elf/dl-diagnostics.c

   1 /* Print diagnostics data in ld.so.
   2    Copyright (C) 2021 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, see
  17    <https://www.gnu.org/licenses/>.  */
  18
  19 #include <gnu/lib-names.h>
  20 #include <stdbool.h>
  21 #include <stddef.h>
  22 #include <unistd.h>
  23
  24 #include <dl-diagnostics.h>
  25 #include <dl-hwcaps.h>
  26 #include <dl-main.h>
  27 #include <dl-procinfo.h>
  28 #include <dl-sysdep.h>
  29 #include <ldsodefs.h>
  30 #include "trusted-dirs.h"
  31 #include "version.h"
  32
  33 /* Write CH to standard output.  */
  34 static void
  35 _dl_putc (char ch)
  36 {
  37   _dl_write (STDOUT_FILENO, &ch, 1);
  38 }
  39
  40 /* Print CH to standard output, quoting it if necessary.  */
  41 static void
  42 print_quoted_char (char ch)
  43 {
  44   if (ch < ' ' || ch > '~')
  45     {
  46       char buf[4];
  47       buf[0] = '\\';
  48       buf[1] = '0' + ((ch >> 6) & 7);
  49       buf[2] = '0' + ((ch >> 6) & 7);
  50       buf[3] = '0' + (ch & 7);
  51       _dl_write (STDOUT_FILENO, buf, 4);
  52     }
  53   else
  54     {
  55       if (ch == '\\' || ch == '"')
  56         _dl_putc ('\\');
  57       _dl_putc (ch);
  58     }
  59 }
  60
  61 /* Print S of LEN bytes to standard output, quoting characters as
  62    needed.  */
  63 static void
  64 print_string_length (const char *s, size_t len)
  65 {
  66   _dl_putc ('"');
  67   for (size_t i = 0; i < len; ++i)
  68     print_quoted_char (s[i]);
  69   _dl_putc ('"');
  70 }
  71
  72 void
  73 _dl_diagnostics_print_string (const char *s)
  74 {
  75   if (s == NULL)
  76     {
  77       _dl_printf ("0x0");
  78       return;
  79     }
  80
  81   _dl_putc ('"');
  82   while (*s != '\0')
  83     {
  84       print_quoted_char (*s);
  85       ++s;
  86     }
  87   _dl_putc ('"');
  88 }
  89
  90 void
  91 _dl_diagnostics_print_labeled_string (const char *label, const char *s)
  92 {
  93   _dl_printf ("%s=", label);
  94   _dl_diagnostics_print_string (s);
  95   _dl_putc ('\n');
  96 }
  97
  98 void
  99 _dl_diagnostics_print_labeled_value (const char *label, uint64_t value)
 100 {
 101   if (sizeof (value) == sizeof (unsigned long int))
 102     /* _dl_printf can print 64-bit values directly.  */
 103     _dl_printf ("%s=0x%lx\n", label, (unsigned long int) value);
 104   else
 105     {
 106       uint32_t high = value >> 32;
 107       uint32_t low = value;
 108       if (high == 0)
 109         _dl_printf ("%s=0x%x\n", label, low);
 110       else
 111         _dl_printf ("%s=0x%x%08x\n", label, high, low);
 112     }
 113 }
 114
 115 /* Return true if ENV is an unfiltered environment variable.  */
 116 static bool
 117 unfiltered_envvar (const char *env, size_t *name_length)
 118 {
 119   char *env_equal = strchr (env, '=');
 120   if (env_equal == NULL)
 121     {
 122       /* Always dump malformed entries.  */
 123       *name_length = strlen (env);
 124       return true;
 125     }
 126   size_t envname_length = env_equal - env;
 127   *name_length = envname_length;
 128
 129   /* LC_ and LD_ variables.  */
 130   if (env[0] == 'L' && (env[1] == 'C' || env[1] == 'D')
 131       && env[2] == '_')
 132     return true;
 133
 134   /* MALLOC_ variables.  */
 135   if (strncmp (env, "MALLOC_", strlen ("MALLOC_")) == 0)
 136     return true;
 137
 138   static const char unfiltered[] =
 139     "DATEMSK\0"
 140     "GCONV_PATH\0"
 141     "GETCONF_DIR\0"
 142     "GETCONF_DIR\0"
 143     "GLIBC_TUNABLES\0"
 144     "GMON_OUTPUT_PREFIX\0"
 145     "HESIOD_CONFIG\0"
 146     "HES_DOMAIN\0"
 147     "HOSTALIASES\0"
 148     "I18NPATH\0"
 149     "IFS\0"
 150     "LANG\0"
 151     "LOCALDOMAIN\0"
 152     "LOCPATH\0"
 153     "MSGVERB\0"
 154     "NIS_DEFAULTS\0"
 155     "NIS_GROUP\0"
 156     "NIS_PATH\0"
 157     "NLSPATH\0"
