xref: /openbmc/qemu/util/selfmap.c (revision 3202d8e4047d5f4def96b5404633307c86e8db95)
1  /*
2   * Utility function to get QEMU's own process map
3   *
4   * Copyright (c) 2020 Linaro Ltd
5   *
6   * SPDX-License-Identifier: GPL-2.0-or-later
7   */
8  
9  #include "qemu/osdep.h"
10  #include "qemu/cutils.h"
11  #include "qemu/selfmap.h"
12  
13  IntervalTreeRoot *read_self_maps(void)
14  {
15      IntervalTreeRoot *root;
16      gchar *maps, **lines;
17      guint i, nlines;
18  
19      if (!g_file_get_contents("/proc/self/maps", &maps, NULL, NULL)) {
20          return NULL;
21      }
22  
23      root = g_new0(IntervalTreeRoot, 1);
24      lines = g_strsplit(maps, "\n", 0);
25      nlines = g_strv_length(lines);
26  
27      for (i = 0; i < nlines; i++) {
28          gchar **fields = g_strsplit(lines[i], " ", 6);
29          guint nfields = g_strv_length(fields);
30  
31          if (nfields > 4) {
32              uint64_t start, end, offset, inode;
33              unsigned dev_maj, dev_min;
34              int errors = 0;
35              const char *p;
36  
37              errors |= qemu_strtou64(fields[0], &p, 16, &start);
38              errors |= qemu_strtou64(p + 1, NULL, 16, &end);
39              errors |= qemu_strtou64(fields[2], NULL, 16, &offset);
40              errors |= qemu_strtoui(fields[3], &p, 16, &dev_maj);
41              errors |= qemu_strtoui(p + 1, NULL, 16, &dev_min);
42              errors |= qemu_strtou64(fields[4], NULL, 10, &inode);
43  
44              if (!errors) {
45                  size_t path_len;
46                  MapInfo *e;
47  
48                  if (nfields == 6) {
49                      p = fields[5];
50                      p += strspn(p, " ");
51                      path_len = strlen(p) + 1;
52                  } else {
53                      p = NULL;
54                      path_len = 0;
55                  }
56  
57                  e = g_malloc0(sizeof(*e) + path_len);
58  
59                  e->itree.start = start;
60                  e->itree.last = end - 1;
61                  e->offset = offset;
62                  e->dev = makedev(dev_maj, dev_min);
63                  e->inode = inode;
64  
65                  e->is_read  = fields[1][0] == 'r';
66                  e->is_write = fields[1][1] == 'w';
67                  e->is_exec  = fields[1][2] == 'x';
68                  e->is_priv  = fields[1][3] == 'p';
69  
70                  if (path_len) {
71                      e->path = memcpy(e + 1, p, path_len);
72                  }
73  
74                  interval_tree_insert(&e->itree, root);
75              }
76          }
77          g_strfreev(fields);
78      }
79      g_strfreev(lines);
80      g_free(maps);
81  
82      return root;
83  }
84  
85  /**
86   * free_self_maps:
87   * @root: an interval tree
88   *
89   * Free a tree of MapInfo structures.
90   * Since we allocated each MapInfo in one chunk, we need not consider the
91   * contents and can simply free each RBNode.
92   */
93  
94  static void free_rbnode(RBNode *n)
95  {
96      if (n) {
97          free_rbnode(n->rb_left);
98          free_rbnode(n->rb_right);
99          g_free(n);
100      }
101  }
102  
103  void free_self_maps(IntervalTreeRoot *root)
104  {
105      if (root) {
106          free_rbnode(root->rb_root.rb_node);
107          g_free(root);
108      }
109  }
110