276 lines
8.0 KiB
C
276 lines
8.0 KiB
C
/* Copyright (C) 2001-2021 Free Software Foundation, Inc.
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This file is part of GCC.
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GCC is free software; you can redistribute it and/or modify
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it under the terms of the GNU General Public License as published by
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the Free Software Foundation; either version 3, or (at your option)
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any later version.
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GCC is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License for more details.
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Under Section 7 of GPL version 3, you are granted additional
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permissions described in the GCC Runtime Library Exception, version
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3.1, as published by the Free Software Foundation.
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You should have received a copy of the GNU General Public License and
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a copy of the GCC Runtime Library Exception along with this program;
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see the files COPYING3 and COPYING.RUNTIME respectively. If not, see
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<http://www.gnu.org/licenses/>. */
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/* Locate the FDE entry for a given address, using Darwin's keymgr support. */
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#include "tconfig.h"
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#include "tsystem.h"
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#include <string.h>
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#include <stdlib.h>
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#include "dwarf2.h"
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#include "unwind.h"
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#define NO_BASE_OF_ENCODED_VALUE
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#define DWARF2_OBJECT_END_PTR_EXTENSION
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#include "unwind-pe.h"
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#include "unwind-dw2-fde.h"
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/* Carefully don't include gthr.h. */
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typedef int __gthread_mutex_t;
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#define __gthread_mutex_lock(x) (void)(x)
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#define __gthread_mutex_unlock(x) (void)(x)
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static const fde * _Unwind_Find_registered_FDE (void *pc,
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struct dwarf_eh_bases *bases);
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#define _Unwind_Find_FDE _Unwind_Find_registered_FDE
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#include "unwind-dw2-fde.c"
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#undef _Unwind_Find_FDE
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/* KeyMgr stuff. */
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#define KEYMGR_GCC3_LIVE_IMAGE_LIST 301 /* loaded images */
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#define KEYMGR_GCC3_DW2_OBJ_LIST 302 /* Dwarf2 object list */
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extern void *_keymgr_get_and_lock_processwide_ptr (int);
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extern void _keymgr_set_and_unlock_processwide_ptr (int, void *);
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extern void _keymgr_unlock_processwide_ptr (int);
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struct mach_header;
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struct mach_header_64;
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extern char *getsectdatafromheader (struct mach_header*, const char*,
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const char *, unsigned long *);
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extern char *getsectdatafromheader_64 (struct mach_header_64*, const char*,
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const char *, unsigned long *);
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/* This is referenced from KEYMGR_GCC3_DW2_OBJ_LIST. */
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struct km_object_info {
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struct object *seen_objects;
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struct object *unseen_objects;
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unsigned spare[2];
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};
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/* Node of KEYMGR_GCC3_LIVE_IMAGE_LIST. Info about each resident image. */
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struct live_images {
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unsigned long this_size; /* sizeof (live_images) */
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struct mach_header *mh; /* the image info */
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unsigned long vm_slide;
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void (*destructor)(struct live_images *); /* destructor for this */
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struct live_images *next;
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unsigned int examined_p;
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void *fde;
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void *object_info;
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unsigned long info[2]; /* Future use. */
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};
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/* Bits in the examined_p field of struct live_images. */
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enum {
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EXAMINED_IMAGE_MASK = 1, /* We've seen this one. */
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ALLOCED_IMAGE_MASK = 2, /* The FDE entries were allocated by
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malloc, and must be freed. This isn't
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used by newer libgcc versions. */
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IMAGE_IS_TEXT_MASK = 4, /* This image is in the TEXT segment. */
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DESTRUCTOR_MAY_BE_CALLED_LIVE = 8 /* The destructor may be called on an
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object that's part of the live
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image list. */
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};
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/* Delete any data we allocated on a live_images structure. Either
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IMAGE has already been removed from the
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KEYMGR_GCC3_LIVE_IMAGE_LIST and the struct will be deleted
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after we return, or that list is locked and we're being called
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because this object might be about to be unloaded. Called by
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KeyMgr. */
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static void
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live_image_destructor (struct live_images *image)
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{
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if (image->object_info)
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{
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struct km_object_info *the_obj_info;
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the_obj_info =
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_keymgr_get_and_lock_processwide_ptr (KEYMGR_GCC3_DW2_OBJ_LIST);
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if (the_obj_info)
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{
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seen_objects = the_obj_info->seen_objects;
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unseen_objects = the_obj_info->unseen_objects;
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/* Free any sorted arrays. */
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__deregister_frame_info_bases (image->fde);
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the_obj_info->seen_objects = seen_objects;
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the_obj_info->unseen_objects = unseen_objects;
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}
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_keymgr_set_and_unlock_processwide_ptr (KEYMGR_GCC3_DW2_OBJ_LIST,
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the_obj_info);
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free (image->object_info);
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image->object_info = NULL;
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if (image->examined_p & ALLOCED_IMAGE_MASK)
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free (image->fde);
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image->fde = NULL;
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}
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image->examined_p = 0;
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image->destructor = NULL;
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}
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/* Run through the list of live images. If we can allocate memory,
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give each unseen image a new `struct object'. Even if we can't,
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check whether the PC is inside the FDE of each unseen image.
