elf/tst-dlclose-lazy.c

   1 /* Test lazy binding during dlclose (bug 30425).
   2    Copyright (C) 2023-2024 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 /* This test re-creates a situation that can arise naturally for C++
  20    applications due to the use of vague linkage and differences in the
  21    set of compiler-emitted functions.  A function in
  22    tst-dlclose-lazy-mod1.so (exported_function) interposes a function
  23    in tst-dlclose-lazy-mod2.so.  This function is called from the
  24    destructor in tst-dlclose-lazy-mod2.so, after the destructor for
  25    tst-dlclose-lazy-mod1.so has already completed.  Prior to the fix
  26    for bug 30425, this would lead to a lazy binding failure in
  27    tst-dlclose-lazy-mod1.so because dlclose had already marked the DSO
  28    as unavailable for binding (by setting l_removed).  */
  29
  30 #include <dlfcn.h>
  31 #include <support/xdlfcn.h>
  32 #include <support/check.h>
  33
  34 int
  35 main (void)
  36 {
  37   /* Load tst-dlclose-lazy-mod1.so, indirectly loading
  38      tst-dlclose-lazy-mod2.so.  */
  39   void *handle = xdlopen ("tst-dlclose-lazy-mod1.so", RTLD_GLOBAL | RTLD_LAZY);
  40
  41   /* Invoke the destructor of tst-dlclose-lazy-mod2.so, which calls
  42      into tst-dlclose-lazy-mod1.so after its destructor has been
  43      called.  */
  44   xdlclose (handle);
  45
  46   return 0;
  47 }