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 --- drivers/ntb/Kconfig | 40 ++++++++++++++++++++++++++++++++++++++++ 1 file changed, 40 insertions(+) create mode 100644 drivers/ntb/Kconfig (limited to 'drivers/ntb/Kconfig') diff --git a/drivers/ntb/Kconfig b/drivers/ntb/Kconfig new file mode 100644 index 000000000..df16c755b --- /dev/null +++ b/drivers/ntb/Kconfig @@ -0,0 +1,40 @@ +# SPDX-License-Identifier: GPL-2.0-only +menuconfig NTB + tristate "Non-Transparent Bridge support" + depends on PCI + help + The PCI-E Non-transparent bridge hardware is a point-to-point PCI-E bus + connecting 2 systems. When configured, writes to the device's PCI + mapped memory will be mirrored to a buffer on the remote system. The + ntb Linux driver uses this point-to-point communication as a method to + transfer data from one system to the other. + + If unsure, say N. + +if NTB + +config NTB_MSI + bool "MSI Interrupt Support" + depends on PCI_MSI + help + Support using MSI interrupt forwarding instead of (or in addition to) + hardware doorbells. MSI interrupts typically offer lower latency + than doorbells and more MSI interrupts can be made available to + clients. However this requires an extra memory window and support + in the hardware driver for creating the MSI interrupts. + + If unsure, say N. +source "drivers/ntb/hw/Kconfig" + +source "drivers/ntb/test/Kconfig" + +config NTB_TRANSPORT + tristate "NTB Transport Client" + help + This is a transport driver that enables connected systems to exchange + messages over the ntb hardware. The transport exposes a queue pair api + to client drivers. + + If unsure, say N. + +endif # NTB -- cgit v1.3.1