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 	return copy_from_sockptr_offset(dst, (sockptr_t) src, offset, size);
53 }
54 
copy_from_bpfptr(void * dst,bpfptr_t src,size_t size)55 static inline int copy_from_bpfptr(void *dst, bpfptr_t src, size_t size)
56 {
57 	return copy_from_bpfptr_offset(dst, src, 0, size);
58 }
59 
copy_to_bpfptr_offset(bpfptr_t dst,size_t offset,const void * src,size_t size)60 static inline int copy_to_bpfptr_offset(bpfptr_t dst, size_t offset,
61 					const void *src, size_t size)
62 {
63 	return copy_to_sockptr_offset((sockptr_t) dst, offset, src, size);
64 }
65 
kvmemdup_bpfptr(bpfptr_t src,size_t len)66 static inline void *kvmemdup_bpfptr(bpfptr_t src, size_t len)
67 {
68 	void *p = kvmalloc(len, GFP_USER | __GFP_NOWARN);
69 
70 	if (!p)
71 		return ERR_PTR(-ENOMEM);
72 	if (copy_from_bpfptr(p, src, len)) {
73 		kvfree(p);
74 		return ERR_PTR(-EFAULT);
75 	}
76 	return p;
77 }
78 
strncpy_from_bpfptr(char * dst,bpfptr_t src,size_t count)79 static inline long strncpy_from_bpfptr(char *dst, bpfptr_t src, size_t count)
80 {
81 	return strncpy_from_sockptr(dst, (sockptr_t) src, count);
82 }
83 
84 #endif /* _LINUX_BPFPTR_H */
85