1/* Copyright (C) 2001, 2002, 2003, 2005 Free Software Foundation, Inc. 2 3 This file is part of GCC. 4 5 GCC is free software; you can redistribute it and/or modify 6 it under the terms of the GNU General Public License as published by 7 the Free Software Foundation; either version 2, or (at your option) 8 any later version. 9 10 GCC is distributed in the hope that it will be useful, 11 but WITHOUT ANY WARRANTY; without even the implied warranty of 12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 13 GNU General Public License for more details. 14 15 You should have received a copy of the GNU General Public License 16 along with GCC; see the file COPYING. If not, write to 17 the Free Software Foundation, 51 Franklin Street, Fifth Floor, 18 Boston, MA 02110-1301, USA. */ 19 20/* As a special exception, if you link this library with other files, 21 some of which are compiled with GCC, to produce an executable, 22 this library does not by itself cause the resulting executable 23 to be covered by the GNU General Public License. 24 This exception does not however invalidate any other reasons why 25 the executable file might be covered by the GNU General Public License. */ 26 27/* Locate the FDE entry for a given address, using Darwin's keymgr support. */ 28 29#include "tconfig.h" 30#include "tsystem.h" 31#include <string.h> 32#include <stdlib.h> 33#include "dwarf2.h" 34#include "unwind.h" 35#define NO_BASE_OF_ENCODED_VALUE 36#define DWARF2_OBJECT_END_PTR_EXTENSION 37#include "unwind-pe.h" 38#include "unwind-dw2-fde.h" 39/* Carefully don't include gthr.h. */ 40 41typedef int __gthread_mutex_t; 42#define __gthread_mutex_lock(x) (void)(x) 43#define __gthread_mutex_unlock(x) (void)(x) 44 45static const fde * _Unwind_Find_registered_FDE (void *pc, 46 struct dwarf_eh_bases *bases); 47 48#define _Unwind_Find_FDE _Unwind_Find_registered_FDE 49#include "unwind-dw2-fde.c" 50#undef _Unwind_Find_FDE 51 52/* KeyMgr stuff. */ 53#define KEYMGR_GCC3_LIVE_IMAGE_LIST 301 /* loaded images */ 54#define KEYMGR_GCC3_DW2_OBJ_LIST 302 /* Dwarf2 object list */ 55 56extern void *_keymgr_get_and_lock_processwide_ptr (int); 57extern void _keymgr_set_and_unlock_processwide_ptr (int, void *); 58extern void _keymgr_unlock_processwide_ptr (int); 59 60struct mach_header; 61struct mach_header_64; 62extern char *getsectdatafromheader (struct mach_header*, const char*, 63 const char *, unsigned long *); 64extern char *getsectdatafromheader_64 (struct mach_header_64*, const char*, 65 const char *, unsigned long *); 66 67/* This is referenced from KEYMGR_GCC3_DW2_OBJ_LIST. */ 68struct km_object_info { 69 struct object *seen_objects; 70 struct object *unseen_objects; 71 unsigned spare[2]; 72}; 73 74/* Node of KEYMGR_GCC3_LIVE_IMAGE_LIST. Info about each resident image. */ 75struct live_images { 76 unsigned long this_size; /* sizeof (live_images) */ 77 struct mach_header *mh; /* the image info */ 78 unsigned long vm_slide; 79 void (*destructor)(struct live_images *); /* destructor for this */ 80 struct live_images *next; 81 unsigned int examined_p; 82 void *fde; 83 void *object_info; 84 unsigned long info[2]; /* Future use. */ 85}; 86 87/* Bits in the examined_p field of struct live_images. */ 88enum { 89 EXAMINED_IMAGE_MASK = 1, /* We've seen this one. */ 90 ALLOCED_IMAGE_MASK = 2, /* The FDE entries were allocated by 91 malloc, and must be freed. This isn't 92 used by newer libgcc versions. */ 93 IMAGE_IS_TEXT_MASK = 4, /* This image is in the TEXT segment. */ 94 DESTRUCTOR_MAY_BE_CALLED_LIVE = 8 /* The destructor may be called on an 95 object that's part of the live 96 image list. */ 97}; 98 99/* Delete any data we allocated on a live_images structure. Either 100 IMAGE has already been removed from the 101 KEYMGR_GCC3_LIVE_IMAGE_LIST and the struct will be deleted 102 after we return, or that list is locked and we're being called 103 because this object might be about to be unloaded. Called by 104 KeyMgr. */ 105 106static void 107live_image_destructor (struct live_images *image) 108{ 109 if (image->object_info) 110 { 111 struct km_object_info *the_obj_info; 112 113 the_obj_info = 114 _keymgr_get_and_lock_processwide_ptr (KEYMGR_GCC3_DW2_OBJ_LIST); 115 if (the_obj_info) 116 { 117 seen_objects = the_obj_info->seen_objects; 118 