compiler-rt/lib/msan/msan_dl.cpp

   1 //===-- msan_dl.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 // This file is a part of MemorySanitizer.
  10 //
  11 // Helper functions for unpoisoning results of dladdr and dladdr1.
  12 //===----------------------------------------------------------------------===//
  13
  14 #include "msan_dl.h"
  15
  16 #include <dlfcn.h>
  17 #include <elf.h>
  18 #include <link.h>
  19
  20 #include "msan_poisoning.h"
  21
  22 namespace __msan {
  23
  24 void UnpoisonDllAddrInfo(void *info) {
  25   Dl_info *ptr = (Dl_info *)(info);
  26   __msan_unpoison(ptr, sizeof(*ptr));
  27   if (ptr->dli_fname)
  28     __msan_unpoison(ptr->dli_fname, internal_strlen(ptr->dli_fname) + 1);
  29   if (ptr->dli_sname)
  30     __msan_unpoison(ptr->dli_sname, internal_strlen(ptr->dli_sname) + 1);
  31 }
  32
  33 #if SANITIZER_GLIBC
  34 void UnpoisonDllAddr1ExtraInfo(void **extra_info, int flags) {
  35   if (flags == RTLD_DL_SYMENT) {
  36     __msan_unpoison(extra_info, sizeof(void *));
  37
  38     ElfW(Sym) *s = *((ElfW(Sym) **)(extra_info));
  39     __msan_unpoison(s, sizeof(ElfW(Sym)));
  40   } else if (flags == RTLD_DL_LINKMAP) {
  41     __msan_unpoison(extra_info, sizeof(void *));
  42
  43     struct link_map *map = *((struct link_map **)(extra_info));
  44
  45     // Walk forward
  46     for (auto *ptr = map; ptr; ptr = ptr->l_next) {
  47       __msan_unpoison(ptr, sizeof(struct link_map));
  48       if (ptr->l_name)
  49         __msan_unpoison(ptr->l_name, internal_strlen(ptr->l_name) + 1);
  50     }
  51
  52     if (!map)
  53       return;
  54
  55     // Walk backward
  56     for (auto *ptr = map->l_prev; ptr; ptr = ptr->l_prev) {
  57       __msan_unpoison(ptr, sizeof(struct link_map));
  58       if (ptr->l_name)
  59         __msan_unpoison(ptr->l_name, internal_strlen(ptr->l_name) + 1);
  60     }
  61   }
  62 }
  63 #endif
  64
  65 }  // namespace __msan