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 <errno.h>
18#include <fcntl.h>
19#include <stdio.h>
20#include <stdlib.h>
21#include <string.h>
22#include <unistd.h>
23
24#include <pagemap/pagemap.h>
25
26#include "pm_map.h"
27
28static int read_maps(pm_process_t *proc);
29
30#define MAX_FILENAME 64
31
32int pm_process_create(pm_kernel_t *ker, pid_t pid, pm_process_t **proc_out) {
33    pm_process_t *proc;
34    char filename[MAX_FILENAME];
35    int error;
36
37    if (!ker || !proc_out)
38        return -1;
39
40    proc = calloc(1, sizeof(*proc));
41    if (!proc)
42        return errno;
43
44    proc->ker = ker;
45    proc->pid = pid;
46
47    error = snprintf(filename, MAX_FILENAME, "/proc/%d/pagemap", pid);
48    if (error < 0 || error >= MAX_FILENAME) {
49        error = (error < 0) ? (errno) : (-1);
50        free(proc);
51        return error;
52    }
53
54    proc->pagemap_fd = open(filename, O_RDONLY);
55    if (proc->pagemap_fd < 0) {
56        error = errno;
57        free(proc);
58        return error;
59    }
60
61    error = read_maps(proc);
62    if (error) {
63        free(proc);
64        return error;
65    }
66
67    *proc_out = proc;
68
69    return 0;
70}
71
72int pm_process_usage_flags(pm_process_t *proc, pm_memusage_t *usage_out,
73                        uint64_t flags_mask, uint64_t required_flags)
74{
75    pm_memusage_t usage, map_usage;
76    int error;
77    int i;
78
79    if (!proc || !usage_out)
80        return -1;
81
82    pm_memusage_zero(&usage);
83
84    for (i = 0; i < proc->num_maps; i++) {
85        error = pm_map_usage_flags(proc->maps[i], &map_usage, flags_mask,
86                                   required_flags);
87        if (error) return error;
88
89        pm_memusage_add(&usage, &map_usage);
90    }
91
92    memcpy(usage_out, &usage, sizeof(pm_memusage_t));
93
94    return 0;
95
96}
97
98int pm_process_usage(pm_process_t *proc, pm_memusage_t *usage_out) {
99    return pm_process_usage_flags(proc, usage_out, 0, 0);
100}
101
102int pm_process_pagemap_range(pm_process_t *proc,
103                             unsigned long low, unsigned long high,
104                             uint64_t **range_out, size_t *len) {
105    int firstpage, numpages;
106    uint64_t *range;
107    off_t off;
108    int error;
109
110    if (!proc || (low >= high) || !range_out || !len)
111        return -1;
112
113    firstpage = low / proc->ker->pagesize;
114    numpages = (high - low) / proc->ker->pagesize;
115
116    range = malloc(numpages * sizeof(uint64_t));
117    if (!range)
118        return errno;
119
120    off = lseek(proc->pagemap_fd, firstpage * sizeof(uint64_t), SEEK_SET);
121    if (off == (off_t)-1) {
122        error = errno;
123        free(range);
124        return error;
125    }
126    error = read(proc->pagemap_fd, (char*)range, numpages * sizeof(uint64_t));
127    if (error == 0) {
128        /* EOF, mapping is not in userspace mapping range (probably vectors) */
129        *len = 0;
130        free(range);
131        *range_out = NULL;
132        return 0;
133    } else if (error < 0 || (error > 0 && error < (int)(numpages * sizeof(uint64_t)))) {
134        error = (error < 0) ? errno : -1;
135        free(range);
136        return error;
137    }
138
139    *range_out = range;
140    *len = numpages;
141
142    return 0;
143}
144
145int pm_process_maps(pm_process_t *proc, pm_map_t ***maps_out, size_t *len) {
146    pm_map_t **maps;
147
148    if (!proc || !maps_out || !len)
149        return -1;
150
151    if (proc->num_maps) {
152        maps = malloc(proc->num_maps * sizeof(pm_map_t*));
153        if (!maps)
154            return errno;
155
156        memcpy(maps, proc->maps, proc->num_maps * sizeof(pm_map_t*));
157
158        *maps_out = maps;
159    } else {
160        *maps_out = NULL;
