Wed Jun 1 21:21:55 2016 UTC ()
PR toolchain/51121:
__CTOR_LIST__ and __CTOR_LIST_END__ are logically the same object, but
due to the start marker, the former has to be declared as array of fixed
size. Newer GCC versions take the liberty of exploiting the UB of
accessing global objects past the end to unconditionally load zero
values in that case. Two fixes are possible:
(1) Pruning via inline assembler as done by GCC's own CRT copy.
(2) Pruning via weak references as done for linker sets.
Since the second part is known and required to work anyway, prefer this
approach. In theory, the labels could be replaced completely, except
that GNU as doesn't provide start/end symbols for sections containing
dots.


(joerg)
diff -r1.9 -r1.10 src/lib/csu/common/crtbegin.c
cvs diff -r1.9 -r1.10 src/lib/csu/common/crtbegin.c (expand / switch to unified diff)

--- src/lib/csu/common/crtbegin.c 2014/05/06 16:02:10 1.9
+++ src/lib/csu/common/crtbegin.c 2016/06/01 21:21:55 1.10
@@ -17,38 +17,43 @@ @@ -17,38 +17,43 @@
17 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 17 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
18 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 18 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
19 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 19 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
20 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 20 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
21 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 21 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
22 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 22 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
23 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 23 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
24 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 24 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
25 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 25 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
26 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 26 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
27 * POSSIBILITY OF SUCH DAMAGE. 27 * POSSIBILITY OF SUCH DAMAGE.
28 */ 28 */
29#include <sys/cdefs.h> 29#include <sys/cdefs.h>
30__RCSID("$NetBSD: crtbegin.c,v 1.9 2014/05/06 16:02:10 joerg Exp $"); 30__RCSID("$NetBSD: crtbegin.c,v 1.10 2016/06/01 21:21:55 joerg Exp $");
31 31
32#include "crtbegin.h" 32#include "crtbegin.h"
33 33
34typedef void (*fptr_t)(void); 34typedef void (*fptr_t)(void);
35 35
36__dso_hidden const fptr_t __JCR_LIST__[0] __section(".jcr"); 36__dso_hidden const fptr_t __JCR_LIST__[0] __section(".jcr");
37 37
38__weakref_visible void Jv_RegisterClasses(const fptr_t *) 38__weakref_visible void Jv_RegisterClasses(const fptr_t *)
39 __weak_reference(_Jv_RegisterClasses); 39 __weak_reference(_Jv_RegisterClasses);
40 40
41#if !defined(HAVE_INITFINI_ARRAY) 41#if !defined(HAVE_INITFINI_ARRAY)
 42__weakref_visible const fptr_t __CTOR_LIST__start[]
 43 __weak_reference(__CTOR_LIST__);
 44__weakref_visible const fptr_t __CTOR_LIST__end[]
 45 __weak_reference(__CTOR_LIST_END__);
 46
42__dso_hidden const fptr_t __aligned(sizeof(void *)) __CTOR_LIST__[] __section(".ctors") = { 47__dso_hidden const fptr_t __aligned(sizeof(void *)) __CTOR_LIST__[] __section(".ctors") = {
43 (fptr_t) -1, 48 (fptr_t) -1,
44}; 49};
45__dso_hidden extern const fptr_t __CTOR_LIST_END__[]; 50__dso_hidden extern const fptr_t __CTOR_LIST_END__[];
46#endif 51#endif
47 52
