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- /* Copyright (C) 2001-2022 Free Software Foundation, Inc.
- This file is part of GCC.
- GCC is free software; you can redistribute it and/or modify
- it under the terms of the GNU General Public License as published by
- the Free Software Foundation; either version 3, or (at your option)
- any later version.
- GCC 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 General Public License for more details.
- Under Section 7 of GPL version 3, you are granted additional
- permissions described in the GCC Runtime Library Exception, version
- 3.1, as published by the Free Software Foundation.
- You should have received a copy of the GNU General Public License and
- a copy of the GCC Runtime Library Exception along with this program;
- see the files COPYING3 and COPYING.RUNTIME respectively. If not, see
- <http://www.gnu.org/licenses/>. */
- /* Locate the FDE entry for a given address, using Darwin's keymgr support. */
- #include "tconfig.h"
- #include "tsystem.h"
- #include <string.h>
- #include <stdlib.h>
- #include "dwarf2.h"
- #include "unwind.h"
- #define NO_BASE_OF_ENCODED_VALUE
- #define DWARF2_OBJECT_END_PTR_EXTENSION
- #include "unwind-pe.h"
- #include "unwind-dw2-fde.h"
- /* Carefully don't include gthr.h. */
- typedef int __gthread_mutex_t;
- #define __gthread_mutex_lock(x) (void)(x)
- #define __gthread_mutex_unlock(x) (void)(x)
- static const fde * _Unwind_Find_registered_FDE (void *pc,
- struct dwarf_eh_bases *bases);
- #define _Unwind_Find_FDE _Unwind_Find_registered_FDE
- #include "unwind-dw2-fde.c"
- #undef _Unwind_Find_FDE
- /* KeyMgr stuff. */
- #define KEYMGR_GCC3_LIVE_IMAGE_LIST 301 /* loaded images */
- #define KEYMGR_GCC3_DW2_OBJ_LIST 302 /* Dwarf2 object list */
- extern void *_keymgr_get_and_lock_processwide_ptr (int);
- extern void _keymgr_set_and_unlock_processwide_ptr (int, void *);
- extern void _keymgr_unlock_processwide_ptr (int);
- struct mach_header;
- struct mach_header_64;
- extern char *getsectdatafromheader (struct mach_header*, const char*,
- const char *, unsigned long *);
- extern char *getsectdatafromheader_64 (struct mach_header_64*, const char*,
- const char *, unsigned long *);
- /* This is referenced from KEYMGR_GCC3_DW2_OBJ_LIST. */
- struct km_object_info {
- struct object *seen_objects;
- struct object *unseen_objects;
- unsigned spare[2];
- };
- /* Node of KEYMGR_GCC3_LIVE_IMAGE_LIST. Info about each resident image. */
- struct live_images {
- unsigned long this_size; /* sizeof (live_images) */
- struct mach_header *mh; /* the image info */
- unsigned long vm_slide;
- void (*destructor)(struct live_images *); /* destructor for this */
- struct live_images *next;
- unsigned int examined_p;
- void *fde;
- void *object_info;
- unsigned long info[2]; /* Future use. */
- };
- /* Bits in the examined_p field of struct live_images. */
- enum {
- EXAMINED_IMAGE_MASK = 1, /* We've seen this one. */
- ALLOCED_IMAGE_MASK = 2, /* The FDE entries were allocated by
- malloc, and must be freed. This isn't
- used by newer libgcc versions. */
- IMAGE_IS_TEXT_MASK = 4, /* This image is in the TEXT segment. */
- DESTRUCTOR_MAY_BE_CALLED_LIVE = 8 /* The destructor may be called on an
- object that's part of the live
- image list. */
- };
- /* Delete any data we allocated on a live_images structure. Either
- IMAGE has already been removed from the
- KEYMGR_GCC3_LIVE_IMAGE_LIST and the struct will be deleted
- after we return, or that list is locked and we're being called
- because this object might be about to be unloaded. Called by
- KeyMgr. */
- static void
- live_image_destructor (struct live_images *image)
- {
- if (image->object_info)
- {
- struct km_object_info *the_obj_info;
- the_obj_info =
- _keymgr_get_and_lock_processwide_ptr (KEYMGR_GCC3_DW2_OBJ_LIST);
- if (the_obj_info)
- {
- seen_objects = the_obj_info->seen_objects;
- unseen_objects = the_obj_info->unseen_objects;
- /* Free any sorted arrays. */
- __deregister_frame_info_bases (image->fde);
- the_obj_info->seen_objects = seen_objects;
- the_obj_info->unseen_objects = unseen_objects;
- }
- _keymgr_set_and_unlock_processwide_ptr (KEYMGR_GCC3_DW2_OBJ_LIST,
- the_obj_info);
- free (image->object_info);
- image->object_info = NULL;
- if (image->examined_p & ALLOCED_IMAGE_MASK)
- free (image->fde);
- image->fde = NULL;
- }
- image->examined_p = 0;
- image->destructor = NULL;
- }
- /* Run through the list of live images. If we can allocate memory,
- give each unseen image a new `struct object'. Even if we can't,
- check whether the PC is inside the FDE of each unseen image.