 158     "PATH\0"
 159     "POSIXLY_CORRECT\0"
 160     "RESOLV_HOST_CONF\0"
 161     "RES_OPTIONS\0"
 162     "SEV_LEVEL\0"
 163     "TMPDIR\0"
 164     "TZ\0"
 165     "TZDIR\0"
 166     /* Two null bytes at the end to mark the end of the list via an
 167        empty substring.  */
 168     ;
 169   for (const char *candidate = unfiltered; *candidate != '\0'; )
 170     {
 171       size_t candidate_length = strlen (candidate);
 172       if (candidate_length == envname_length
 173           && memcmp (candidate, env, candidate_length) == 0)
 174         return true;
 175       candidate += candidate_length + 1;
 176     }
 177
 178   return false;
 179 }
 180
 181 /* Dump the process environment.  */
 182 static void
 183 print_environ (char **environ)
 184 {
 185   unsigned int index = 0;
 186   for (char **envp = environ; *envp != NULL; ++envp)
 187     {
 188       char *env = *envp;
 189       size_t name_length;
 190       bool unfiltered = unfiltered_envvar (env, &name_length);
 191       _dl_printf ("env%s[0x%x]=",
 192                   unfiltered ? "" : "_filtered", index);
 193       if (unfiltered)
 194         _dl_diagnostics_print_string (env);
 195       else
 196         print_string_length (env, name_length);
 197       _dl_putc ('\n');
 198       ++index;
 199     }
 200 }
 201
 202 /* Print configured paths and the built-in search path.  */
 203 static void
 204 print_paths (void)
 205 {
 206   _dl_diagnostics_print_labeled_string ("path.prefix", PREFIX);
 207   _dl_diagnostics_print_labeled_string ("path.rtld", RTLD);
 208   _dl_diagnostics_print_labeled_string ("path.sysconfdir", SYSCONFDIR);
 209
 210   unsigned int index = 0;
 211   static const char *system_dirs = SYSTEM_DIRS "\0";
 212   for (const char *e = system_dirs; *e != '\0'; )
 213     {
 214       size_t len = strlen (e);
 215       _dl_printf ("path.system_dirs[0x%x]=", index);
 216       print_string_length (e, len);
 217       _dl_putc ('\n');
 218       ++index;
 219       e += len + 1;
 220     }
 221 }
 222
 223 /* Print information about the glibc version.  */
 224 static void
 225 print_version (void)
 226 {
 227   _dl_diagnostics_print_labeled_string ("version.release", RELEASE);
 228   _dl_diagnostics_print_labeled_string ("version.version", VERSION);
 229 }
 230
 231 void
 232 _dl_print_diagnostics (char **environ)
 233 {
 234 #ifdef HAVE_DL_DISCOVER_OSVERSION
 235   _dl_diagnostics_print_labeled_value
 236     ("dl_discover_osversion", _dl_discover_osversion ());
 237 #endif
 238   _dl_diagnostics_print_labeled_string ("dl_dst_lib", DL_DST_LIB);
 239   _dl_diagnostics_print_labeled_value ("dl_hwcap", GLRO (dl_hwcap));
 240   _dl_diagnostics_print_labeled_value ("dl_hwcap_important", HWCAP_IMPORTANT);
 241   _dl_diagnostics_print_labeled_value ("dl_hwcap2", GLRO (dl_hwcap2));
 242   _dl_diagnostics_print_labeled_string
 243     ("dl_hwcaps_subdirs", _dl_hwcaps_subdirs);
 244   _dl_diagnostics_print_labeled_value
 245     ("dl_hwcaps_subdirs_active", _dl_hwcaps_subdirs_active ());
 246   _dl_diagnostics_print_labeled_value ("dl_osversion", GLRO (dl_osversion));
 247   _dl_diagnostics_print_labeled_value ("dl_pagesize", GLRO (dl_pagesize));
 248   _dl_diagnostics_print_labeled_string ("dl_platform", GLRO (dl_platform));
 249   _dl_diagnostics_print_labeled_string
 250     ("dl_profile_output", GLRO (dl_profile_output));
 251   _dl_diagnostics_print_labeled_value
 252     ("dl_string_platform", _dl_string_platform ( GLRO (dl_platform)));
 253
 254   _dl_diagnostics_print_labeled_string ("dso.ld", LD_SO);
 255   _dl_diagnostics_print_labeled_string ("dso.libc", LIBC_SO);
 256
 257   print_environ (environ);
 258   print_paths ();
 259   print_version ();
 260
 261   _dl_diagnostics_kernel ();
 262   _dl_diagnostics_cpu ();
 263
 264   _exit (EXIT_SUCCESS);
 265 }