161    }
162    *len = proc->num_maps;
163
164    return 0;
165}
166
167int pm_process_workingset(pm_process_t *proc,
168                          pm_memusage_t *ws_out, int reset) {
169    pm_memusage_t ws, map_ws;
170    char filename[MAX_FILENAME];
171    int fd;
172    int i, j;
173    int error;
174
175    if (!proc)
176        return -1;
177
178    if (ws_out) {
179        pm_memusage_zero(&ws);
180        for (i = 0; i < proc->num_maps; i++) {
181            error = pm_map_workingset(proc->maps[i], &map_ws);
182            if (error) return error;
183
184            pm_memusage_add(&ws, &map_ws);
185        }
186
187        memcpy(ws_out, &ws, sizeof(ws));
188    }
189
190    if (reset) {
191        error = snprintf(filename, MAX_FILENAME, "/proc/%d/clear_refs",
192                         proc->pid);
193        if (error < 0 || error >= MAX_FILENAME) {
194            return (error < 0) ? (errno) : (-1);
195        }
196
197        fd = open(filename, O_WRONLY);
198        if (fd < 0)
199            return errno;
200
201        write(fd, "1\n", strlen("1\n"));
202
203        close(fd);
204    }
205
206    return 0;
207}
208
209int pm_process_destroy(pm_process_t *proc) {
210    if (!proc)
211        return -1;
212
213    free(proc->maps);
214    close(proc->pagemap_fd);
215    free(proc);
216
217    return 0;
218}
219
220#define INITIAL_MAPS 10
221#define MAX_LINE 1024
222#define MAX_PERMS 5
223
224/*
225 * #define FOO 123
226 * S(FOO) => "123"
227 */
228#define _S(n) #n
229#define S(n) _S(n)
230
231static int read_maps(pm_process_t *proc) {
232    char filename[MAX_FILENAME];
233    char line[MAX_LINE], name[MAX_LINE], perms[MAX_PERMS];
234    FILE *maps_f;
235    pm_map_t *map, **maps, **new_maps;
236    int maps_count, maps_size;
237    int error;
238
239    if (!proc)
240        return -1;
241
242    maps = calloc(INITIAL_MAPS, sizeof(pm_map_t*));
243    if (!maps)
244        return errno;
245    maps_count = 0; maps_size = INITIAL_MAPS;
246
247    error = snprintf(filename, MAX_FILENAME, "/proc/%d/maps", proc->pid);
248    if (error < 0 || error >= MAX_FILENAME)
249        return (error < 0) ? (errno) : (-1);
250
251    maps_f = fopen(filename, "r");
252    if (!maps_f)
253        return errno;
254
255    while (fgets(line, MAX_LINE, maps_f)) {
256        if (maps_count >= maps_size) {
257            new_maps = realloc(maps, 2 * maps_size * sizeof(pm_map_t*));
258            if (!new_maps) {
259                error = errno;
260                free(maps);
261                fclose(maps_f);
262                return error;
263            }
264            maps = new_maps;
265            maps_size *= 2;
266        }
267
268        maps[maps_count] = map = calloc(1, sizeof(*map));
269
270        map->proc = proc;
271
272        name[0] = '\0';
273        sscanf(line, "%lx-%lx %s %lx %*s %*d %" S(MAX_LINE) "s",
274               &map->start, &map->end, perms, &map->offset, name);
275
276        map->name = malloc(strlen(name) + 1);
277        if (!map->name) {
278            error = errno;
279            for (; maps_count > 0; maps_count--)
280                pm_map_destroy(maps[maps_count]);
281            free(maps);
282            return error;
283        }
284        strcpy(map->name, name);
285        if (perms[0] == 'r') map->flags |= PM_MAP_READ;
286        if (perms[1] == 'w') map->flags |= PM_MAP_WRITE;
287        if (perms[2] == 'x') map->flags |= PM_MAP_EXEC;
288
289        maps_count++;
290    }
291
292    fclose(maps_f);
293
294    new_maps = realloc(maps, maps_count * sizeof(pm_map_t*));
295    if (maps_count && !new_maps) {
296        error = errno;
297        free(maps);
298        return error;
299    }
300
301    proc->maps = new_maps;
302    proc->num_maps = maps_count;
303
304    return 0;
305}
306