compiler-rt/lib/sanitizer_common/sanitizer_procmaps_solaris.cpp

   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