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, 34 insertions, 0 deletions

diff --git a/drivers/mtd/Makefile b/drivers/mtd/Makefile
new file mode 100644
index 000000000..7b6dd53e8
--- /dev/null
+++ b/drivers/mtd/Makefile
@@ -0,0 +1,34 @@
+# SPDX-License-Identifier: GPL-2.0
+#
+# Makefile for the memory technology device drivers.
+#
+
+# Core functionality.
+obj-$(CONFIG_MTD)		+= mtd.o
+mtd-y				:= mtdcore.o mtdsuper.o mtdconcat.o mtdpart.o mtdchar.o
+mtd-$(CONFIG_MTD_VIRT_CONCAT)	+= mtd_virt_concat.o
+
+obj-y				+= parsers/
+
+# 'Users' - code which presents functionality to userspace.
+obj-$(CONFIG_MTD_BLKDEVS)	+= mtd_blkdevs.o
+obj-$(CONFIG_MTD_BLOCK)		+= mtdblock.o
+obj-$(CONFIG_MTD_BLOCK_RO)	+= mtdblock_ro.o
+obj-$(CONFIG_FTL)		+= ftl.o
+obj-$(CONFIG_NFTL)		+= nftl.o
+obj-$(CONFIG_INFTL)		+= inftl.o
+obj-$(CONFIG_RFD_FTL)		+= rfd_ftl.o
+obj-$(CONFIG_SSFDC)		+= ssfdc.o
+obj-$(CONFIG_SM_FTL)		+= sm_ftl.o
+obj-$(CONFIG_MTD_OOPS)		+= mtdoops.o
+obj-$(CONFIG_MTD_PSTORE)	+= mtdpstore.o
+obj-$(CONFIG_MTD_SWAP)		+= mtdswap.o
+
+nftl-objs		:= nftlcore.o nftlmount.o
+inftl-objs		:= inftlcore.o inftlmount.o
+
+obj-y		+= chips/ lpddr/ maps/ devices/ nand/ tests/
+
+obj-$(CONFIG_MTD_SPI_NOR)	+= spi-nor/
+obj-$(CONFIG_MTD_UBI)		+= ubi/
+obj-$(CONFIG_MTD_HYPERBUS)	+= hyperbus/