llvm-project

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//===-- sanitizer_procmaps_linux.cpp --------------------------------------===//
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//
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// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
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// See https://llvm.org/LICENSE.txt for license information.
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// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
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//
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//===----------------------------------------------------------------------===//
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//
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// Information about the process mappings (Linux-specific parts).
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//===----------------------------------------------------------------------===//
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#include "sanitizer_platform.h"
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#if SANITIZER_LINUX
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#include "sanitizer_common.h"
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#include "sanitizer_procmaps.h"
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namespace __sanitizer {
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void ReadProcMaps(ProcSelfMapsBuff *proc_maps) {
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  if (!ReadFileToBuffer("/proc/self/maps", &proc_maps->data,
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                        &proc_maps->mmaped_size, &proc_maps->len)) {
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    proc_maps->data = nullptr;
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    proc_maps->mmaped_size = 0;
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    proc_maps->len = 0;
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  }
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}
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static bool IsOneOf(char c, char c1, char c2) {
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  return c == c1 || c == c2;
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}
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bool MemoryMappingLayout::Next(MemoryMappedSegment *segment) {
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  if (Error()) return false; // simulate empty maps
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  char *last = data_.proc_self_maps.data + data_.proc_self_maps.len;
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  if (data_.current >= last) return false;
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  char *next_line =
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      (char *)internal_memchr(data_.current, '\n', last - data_.current);
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  if (next_line == 0)
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    next_line = last;
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  // Example: 08048000-08056000 r-xp 00000000 03:0c 64593   /foo/bar
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  segment->start = ParseHex(&data_.current);
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  CHECK_EQ(*data_.current++, '-');
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  segment->end = ParseHex(&data_.current);
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  CHECK_EQ(*data_.current++, ' ');
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  CHECK(IsOneOf(*data_.current, '-', 'r'));
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  segment->protection = 0;
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  if (*data_.current++ == 'r') segment->protection |= kProtectionRead;
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  CHECK(IsOneOf(*data_.current, '-', 'w'));
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  if (*data_.current++ == 'w') segment->protection |= kProtectionWrite;
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  CHECK(IsOneOf(*data_.current, '-', 'x'));
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  if (*data_.current++ == 'x') segment->protection |= kProtectionExecute;
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  CHECK(IsOneOf(*data_.current, 's', 'p'));
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  if (*data_.current++ == 's') segment->protection |= kProtectionShared;
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  CHECK_EQ(*data_.current++, ' ');
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  segment->offset = ParseHex(&data_.current);
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  CHECK_EQ(*data_.current++, ' ');
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  ParseHex(&data_.current);
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  CHECK_EQ(*data_.current++, ':');
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  ParseHex(&data_.current);
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  CHECK_EQ(*data_.current++, ' ');
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  while (IsDecimal(*data_.current)) data_.current++;
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  // Qemu may lack the trailing space.
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  // https://github.com/google/sanitizers/issues/160
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  // CHECK_EQ(*data_.current++, ' ');
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  // Skip spaces.
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  while (data_.current < next_line && *data_.current == ' ') data_.current++;
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  // Fill in the filename.
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  if (segment->filename) {
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    uptr len =
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        Min((uptr)(next_line - data_.current), segment->filename_size - 1);
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    internal_strncpy(segment->filename, data_.current, len);
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    segment->filename[len] = 0;
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  }
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  data_.current = next_line + 1;
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  return true;
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}
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}  // namespace __sanitizer
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#endif  // SANITIZER_LINUX
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