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/intel/perfmon.h | 64 +++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 64 insertions(+) create mode 100644 drivers/iommu/intel/perfmon.h (limited to 'drivers/iommu/intel/perfmon.h') diff --git a/drivers/iommu/intel/perfmon.h b/drivers/iommu/intel/perfmon.h new file mode 100644 index 000000000..58606af9a --- /dev/null +++ b/drivers/iommu/intel/perfmon.h @@ -0,0 +1,64 @@ +/* SPDX-License-Identifier: GPL-2.0 */ + +/* + * PERFCFGOFF_REG, PERFFRZOFF_REG + * PERFOVFOFF_REG, PERFCNTROFF_REG + */ +#define IOMMU_PMU_NUM_OFF_REGS 4 +#define IOMMU_PMU_OFF_REGS_STEP 4 + +#define IOMMU_PMU_FILTER_REQUESTER_ID 0x01 +#define IOMMU_PMU_FILTER_DOMAIN 0x02 +#define IOMMU_PMU_FILTER_PASID 0x04 +#define IOMMU_PMU_FILTER_ATS 0x08 +#define IOMMU_PMU_FILTER_PAGE_TABLE 0x10 + +#define IOMMU_PMU_FILTER_EN BIT(31) + +#define IOMMU_PMU_CFG_OFFSET 0x100 +#define IOMMU_PMU_CFG_CNTRCAP_OFFSET 0x80 +#define IOMMU_PMU_CFG_CNTREVCAP_OFFSET 0x84 +#define IOMMU_PMU_CFG_SIZE 0x8 +#define IOMMU_PMU_CFG_FILTERS_OFFSET 0x4 + +#define IOMMU_PMU_CAP_REGS_STEP 8 + +#define iommu_cntrcap_pcc(p) ((p) & 0x1) +#define iommu_cntrcap_cw(p) (((p) >> 8) & 0xff) +#define iommu_cntrcap_ios(p) (((p) >> 16) & 0x1) +#define iommu_cntrcap_egcnt(p) (((p) >> 28) & 0xf) + +#define IOMMU_EVENT_CFG_EGI_SHIFT 8 +#define IOMMU_EVENT_CFG_ES_SHIFT 32 +#define IOMMU_EVENT_CFG_INT BIT_ULL(1) + +#define iommu_event_select(p) ((p) & 0xfffffff) +#define iommu_event_group(p) (((p) >> 28) & 0xf) + +#ifdef CONFIG_INTEL_IOMMU_PERF_EVENTS +int alloc_iommu_pmu(struct intel_iommu *iommu); +void free_iommu_pmu(struct intel_iommu *iommu); +void iommu_pmu_register(struct intel_iommu *iommu); +void iommu_pmu_unregister(struct intel_iommu *iommu); +#else +static inline int +alloc_iommu_pmu(struct intel_iommu *iommu) +{ + return 0; +} + +static inline void +free_iommu_pmu(struct intel_iommu *iommu) +{ +} + +static inline void +iommu_pmu_register(struct intel_iommu *iommu) +{ +} + +static inline void +iommu_pmu_unregister(struct intel_iommu *iommu) +{ +} +#endif /* CONFIG_INTEL_IOMMU_PERF_EVENTS */ -- cgit v1.3.1