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*/
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static inline const fde *
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examine_objects (void *pc, struct dwarf_eh_bases *bases, int dont_alloc)
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{
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const fde *result = NULL;
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struct live_images *image;
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image = _keymgr_get_and_lock_processwide_ptr (KEYMGR_GCC3_LIVE_IMAGE_LIST);
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for (; image != NULL; image = image->next)
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if ((image->examined_p & EXAMINED_IMAGE_MASK) == 0)
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{
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char *fde = NULL;
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unsigned long sz;
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/* For ppc only check whether or not we have __DATA eh frames. */
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#ifdef __ppc__
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fde = getsectdatafromheader (image->mh, "__DATA", "__eh_frame", &sz);
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#endif
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if (fde == NULL)
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{
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#if __LP64__
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fde = getsectdatafromheader_64 ((struct mach_header_64 *) image->mh,
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"__TEXT", "__eh_frame", &sz);
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#else
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fde = getsectdatafromheader (image->mh, "__TEXT",
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"__eh_frame", &sz);
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#endif
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if (fde != NULL)
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image->examined_p |= IMAGE_IS_TEXT_MASK;
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}
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/* If .eh_frame is empty, don't register at all. */
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if (fde != NULL && sz > 0)
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{
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char *real_fde = (fde + image->vm_slide);
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struct object *ob = NULL;
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struct object panicob;
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if (! dont_alloc)
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ob = calloc (1, sizeof (struct object));
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dont_alloc |= ob == NULL;
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if (dont_alloc)
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ob = &panicob;
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ob->pc_begin = (void *)-1;
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ob->tbase = 0;
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ob->dbase = 0;
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ob->u.single = (struct dwarf_fde *)real_fde;
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ob->s.i = 0;
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ob->s.b.encoding = DW_EH_PE_omit;
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ob->fde_end = real_fde + sz;
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image->fde = real_fde;
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result = search_object (ob, pc);
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if (! dont_alloc)
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{
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struct object **p;
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image->destructor = live_image_destructor;
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image->object_info = ob;
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image->examined_p |= (EXAMINED_IMAGE_MASK
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/* Insert the object into the classified list. */
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for (p = &seen_objects; *p ; p = &(*p)->next)
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if ((*p)->pc_begin < ob->pc_begin)
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break;
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ob->next = *p;
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*p = ob;
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}
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if (result)
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{
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int encoding;
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_Unwind_Ptr func;
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bases->tbase = ob->tbase;
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bases->dbase = ob->dbase;
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encoding = ob->s.b.encoding;
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if (ob->s.b.mixed_encoding)
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encoding = get_fde_encoding (result);
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read_encoded_value_with_base (encoding,
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base_from_object (encoding, ob),
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result->pc_begin, &func);
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bases->func = (void *) func;
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break;
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}
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}
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else
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image->examined_p |= EXAMINED_IMAGE_MASK;
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}
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_keymgr_unlock_processwide_ptr (KEYMGR_GCC3_LIVE_IMAGE_LIST);
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return result;
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}
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const fde *
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_Unwind_Find_FDE (void *pc, struct dwarf_eh_bases *bases)
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{
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struct km_object_info *the_obj_info;
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const fde *ret = NULL;
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the_obj_info =
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_keymgr_get_and_lock_processwide_ptr (KEYMGR_GCC3_DW2_OBJ_LIST);
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if (! the_obj_info)
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the_obj_info = calloc (1, sizeof (*the_obj_info));
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if (the_obj_info != NULL)
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{
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seen_objects = the_obj_info->seen_objects;
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unseen_objects = the_obj_info->unseen_objects;
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ret = _Unwind_Find_registered_FDE (pc, bases);
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}
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/* OK, didn't find it in the list of FDEs we've seen before,
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so go through and look at the new ones. */
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if (ret == NULL)
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ret = examine_objects (pc, bases, the_obj_info == NULL);
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if (the_obj_info != NULL)
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{
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the_obj_info->seen_objects = seen_objects;
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the_obj_info->unseen_objects = unseen_objects;
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}
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_keymgr_set_and_unlock_processwide_ptr (KEYMGR_GCC3_DW2_OBJ_LIST,
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the_obj_info);
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return ret;
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}
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