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/iommu/amd/Kconfig | 53 +++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 53 insertions(+) create mode 100644 drivers/iommu/amd/Kconfig (limited to 'drivers/iommu/amd/Kconfig') diff --git a/drivers/iommu/amd/Kconfig b/drivers/iommu/amd/Kconfig new file mode 100644 index 000000000..588355ff7 --- /dev/null +++ b/drivers/iommu/amd/Kconfig @@ -0,0 +1,53 @@ +# SPDX-License-Identifier: GPL-2.0-only +# AMD IOMMU support +config AMD_IOMMU + bool "AMD IOMMU support" + select SWIOTLB + select PCI_MSI + select PCI_ATS + select PCI_PRI + select PCI_PASID + select IRQ_MSI_LIB + select MMU_NOTIFIER + select IOMMU_API + select IOMMU_IOVA + select IOMMU_SVA + select IOMMU_IOPF + select IOMMUFD_DRIVER if IOMMUFD + select GENERIC_PT + select IOMMU_PT + select IOMMU_PT_AMDV1 + select IOMMU_PT_X86_64 + depends on X86_64 && PCI && ACPI && HAVE_CMPXCHG_DOUBLE + help + With this option you can enable support for AMD IOMMU hardware in + your system. An IOMMU is a hardware component which provides + remapping of DMA memory accesses from devices. With an AMD IOMMU you + can isolate the DMA memory of different devices and protect the + system from misbehaving device drivers or hardware. + + You can find out if your system has an AMD IOMMU if you look into + your BIOS for an option to enable it or if you have an IVRS ACPI + table. + +config AMD_IOMMU_IOMMUFD + bool "Enable IOMMUFD features for AMD IOMMU (EXPERIMENTAL)" + depends on IOMMUFD + depends on AMD_IOMMU + help + Support for IOMMUFD features intended to support virtual machines + with accelerated virtual IOMMUs. + + Say Y here if you are doing development and testing on this feature. + +config AMD_IOMMU_DEBUGFS + bool "Enable AMD IOMMU internals in DebugFS" + depends on AMD_IOMMU && IOMMU_DEBUGFS + help + !!!WARNING!!! !!!WARNING!!! !!!WARNING!!! !!!WARNING!!! + + DO NOT ENABLE THIS OPTION UNLESS YOU REALLY, -REALLY- KNOW WHAT YOU ARE DOING!!! + Exposes AMD IOMMU device internals in DebugFS. + + This option is -NOT- intended for production environments, and should + not generally be enabled. -- cgit v1.3.1