xref: /openbmc/qemu/util/selfmap.c (revision 4921d0a7)
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