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
bpfptr_is_kernel(bpfptr_t bpfptr)11 static inline bool bpfptr_is_kernel(bpfptr_t bpfptr)
12 {
13 return bpfptr.is_kernel;
14 }
15
KERNEL_BPFPTR(void * p)16 static inline bpfptr_t KERNEL_BPFPTR(void *p)
17 {
18 return (bpfptr_t) { .kernel = p, .is_kernel = true };
19 }
20
USER_BPFPTR(void __user * p)21 static inline bpfptr_t USER_BPFPTR(void __user *p)
22 {
23 return (bpfptr_t) { .user = p };
24 }
25
make_bpfptr(u64 addr,bool is_kernel)26 static 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
bpfptr_is_null(bpfptr_t bpfptr)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
bpfptr_add(bpfptr_t * bpfptr,size_t val)41 static 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
copy_from_bpfptr_offset(void * dst,bpfptr_t src,size_t offset,size_t size)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(src))
53 return copy_from_user(dst, src.user + offset, size);
54 return copy_from_kernel_nofault(dst, src.kernel + offset, size);
55 }
56
copy_from_bpfptr(void * dst,bpfptr_t src,size_t size)57 static 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
copy_to_bpfptr_offset(bpfptr_t dst,size_t offset,const void * src,size_t size)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((sockptr_t) dst, offset, src, size);
66 }
67
kvmemdup_bpfptr_noprof(bpfptr_t src,size_t len)68 static 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(-ENOMEM);
74 if (copy_from_bpfptr(p, src, len)) {
75 kvfree(p);
76 return ERR_PTR(-EFAULT);
77 }
78 return p;
79 }
80 #define kvmemdup_bpfptr(...) alloc_hooks(kvmemdup_bpfptr_noprof(__VA_ARGS__))
81
strncpy_from_bpfptr(char * dst,bpfptr_t src,size_t count)82 static inline long strncpy_from_bpfptr(char *dst, bpfptr_t src, size_t count)
83 {
84 if (bpfptr_is_kernel(src))
85 return strncpy_from_kernel_nofault(dst, src.kernel, count);
86 return strncpy_from_user(dst, src.user, count);
87 }
88
89 #endif /* _LINUX_BPFPTR_H */
90