[BZ #15897] dlfcn: do not mark dlopen/dlclose as leaf functions

Since the dlopen funcs might invoke a constructor that calls a func
that is in the same compilation unit as the caller, we cannot mark
them as leaf funcs.

Similarly, dlclose might invoke a destructor that calls a func that
is in the same compilation unit as the caller.

URL: https://sourceware.org/bugzilla/show_bug.cgi?id=15897
Reportedy-by: Fabrice Bauzac <libnoon@gmail.com>
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
This commit is contained in:
Mike Frysinger 2013-08-26 00:21:26 -04:00
parent 7f9d003410
commit 3b813b2965
7 changed files with 160 additions and 6 deletions

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@ -1,3 +1,20 @@
2013-08-27 Mike Frysinger <vapier@gentoo.org>
[BZ #15897]
* dlfcn/Makefile (tests): Add bug-dl-leaf.
(modules-names): Add bug-dl-leaf-lib and bug-dl-leaf-lib-cb.
($(objpfx)bug-dl-leaf): New rule.
($(objpfx)bug-dl-leaf.so): Likewise.
($(objpfx)bug-dl-leaf.out): Likewise.
($(objpfx)bug-dl-leaf-lib.so): Likewise.
($(objpfx)bug-dl-leaf-lib-cb.so): Likewise.
* dlfcn/bug-dl-leaf.c: New test.
* dlfcn/bug-dl-leaf-lib.c: Likewise.
* dlfcn/bug-dl-leaf-lib-cb.c: Likewise.
* dlfcn/dlfcn.h (dlopen): Change __THROW to __THROWNL.
(dlclose): Likewise.
(dlmopen): Likewise.
2013-08-27 Roland McGrath <roland@hack.frob.com>
* include/netdb.h [!_ISOMAC]:

2
NEWS
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@ -9,7 +9,7 @@ Version 2.19
* The following bugs are resolved with this release:
14699, 15531, 15532, 15736, 15749, 15797, 15867, 15890
14699, 15531, 15532, 15736, 15749, 15797, 15867, 15890, 15897.
* CVE-2013-4237 The readdir_r function could write more than NAME_MAX bytes
to the d_name member of struct dirent, or omit the terminating NUL

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@ -35,12 +35,13 @@ endif
ifeq (yes,$(build-shared))
tests = glrefmain failtest tst-dladdr default errmsg1 tstcxaatexit \
bug-dlopen1 bug-dlsym1 tst-dlinfo bug-atexit1 bug-atexit2 \
bug-atexit3 tstatexit
bug-atexit3 tstatexit bug-dl-leaf
endif
modules-names = glreflib1 glreflib2 glreflib3 failtestmod defaultmod1 \
defaultmod2 errmsg1mod modatexit modcxaatexit \
bug-dlsym1-lib1 bug-dlsym1-lib2 bug-atexit1-lib \
bug-atexit2-lib bug-atexit3-lib
bug-atexit2-lib bug-atexit3-lib bug-dl-leaf-lib \
bug-dl-leaf-lib-cb
failtestmod.so-no-z-defs = yes
glreflib2.so-no-z-defs = yes
@ -132,3 +133,8 @@ $(objpfx)bug-atexit2.out: $(objpfx)bug-atexit2-lib.so
LDLIBS-bug-atexit3-lib.so = -lstdc++ -lgcc_eh
$(objpfx)bug-atexit3: $(libdl)
$(objpfx)bug-atexit3.out: $(objpfx)bug-atexit3-lib.so
$(objpfx)bug-dl-leaf: $(objpfx)bug-dl-leaf-lib.so
$(objpfx)bug-dl-leaf.out: $(objpfx)bug-dl-leaf-lib-cb.so
$(objpfx)bug-dl-leaf-lib.so: $(libdl)
$(objpfx)bug-dl-leaf-lib-cb.so: $(objpfx)bug-dl-leaf-lib.so

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@ -0,0 +1,35 @@
/* Make sure dlopen/dlclose are not marked as leaf functions.
See bug-dl-leaf-lib.c for details.
Copyright (C) 2013 Free Software Foundation, Inc.
This file is part of the GNU C Library.
Contributed by Mike Frysinger <vapier@gentoo.org>
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/>. */
extern void check_val_init (void);
extern void check_val_fini (void);
__attribute__ ((__constructor__))
void construct (void)
{
check_val_init ();
}
__attribute__ ((__destructor__))
void destruct (void)
{
check_val_fini ();
}

71
dlfcn/bug-dl-leaf-lib.c Normal file
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@ -0,0 +1,71 @@
/* Make sure dlopen/dlclose are not marked as leaf functions.
Copyright (C) 2013 Free Software Foundation, Inc.
This file is part of the GNU C Library.
Contributed by Mike Frysinger <vapier@gentoo.org>
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/>. */
/* The bug-dl-leaf.c file will call our lib_main directly. We do this to
keep things simple -- no need to use --export-dynamic with the linker
or build the main ELF as a PIE.
The lib_main func will modify some of its state while dlopening and
dlclosing the bug-dl-leaf-lib-cb.so library. The constructors and
destructors in that library will call back into this library to also
muck with state (the check_val_xxx funcs).
If dlclose/dlopen are marked as "leaf" functions, then with newer
versions of gcc, the state modification won't work correctly. */
#include <assert.h>
#include <dlfcn.h>
static int val = 1;
static int called = 0;
void check_val_init (void)
{
called = 1;
assert (val == 2);
}
void check_val_fini (void)
{
called = 2;
assert (val == 4);
}
int lib_main (void)
{
int ret;
void *hdl;
/* Make sure the constructor sees the updated val. */
val = 2;
hdl = dlopen ("bug-dl-leaf-lib-cb.so", RTLD_GLOBAL | RTLD_LAZY);
val = 3;
assert (hdl);
assert (called == 1);
/* Make sure the destructor sees the updated val. */
val = 4;
ret = dlclose (hdl);
val = 5;
assert (ret == 0);
assert (called == 2);
return !val;
}

25
dlfcn/bug-dl-leaf.c Normal file
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@ -0,0 +1,25 @@
/* Make sure dlopen/dlclose are not marked as leaf functions.
See bug-dl-leaf-lib.c for details.
Copyright (C) 2013 Free Software Foundation, Inc.
This file is part of the GNU C Library.
Contributed by Mike Frysinger <vapier@gentoo.org>
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/>. */
#define TEST_FUNCTION lib_main ()
extern int lib_main (void);
#include "../test-skeleton.c"

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@ -53,11 +53,11 @@ __BEGIN_DECLS
/* Open the shared object FILE and map it in; return a handle that can be
passed to `dlsym' to get symbol values from it. */
extern void *dlopen (const char *__file, int __mode) __THROW;
extern void *dlopen (const char *__file, int __mode) __THROWNL;
/* Unmap and close a shared object opened by `dlopen'.
The handle cannot be used again after calling `dlclose'. */
extern int dlclose (void *__handle) __THROW __nonnull ((1));
extern int dlclose (void *__handle) __THROWNL __nonnull ((1));
/* Find the run-time address in the shared object HANDLE refers to
of the symbol called NAME. */
@ -66,7 +66,7 @@ extern void *dlsym (void *__restrict __handle,
#ifdef __USE_GNU
/* Like `dlopen', but request object to be allocated in a new namespace. */
extern void *dlmopen (Lmid_t __nsid, const char *__file, int __mode) __THROW;
extern void *dlmopen (Lmid_t __nsid, const char *__file, int __mode) __THROWNL;
/* Find the run-time address in the shared object HANDLE refers to
of the symbol called NAME with VERSION. */