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Diffstat (limited to 'dlfcn/tst-rec-dlopen.c')
-rw-r--r-- | dlfcn/tst-rec-dlopen.c | 144 |
1 files changed, 144 insertions, 0 deletions
diff --git a/dlfcn/tst-rec-dlopen.c b/dlfcn/tst-rec-dlopen.c new file mode 100644 index 0000000000..35b08d4b63 --- /dev/null +++ b/dlfcn/tst-rec-dlopen.c @@ -0,0 +1,144 @@ +/* Test recursive dlopen using malloc hooks. + Copyright (C) 1998-2014 Free Software Foundation, Inc. + This file is part of the GNU C Library. + Contributed by Ulrich Drepper <drepper@cygnus.com>, 1998. + + The GNU C Library is free software; you can redistribute it and/or + modify it under the terms of the GNU Lesser General Public + License as published by the Free Software Foundation; either + version 2.1 of the License, or (at your option) any later version. + + The GNU C Library is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public + License along with the GNU C Library; if not, see + <http://www.gnu.org/licenses/>. */ + +#include <stdio.h> +#include <stdlib.h> +#include <malloc.h> +#include <dlfcn.h> + +#define DSO "moddummy1.so" +#define FUNC "dummy1" + +#define DSO1 "moddummy2.so" +#define FUNC1 "dummy2" + +/* Result of the called function. */ +int func_result; + +/* Prototype for my hook. */ +void *custom_malloc_hook (size_t, const void *); + +/* Pointer to old malloc hooks. */ +void *(*old_malloc_hook) (size_t, const void *); + +/* Call function func_name in DSO dso_name via dlopen. */ +void +call_func (const char *dso_name, const char *func_name) +{ + int ret; + void *dso; + int (*func) (void); + char *err; + + /* Open the DSO. */ + dso = dlopen (dso_name, RTLD_NOW|RTLD_GLOBAL); + if (dso == NULL) + { + err = dlerror (); + fprintf (stderr, "%s\n", err); + exit (1); + } + /* Clear any errors. */ + dlerror (); + + /* Lookup func. */ + *(void **) (&func) = dlsym (dso, func_name); + if (func == NULL) + { + err = dlerror (); + if (err != NULL) + { + fprintf (stderr, "%s\n", err); + exit (1); + } + } + /* Call func. */ + func_result = (*func) (); + + /* Close the library and look for errors too. */ + ret = dlclose (dso); + if (ret != 0) + { + err = dlerror (); + fprintf (stderr, "%s\n", err); + exit (1); + } + +} + +/* Empty hook that does nothing. */ +void * +custom_malloc_hook (size_t size, const void *caller) +{ + void *result; + /* Restore old hooks. */ + __malloc_hook = old_malloc_hook; + /* First call a function in another library via dlopen. */ + call_func (DSO1, FUNC1); + /* Called recursively. */ + result = malloc (size); + /* Restore new hooks. */ + __malloc_hook = custom_malloc_hook; + return result; +} + +static int +do_test (void) +{ + /* Save old hook. */ + old_malloc_hook = __malloc_hook; + /* Install new hook. */ + __malloc_hook = custom_malloc_hook; + + /* Bug 17702 fixes two things: + * A recursive dlopen unmapping the ld.so.cache. + * An assertion that _r_debug is RT_CONSISTENT at entry to dlopen. + We can only test the latter. Testing the former requires modifying + ld.so.conf to cache the dummy libraries, then running ldconfig, + then run the test. If you do all of that (and glibc's test + infrastructure doesn't support that yet) then the test will + SEGFAULT without the fix. If you don't do that, then the test + will abort because of the assert described in detail below. */ + call_func (DSO, FUNC); + + /* Restore old hook. */ + __malloc_hook = old_malloc_hook; + + /* The function dummy2() is called by the malloc hook. Check to + see that it was called. This ensures the second recursive + dlopen happened and we called the function in that library. + Before the fix you either get a SIGSEGV when accessing mmap'd + ld.so.cache data or an assertion failure about _r_debug not + beint RT_CONSISTENT. We don't test for the SIGSEGV since it + would require finding moddummy1 or moddummy2 in the cache and + we don't have any infrastructure to test that, but the _r_debug + assertion triggers. */ + printf ("Returned result is %d\n", func_result); + if (func_result <= 0) + { + printf ("FAIL: Function call_func() not called.\n"); + exit (1); + } + + printf ("PASS: Function call_func() called more than once.\n"); + return 0; +} + +#define TEST_FUNCTION do_test () +#include "../test-skeleton.c" |