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, 47 insertions, 0 deletions

diff --git a/drivers/dma/stm32/Kconfig b/drivers/dma/stm32/Kconfig
new file mode 100644
index 000000000..4d8d80631
--- /dev/null
+++ b/drivers/dma/stm32/Kconfig
@@ -0,0 +1,47 @@
+# SPDX-License-Identifier: GPL-2.0-only
+#
+# STM32 DMA controllers drivers
+#
+if ARCH_STM32 || COMPILE_TEST
+
+config STM32_DMA
+	bool "STMicroelectronics STM32 DMA support"
+	select DMA_ENGINE
+	select DMA_VIRTUAL_CHANNELS
+	help
+	  Enable support for the on-chip DMA controller on STMicroelectronics
+	  STM32 platforms.
+	  If you have a board based on STM32 SoC with such DMA controller
+	  and want to use DMA say Y here.
+
+config STM32_DMAMUX
+	bool "STMicroelectronics STM32 DMA multiplexer support"
+	depends on STM32_DMA
+	help
+	  Enable support for the on-chip DMA multiplexer on STMicroelectronics
+	  STM32 platforms.
+	  If you have a board based on STM32 SoC with such DMA multiplexer
+	  and want to use DMAMUX say Y here.
+
+config STM32_MDMA
+	bool "STMicroelectronics STM32 master DMA support"
+	depends on OF
+	select DMA_ENGINE
+	select DMA_VIRTUAL_CHANNELS
+	help
+	  Enable support for the on-chip MDMA controller on STMicroelectronics
+	  STM32 platforms.
+	  If you have a board based on STM32 SoC with such DMA controller
+	  and want to use MDMA say Y here.
+
+config STM32_DMA3
+	tristate "STMicroelectronics STM32 DMA3 support"
+	select DMA_ENGINE
+	select DMA_VIRTUAL_CHANNELS
+	help
+	  Enable support for the on-chip DMA3 controller on STMicroelectronics
+	  STM32 platforms.
+	  If you have a board based on STM32 SoC with such DMA3 controller
+	  and want to use DMA3, say Y here.
+
+endif