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>

2 files changed, 64 insertions, 0 deletions

diff --git a/Documentation/PCI/endpoint/function/binding/pci-ntb.rst b/Documentation/PCI/endpoint/function/binding/pci-ntb.rst
new file mode 100644
index 000000000..40253d3d5
--- /dev/null
+++ b/Documentation/PCI/endpoint/function/binding/pci-ntb.rst
@@ -0,0 +1,38 @@
+.. SPDX-License-Identifier: GPL-2.0
+
+==========================
+PCI NTB Endpoint Function
+==========================
+
+1) Create a subdirectory to pci_epf_ntb directory in configfs.
+
+Standard EPF Configurable Fields:
+
+================   ===========================================================
+vendorid	   should be 0x104c
+deviceid	   should be 0xb00d for TI's J721E SoC
+revid		   don't care
+progif_code	   don't care
+subclass_code	   should be 0x00
+baseclass_code	   should be 0x5
+cache_line_size	   don't care
+subsys_vendor_id   don't care
+subsys_id	   don't care
+interrupt_pin	   don't care
+msi_interrupts	   don't care
+msix_interrupts	   don't care
+================   ===========================================================
+
+2) Create a subdirectory to directory created in 1
+
+NTB EPF specific configurable fields:
+
+================   ===========================================================
+db_count	   Number of doorbells; default = 4
+mw1     	   size of memory window1
+mw2     	   size of memory window2
+mw3     	   size of memory window3
+mw4     	   size of memory window4
+num_mws     	   Number of memory windows; max = 4
+spad_count     	   Number of scratchpad registers; default = 64
+================   ===========================================================
diff --git a/Documentation/PCI/endpoint/function/binding/pci-test.rst b/Documentation/PCI/endpoint/function/binding/pci-test.rst
new file mode 100644
index 000000000..57ee866fb
--- /dev/null
+++ b/Documentation/PCI/endpoint/function/binding/pci-test.rst
@@ -0,0 +1,26 @@
+.. SPDX-License-Identifier: GPL-2.0
+
+==========================
+PCI Test Endpoint Function
+==========================
+
+name: Should be "pci_epf_test" to bind to the pci_epf_test driver.
+
+Configurable Fields:
+
+================   ===========================================================
+vendorid	   should be 0x104c
+deviceid	   should be 0xb500 for DRA74x and 0xb501 for DRA72x
+revid		   don't care
+progif_code	   don't care
+subclass_code	   don't care
+baseclass_code	   should be 0xff
+cache_line_size	   don't care
+subsys_vendor_id   don't care
+subsys_id	   don't care
+interrupt_pin	   Should be 1 - INTA, 2 - INTB, 3 - INTC, 4 -INTD
+msi_interrupts	   Should be 1 to 32 depending on the number of MSI interrupts
+		   to test
+msix_interrupts	   Should be 1 to 2048 depending on the number of MSI-X
+		   interrupts to test
+================   ===========================================================