1 /*
2  * Copyright (C) 2014 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 <err.h>
18 #include <errno.h>
19 #include <fcntl.h>
20 #include <inttypes.h>
21 #include <stdarg.h>
22 #include <stdint.h>
23 #include <stdio.h>
24 #include <string.h>
25 #include <sys/stat.h>
26 #include <sys/types.h>
27 #include <unistd.h>
28 
29 #include <android-base/unique_fd.h>
30 
31 #include "NativeInfo.h"
32 
NativeFormatFloat(char * buffer,size_t buffer_len,uint64_t value,uint64_t divisor)33 void NativeFormatFloat(char* buffer, size_t buffer_len, uint64_t value, uint64_t divisor) {
34   uint64_t hundreds = ((((value % divisor) * 1000) / divisor) + 5) / 10;
35   snprintf(buffer, buffer_len, "%" PRIu64 ".%02" PRIu64, value / divisor, hundreds);
36 }
37 
38 // This function is not re-entrant since it uses a static buffer for
39 // the line data.
NativeGetInfo(int smaps_fd,size_t * rss_bytes,size_t * va_bytes)40 void NativeGetInfo(int smaps_fd, size_t* rss_bytes, size_t* va_bytes) {
41   size_t total_rss_bytes = 0;
42   size_t total_va_bytes = 0;
43   bool native_map = false;
44 
45   char buf[1024];
46   size_t buf_start = 0;
47   size_t buf_bytes = 0;
48   while (true) {
49     ssize_t bytes =
50         TEMP_FAILURE_RETRY(read(smaps_fd, buf + buf_bytes, sizeof(buf) - buf_bytes - 1));
51     if (bytes <= 0) {
52       break;
53     }
54     buf_bytes += bytes;
55     while (buf_bytes > 0) {
56       char* newline = reinterpret_cast<char*>(memchr(&buf[buf_start], '\n', buf_bytes));
57       if (newline == nullptr) {
58         break;
59       }
60       *newline = '\0';
61       uintptr_t start, end;
62       int name_pos;
63       size_t native_rss_kB;
64       if (sscanf(&buf[buf_start], "%" SCNxPTR "-%" SCNxPTR " %*4s %*x %*x:%*x %*d %n", &start, &end,
65                  &name_pos) == 2) {
66         char* map_name = &buf[buf_start + name_pos];
67         if (strcmp(map_name, "[anon:libc_malloc]") == 0 || strcmp(map_name, "[heap]") == 0 ||
68             strncmp(map_name, "[anon:scudo:", 12) == 0 ||
69             strncmp(map_name, "[anon:GWP-ASan", 14) == 0) {
70           total_va_bytes += end - start;
71           native_map = true;
72         } else {
73           native_map = false;
74         }
75       } else if (native_map && sscanf(&buf[buf_start], "Rss: %zu", &native_rss_kB) == 1) {
76         total_rss_bytes += native_rss_kB * 1024;
77       }
78       buf_bytes -= newline - &buf[buf_start] + 1;
79       buf_start = newline - buf + 1;
80     }
81     if (buf_start > 0) {
82       if (buf_bytes > 0) {
83         memmove(buf, &buf[buf_start], buf_bytes);
84       }
85       buf_start = 0;
86     }
87   }
88   *rss_bytes = total_rss_bytes;
89   *va_bytes = total_va_bytes;
90 }
91 
NativePrintInfo(const char * preamble)92 void NativePrintInfo(const char* preamble) {
93   size_t rss_bytes;
94   size_t va_bytes;
95 
96   android::base::unique_fd smaps_fd(open("/proc/self/smaps", O_RDONLY));
97   if (smaps_fd == -1) {
98     err(1, "Cannot open /proc/self/smaps");
99   }
100 
101   NativeGetInfo(smaps_fd, &rss_bytes, &va_bytes);
102 
103   // Avoid any allocations, so use special non-allocating printfs.
104   char buffer[256];
105   NativeFormatFloat(buffer, sizeof(buffer), rss_bytes, 1024 * 1024);
106   dprintf(STDOUT_FILENO, "%sNative RSS: %zu bytes %sMB\n", preamble, rss_bytes, buffer);
107   NativeFormatFloat(buffer, sizeof(buffer), va_bytes, 1024 * 1024);
108   dprintf(STDOUT_FILENO, "%sNative VA Space: %zu bytes %sMB\n", preamble, va_bytes, buffer);
109 }
110