root/maint/gnulib/tests/qemu.h

/* */

INCLUDED FROM

DEFINITIONS

1. is_running_under_qemu_user

   1 /* Determine whether the current process is running under QEMU.
   2    Copyright (C) 2021 Free Software Foundation, Inc.
   3 
   4    This file is free software: you can redistribute it and/or modify
   5    it under the terms of the GNU Lesser General Public License as
   6    published by the Free Software Foundation; either version 2.1 of the
   7    License, or (at your option) any later version.
   8 
   9    This file is distributed in the hope that it will be useful,
  10    but WITHOUT ANY WARRANTY; without even the implied warranty of
  11    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12    GNU Lesser General Public License for more details.
  13 
  14    You should have received a copy of the GNU Lesser General Public License
  15    along with this program.  If not, see <https://www.gnu.org/licenses/>.  */
  16 
  17 /* Written by Bruno Haible <bruno@clisp.org>, 2021.  */
  18 
  19 #include <stdbool.h>
  20 #ifdef __linux__
  21 # include <fcntl.h>
  22 # include <string.h>
  23 # include <unistd.h>
  24 #endif
  25 
  26 /* This function determines whether the current process is running under QEMU
  27    (user-mode).
  28 
  29    It does so by looking at parts of the environment that QEMU does not emulate
  30    100% perfectly well.
  31 
  32    For comparison, the techniques given in the paper
  33      Thomas Raffetseder, Christopher Kruegel, Engin Kirda
  34      "Detecting System Emulators"
  35      2007
  36      https://publik.tuwien.ac.at/files/pub-inf_5317.pdf
  37    apply to both the QEMU system mode and QEMU user mode.  */
  38 
  39 static bool
  40 is_running_under_qemu_user (void)
     /*  */
  41 {
  42 #ifdef __linux__
  43   char buf[4096 + 1];
  44   int fd;
  45 
  46 # if defined __m68k__
  47   fd = open ("/proc/hardware", O_RDONLY);
  48   if (fd >= 0)
  49     {
  50       int n = read (fd, buf, sizeof (buf) - 1);
  51       close (fd);
  52       if (n > 0)
  53         {
  54           buf[n] = '\0';
  55           if (strstr (buf, "qemu") != NULL)
  56             return true;
  57         }
  58     }
  59 # endif
  60 
  61   fd = open ("/proc/cpuinfo", O_RDONLY);
  62   if (fd >= 0)
  63     {
  64       int n = read (fd, buf, sizeof (buf) - 1);
  65       close (fd);
  66       if (n > 0)
  67         {
  68           buf[n] = '\0';
  69 # if defined __hppa__
  70           if (strstr (buf, "QEMU") != NULL)
  71             return true;
  72 # endif
  73 # if !(defined __i386__ || defined __x86_64__)
  74           if (strstr (buf, "AuthenticAMD") != NULL
  75               || strstr (buf, "GenuineIntel") != NULL)
  76             return true;
  77 # endif
  78 # if !(defined __arm__ || defined __aarch64__)
  79           if (strstr (buf, "ARM") != NULL
  80               || strcasestr (buf, "aarch64") != NULL)
  81             return true;
  82 # endif
  83 # if !defined __sparc__
  84           if (strcasestr (buf, "SPARC") != NULL)
  85             return true;
  86 # endif
  87 # if !defined __powerpc__
  88           if (strstr (buf, "POWER") != NULL)
  89             return true;
  90 # endif
  91         }
  92     }
  93 
  94   /* If you need more heuristics, look at system calls that are not perfectly
  95      well emulated in qemu/linux-user/syscall.c.  */
  96 #endif
  97 
  98   return false;
  99 }

/* */