| /* Copyright (C) 2000 Free Software Foundation, Inc. |
| Contributed by Richard Henderson <rth@cygnus.com>. |
| |
| This file is part of GNU CC. |
| |
| GNU CC 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 2, or (at your option) |
| any later version. |
| |
| GNU CC 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. |
| |
| You should have received a copy of the GNU General Public License |
| along with GNU CC; see the file COPYING. If not, write to |
| the Free Software Foundation, 59 Temple Place - Suite 330, |
| Boston, MA 02111-1307, USA. */ |
| |
| /* As a special exception, if you link this library with other files, |
| some of which are compiled with GCC, to produce an executable, |
| this library does not by itself cause the resulting executable |
| to be covered by the GNU General Public License. |
| This exception does not however invalidate any other reasons why |
| the executable file might be covered by the GNU General Public License. */ |
| |
| /* Locate the FDE entry for a given address, using glibc ld.so routines |
| to avoid register/deregister calls at DSO load/unload. */ |
| |
| #include <stdlib.h> |
| #include <link.h> |
| #include <bits/libc-lock.h> |
| #include "frame-ia64.h" |
| |
| |
| /* Initialized by crtbegin from the main application. */ |
| extern Elf64_Ehdr *__ia64_app_header; |
| |
| /* ??? A redeclaration of the lock in ld.so. Perhaps this should |
| appear in <link.h> in a new glibc version. */ |
| __libc_lock_define (extern, _dl_load_lock) |
| |
| /* ??? _dl_load_lock is not exported from glibc 2.1, but it is |
| from glibc 2.2. Remove this when folks have migrated. */ |
| #pragma weak _dl_load_lock |
| |
| /* This always exists, even in a static application. */ |
| extern struct link_map *_dl_loaded; |
| |
| static fde * |
| find_fde_for_dso (Elf64_Addr pc, Elf64_Ehdr *ehdr) |
| { |
| Elf64_Phdr *phdr, *p_unwind; |
| long n, match; |
| Elf64_Addr load_base, seg_base; |
| fde *f_base; |
| size_t lo, hi; |
| |
| /* Verify that we are looking at an ELF header. */ |
| if (ehdr->e_ident[0] != 0x7f |
| || ehdr->e_ident[1] != 'E' |
| || ehdr->e_ident[2] != 'L' |
| || ehdr->e_ident[3] != 'F' |
| || ehdr->e_ident[EI_CLASS] != ELFCLASS64 |
| || ehdr->e_ident[EI_DATA] != ELFDATA2LSB |
| || ehdr->e_machine != EM_IA_64) |
| abort (); |
| |
| match = 0; |
| phdr = (Elf64_Phdr *)((char *)ehdr + ehdr->e_phoff); |
| load_base = (ehdr->e_type == ET_DYN ? (Elf64_Addr)ehdr : 0); |
| p_unwind = NULL; |
| |
| /* See if PC falls into one of the loaded segments. Find the unwind |
| segment at the same time. */ |
| for (n = ehdr->e_phnum; --n >= 0; phdr++) |
| { |
| if (phdr->p_type == PT_LOAD) |
| { |
| Elf64_Addr vaddr = phdr->p_vaddr + load_base; |
| if (pc >= vaddr && pc < vaddr + phdr->p_memsz) |
| match = 1; |
| } |
| else if (phdr->p_type == PT_IA_64_UNWIND) |
| p_unwind = phdr; |
| } |
| if (!match || !p_unwind) |
| return NULL; |
| |
| /* Search for the FDE within the unwind segment. */ |
| |
| f_base = (fde *) (p_unwind->p_vaddr + load_base); |
| seg_base = (Elf64_Addr) ehdr; |
| lo = 0; |
| hi = p_unwind->p_memsz / sizeof (fde); |
| |
| while (lo < hi) |
| { |
| size_t mid = (lo + hi) / 2; |
| fde *f = f_base + mid; |
| |
| if (pc < f->start_offset + seg_base) |
| hi = mid; |
| else if (pc >= f->end_offset + seg_base) |
| lo = mid + 1; |
| else |
| return f; |
| } |
| |
| return NULL; |
| } |
| |
| /* Return a pointer to the FDE for the function containing PC. */ |
| fde * |
| __ia64_find_fde (void *pc, void **pc_base) |
| { |
| fde *ret; |
| struct link_map *map; |
| |
| /* Check the main application first, hoping that most of the user's |
| code is there instead of in some library. */ |
| ret = find_fde_for_dso ((Elf64_Addr)pc, __ia64_app_header); |
| if (ret) |
| { |
| *pc_base = __ia64_app_header; |
| return ret; |
| } |
| |
| /* Glibc is probably unique in that we can (with certain restrictions) |
| dynamicly load libraries into staticly linked applications. Thus |
| we _always_ check _dl_loaded. */ |
| |
| if (&_dl_load_lock) |
| __libc_lock_lock (_dl_load_lock); |
| |
| for (map = _dl_loaded; map ; map = map->l_next) |
| { |
| /* Skip the main application's entry. */ |
| if (map->l_name[0] == 0) |
| continue; |
| ret = find_fde_for_dso ((Elf64_Addr)pc, (Elf64_Ehdr *)map->l_addr); |
| if (ret) |
| break; |
| } |
| |
| if (&_dl_load_lock) |
| __libc_lock_unlock (_dl_load_lock); |
| |
| *pc_base = (void *)(map ? map->l_addr : 0); |
| return ret; |
| } |