[src/trunk]: src/libexec/ld.elf_so/arch/arm Add a ld.elf_so internals version...

[matt <matt%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/2f09e63a1557
branches:  trunk
changeset: 786274:2f09e63a1557
user:      matt <matt%NetBSD.org@localhost>
date:      Wed Apr 24 22:32:29 2013 +0000

description:
Add a ld.elf_so internals version of __gnu_Unwind_Find_exidx for that the
libgcc EHABI can find the exception tables for a supplied PC.

diffstat:

 libexec/ld.elf_so/arch/arm/find_exidx.c |  86 +++++++++++++++++++++++++++++++++
 1 files changed, 86 insertions(+), 0 deletions(-)

diffs (90 lines):

diff -r c43e1e89db24 -r 2f09e63a1557 libexec/ld.elf_so/arch/arm/find_exidx.c
--- /dev/null   Thu Jan 01 00:00:00 1970 +0000
+++ b/libexec/ld.elf_so/arch/arm/find_exidx.c   Wed Apr 24 22:32:29 2013 +0000
@@ -0,0 +1,86 @@
+/*-
+ * Copyright (c) 2013 The NetBSD Foundation, Inc.
+ * All rights reserved.
+ *
+ * This code is derived from software contributed to The NetBSD Foundation
+ * by Matt Thomas of 3am Software Foundry.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
+ * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
+ * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+ * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
+ * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include <sys/cdefs.h>
+#ifndef lint
+__RCSID("$NetBSD: find_exidx.c,v 1.1 2013/04/24 22:32:29 matt Exp $");
+#endif /* not lint */
+
+#include "debug.h"
+#include "rtld.h"
+
+_Unwind_Ptr
+__gnu_Unwind_Find_exidx(_Unwind_Ptr pc, int * pcount)
+{
+       const Obj_Entry *obj;
+       _Unwind_Ptr start = NULL;
+       int count = 0;
+
+       dbg(("__gnu_Unwind_Find_exidx"));
+
+       _rtld_shared_enter();
+
+       vaddr_t va = (vaddr_t)pc; 
+       for (obj = _rtld_objlist; obj != NULL; obj = obj->next) {
+               /*
+                * If the address we are looking for is inside this object,
+                * we've found the object to inspect.
+                */
+               if ((vaddr_t)obj->mapbase <= va
+                   && va < (vaddr_t)obj->mapbase + obj->mapsize)
+                       break;
+       }
+
+       /*
+        * If we found an object and it has some exception data, we 
+        * need to see if the address matches a PT_LOAD section.
+        */
+       if (obj != NULL && obj->exidx_start != NULL) {
+               va -= (vaddr_t)obj->mapbase;
+               const Elf_Phdr *ph = obj->phdr;
+               const Elf_Phdr * const phlimit = ph + obj->phsize / sizeof(*ph);
+               for (; ph < phlimit; ph++) {
+                       if (ph->p_type == PT_LOAD
+                           && ph->p_vaddr <= va
+                           && va < ph->p_vaddr + ph->p_memsz) {
+                               count = obj->exidx_sz / 8;
+                               start = obj->exidx_start;
+                               break;
+                       }
+               }
+       }
+
+       _rtld_shared_exit();
+
+       /*
+        * deal with the return values.
+        */
+       *pcount = count;
+       return start;
+}