1 files changed, 88 insertions, 0 deletions
diff --git a/include/linux/bpfptr.h b/include/linux/bpfptr.h
new file mode 100644
index 000000000000..79b2f78eec1a
--- /dev/null
+++ b/include/linux/bpfptr.h
@@ -0,0 +1,88 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/* A pointer that can point to either kernel or userspace memory. */
+#ifndef _LINUX_BPFPTR_H
+#define _LINUX_BPFPTR_H
+
+#include <linux/mm.h>
+#include <linux/sockptr.h>
+
+typedef sockptr_t bpfptr_t;
+
+static inline bool bpfptr_is_kernel(bpfptr_t bpfptr)
+{
+	return bpfptr.is_kernel;
+}
+
+static inline bpfptr_t KERNEL_BPFPTR(void *p)
+{
+	return (bpfptr_t) { .kernel = p, .is_kernel = true };
+}
+
+static inline bpfptr_t USER_BPFPTR(void __user *p)
+{
+	return (bpfptr_t) { .user = p };
+}
+
+static inline bpfptr_t make_bpfptr(u64 addr, bool is_kernel)
+{
+	if (is_kernel)
+		return KERNEL_BPFPTR((void*) (uintptr_t) addr);
+	else
+		return USER_BPFPTR(u64_to_user_ptr(addr));
+}
+
+static inline bool bpfptr_is_null(bpfptr_t bpfptr)
+{
+	if (bpfptr_is_kernel(bpfptr))
+		return !bpfptr.kernel;
+	return !bpfptr.user;
+}
+
+static inline void bpfptr_add(bpfptr_t *bpfptr, size_t val)
+{
+	if (bpfptr_is_kernel(*bpfptr))
+		bpfptr->kernel += val;
+	else
+		bpfptr->user += val;
+}
+
+static inline int copy_from_bpfptr_offset(void *dst, bpfptr_t src,
+					  size_t offset, size_t size)
+{
+	if (!bpfptr_is_kernel(src))
+		return copy_from_user(dst, src.user + offset, size);
+	return copy_from_kernel_nofault(dst, src.kernel + offset, size);
+}
+
+static inline int copy_from_bpfptr(void *dst, bpfptr_t src, size_t size)
+{
+	return copy_from_bpfptr_offset(dst, src, 0, size);
+}
+
+static inline int copy_to_bpfptr_offset(bpfptr_t dst, size_t offset,
+					const void *src, size_t size)
+{
+	return copy_to_sockptr_offset((sockptr_t) dst, offset, src, size);
+}
+
+static inline void *kvmemdup_bpfptr(bpfptr_t src, size_t len)
+{
+	void *p = kvmalloc(len, GFP_USER | __GFP_NOWARN);
+
+	if (!p)
+		return ERR_PTR(-ENOMEM);
+	if (copy_from_bpfptr(p, src, len)) {
+		kvfree(p);
+		return ERR_PTR(-EFAULT);
+	}
+	return p;
+}
+
+static inline long strncpy_from_bpfptr(char *dst, bpfptr_t src, size_t count)
+{
+	if (bpfptr_is_kernel(src))
+		return strncpy_from_kernel_nofault(dst, src.kernel, count);
+	return strncpy_from_user(dst, src.user, count);
+}
+
+#endif /* _LINUX_BPFPTR_H */