- */
- static inline const fde *
- examine_objects (void *pc, struct dwarf_eh_bases *bases, int dont_alloc)
- {
- const fde *result = NULL;
- struct live_images *image;
- image = _keymgr_get_and_lock_processwide_ptr (KEYMGR_GCC3_LIVE_IMAGE_LIST);
- for (; image != NULL; image = image->next)
- if ((image->examined_p & EXAMINED_IMAGE_MASK) == 0)
- {
- char *fde = NULL;
- unsigned long sz;
- /* For ppc only check whether or not we have __DATA eh frames. */
- #ifdef __ppc__
- fde = getsectdatafromheader (image->mh, "__DATA", "__eh_frame", &sz);
- #endif
- if (fde == NULL)
- {
- #if __LP64__
- fde = getsectdatafromheader_64 ((struct mach_header_64 *) image->mh,
- "__TEXT", "__eh_frame", &sz);
- #else
- fde = getsectdatafromheader (image->mh, "__TEXT",
- "__eh_frame", &sz);
- #endif
- if (fde != NULL)
- image->examined_p |= IMAGE_IS_TEXT_MASK;
- }
- /* If .eh_frame is empty, don't register at all. */
- if (fde != NULL && sz > 0)
- {
- char *real_fde = (fde + image->vm_slide);
- struct object *ob = NULL;
- struct object panicob;
- if (! dont_alloc)
- ob = calloc (1, sizeof (struct object));
- dont_alloc |= ob == NULL;
- if (dont_alloc)
- ob = &panicob;
- ob->pc_begin = (void *)-1;
- ob->tbase = 0;
- ob->dbase = 0;
- ob->u.single = (struct dwarf_fde *)real_fde;
- ob->s.i = 0;
- ob->s.b.encoding = DW_EH_PE_omit;
- ob->fde_end = real_fde + sz;
- image->fde = real_fde;
- result = search_object (ob, pc);
- if (! dont_alloc)
- {
- struct object **p;
- image->destructor = live_image_destructor;
- image->object_info = ob;
- image->examined_p |= (EXAMINED_IMAGE_MASK
- | DESTRUCTOR_MAY_BE_CALLED_LIVE);
- /* Insert the object into the classified list. */
- for (p = &seen_objects; *p ; p = &(*p)->next)
- if ((*p)->pc_begin < ob->pc_begin)
- break;
- ob->next = *p;
- *p = ob;
- }
- if (result)
- {
- int encoding;
- _Unwind_Ptr func;
- bases->tbase = ob->tbase;
- bases->dbase = ob->dbase;
- encoding = ob->s.b.encoding;
- if (ob->s.b.mixed_encoding)
- encoding = get_fde_encoding (result);
- read_encoded_value_with_base (encoding,
- base_from_object (encoding, ob),
- result->pc_begin, &func);
- bases->func = (void *) func;
- break;
- }
- }
- else
- image->examined_p |= EXAMINED_IMAGE_MASK;
- }
- _keymgr_unlock_processwide_ptr (KEYMGR_GCC3_LIVE_IMAGE_LIST);
- return result;
- }
- const fde *
- _Unwind_Find_FDE (void *pc, struct dwarf_eh_bases *bases)
- {
- struct km_object_info *the_obj_info;
- const fde *ret = NULL;
- the_obj_info =
- _keymgr_get_and_lock_processwide_ptr (KEYMGR_GCC3_DW2_OBJ_LIST);
- if (! the_obj_info)
- the_obj_info = calloc (1, sizeof (*the_obj_info));
- if (the_obj_info != NULL)
- {
- seen_objects = the_obj_info->seen_objects;
- unseen_objects = the_obj_info->unseen_objects;
- ret = _Unwind_Find_registered_FDE (pc, bases);
- }
- /* OK, didn't find it in the list of FDEs we've seen before,
- so go through and look at the new ones. */
- if (ret == NULL)
- ret = examine_objects (pc, bases, the_obj_info == NULL);
- if (the_obj_info != NULL)
- {
- the_obj_info->seen_objects = seen_objects;
- the_obj_info->unseen_objects = unseen_objects;
- }
- _keymgr_set_and_unlock_processwide_ptr (KEYMGR_GCC3_DW2_OBJ_LIST,
- the_obj_info);
- return ret;
- }
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