1 /*
2 * Copyright (C) 2008 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 * http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17 #include <dirent.h>
18 #include <errno.h>
19 #include <fcntl.h>
20 #include <stdint.h>
21 #include <stdlib.h>
22 #include <sys/stat.h>
23 #include <sys/types.h>
24 #include <unistd.h>
25
26 #include <pagemap/pagemap.h>
27
pm_kernel_create(pm_kernel_t ** ker_out)28 int pm_kernel_create(pm_kernel_t **ker_out) {
29 pm_kernel_t *ker;
30 int error;
31
32 if (!ker_out)
33 return 1;
34
35 ker = calloc(1, sizeof(*ker));
36 if (!ker)
37 return errno;
38
39 ker->kpagecount_fd = open("/proc/kpagecount", O_RDONLY);
40 if (ker->kpagecount_fd < 0) {
41 error = errno;
42 free(ker);
43 return error;
44 }
45
46 ker->kpageflags_fd = open("/proc/kpageflags", O_RDONLY);
47 if (ker->kpageflags_fd < 0) {
48 error = errno;
49 close(ker->kpagecount_fd);
50 free(ker);
51 return error;
52 }
53
54 ker->pagesize = getpagesize();
55
56 *ker_out = ker;
57
58 return 0;
59 }
60
61 #define INIT_PIDS 20
pm_kernel_pids(pm_kernel_t * ker,pid_t ** pids_out,size_t * len)62 int pm_kernel_pids(pm_kernel_t *ker, pid_t **pids_out, size_t *len) {
63 DIR *proc;
64 struct dirent *dir;
65 pid_t pid, *pids, *new_pids;
66 size_t pids_count, pids_size;
67 int error;
68
69 proc = opendir("/proc");
70 if (!proc)
71 return errno;
72
73 pids = malloc(INIT_PIDS * sizeof(pid_t));
74 if (!pids) {
75 closedir(proc);
76 return errno;
77 }
78 pids_count = 0; pids_size = INIT_PIDS;
79
80 while ((dir = readdir(proc))) {
81 if (sscanf(dir->d_name, "%d", &pid) < 1)
82 continue;
83
84 if (pids_count >= pids_size) {
85 new_pids = realloc(pids, 2 * pids_size * sizeof(pid_t));
86 if (!new_pids) {
87 error = errno;
88 free(pids);
89 closedir(proc);
90 return error;
91 }
92 pids = new_pids;
93 pids_size = 2 * pids_size;
94 }
95
96 pids[pids_count] = pid;
97
98 pids_count++;
99 }
100
101 closedir(proc);
102
103 new_pids = realloc(pids, pids_count * sizeof(pid_t));
104 if (!new_pids) {
105 error = errno;
106 free(pids);
107 return error;
108 }
109
110 *pids_out = new_pids;
111 *len = pids_count;
112
113 return 0;
114 }
115
pm_kernel_count(pm_kernel_t * ker,unsigned long pfn,uint64_t * count_out)116 int pm_kernel_count(pm_kernel_t *ker, unsigned long pfn, uint64_t *count_out) {
117 off_t off;
118
119 if (!ker || !count_out)
120 return -1;
121
122 off = lseek(ker->kpagecount_fd, pfn * sizeof(uint64_t), SEEK_SET);
123 if (off == (off_t)-1)
124 return errno;
125 if (read(ker->kpagecount_fd, count_out, sizeof(uint64_t)) <
126 (ssize_t)sizeof(uint64_t))
127 return errno;
128
129 return 0;
130 }
131
pm_kernel_flags(pm_kernel_t * ker,unsigned long pfn,uint64_t * flags_out)132 int pm_kernel_flags(pm_kernel_t *ker, unsigned long pfn, uint64_t *flags_out) {
133 off_t off;
134
135 if (!ker || !flags_out)
136 return -1;
137
138 off = lseek(ker->kpageflags_fd, pfn * sizeof(uint64_t), SEEK_SET);
139 if (off == (off_t)-1)
140 return errno;
141 if (read(ker->kpageflags_fd, flags_out, sizeof(uint64_t)) <
142 (ssize_t)sizeof(uint64_t))
143 return errno;
144
145 return 0;
146 }
147
pm_kernel_destroy(pm_kernel_t * ker)148 int pm_kernel_destroy(pm_kernel_t *ker) {
149 if (!ker)
150 return -1;
151
152 close(ker->kpagecount_fd);
153 close(ker->kpageflags_fd);
154
155 free(ker);
156
157 return 0;
158 }
159