From 6668ed271eaefaa63e686bdfbedaeb7b8e492722 Mon Sep 17 00:00:00 2001 From: Kumar Kartikeya Dwivedi Date: Fri, 4 Sep 2026 10:43:19 +0200 Subject: selftests/bpf: Reject graph kptr use after RCU unlock 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 Link: https://lore.kernel.org/r/20260904084325.52250-7-memxor@gmail.com Signed-off-by: Alexei Starovoitov --- Documentation/PCI/controller/index.rst | 10 +++++++ .../PCI/controller/rcar-pcie-firmware.rst | 32 ++++++++++++++++++++++ 2 files changed, 42 insertions(+) create mode 100644 Documentation/PCI/controller/index.rst create mode 100644 Documentation/PCI/controller/rcar-pcie-firmware.rst (limited to 'Documentation/PCI/controller') diff --git a/Documentation/PCI/controller/index.rst b/Documentation/PCI/controller/index.rst new file mode 100644 index 000000000..c2ce9ccdc --- /dev/null +++ b/Documentation/PCI/controller/index.rst @@ -0,0 +1,10 @@ +.. SPDX-License-Identifier: GPL-2.0 + +=========================================== +PCI Native Host Bridge and Endpoint Drivers +=========================================== + +.. toctree:: + :maxdepth: 2 + + rcar-pcie-firmware diff --git a/Documentation/PCI/controller/rcar-pcie-firmware.rst b/Documentation/PCI/controller/rcar-pcie-firmware.rst new file mode 100644 index 000000000..67d3bf66e --- /dev/null +++ b/Documentation/PCI/controller/rcar-pcie-firmware.rst @@ -0,0 +1,32 @@ +.. SPDX-License-Identifier: GPL-2.0 + +================================================= +Firmware of PCIe controller for Renesas R-Car V4H +================================================= + +Renesas R-Car V4H (r8a779g0) has a PCIe controller, requiring a specific +firmware download during startup. + +However, Renesas currently cannot distribute the firmware free of charge. + +The firmware file "104_PCIe_fw_addr_data_ver1.05.txt" (note that the file name +might be different between different datasheet revisions) can be found in the +datasheet encoded as text, and as such, the file's content must be converted +back to binary form. This can be achieved using the following example script: + +.. code-block:: sh + + $ awk '/^\s*0x[0-9A-Fa-f]{4}\s+0x[0-9A-Fa-f]{4}/ { print substr($2,5,2) substr($2,3,2) }' \ + 104_PCIe_fw_addr_data_ver1.05.txt | \ + xxd -p -r > rcar_gen4_pcie.bin + +Once the text content has been converted into a binary firmware file, verify +its checksum as follows: + +.. code-block:: sh + + $ sha1sum rcar_gen4_pcie.bin + 1d0bd4b189b4eb009f5d564b1f93a79112994945 rcar_gen4_pcie.bin + +The resulting binary file called "rcar_gen4_pcie.bin" should be placed in the +"/lib/firmware" directory before the driver runs. -- cgit v1.3.1