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

   1 /* Operating system specific code  for generic dynamic loader functions.
   2    Copyright (C) 2000, 2001, 2002, 2004 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 Lesser General Public
   7    License as published by the Free Software Foundation; either
   8    version 2.1 of the 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    Lesser General Public License for more details.
  14
  15    You should have received a copy of the GNU Lesser General Public
  16    License along with the GNU C Library; if not, write to the Free
  17    Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
  18    02111-1307 USA.  */
  19
  20 #include <string.h>
  21 #include <fcntl.h>
  22 #include <sys/sysctl.h>
  23 #include <sys/utsname.h>
  24 #include "kernel-features.h"
  25
  26 #ifndef MIN
  27 # define MIN(a,b) (((a)<(b))?(a):(b))
  28 #endif
  29
  30 #ifdef SHARED
  31 /* This is the function used in the dynamic linker to print the fatal error
  32    message.  */
  33 static inline void
  34 __attribute__ ((__noreturn__))
  35 dl_fatal (const char *str)
  36 {
  37   _dl_dprintf (2, str);
  38   _exit (1);
  39 }
  40 #endif
  41
  42
  43 #define DL_SYSDEP_OSCHECK(FATAL) \
  44   do {                                                                        \
  45     /* Test whether the kernel is new enough.  This test is only              \
  46        performed if the library is not compiled to run on all                 \
  47        kernels.  */                                                           \
  48     if (__LINUX_KERNEL_VERSION > 0)                                           \
  49       {                                                                       \
  50         char bufmem[64];                                                      \
  51         char *buf = bufmem;                                                   \
  52         unsigned int version;                                                 \
  53         int parts;                                                            \
  54         char *cp;                                                             \
  55         struct utsname uts;                                                   \
  56                                                                               \
  57         /* Try the uname syscall */                                           \
  58         if (__uname (&uts))                                                   \
  59           {                                                                   \
  60             /* This was not successful.  Now try reading the /proc            \
  61                filesystem.  */                                                \
  62             ssize_t reslen;                                                   \
  63             int fd = __open ("/proc/sys/kernel/osrelease", O_RDONLY);         \
  64             if (fd == -1                                                      \
  65                 || (reslen = __read (fd, bufmem, sizeof (bufmem))) <= 0)      \
  66               /* This also didn't work.  We give up since we cannot           \
  67                  make sure the library can actually work.  */                 \
  68               FATAL ("FATAL: cannot determine kernel version\n");             \
  69             __close (fd);                                                     \
  70             buf[MIN (reslen, (ssize_t) sizeof (bufmem) - 1)] = '\0';          \
  71           }                                                                   \
  72         else                                                                  \
  73           buf = uts.release;                                                  \
  74                                                                               \
  75         /* Now convert it into a number.  The string consists of at most      \
  76            three parts.  */                                                   \
  77         version = 0;                                                          \
  78         parts = 0;                                                            \
  79         cp = buf;                                                             \
  80         while ((*cp >= '0') && (*cp <= '9'))                                  \
  81           {                                                                   \
  82             unsigned int here = *cp++ - '0';                                  \
  83                                                                               \
  84             while ((*cp >= '0') && (*cp <= '9'))                              \
  85               {                                                               \
  86                 here *= 10;                                                   \
  87                 here += *cp++ - '0';                                          \
  88               }                                                               \
  89                                                                               \
  90             ++parts;                                                          \
  91             version <<= 8;                                                    \
  92             version |= here;                                                  \
  93                                                                               \
  94             if (*cp++ != '.')                                                 \
  95               /* Another part following?  */                                  \
  96               break;                                                          \
  97           }                                                                   \
  98                                                                               \
  99         if (parts < 3)                                                        \
 100           version <<= 8 * (3 - parts);                                        \
 101                                                                               \
 102         /* Now we can test with the required version.  */                     \
 103         if (version < __LINUX_KERNEL_VERSION)                                 \
 104           /* Not sufficent.  */                                               \
 105           FATAL ("FATAL: kernel too old\n");                                  \
 106                                                                               \
 107         GLRO(dl_osversion) = version;                                         \
 108       }                                                                       \
 109   } while (0)