Home | History | Annotate | Download | only in libmemunreachable
      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 #include <inttypes.h>
     18 #include <fcntl.h>
     19 #include <string.h>
     20 #include <unistd.h>
     21 
     22 #include <android-base/unique_fd.h>
     23 
     24 #include "LineBuffer.h"
     25 #include "ProcessMappings.h"
     26 #include "log.h"
     27 
     28 // This function is not re-entrant since it uses a static buffer for
     29 // the line data.
     30 bool ProcessMappings(pid_t pid, allocator::vector<Mapping>& mappings) {
     31   char map_buffer[1024];
     32   snprintf(map_buffer, sizeof(map_buffer), "/proc/%d/maps", pid);
     33   android::base::unique_fd fd(open(map_buffer, O_RDONLY));
     34   if (fd == -1) {
     35     return false;
     36   }
     37 
     38   LineBuffer line_buf(fd, map_buffer, sizeof(map_buffer));
     39   char* line;
     40   size_t line_len;
     41   while (line_buf.GetLine(&line, &line_len)) {
     42     int name_pos;
     43     char perms[5];
     44     Mapping mapping{};
     45     if (sscanf(line, "%" SCNxPTR "-%" SCNxPTR " %4s %*x %*x:%*x %*d %n",
     46         &mapping.begin, &mapping.end, perms, &name_pos) == 3) {
     47       if (perms[0] == 'r') {
     48         mapping.read = true;
     49       }
     50       if (perms[1] == 'w') {
     51         mapping.write = true;
     52       }
     53       if (perms[2] == 'x') {
     54         mapping.execute = true;
     55       }
     56       if (perms[3] == 'p') {
     57         mapping.priv = true;
     58       }
     59       if ((size_t)name_pos < line_len) {
     60         strlcpy(mapping.name, line + name_pos, sizeof(mapping.name));
     61       }
     62       mappings.emplace_back(mapping);
     63     }
     64   }
     65   return true;
     66 }
     67