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/* Test interactions of dlopen, NODELETE, and relocations.
Copyright (C) 2019-2025 Free Software Foundation, Inc.
This file is part of the GNU C Library.
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
<https://www.gnu.org/licenses/>. */
/* This test exercises NODELETE propagation due to data relocations
and unique symbols, and the interaction with already-loaded
objects. Some test objects are written in C++, to produce unique
symbol definitions.
First test: Global scope variant, data relocation as the NODELETE
trigger. mod1 is loaded first with a separate dlopen call.
mod2 ---(may_finalize_mod1 relocation dependency)---> mod1
(NODELETE) (marked as NODELETE)
Second test: Local scope variant, data relocation. mod3 is loaded
first, then mod5.
mod5 ---(DT_NEEDED)---> mod4 ---(DT_NEEDED)---> mod3
(NODELETE) (not NODELETE) ^
\ / (marked as
`--(may_finalize_mod3 relocation dependency)--/ NODELETE)
Third test: Shared local scope with unique symbol. mod6 is loaded
first, then mod7. No explicit dependencies between the two
objects, so first object has to be opened with RTLD_GLOBAL.
mod7 ---(unique symbol)---> mod6
(marked as NODELETE)
Forth test: Non-shared scopes with unique symbol. mod8 and mod10
are loaded from the main program. mod8 loads mod9 from an ELF
constructor, mod10 loads mod11. There are no DT_NEEDED
dependencies. mod9 is promoted to the global scope form the main
program. The unique symbol dependency is:
mod9 ---(unique symbol)---> mod11
(marked as NODELETE)
Fifth test: Shared local scope with unique symbol, like test 3, but
this time, there is also a DT_NEEDED dependency (so no RTLD_GLOBAL
needed):
DT_NEEDED
mod13 ---(unique symbol)---> mod12
(marked as NODELETE)
Sixth test: NODELETE status is retained after relocation failure
with unique symbol dependency. The object graph ensures that the
unique symbol binding is processed before the dlopen failure.
DT_NEEDED
mod17 --(DT_NEEDED)--> mod15 --(unique symbol)--> mod14
\ ^ (RTLD_NODELETE)
\ (DT_NEEDED)
\ |
`---(DT_NEEDED)--> mod16
(fails to relocate)
mod14 is loaded first, and the loading mod17 is attempted.
mod14 must remain NODELETE after opening mod17 failed. */
#include <stdio.h>
#include <string.h>
#include <stdbool.h>
#include <support/check.h>
#include <support/xdlfcn.h>
static int
do_test (void)
{
/* First case: global scope, regular data symbol. Open the object
which is not NODELETE initially. */
void *mod1 = xdlopen ("tst-dlopen-nodelete-reloc-mod1.so",
RTLD_NOW | RTLD_GLOBAL);
/* This is used to indicate that the ELF destructor may be
called. */
bool *may_finalize_mod1 = xdlsym (mod1, "may_finalize_mod1");
/* Open the NODELETE object. */
void *mod2 = xdlopen ("tst-dlopen-nodelete-reloc-mod2.so", RTLD_NOW);
/* This has no effect because the DSO is directly marked as
NODELETE. */
xdlclose (mod2);
/* This has no effect because the DSO has been indirectly marked as
NODELETE due to a relocation dependency. */
xdlclose (mod1);
/* Second case: local scope, regular data symbol. Open the object
which is not NODELETE initially. */
void *mod3 = xdlopen ("tst-dlopen-nodelete-reloc-mod3.so", RTLD_NOW);
bool *may_finalize_mod3 = xdlsym (mod3, "may_finalize_mod3");
/* Open the NODELETE object. */
void *mod5 = xdlopen ("tst-dlopen-nodelete-reloc-mod5.so", RTLD_NOW);
/* Again those have no effect because of NODELETE. */
xdlclose (mod5);
xdlclose (mod3);
/* Third case: Unique symbol. */
void *mod6 = xdlopen ("tst-dlopen-nodelete-reloc-mod6.so",
RTLD_NOW | RTLD_GLOBAL);
bool *may_finalize_mod6 = xdlsym (mod6, "may_finalize_mod6");
void *mod7 = xdlopen ("tst-dlopen-nodelete-reloc-mod7.so", RTLD_NOW);
bool *may_finalize_mod7 = xdlsym (mod7, "may_finalize_mod7");
/* This should not have any effect because of the unique symbol and
the resulting NODELETE status. */
xdlclose (mod6);
/* mod7 is not NODELETE and can be closed. */
*may_finalize_mod7 = true;
xdlclose (mod7);
/* Fourth case: Unique symbol, indirect loading. */
void *mod8 = xdlopen ("tst-dlopen-nodelete-reloc-mod8.so", RTLD_NOW);
/* Also promote to global scope. */
void *mod9 = xdlopen ("tst-dlopen-nodelete-reloc-mod9.so",
RTLD_NOW | RTLD_NOLOAD | RTLD_GLOBAL);
bool *may_finalize_mod9 = xdlsym (mod9, "may_finalize_mod9");
xdlclose (mod9); /* Drop mod9 reference. */
void *mod10 = xdlopen ("tst-dlopen-nodelete-reloc-mod10.so", RTLD_NOW);
void *mod11 = xdlopen ("tst-dlopen-nodelete-reloc-mod11.so",
RTLD_NOW | RTLD_NOLOAD);
bool *may_finalize_mod11 = xdlsym (mod11, "may_finalize_mod11");
xdlclose (mod11); /* Drop mod11 reference. */
/* mod11 is not NODELETE and can be closed. */
*may_finalize_mod11 = true;
/* Trigger closing of mod11, too. */
xdlclose (mod10);
/* Does not trigger closing of mod9. */
xdlclose (mod8);
/* Fifth case: Unique symbol, with DT_NEEDED dependency. */
void *mod12 = xdlopen ("tst-dlopen-nodelete-reloc-mod12.so", RTLD_NOW);
bool *may_finalize_mod12 = xdlsym (mod12, "may_finalize_mod12");
void *mod13 = xdlopen ("tst-dlopen-nodelete-reloc-mod13.so", RTLD_NOW);
bool *may_finalize_mod13 = xdlsym (mod13, "may_finalize_mod13");
/* This should not have any effect because of the unique symbol. */
xdlclose (mod12);
/* mod13 is not NODELETE and can be closed. */
*may_finalize_mod13 = true;
xdlclose (mod13);
/* Sixth case: Unique symbol binding must not cause loss of NODELETE
status. */
void *mod14 = xdlopen ("tst-dlopen-nodelete-reloc-mod14.so",
RTLD_NOW | RTLD_NODELETE);
bool *may_finalize_mod14 = xdlsym (mod14, "may_finalize_mod14");
TEST_VERIFY (dlopen ("tst-dlopen-nodelete-reloc-mod17.so", RTLD_NOW)
== NULL);
const char *message = dlerror ();
printf ("info: test 6 message: %s\n", message);
/* This must not close the object, it must still be NODELETE. */
xdlclose (mod14);
xdlopen ("tst-dlopen-nodelete-reloc-mod14.so", RTLD_NOW | RTLD_NOLOAD);
/* Prepare for process exit. Destructors for NODELETE objects will
be invoked. */
*may_finalize_mod1 = true;
*may_finalize_mod3 = true;
*may_finalize_mod6 = true;
*may_finalize_mod9 = true;
*may_finalize_mod12 = true;
*may_finalize_mod14 = true;
return 0;
}
#include <support/test-driver.c>
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