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(p: (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: *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(bpfptr: src))
53 return copy_from_user(to: dst, from: src.user + offset, n: size);
54 return copy_from_kernel_nofault(dst, src: 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, offset: 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(dst: (sockptr_t) dst, offset, src, size);
66}
67
68static inline void *kvmemdup_bpfptr_noprof(bpfptr_t src, size_t len)
69{
70 void *p = kvmalloc_noprof(len, GFP_USER | __GFP_NOWARN);
71
72 if (!p)
73 return ERR_PTR(error: -ENOMEM);
74 if (copy_from_bpfptr(dst: p, src, size: len)) {
75 kvfree(addr: p);
76 return ERR_PTR(error: -EFAULT);
77 }
78 return p;
79}
80#define kvmemdup_bpfptr(...) alloc_hooks(kvmemdup_bpfptr_noprof(__VA_ARGS__))
81
82static inline long strncpy_from_bpfptr(char *dst, bpfptr_t src, size_t count)
83{
84 if (bpfptr_is_kernel(bpfptr: src))
85 return strncpy_from_kernel_nofault(dst, unsafe_addr: src.kernel, count);
86 return strncpy_from_user(dst, src: src.user, count);
87}
88
89#endif /* _LINUX_BPFPTR_H */
90

source code of linux/include/linux/bpfptr.h