1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
|
/* SPDX-License-Identifier: LGPL-2.1-or-later */
#include <errno.h>
#include <sys/stat.h>
#include <unistd.h>
#if HAVE_LINUX_MEMFD_H
#include <linux/memfd.h>
#endif
#include <stdio.h>
#include <sys/prctl.h>
#include "alloc-util.h"
#include "fd-util.h"
#include "macro.h"
#include "memfd-util.h"
#include "missing_fcntl.h"
#include "missing_mman.h"
#include "missing_syscall.h"
#include "string-util.h"
#include "utf8.h"
int memfd_new(const char *name) {
_cleanup_free_ char *g = NULL;
int fd;
if (!name) {
char pr[17] = {};
/* If no name is specified we generate one. We include
* a hint indicating our library implementation, and
* add the thread name to it */
assert_se(prctl(PR_GET_NAME, (unsigned long) pr) >= 0);
if (isempty(pr))
name = "sd";
else {
_cleanup_free_ char *e = NULL;
e = utf8_escape_invalid(pr);
if (!e)
return -ENOMEM;
g = strjoin("sd-", e);
if (!g)
return -ENOMEM;
name = g;
}
}
fd = memfd_create(name, MFD_ALLOW_SEALING | MFD_CLOEXEC);
if (fd < 0)
return -errno;
return fd;
}
int memfd_map(int fd, uint64_t offset, size_t size, void **p) {
void *q;
int sealed;
assert(fd >= 0);
assert(size > 0);
assert(p);
sealed = memfd_get_sealed(fd);
if (sealed < 0)
return sealed;
if (sealed)
q = mmap(NULL, size, PROT_READ, MAP_PRIVATE, fd, offset);
else
q = mmap(NULL, size, PROT_READ | PROT_WRITE, MAP_SHARED, fd, offset);
if (q == MAP_FAILED)
return -errno;
*p = q;
return 0;
}
int memfd_set_sealed(int fd) {
int r;
assert(fd >= 0);
r = fcntl(fd, F_ADD_SEALS, F_SEAL_SHRINK | F_SEAL_GROW | F_SEAL_WRITE | F_SEAL_SEAL);
if (r < 0)
return -errno;
return 0;
}
int memfd_get_sealed(int fd) {
int r;
assert(fd >= 0);
r = fcntl(fd, F_GET_SEALS);
if (r < 0)
return -errno;
return r == (F_SEAL_SHRINK | F_SEAL_GROW | F_SEAL_WRITE | F_SEAL_SEAL);
}
int memfd_get_size(int fd, uint64_t *sz) {
struct stat stat;
int r;
assert(fd >= 0);
assert(sz);
r = fstat(fd, &stat);
if (r < 0)
return -errno;
*sz = stat.st_size;
return 0;
}
int memfd_set_size(int fd, uint64_t sz) {
int r;
assert(fd >= 0);
r = ftruncate(fd, sz);
if (r < 0)
return -errno;
return 0;
}
int memfd_new_and_map(const char *name, size_t sz, void **p) {
_cleanup_close_ int fd = -1;
int r;
assert(sz > 0);
assert(p);
fd = memfd_new(name);
if (fd < 0)
return fd;
r = memfd_set_size(fd, sz);
if (r < 0)
return r;
r = memfd_map(fd, 0, sz, p);
if (r < 0)
return r;
return TAKE_FD(fd);
}
|
