bpf: mark a NULL kfunc argument precisegrafted

check_kfunc_arg() allows bpf_register_is_null() for nullable arguments
w/o marking the underlying scalar register precise. Hence a checkpoint
created on such a path would prune against arbitrary scalar value.

Fixes: 3bda08b63670 ("bpf: Allow NULL buffers in bpf_dynptr_slice(_rw)")
Signed-off-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/r/20260904-register-is-null-precise-fixes-v1-5-0f5a360ff15d@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

1 files changed, 71 insertions, 0 deletions

diff --git a/drivers/iommu/intel/perf.h b/drivers/iommu/intel/perf.h
new file mode 100644
index 000000000..1d4baad7e
--- /dev/null
+++ b/drivers/iommu/intel/perf.h
@@ -0,0 +1,71 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * perf.h - performance monitor header
+ *
+ * Copyright (C) 2021 Intel Corporation
+ *
+ * Author: Lu Baolu <baolu.lu@linux.intel.com>
+ */
+
+enum latency_type {
+	DMAR_LATENCY_INV_IOTLB = 0,
+	DMAR_LATENCY_INV_DEVTLB,
+	DMAR_LATENCY_INV_IEC,
+	DMAR_LATENCY_NUM
+};
+
+enum latency_count {
+	COUNTS_10e2 = 0,	/* < 0.1us	*/
+	COUNTS_10e3,		/* 0.1us ~ 1us	*/
+	COUNTS_10e4,		/* 1us ~ 10us	*/
+	COUNTS_10e5,		/* 10us ~ 100us	*/
+	COUNTS_10e6,		/* 100us ~ 1ms	*/
+	COUNTS_10e7,		/* 1ms ~ 10ms	*/
+	COUNTS_10e8_plus,	/* 10ms and plus*/
+	COUNTS_MIN,
+	COUNTS_MAX,
+	COUNTS_SUM,
+	COUNTS_NUM
+};
+
+struct latency_statistic {
+	bool enabled;
+	u64 counter[COUNTS_NUM];
+	u64 samples;
+};
+
+#ifdef CONFIG_DMAR_PERF
+int dmar_latency_enable(struct intel_iommu *iommu, enum latency_type type);
+void dmar_latency_disable(struct intel_iommu *iommu, enum latency_type type);
+bool dmar_latency_enabled(struct intel_iommu *iommu, enum latency_type type);
+void dmar_latency_update(struct intel_iommu *iommu, enum latency_type type,
+			 u64 latency);
+void dmar_latency_snapshot(struct intel_iommu *iommu, char *str, size_t size);
+#else
+static inline int
+dmar_latency_enable(struct intel_iommu *iommu, enum latency_type type)
+{
+	return -EINVAL;
+}
+
+static inline void
+dmar_latency_disable(struct intel_iommu *iommu, enum latency_type type)
+{
+}
+
+static inline bool
+dmar_latency_enabled(struct intel_iommu *iommu, enum latency_type type)
+{
+	return false;
+}
+
+static inline void
+dmar_latency_update(struct intel_iommu *iommu, enum latency_type type, u64 latency)
+{
+}
+
+static inline void
+dmar_latency_snapshot(struct intel_iommu *iommu, char *str, size_t size)
+{
+}
+#endif /* CONFIG_DMAR_PERF */