Set NODELETE flag when opening already open objects with RTLD_NODELETE

The DF_1_NODELETE flag is set too late when opening a DSO, due to
which, if a DSO is already open, subsequently opening it with
RTLD_NODELETE fails to set the DF_1_NODELETE flag.  This patch fixes
this by setting the flag immediately after bumping the opencount.

Verified on x86_64.

	[BZ #18676]
	* elf/tst-nodelete-opened.c: New test case.
	* elf/tst-nodelete-opened-lib.c: New test case module.
	* elf/Makefile (tests, modules-names): Use them.
	* elf/dl-open.c (dl_open_worker): Set DF_1_NODELETE flag
	early.
This commit is contained in:
Siddhesh Poyarekar 2015-07-16 08:53:28 +05:30
parent c59f721c73
commit b632bdd3f7
6 changed files with 106 additions and 8 deletions

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@ -1,3 +1,12 @@
2015-07-16 Siddhesh Poyarekar <siddhesh@redhat.com>
[BZ #18676]
* elf/tst-nodelete-opened.c: New test case.
* elf/tst-nodelete-opened-lib.c: New test case module.
* elf/Makefile (tests, modules-names): Use them.
* elf/dl-open.c (dl_open_worker): Set DF_1_NODELETE flag
early.
2015-07-15 David S. Miller <davem@davemloft.net>
* sysdeps/sparc/nptl/pthread_barrier_init.c: Include

2
NEWS
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@ -27,7 +27,7 @@ Version 2.22
18522, 18527, 18528, 18529, 18530, 18532, 18533, 18534, 18536, 18539,
18540, 18542, 18544, 18545, 18546, 18547, 18549, 18553, 18557, 18558,
18569, 18583, 18585, 18586, 18592, 18593, 18594, 18602, 18612, 18613,
18619, 18633, 18641, 18643, 18648.
18619, 18633, 18641, 18643, 18648, 18676.
* Cache information can be queried via sysconf() function on s390 e.g. with
_SC_LEVEL1_ICACHE_SIZE as argument.

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@ -148,7 +148,7 @@ tests += loadtest restest1 preloadtest loadfail multiload origtest resolvfail \
tst-unique1 tst-unique2 $(if $(CXX),tst-unique3 tst-unique4 \
tst-nodelete) \
tst-initorder tst-initorder2 tst-relsort1 tst-null-argv \
tst-ptrguard1 tst-tlsalign tst-tlsalign-extern
tst-ptrguard1 tst-tlsalign tst-tlsalign-extern tst-nodelete-opened
# reldep9
ifeq ($(build-hardcoded-path-in-tests),yes)
tests += tst-dlopen-aout
@ -218,7 +218,7 @@ modules-names = testobj1 testobj2 testobj3 testobj4 testobj5 testobj6 \
tst-initorder2d \
tst-relsort1mod1 tst-relsort1mod2 tst-array2dep \
tst-array5dep tst-null-argv-lib \
tst-tlsalign-lib
tst-tlsalign-lib tst-nodelete-opened-lib
ifeq (yes,$(have-protected-data))
modules-names += tst-protected1moda tst-protected1modb
tests += tst-protected1a tst-protected1b
@ -525,6 +525,8 @@ $(objpfx)tst-initordera4.so: $(objpfx)tst-initordera3.so
$(objpfx)tst-initorder: $(objpfx)tst-initordera4.so $(objpfx)tst-initordera1.so $(objpfx)tst-initorderb2.so
$(objpfx)tst-null-argv: $(objpfx)tst-null-argv-lib.so
$(objpfx)tst-tlsalign: $(objpfx)tst-tlsalign-lib.so
$(objpfx)tst-nodelete-opened.out: $(objpfx)tst-nodelete-opened-lib.so
$(objpfx)tst-nodelete-opened: $(libdl)
$(objpfx)tst-tlsalign-extern: $(objpfx)tst-tlsalign-vars.o
$(objpfx)tst-tlsalign-extern-static: $(objpfx)tst-tlsalign-vars.o

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@ -226,6 +226,12 @@ dl_open_worker (void *a)
args->map = new = _dl_map_object (call_map, file, lt_loaded, 0,
mode | __RTLD_CALLMAP, args->nsid);
/* Mark the object as not deletable if the RTLD_NODELETE flags was passed.
Do this early so that we don't skip marking the object if it was
already loaded. */
if (__glibc_unlikely (mode & RTLD_NODELETE))
new->l_flags_1 |= DF_1_NODELETE;
/* If the pointer returned is NULL this means the RTLD_NOLOAD flag is
set and the object is not already loaded. */
if (new == NULL)
@ -564,11 +570,6 @@ TLS generation counter wrapped! Please report this."));
/* It failed. */
return;
/* Mark the object as not deletable if the RTLD_NODELETE flags was
passed. */
if (__glibc_unlikely (mode & RTLD_NODELETE))
new->l_flags_1 |= DF_1_NODELETE;
#ifndef SHARED
/* We must be the static _dl_open in libc.a. A static program that
has loaded a dynamic object now has competition. */

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@ -0,0 +1,19 @@
/* Verify that objects opened with RTLD_NODELETE are not unloaded - the DSO.
Copyright (C) 2015 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
<http://www.gnu.org/licenses/>. */
int foo_var = 42;

67
elf/tst-nodelete-opened.c Normal file
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@ -0,0 +1,67 @@
/* Verify that an already opened DSO opened agained with RTLD_NODELETE actually
sets the NODELETE flag.
Copyright (C) 2015 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
<http://www.gnu.org/licenses/>. */
#include <dlfcn.h>
#include <stdio.h>
int
do_test (void)
{
void *h1 = dlopen ("$ORIGIN/tst-nodelete-opened-lib.so", RTLD_LAZY);
if (h1 == NULL)
{
printf ("h1: failed to open DSO: %s\n", dlerror ());
return 1;
}
void *h2 = dlopen ("$ORIGIN/tst-nodelete-opened-lib.so",
RTLD_LAZY | RTLD_NODELETE);
if (h2 == NULL)
{
printf ("h2: failed to open DSO: %s\n", dlerror ());
return 1;
}
int *foo = dlsym (h2, "foo_var");
if (foo == NULL)
{
printf ("failed to load symbol foo_var: %s\n", dlerror ());
return 1;
}
if (dlclose (h1) != 0)
{
printf ("h1: dlclose failed: %s\n", dlerror ());
return 1;
}
if (dlclose (h2) != 0)
{
printf ("h2: dlclose failed: %s\n", dlerror ());
return 1;
}
printf ("foo == %d\n", *foo);
return 0;
}
#define TEST_FUNCTION do_test ()
#include "../test-skeleton.c"