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
  15 // Avoid conflict between `_TIME_BITS` defined vs. `_FILE_OFFSET_BITS`
  16 // undefined in some Linux configurations.
  17 #undef _TIME_BITS
  18 #include "sanitizer_platform.h"
  19 #if SANITIZER_SOLARIS
  20 #  include <fcntl.h>
  21 #  include <limits.h>
  22 #  include <procfs.h>
  23
  24 #  include "sanitizer_common.h"
  25 #  include "sanitizer_procmaps.h"
  26
  27 namespace __sanitizer {
  28
  29 void ReadProcMaps(ProcSelfMapsBuff *proc_maps) {
  30   uptr fd = internal_open("/proc/self/xmap", O_RDONLY);
  31   CHECK_NE(fd, -1);
  32   uptr Size = internal_filesize(fd);
  33   CHECK_GT(Size, 0);
  34
  35   // Allow for additional entries by following mmap.
  36   size_t MmapedSize = Size * 4 / 3;
  37   void *VmMap = MmapOrDie(MmapedSize, "ReadProcMaps()");
  38   Size = internal_read(fd, VmMap, MmapedSize);
  39   CHECK_NE(Size, -1);
  40   internal_close(fd);
  41   proc_maps->data = (char *)VmMap;
  42   proc_maps->mmaped_size = MmapedSize;
  43   proc_maps->len = Size;
  44 }
  45
  46 bool MemoryMappingLayout::Next(MemoryMappedSegment *segment) {
  47   if (Error()) return false; // simulate empty maps
  48   char *last = data_.proc_self_maps.data + data_.proc_self_maps.len;
  49   if (data_.current >= last) return false;
  50
  51   prxmap_t *xmapentry =
  52       const_cast<prxmap_t *>(reinterpret_cast<const prxmap_t *>(data_.current));
  53
  54   segment->start = (uptr)xmapentry->pr_vaddr;
  55   segment->end = (uptr)(xmapentry->pr_vaddr + xmapentry->pr_size);
  56   segment->offset = (uptr)xmapentry->pr_offset;
  57
  58   segment->protection = 0;
  59   if ((xmapentry->pr_mflags & MA_READ) != 0)
  60     segment->protection |= kProtectionRead;
  61   if ((xmapentry->pr_mflags & MA_WRITE) != 0)
  62     segment->protection |= kProtectionWrite;
  63   if ((xmapentry->pr_mflags & MA_EXEC) != 0)
  64     segment->protection |= kProtectionExecute;
  65   if ((xmapentry->pr_mflags & MA_SHARED) != 0)
  66     segment->protection |= kProtectionShared;
  67
  68   if (segment->filename != NULL && segment->filename_size > 0) {
  69     char proc_path[PATH_MAX + 1];
  70
  71     // Avoid unnecessary readlink on unnamed entires.
  72     if (xmapentry->pr_mapname[0] == '\0')
  73       segment->filename[0] = '\0';
  74     else {
  75       internal_snprintf(proc_path, sizeof(proc_path), "/proc/self/path/%s",
  76                         xmapentry->pr_mapname);
  77       ssize_t sz = internal_readlink(proc_path, segment->filename,
  78                                      segment->filename_size - 1);
  79
  80       // If readlink failed, the map is anonymous.
  81       if (sz == -1)
  82         segment->filename[0] = '\0';
  83       else if ((size_t)sz < segment->filename_size)
  84         // readlink doesn't NUL-terminate.
  85         segment->filename[sz] = '\0';
  86     }
  87   }
  88
  89   data_.current += sizeof(prxmap_t);
  90
  91   return true;
  92 }
  93
  94 }  // namespace __sanitizer
  95
  96 #endif  // SANITIZER_SOLARIS