=  bcm_cygnus.o
+
+# Hurricane 2
+obj-$(CONFIG_ARCH_BCM_HR2)	+= bcm_hr2.o
+
+# Northstar Plus
+obj-$(CONFIG_ARCH_BCM_NSP)	+= bcm_nsp.o
+
+ifeq ($(CONFIG_ARCH_BCM_NSP),y)
+obj-$(CONFIG_SMP)		+= platsmp.o
+endif
+
+# BCM281XX
+obj-$(CONFIG_ARCH_BCM_281XX)	+= board_bcm281xx.o
+
+# BCM21664
+obj-$(CONFIG_ARCH_BCM_21664)	+= board_bcm21664.o
+
+# BCM23550
+obj-$(CONFIG_ARCH_BCM_23550)	+= board_bcm23550.o
+
+# BCM281XX, BCM21664 and BCM23550 SMP support
+obj-$(CONFIG_ARCH_BCM_MOBILE_SMP) += platsmp.o
+
+# BCM281XX and BCM21664 L2 cache control
+obj-$(CONFIG_ARCH_BCM_MOBILE_L2_CACHE) += kona_l2_cache.o
+
+# Support for secure monitor traps
+obj-$(CONFIG_ARCH_BCM_MOBILE_SMC) += bcm_kona_smc.o
+CFLAGS_REMOVE_bcm_kona_smc.o += $(CC_FLAGS_FTRACE)
+
+# BCM2835
+ifeq ($(CONFIG_ARCH_BCM2835),y)
+obj-y				+= board_bcm2835.o
+obj-y				+= bcm2711.o
+ifeq ($(CONFIG_ARM),y)
+obj-$(CONFIG_SMP)		+= platsmp.o
+endif
+endif
+
+# BCM5301X
+obj-$(CONFIG_ARCH_BCM_5301X)	+= bcm_5301x.o
+ifeq ($(CONFIG_ARCH_BCM_5301X),y)
+obj-$(CONFIG_SMP)		+= platsmp.o
+endif
+
+ifeq ($(CONFIG_ARCH_BRCMSTB),y)
+CFLAGS_platsmp-brcmstb.o	+= -march=armv7-a
+obj-y				+= brcmstb.o
+obj-$(CONFIG_SMP)		+= platsmp-brcmstb.o
+endif
+
+# BCMBCA
+ifeq ($(CONFIG_ARCH_BCMBCA),y)
+obj-$(CONFIG_DEBUG_BCMBCA)	+= board_bcmbca.o
+obj-$(CONFIG_SMP)		+= bcm63xx_smp.o bcm63xx_pmb.o
+endif