sysdeps/unix/sysv/linux/dl-osinfo.h

   1 /* Operating system specific code  for generic dynamic loader functions.
   2    Copyright (C) 2000, 2001 Free Software Foundation, Inc.
   3    This file is part of the GNU C Library.
   4
   5    The GNU C Library is free software; you can redistribute it and/or
   6    modify it under the terms of the GNU Library General Public License as
   7    published by the Free Software Foundation; either version 2 of the
   8    License, or (at your option) any later version.
   9
  10    The GNU C Library is distributed in the hope that it will be useful,
  11    but WITHOUT ANY WARRANTY; without even the implied warranty of
  12    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13    Library General Public License for more details.
  14
  15    You should have received a copy of the GNU Library General Public
  16    License along with the GNU C Library; see the file COPYING.LIB.  If not,
  17    write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  18    Boston, MA 02111-1307, USA.  */
  19
  20 #include <string.h>
  21 #include <sys/sysctl.h>
  22 #include <sys/utsname.h>
  23 #include "kernel-features.h"
  24
  25 #ifndef MIN
  26 # define MIN(a,b) (((a)<(b))?(a):(b))
  27 #endif
  28
  29 #ifdef SHARED
  30 /* This is the function used in the dynamic linker to print the fatal error
  31    message.  */
  32 static inline void
  33 __attribute__ ((__noreturn__))
  34 dl_fatal (const char *str)
  35 {
  36   _dl_dprintf (2, str);
  37   _exit (1);
  38 }
  39 #endif
  40
  41
  42 #define DL_SYSDEP_OSCHECK(FATAL) \
  43   do {                                                                        \
  44     /* Test whether the kernel is new enough.  This test is only              \
  45        performed if the library is not compiled to run on all                 \
  46        kernels.  */                                                           \
  47     if (__LINUX_KERNEL_VERSION > 0)                                           \
  48       {                                                                       \
  49         char bufmem[64];                                                      \
  50         char *buf = bufmem;                                                   \
  51         unsigned int version;                                                 \
  52         int parts;                                                            \
  53         char *cp;                                                             \
  54         struct utsname uts;                                                   \
  55                                                                               \
  56         /* Try the uname syscall */                                           \
  57         if (__uname (&uts))                                                   \
  58           {                                                                   \
  59             /* This was not successful.  Now try reading the /proc            \
  60                filesystem.  */                                                \
  61             ssize_t reslen;                                                   \
  62             int fd = __open ("/proc/sys/kernel/osrelease", O_RDONLY);         \
  63             if (fd == -1                                                      \
  64                 || (reslen = __read (fd, bufmem, sizeof (bufmem))) <= 0)      \
  65               /* This also didn't work.  We give up since we cannot           \
  66                  make sure the library can actually work.  */                 \
  67               FATAL ("FATAL: cannot determine library version\n");            \
  68             __close (fd);                                                     \
  69             buf[MIN (reslen, (ssize_t) sizeof (bufmem) - 1)] = '\0';          \
  70           }                                                                   \
  71         else                                                                  \
  72           buf = uts.release;                                                  \
  73                                                                               \
  74         /* Now convert it into a number.  The string consists of at most      \
  75            three parts.  */                                                   \
  76         version = 0;                                                          \
  77         parts = 0;                                                            \
  78         cp = buf;                                                             \
  79         while ((*cp >= '0') && (*cp <= '9'))                                  \
  80           {                                                                   \
  81             unsigned int here = *cp++ - '0';                                  \
  82                                                                               \
  83             while ((*cp >= '0') && (*cp <= '9'))                              \
  84               {                                                               \
  85                 here *= 10;                                                   \
  86                 here += *cp++ - '0';                                          \
  87               }                                                               \
  88                                                                               \
  89             ++parts;                                                          \
  90             version <<= 8;                                                    \
  91             version |= here;                                                  \
  92                                                                               \
  93             if (*cp++ != '.')                                                 \
  94               /* Another part following?  */                                  \
  95               break;                                                          \
  96           }                                                                   \
  97                                                                               \
  98         if (parts < 3)                                                        \
  99           version <<= 8 * (3 - parts);                                        \
 100                                                                               \
 101         /* Now we can test with the required version.  */                     \
 102         if (version < __LINUX_KERNEL_VERSION)                                 \
 103           /* Not sufficent.  */                                               \
 104           FATAL ("FATAL: kernel too old\n");                                  \
 105                                                                               \
 106         _dl_osversion = version;                                              \
 107       }                                                                       \
 108   } while (0)