From 3b813b29653a3ebfd78c2529127a9967d8f2857d Mon Sep 17 00:00:00 2001 From: Mike Frysinger Date: Mon, 26 Aug 2013 00:21:26 -0400 Subject: [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 Signed-off-by: Mike Frysinger --- dlfcn/Makefile | 10 +++++-- dlfcn/bug-dl-leaf-lib-cb.c | 35 +++++++++++++++++++++++ dlfcn/bug-dl-leaf-lib.c | 71 ++++++++++++++++++++++++++++++++++++++++++++++ dlfcn/bug-dl-leaf.c | 25 ++++++++++++++++ dlfcn/dlfcn.h | 6 ++-- 5 files changed, 142 insertions(+), 5 deletions(-) create mode 100644 dlfcn/bug-dl-leaf-lib-cb.c create mode 100644 dlfcn/bug-dl-leaf-lib.c create mode 100644 dlfcn/bug-dl-leaf.c (limited to 'dlfcn') diff --git a/dlfcn/Makefile b/dlfcn/Makefile index 57a727189d..f3c6df9c1b 100644 --- a/dlfcn/Makefile +++ b/dlfcn/Makefile @@ -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 diff --git a/dlfcn/bug-dl-leaf-lib-cb.c b/dlfcn/bug-dl-leaf-lib-cb.c new file mode 100644 index 0000000000..e028c047a5 --- /dev/null +++ b/dlfcn/bug-dl-leaf-lib-cb.c @@ -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 + + 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 + . */ + +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 (); +} diff --git a/dlfcn/bug-dl-leaf-lib.c b/dlfcn/bug-dl-leaf-lib.c new file mode 100644 index 0000000000..e5955422d1 --- /dev/null +++ b/dlfcn/bug-dl-leaf-lib.c @@ -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 + + 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 + . */ + +/* 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 +#include + +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; +} diff --git a/dlfcn/bug-dl-leaf.c b/dlfcn/bug-dl-leaf.c new file mode 100644 index 0000000000..c3fbe757fb --- /dev/null +++ b/dlfcn/bug-dl-leaf.c @@ -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 + + 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 + . */ + +#define TEST_FUNCTION lib_main () +extern int lib_main (void); + +#include "../test-skeleton.c" diff --git a/dlfcn/dlfcn.h b/dlfcn/dlfcn.h index 241b554165..1ed47b1d1e 100644 --- a/dlfcn/dlfcn.h +++ b/dlfcn/dlfcn.h @@ -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. */ -- cgit 1.4.1