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/gpu/host1x/Kconfig | 30 ++++++++++++++++++++++++++++++ 1 file changed, 30 insertions(+) create mode 100644 drivers/gpu/host1x/Kconfig (limited to 'drivers/gpu/host1x/Kconfig') diff --git a/drivers/gpu/host1x/Kconfig b/drivers/gpu/host1x/Kconfig new file mode 100644 index 000000000..e6c78ae20 --- /dev/null +++ b/drivers/gpu/host1x/Kconfig @@ -0,0 +1,30 @@ +# SPDX-License-Identifier: GPL-2.0-only + +config TEGRA_HOST1X_CONTEXT_BUS + bool + +config TEGRA_HOST1X + tristate "NVIDIA Tegra host1x driver" + depends on ARCH_TEGRA || COMPILE_TEST + select DMA_SHARED_BUFFER + select TEGRA_HOST1X_CONTEXT_BUS + select IOMMU_IOVA + help + Driver for the NVIDIA Tegra host1x hardware. + + The Tegra host1x module is the DMA engine for register access to + Tegra's graphics- and multimedia-related modules. The modules served + by host1x are referred to as clients. host1x includes some other + functionality, such as synchronization. + +if TEGRA_HOST1X + +config TEGRA_HOST1X_FIREWALL + bool "Enable HOST1X security firewall" + default y + help + Say yes if kernel should protect command streams from tampering. + + If unsure, choose Y. + +endif -- cgit v1.3.1