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, 38 insertions, 0 deletions

diff --git a/fs/nfs/Makefile b/fs/nfs/Makefile
new file mode 100644
index 000000000..c895521f2
--- /dev/null
+++ b/fs/nfs/Makefile
@@ -0,0 +1,38 @@
+# SPDX-License-Identifier: GPL-2.0
+#
+# Makefile for the Linux nfs filesystem routines.
+#
+
+obj-$(CONFIG_NFS_FS) += nfs.o
+
+CFLAGS_nfstrace.o += -I$(src)
+nfs-y 			:= client.o dir.o file.o getroot.o inode.o super.o \
+			   io.o direct.o pagelist.o read.o symlink.o unlink.o \
+			   write.o namespace.o mount_clnt.o nfstrace.o \
+			   export.o sysfs.o fs_context.o
+nfs-$(CONFIG_ROOT_NFS)	+= nfsroot.o
+nfs-$(CONFIG_SYSCTL)	+= sysctl.o
+nfs-$(CONFIG_NFS_FSCACHE) += fscache.o
+nfs-$(CONFIG_NFS_LOCALIO) += localio.o
+
+obj-$(CONFIG_NFS_V2) += nfsv2.o
+nfsv2-y := nfs2super.o proc.o nfs2xdr.o
+
+obj-$(CONFIG_NFS_V3) += nfsv3.o
+nfsv3-y := nfs3super.o nfs3client.o nfs3proc.o nfs3xdr.o
+nfsv3-$(CONFIG_NFS_V3_ACL) += nfs3acl.o
+
+obj-$(CONFIG_NFS_V4) += nfsv4.o
+CFLAGS_nfs4trace.o += -I$(src)
+nfsv4-y := nfs4proc.o nfs4xdr.o nfs4state.o nfs4renewd.o nfs4super.o nfs4file.o \
+	  delegation.o nfs4idmap.o callback.o callback_xdr.o callback_proc.o \
+	  nfs4namespace.o nfs4getroot.o nfs4client.o nfs4session.o \
+	  dns_resolve.o nfs4trace.o pnfs.o pnfs_dev.o pnfs_nfs.o
+nfsv4-$(CONFIG_NFS_USE_LEGACY_DNS) += cache_lib.o
+nfsv4-$(CONFIG_SYSCTL)	+= nfs4sysctl.o
+nfsv4-$(CONFIG_NFS_V4_0)	+= nfs40client.o nfs40proc.o
+nfsv4-$(CONFIG_NFS_V4_2)	+= nfs42proc.o nfs42xattr.o
+
+obj-$(CONFIG_PNFS_FILE_LAYOUT) += filelayout/
+obj-$(CONFIG_PNFS_BLOCK) += blocklayout/
+obj-$(CONFIG_PNFS_FLEXFILE_LAYOUT) += flexfilelayout/