1/* SPDX-License-Identifier: GPL-2.0-only */
2/* A pointer that can point to either kernel or userspace memory. */
3#ifndef _LINUX_BPFPTR_H
4#define _LINUX_BPFPTR_H
5
6#include <linux/mm.h>
7#include <linux/sockptr.h>
8
9typedef sockptr_t bpfptr_t;
10
11static inline bool bpfptr_is_kernel(bpfptr_t bpfptr)
12{
13	return bpfptr.is_kernel;
14}
15
16static inline bpfptr_t KERNEL_BPFPTR(void *p)
17{
18	return (bpfptr_t) { .kernel = p, .is_kernel = true };
19}
20
21static inline bpfptr_t USER_BPFPTR(void __user *p)
22{
23	return (bpfptr_t) { .user = p };
24}
25
26static inline bpfptr_t make_bpfptr(u64 addr, bool is_kernel)
27{
28	if (is_kernel)
29		return KERNEL_BPFPTR((void*) (uintptr_t) addr);
30	else
31		return USER_BPFPTR(u64_to_user_ptr(addr));
32}
33
34static inline bool bpfptr_is_null(bpfptr_t bpfptr)
35{
36	if (bpfptr_is_kernel(bpfptr))
37		return !bpfptr.kernel;
38	return !bpfptr.user;
39}
40
41static inline void bpfptr_add(bpfptr_t *bpfptr, size_t val)
42{
43	if (bpfptr_is_kernel(*bpfptr))
44		bpfptr->kernel += val;
45	else
46		bpfptr->user += val;
47}
48
49static inline int copy_from_bpfptr_offset(void *dst, bpfptr_t src,
50					  size_t offset, size_t size)
51{
52	if (!bpfptr_is_kernel(src))
53		return copy_from_user(dst, src.user + offset, size);
54	return copy_from_kernel_nofault(dst, src.kernel + offset, size);
55}
56
57static inline int copy_from_bpfptr(void *dst, bpfptr_t src, size_t size)
58{
59	return copy_from_bpfptr_offset(dst, src, 0, size);
60}
61
62static inline int copy_to_bpfptr_offset(bpfptr_t dst, size_t offset,
63					const void *src, size_t size)
64{
65	return copy_to_sockptr_offset((sockptr_t) dst, offset, src, size);
66}
67
68static inline void *kvmemdup_bpfptr(bpfptr_t src, size_t len)
69{
70	void *p = kvmalloc(len, GFP_USER | __GFP_NOWARN);
71
72	if (!p)
73		return ERR_PTR(-ENOMEM);
74	if (copy_from_bpfptr(p, src, len)) {
75		kvfree(p);
76		return ERR_PTR(-EFAULT);
77	}
78	return p;
79}
80
81static inline long strncpy_from_bpfptr(char *dst, bpfptr_t src, size_t count)
82{
83	if (bpfptr_is_kernel(src))
84		return strncpy_from_kernel_nofault(dst, src.kernel, count);
85	return strncpy_from_user(dst, src.user, count);
86}
87
88#endif /* _LINUX_BPFPTR_H */
89