From: Alexei Starovoitov <ast@xxxxxxxxxx>
Similar to sockptr_t introduce bpfptr_t with few additions:
make_bpfptr() creates new user/kernel pointer in the same address space as
existing user/kernel pointer.
bpfptr_add() advances the user/kernel pointer.
Signed-off-by: Alexei Starovoitov <ast@xxxxxxxxxx>
Acked-by: Andrii Nakryiko <andrii@xxxxxxxxxx>
---
include/linux/bpfptr.h | 75 ++++++++++++++++++++++++++++++++++++++++++
1 file changed, 75 insertions(+)
create mode 100644 include/linux/bpfptr.h
diff --git a/include/linux/bpfptr.h b/include/linux/bpfptr.h
new file mode 100644
index 000000000000..5cdeab497cb3
--- /dev/null
+++ b/include/linux/bpfptr.h
@@ -0,0 +1,75 @@
+/* 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/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)
+{
+ return copy_from_sockptr_offset(dst, (sockptr_t) src, 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 *memdup_bpfptr(bpfptr_t src, size_t len)
+{
+ return memdup_sockptr((sockptr_t) src, len);
+}
+
+static inline long strncpy_from_bpfptr(char *dst, bpfptr_t src, size_t count)
+{
+ return strncpy_from_sockptr(dst, (sockptr_t) src, count);
+}
+
+#endif /* _LINUX_BPFPTR_H */
--
2.30.2