unseen_objects = the_obj_info->unseen_objects; 119 120 /* Free any sorted arrays. */ 121 __deregister_frame_info_bases (image->fde); 122 123 the_obj_info->seen_objects = seen_objects; 124 the_obj_info->unseen_objects = unseen_objects; 125 } 126 _keymgr_set_and_unlock_processwide_ptr (KEYMGR_GCC3_DW2_OBJ_LIST, 127 the_obj_info); 128 129 free (image->object_info); 130 image->object_info = NULL; 131 if (image->examined_p & ALLOCED_IMAGE_MASK) 132 free (image->fde); 133 image->fde = NULL; 134 } 135 image->examined_p = 0; 136 image->destructor = NULL; 137} 138 139/* Run through the list of live images. If we can allocate memory, 140 give each unseen image a new `struct object'. Even if we can't, 141 check whether the PC is inside the FDE of each unseen image. 142 */ 143 144static inline const fde * 145examine_objects (void *pc, struct dwarf_eh_bases *bases, int dont_alloc) 146{ 147 const fde *result = NULL; 148 struct live_images *image; 149 150 image = _keymgr_get_and_lock_processwide_ptr (KEYMGR_GCC3_LIVE_IMAGE_LIST); 151 152 for (; image != NULL; image = image->next) 153 if ((image->examined_p & EXAMINED_IMAGE_MASK) == 0) 154 { 155 char *fde = NULL; 156 unsigned long sz; 157 158 /* For ppc only check whether or not we have __DATA eh frames. */ 159#ifdef __ppc__ 160 fde = getsectdatafromheader (image->mh, "__DATA", "__eh_frame", &sz); 161#endif 162 163 if (fde == NULL) 164 { 165#if __LP64__ 166 fde = getsectdatafromheader_64 ((struct mach_header_64 *) image->mh, 167 "__TEXT", "__eh_frame", &sz); 168#else 169 fde = getsectdatafromheader (image->mh, "__TEXT", 170 "__eh_frame", &sz); 171#endif 172 if (fde != NULL) 173 image->examined_p |= IMAGE_IS_TEXT_MASK; 174 } 175 176 /* If .eh_frame is empty, don't register at all. */ 177 if (fde != NULL && sz > 0) 178 { 179 char *real_fde = (fde + image->vm_slide); 180 struct object *ob = NULL; 181 struct object panicob; 182 183 if (! dont_alloc) 184 ob = calloc (1, sizeof (struct object)); 185 dont_alloc |= ob == NULL; 186 if (dont_alloc) 187 ob = &panicob; 188 189 ob->pc_begin = (void *)-1; 190 ob->tbase = 0; 191 ob->dbase = 0; 192 ob->u.single = (struct dwarf_fde *)real_fde; 193 ob->s.i = 0; 194 ob->s.b.encoding = DW_EH_PE_omit; 195 ob->fde_end = real_fde + sz; 196 197 image->fde = real_fde; 198 199 result = search_object (ob, pc); 200 201 if (! dont_alloc) 202 { 203 struct object **p; 204 205 image->destructor = live_image_destructor; 206 image->object_info = ob; 207 208 image->examined_p |= (EXAMINED_IMAGE_MASK 209 | DESTRUCTOR_MAY_BE_CALLED_LIVE); 210 211 /* Insert the object into the classified list. */ 212 for (p = &seen_objects; *p ; p = &(*p)->next) 213 if ((*p)->pc_begin < ob->pc_begin) 214 break; 215 ob->next = *p; 216 *p = ob; 217 } 218 219 if (result) 220 { 221 int encoding; 222 _Unwind_Ptr func; 223 224 bases->tbase = ob->tbase; 225 bases->dbase = ob->dbase; 226 227 encoding = ob->s.b.encoding; 228 if (ob->s.b.mixed_encoding) 229 encoding = get_fde_encoding (result); 230 read_encoded_value_with_base (encoding, 231 base_from_object (encoding, ob), 232 result->pc_begin, &func); 233 bases->func = (void *) func; 234 break; 235 } 236 } 237 else 238 image->examined_p |= EXAMINED_IMAGE_MASK; 239 } 240 241 _keymgr_unlock_processwide_ptr (KEYMGR_GCC3_LIVE_IMAGE_LIST); 242 243 return result; 244} 245 246const fde * 247_Unwind_Find_FDE (void *pc, struct dwarf_eh_bases *bases) 248{ 249 struct km_object_info *the_obj_info; 250 const fde *ret = NULL; 251 252 the_obj_info = 253 _keymgr_get_and_lock_processwide_ptr (KEYMGR_GCC3_DW2_OBJ_LIST); 254 if (! the_obj_info) 255 the_obj_info = calloc (1, sizeof (*the_obj_info)); 256 257 if (the_obj_info != NULL) 258 { 259 seen_objects = the_obj_info->seen_objects; 260 unseen_objects = the_obj_info->unseen_objects; 261 262 ret = _Unwind_Find_registered_FDE (pc, bases); 263 } 264 265 /* OK, didn't find it in the list of FDEs we've seen before, 266 so go through and look at the new ones. */ 267 if (ret == NULL) 268 ret = examine_objects (pc, bases, the_obj_info == NULL); 269 270 if (the_obj_info != NULL) 271 { 272 the_obj_info->seen_objects = seen_objects; 273 the_obj_info->unseen_objects = unseen_objects; 274 } 275 _keymgr_set_and_unlock_processwide_ptr (KEYMGR_GCC3_DW2_OBJ_LIST, 276 the_obj_info); 277 return ret; 278} 279