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 | |
9 | typedef sockptr_t bpfptr_t; |
10 | |
11 | static inline bool bpfptr_is_kernel(bpfptr_t bpfptr) |
12 | { |
13 | return bpfptr.is_kernel; |
14 | } |
15 | |
16 | static inline bpfptr_t KERNEL_BPFPTR(void *p) |
17 | { |
18 | return (bpfptr_t) { .kernel = p, .is_kernel = true }; |
19 | } |
20 | |
21 | static inline bpfptr_t USER_BPFPTR(void __user *p) |
22 | { |
23 | return (bpfptr_t) { .user = p }; |
24 | } |
25 | |
26 | static 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 | |
34 | static 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 | |
41 | static 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 | |
49 | static 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 | |
57 | static 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 | |
62 | static 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 | |
68 | static inline void *kvmemdup_bpfptr(bpfptr_t src, size_t len) |
69 | { |
70 | void *p = kvmalloc(size: 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 | |
81 | static inline long strncpy_from_bpfptr(char *dst, bpfptr_t src, size_t count) |
82 | { |
83 | if (bpfptr_is_kernel(bpfptr: src)) |
84 | return strncpy_from_kernel_nofault(dst, unsafe_addr: src.kernel, count); |
85 | return strncpy_from_user(dst, src: src.user, count); |
86 | } |
87 | |
88 | #endif /* _LINUX_BPFPTR_H */ |
89 | |