dlfcn/tst-dlinfo-phdr.c

   1 /* Test for dlinfo (RTLD_DI_PHDR).
   2    Copyright (C) 2022-2024 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 <dlfcn.h>
  20 #include <link.h>
  21 #include <stdbool.h>
  22 #include <stdio.h>
  23 #include <string.h>
  24 #include <sys/auxv.h>
  25
  26 #include <support/check.h>
  27 #include <support/xdlfcn.h>
  28
  29 /* Used to verify that the program header array appears as expected
  30    among the dl_iterate_phdr callback invocations.  */
  31
  32 struct dlip_callback_args
  33 {
  34   struct link_map *l;           /* l->l_addr is used to find the object.  */
  35   const ElfW(Phdr) *phdr;       /* Expected program header pointed.  */
  36   int phnum;                    /* Expected program header count.  */
  37   bool found;                   /* True if l->l_addr has been found.  */
  38 };
  39
  40 static int
  41 dlip_callback (struct dl_phdr_info *dlpi, size_t size, void *closure)
  42 {
  43   TEST_COMPARE (sizeof (*dlpi), size);
  44   struct dlip_callback_args *args = closure;
  45
  46   if (dlpi->dlpi_addr == args->l->l_addr)
  47     {
  48       TEST_VERIFY (!args->found);
  49       args->found = true;
  50       TEST_VERIFY (args->phdr == dlpi->dlpi_phdr);
  51       TEST_COMPARE (args->phnum, dlpi->dlpi_phnum);
  52     }
  53
  54   return 0;
  55 }
  56
  57 static int
  58 do_test (void)
  59 {
  60   /* Avoid a copy relocation.  */
  61   struct r_debug *debug = xdlsym (RTLD_DEFAULT, "_r_debug");
  62   struct link_map *l = (struct link_map *) debug->r_map;
  63   TEST_VERIFY_EXIT (l != NULL);
  64
  65   do
  66     {
  67       printf ("info: checking link map %p (%p) for \"%s\"\n",
  68               l, l->l_phdr, l->l_name);
  69
  70       /* Cause dlerror () to return an error message.  */
  71       dlsym (RTLD_DEFAULT, "does-not-exist");
  72
  73       /* Use the extension that link maps are valid dlopen handles.  */
  74       const ElfW(Phdr) *phdr;
  75       int phnum = dlinfo (l, RTLD_DI_PHDR, &phdr);
  76       TEST_VERIFY (phnum >= 0);
  77       /* Verify that the error message has been cleared.  */
  78       TEST_COMPARE_STRING (dlerror (), NULL);
  79
  80       TEST_VERIFY (phdr == l->l_phdr);
  81       TEST_COMPARE (phnum, l->l_phnum);
  82
  83       /* Check that we can find PT_DYNAMIC among the array.  */
  84       {
  85         bool dynamic_found = false;
  86         for (int i = 0; i < phnum; ++i)
  87           if (phdr[i].p_type == PT_DYNAMIC)
  88             {
  89               dynamic_found = true;
  90               TEST_COMPARE ((ElfW(Addr)) l->l_ld, l->l_addr + phdr[i].p_vaddr);
  91             }
  92         TEST_VERIFY (dynamic_found);
  93       }
  94
  95       /* Check that dl_iterate_phdr finds the link map with the same
  96          program headers.  */
  97       {
  98         struct dlip_callback_args args =
  99           {
 100             .l =  l,
 101             .phdr = phdr,
 102             .phnum = phnum,
 103             .found = false,
 104           };
 105         TEST_COMPARE (dl_iterate_phdr (dlip_callback, &args), 0);
 106         TEST_VERIFY (args.found);
 107       }
 108
 109       if (l->l_prev == NULL)
 110         {
 111           /* This is the executable, so the information is also
 112              available via getauxval.  */
 113           TEST_COMPARE_STRING (l->l_name, "");
 114           TEST_VERIFY (phdr == (const ElfW(Phdr) *) getauxval (AT_PHDR));
 115           TEST_COMPARE (phnum, getauxval (AT_PHNUM));
 116         }
 117
 118       l = l->l_next;
 119     }
 120   while (l != NULL);
 121
 122   return 0;
 123 }
 124
 125 #include <support/test-driver.c>