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, 64 insertions, 0 deletions

diff --git a/drivers/vfio/cdx/private.h b/drivers/vfio/cdx/private.h
new file mode 100644
index 000000000..4c00bf633
--- /dev/null
+++ b/drivers/vfio/cdx/private.h
@@ -0,0 +1,64 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright (C) 2022-2023, Advanced Micro Devices, Inc.
+ */
+
+#ifndef VFIO_CDX_PRIVATE_H
+#define VFIO_CDX_PRIVATE_H
+
+#include <linux/mutex.h>
+
+#define VFIO_CDX_OFFSET_SHIFT    40
+
+static inline u64 vfio_cdx_index_to_offset(u32 index)
+{
+	return ((u64)(index) << VFIO_CDX_OFFSET_SHIFT);
+}
+
+struct vfio_cdx_irq {
+	u32			flags;
+	u32			count;
+	int			irq_no;
+	struct eventfd_ctx	*trigger;
+	char			*name;
+};
+
+struct vfio_cdx_region {
+	u32			flags;
+	u32			type;
+	u64			addr;
+	resource_size_t		size;
+};
+
+struct vfio_cdx_device {
+	struct vfio_device	vdev;
+	struct vfio_cdx_region	*regions;
+	struct mutex		cdx_irqs_lock;
+	struct vfio_cdx_irq	*cdx_irqs;
+	u32			flags;
+#define BME_SUPPORT BIT(0)
+	u32			msi_count;
+};
+
+#ifdef CONFIG_GENERIC_MSI_IRQ
+int vfio_cdx_set_irqs_ioctl(struct vfio_cdx_device *vdev,
+			    u32 flags, unsigned int index,
+			    unsigned int start, unsigned int count,
+			    void *data);
+
+void vfio_cdx_irqs_cleanup(struct vfio_cdx_device *vdev);
+#else
+static int vfio_cdx_set_irqs_ioctl(struct vfio_cdx_device *vdev,
+				   u32 flags, unsigned int index,
+				   unsigned int start, unsigned int count,
+				   void *data)
+{
+	return -EINVAL;
+}
+
+static void vfio_cdx_irqs_cleanup(struct vfio_cdx_device *vdev)
+{
+}
+#endif
+
+#endif /* VFIO_CDX_PRIVATE_H */