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 --- arch/mips/kvm/Kconfig | 41 +++++++++++++++++++++++++++++++++++++++++ 1 file changed, 41 insertions(+) create mode 100644 arch/mips/kvm/Kconfig (limited to 'arch/mips/kvm/Kconfig') diff --git a/arch/mips/kvm/Kconfig b/arch/mips/kvm/Kconfig new file mode 100644 index 000000000..b1b9a1d67 --- /dev/null +++ b/arch/mips/kvm/Kconfig @@ -0,0 +1,41 @@ +# SPDX-License-Identifier: GPL-2.0 +# +# KVM configuration +# +source "virt/kvm/Kconfig" + +menuconfig VIRTUALIZATION + bool "Virtualization" + help + Say Y here to get to see options for using your Linux host to run + other operating systems inside virtual machines (guests). + This option alone does not add any kernel code. + + If you say N, all options in this submenu will be skipped and disabled. + +if VIRTUALIZATION + +config KVM + tristate "Kernel-based Virtual Machine (KVM) support" + depends on CPU_SUPPORTS_VZ + depends on MIPS_FP_SUPPORT + select EXPORT_UASM + select KVM_COMMON + select KVM_GENERIC_DIRTYLOG_READ_PROTECT + select KVM_MMIO + select KVM_GENERIC_HARDWARE_ENABLING + select HAVE_KVM_READONLY_MEM + help + Support for hosting Guest kernels. + +config KVM_MIPS_DEBUG_COP0_COUNTERS + bool "Maintain counters for COP0 accesses" + depends on KVM + help + Maintain statistics for Guest COP0 accesses. + A histogram of COP0 accesses is printed when the VM is + shutdown. + + If unsure, say N. + +endif # VIRTUALIZATION -- cgit v1.3.1