48#ifdef SHARED 53#ifdef SHARED
49__dso_hidden void *__dso_handle = &__dso_handle; 54__dso_hidden void *__dso_handle = &__dso_handle;
50 55
51__weakref_visible void cxa_finalize(void *) 56__weakref_visible void cxa_finalize(void *)
52 __weak_reference(__cxa_finalize); 57 __weak_reference(__cxa_finalize);
53#else 58#else
54__dso_hidden void *__dso_handle; 59__dso_hidden void *__dso_handle;
@@ -80,56 +85,61 @@ __do_global_ctors_aux(void) @@ -80,56 +85,61 @@ __do_global_ctors_aux(void)
80 return; 85 return;
81 86
82 __initialized = 1; 87 __initialized = 1;
83 88
84#if !defined(__ARM_EABI__) || defined(__ARM_DWARF_EH__) 89#if !defined(__ARM_EABI__) || defined(__ARM_DWARF_EH__)
85 if (register_frame_info) 90 if (register_frame_info)
86 register_frame_info(__EH_FRAME_LIST__, &dwarf_eh_object); 91 register_frame_info(__EH_FRAME_LIST__, &dwarf_eh_object);
87#endif 92#endif
88 93
89 if (Jv_RegisterClasses && __JCR_LIST__[0] != 0) 94 if (Jv_RegisterClasses && __JCR_LIST__[0] != 0)
90 Jv_RegisterClasses(__JCR_LIST__); 95 Jv_RegisterClasses(__JCR_LIST__);
91 96
92#if !defined(HAVE_INITFINI_ARRAY) 97#if !defined(HAVE_INITFINI_ARRAY)
93 for (const fptr_t *p = __CTOR_LIST_END__; p > __CTOR_LIST__ + 1; ) { 98 for (const fptr_t *p = __CTOR_LIST__end; p > __CTOR_LIST__start + 1; ) {
94 (*(*--p))(); 99 (*(*--p))();
95 } 100 }
96#endif 101#endif
97} 102}
98 103
99#if !defined(__ARM_EABI__) || defined(SHARED) || defined(__ARM_DWARF_EH__) 104#if !defined(__ARM_EABI__) || defined(SHARED) || defined(__ARM_DWARF_EH__)
100#if !defined(HAVE_INITFINI_ARRAY) 105#if !defined(HAVE_INITFINI_ARRAY)
 106__weakref_visible const fptr_t __DTOR_LIST__start[]
 107 __weak_reference(__DTOR_LIST__);
 108__weakref_visible const fptr_t __DTOR_LIST__end[]
 109 __weak_reference(__DTOR_LIST_END__);
 110
101__dso_hidden const fptr_t __aligned(sizeof(void *)) __DTOR_LIST__[] __section(".dtors") = { 111__dso_hidden const fptr_t __aligned(sizeof(void *)) __DTOR_LIST__[] __section(".dtors") = {
102 (fptr_t) -1, 112 (fptr_t) -1,
103}; 113};
104__dso_hidden extern const fptr_t __DTOR_LIST_END__[]; 114__dso_hidden extern const fptr_t __DTOR_LIST_END__[];
105#endif 115#endif
106 116
107static void __do_global_dtors_aux(void) __used; 117static void __do_global_dtors_aux(void) __used;
108 118
109static void __section(".text.exit") 119static void __section(".text.exit")
110__do_global_dtors_aux(void) 120__do_global_dtors_aux(void)
111{ 121{
112 static unsigned char __finished; 122 static unsigned char __finished;
113 123
114 if (__finished) 124 if (__finished)
115 return; 125 return;
116 126
117 __finished = 1; 127 __finished = 1;
118 128
119#ifdef SHARED 129#ifdef SHARED
120 if (cxa_finalize) 130 if (cxa_finalize)
121 (*cxa_finalize)(__dso_handle); 131 (*cxa_finalize)(__dso_handle);
122#endif 132#endif
123 133
124#if !defined(HAVE_INITFINI_ARRAY) 134#if !defined(HAVE_INITFINI_ARRAY)
125 for (const fptr_t *p = __DTOR_LIST__ + 1; p < __DTOR_LIST_END__; ) { 135 for (const fptr_t *p = __DTOR_LIST__start + 1; p < __DTOR_LIST__end; ) {
126 (*(*p++))(); 136 (*(*p++))();
127 } 137 }
128#endif 138#endif
129 139
130#if !defined(__ARM_EABI__) || defined(__ARM_DWARF_EH__) 140#if !defined(__ARM_EABI__) || defined(__ARM_DWARF_EH__)
131 if (deregister_frame_info) 141 if (deregister_frame_info)
132 deregister_frame_info(__EH_FRAME_LIST__); 142 deregister_frame_info(__EH_FRAME_LIST__);
133#endif 143#endif
134} 144}
135#endif /* !__ARM_EABI__ || SHARED || __ARM_DWARF_EH__ */ 145#endif /* !__ARM_EABI__ || SHARED || __ARM_DWARF_EH__ */