1 /*
2 * Copyright (C) 2016 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 #define LOG_TAG "MediaUtils"
18 #define LOG_NDEBUG 0
19 #include <utils/Log.h>
20
21 #include <cutils/properties.h>
22 #include <sys/resource.h>
23 #include <unistd.h>
24
25 #include "MediaUtils.h"
26
27 extern "C" size_t __cfi_shadow_size();
28
29 namespace android {
30
limitProcessMemory(const char * property,size_t numberOfBytes,size_t percentageOfTotalMem)31 void limitProcessMemory(
32 const char *property,
33 size_t numberOfBytes,
34 size_t percentageOfTotalMem) {
35
36 if (running_with_asan()) {
37 ALOGW("Running with ASan, skip enforcing memory limitations.");
38 return;
39 }
40
41 long pageSize = sysconf(_SC_PAGESIZE);
42 long numPages = sysconf(_SC_PHYS_PAGES);
43 size_t maxMem = SIZE_MAX;
44
45 if (pageSize > 0 && numPages > 0) {
46 if (size_t(numPages) < SIZE_MAX / size_t(pageSize)) {
47 maxMem = size_t(numPages) * size_t(pageSize);
48 }
49 ALOGV("physMem: %zu", maxMem);
50 if (percentageOfTotalMem > 100) {
51 ALOGW("requested %zu%% of total memory, using 100%%", percentageOfTotalMem);
52 percentageOfTotalMem = 100;
53 }
54 maxMem = maxMem / 100 * percentageOfTotalMem;
55 if (numberOfBytes < maxMem) {
56 maxMem = numberOfBytes;
57 }
58 ALOGV("requested limit: %zu", maxMem);
59 } else {
60 ALOGW("couldn't determine total RAM");
61 }
62
63 int64_t propVal = property_get_int64(property, maxMem);
64 if (propVal > 0 && uint64_t(propVal) <= SIZE_MAX) {
65 maxMem = propVal;
66 }
67
68 // Increase by the size of the CFI shadow mapping. Most of the shadow is not
69 // backed with physical pages, and it is possible for the result to be
70 // higher than total physical memory. This is fine for RLIMIT_AS.
71 size_t cfi_size = __cfi_shadow_size();
72 if (cfi_size) {
73 ALOGV("cfi shadow size: %zu", cfi_size);
74 if (maxMem <= SIZE_MAX - cfi_size) {
75 maxMem += cfi_size;
76 } else {
77 maxMem = SIZE_MAX;
78 }
79 }
80 ALOGV("actual limit: %zu", maxMem);
81
82 struct rlimit limit;
83 getrlimit(RLIMIT_AS, &limit);
84 ALOGV("original limits: %lld/%lld", (long long)limit.rlim_cur, (long long)limit.rlim_max);
85 limit.rlim_cur = maxMem;
86 setrlimit(RLIMIT_AS, &limit);
87 limit.rlim_cur = -1;
88 limit.rlim_max = -1;
89 getrlimit(RLIMIT_AS, &limit);
90 ALOGV("new limits: %lld/%lld", (long long)limit.rlim_cur, (long long)limit.rlim_max);
91
92 }
93
94 } // namespace android
95