xref: /freebsd/contrib/llvm-project/compiler-rt/lib/sanitizer_common/sanitizer_procmaps_solaris.cpp (revision 02e9120893770924227138ba49df1edb3896112a)
1 //===-- sanitizer_procmaps_solaris.cpp ------------------------------------===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8 //
9 // Information about the process mappings (Solaris-specific parts).
10 //===----------------------------------------------------------------------===//
11 
12 // Before Solaris 11.4, <procfs.h> doesn't work in a largefile environment.
13 #undef _FILE_OFFSET_BITS
14 #include "sanitizer_platform.h"
15 #if SANITIZER_SOLARIS
16 #  include <fcntl.h>
17 #  include <limits.h>
18 #  include <procfs.h>
19 
20 #  include "sanitizer_common.h"
21 #  include "sanitizer_procmaps.h"
22 
23 namespace __sanitizer {
24 
25 void ReadProcMaps(ProcSelfMapsBuff *proc_maps) {
26   uptr fd = internal_open("/proc/self/xmap", O_RDONLY);
27   CHECK_NE(fd, -1);
28   uptr Size = internal_filesize(fd);
29   CHECK_GT(Size, 0);
30 
31   // Allow for additional entries by following mmap.
32   size_t MmapedSize = Size * 4 / 3;
33   void *VmMap = MmapOrDie(MmapedSize, "ReadProcMaps()");
34   Size = internal_read(fd, VmMap, MmapedSize);
35   CHECK_NE(Size, -1);
36   internal_close(fd);
37   proc_maps->data = (char *)VmMap;
38   proc_maps->mmaped_size = MmapedSize;
39   proc_maps->len = Size;
40 }
41 
42 bool MemoryMappingLayout::Next(MemoryMappedSegment *segment) {
43   if (Error()) return false; // simulate empty maps
44   char *last = data_.proc_self_maps.data + data_.proc_self_maps.len;
45   if (data_.current >= last) return false;
46 
47   prxmap_t *xmapentry =
48       const_cast<prxmap_t *>(reinterpret_cast<const prxmap_t *>(data_.current));
49 
50   segment->start = (uptr)xmapentry->pr_vaddr;
51   segment->end = (uptr)(xmapentry->pr_vaddr + xmapentry->pr_size);
52   segment->offset = (uptr)xmapentry->pr_offset;
53 
54   segment->protection = 0;
55   if ((xmapentry->pr_mflags & MA_READ) != 0)
56     segment->protection |= kProtectionRead;
57   if ((xmapentry->pr_mflags & MA_WRITE) != 0)
58     segment->protection |= kProtectionWrite;
59   if ((xmapentry->pr_mflags & MA_EXEC) != 0)
60     segment->protection |= kProtectionExecute;
61   if ((xmapentry->pr_mflags & MA_SHARED) != 0)
62     segment->protection |= kProtectionShared;
63 
64   if (segment->filename != NULL && segment->filename_size > 0) {
65     char proc_path[PATH_MAX + 1];
66 
67     // Avoid unnecessary readlink on unnamed entires.
68     if (xmapentry->pr_mapname[0] == '\0')
69       segment->filename[0] = '\0';
70     else {
71       internal_snprintf(proc_path, sizeof(proc_path), "/proc/self/path/%s",
72                         xmapentry->pr_mapname);
73       ssize_t sz = internal_readlink(proc_path, segment->filename,
74                                      segment->filename_size - 1);
75 
76       // If readlink failed, the map is anonymous.
77       if (sz == -1)
78         segment->filename[0] = '\0';
79       else if ((size_t)sz < segment->filename_size)
80         // readlink doesn't NUL-terminate.
81         segment->filename[sz] = '\0';
82     }
83   }
84 
85   data_.current += sizeof(prxmap_t);
86 
87   return true;
88 }
89 
90 }  // namespace __sanitizer
91 
92 #endif  // SANITIZER_SOLARIS
93