1  /* Test lazy binding during dlclose (bug 30425).
       2     Copyright (C) 2023 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  }