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/stats.c | 63 +++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 63 insertions(+) create mode 100644 arch/mips/kvm/stats.c (limited to 'arch/mips/kvm/stats.c') diff --git a/arch/mips/kvm/stats.c b/arch/mips/kvm/stats.c new file mode 100644 index 000000000..3e6682018 --- /dev/null +++ b/arch/mips/kvm/stats.c @@ -0,0 +1,63 @@ +/* + * This file is subject to the terms and conditions of the GNU General Public + * License. See the file "COPYING" in the main directory of this archive + * for more details. + * + * KVM/MIPS: COP0 access histogram + * + * Copyright (C) 2012 MIPS Technologies, Inc. All rights reserved. + * Authors: Sanjay Lal + */ + +#include + +char *kvm_cop0_str[N_MIPS_COPROC_REGS] = { + "Index", + "Random", + "EntryLo0", + "EntryLo1", + "Context", + "PG Mask", + "Wired", + "HWREna", + "BadVAddr", + "Count", + "EntryHI", + "Compare", + "Status", + "Cause", + "EXC PC", + "PRID", + "Config", + "LLAddr", + "Watch Lo", + "Watch Hi", + "X Context", + "Reserved", + "Impl Dep", + "Debug", + "DEPC", + "PerfCnt", + "ErrCtl", + "CacheErr", + "TagLo", + "TagHi", + "ErrorEPC", + "DESAVE" +}; + +void kvm_mips_dump_stats(struct kvm_vcpu *vcpu) +{ +#ifdef CONFIG_KVM_MIPS_DEBUG_COP0_COUNTERS + int i, j; + + kvm_info("\nKVM VCPU[%d] COP0 Access Profile:\n", vcpu->vcpu_id); + for (i = 0; i < N_MIPS_COPROC_REGS; i++) { + for (j = 0; j < N_MIPS_COPROC_SEL; j++) { + if (vcpu->arch.cop0.stat[i][j]) + kvm_info("%s[%d]: %lu\n", kvm_cop0_str[i], j, + vcpu->arch.cop0.stat[i][j]); + } + } +#endif +} -- cgit v1.3.1