| /* Implements unwind table entry lookup for AIX (cf. fde-glibc.c). |
| Copyright (C) 2001, 2002 Free Software Foundation, Inc. |
| Contributed by Timothy Wall <twall@redhat.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. */ |
| |
| #include "tconfig.h" |
| #include "tsystem.h" |
| #include "unwind.h" |
| #include "unwind-ia64.h" |
| |
| #include <dlfcn.h> |
| #include <link.h> |
| #include <sys/mman.h> |
| |
| static struct unw_table_entry * |
| find_fde_for_dso (Elf64_Addr pc, rt_link_map *map, |
| unsigned long* pseg_base, unsigned long* pgp) |
| { |
| rt_segment *seg; |
| Elf64_Addr seg_base; |
| struct unw_table_entry *f_base; |
| size_t lo, hi; |
| |
| /* See if PC falls into one of the loaded segments. */ |
| for (seg = map->l_segments; seg; seg = (rt_segment *)seg->s_next) |
| { |
| if (pc >= seg->s_map_addr && pc < seg->s_map_addr + seg->s_mapsz) |
| break; |
| } |
| if (!seg) |
| return NULL; |
| |
| /* Search for the entry within the unwind table. */ |
| f_base = (struct unw_table_entry *) (map->l_unwind_table); |
| seg_base = (Elf64_Addr) seg->s_map_addr; |
| lo = 0; |
| hi = map->l_unwind_sz / sizeof (struct unw_table_entry); |
| |
| while (lo < hi) |
| { |
| size_t mid = (lo + hi) / 2; |
| struct unw_table_entry *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 { |
| /* AIX executables are *always* dynamic. Look up GP for this |
| object. */ |
| Elf64_Dyn *dyn = map->l_ld; |
| *pgp = 0; |
| for (; dyn->d_tag != DT_NULL ; dyn++) |
| { |
| if (dyn->d_tag == DT_PLTGOT) |
| { |
| *pgp = dyn->d_un.d_ptr; |
| break; |
| } |
| } |
| *pseg_base = seg_base; |
| return f; |
| } |
| } |
| return NULL; |
| } |
| |
| /* Return a pointer to the unwind table entry for the function containing |
| PC. */ |
| struct unw_table_entry * |
| _Unwind_FindTableEntry (void *pc, unsigned long *pseg_base, unsigned long *pgp) |
| { |
| extern rt_r_debug _r_debug; |
| struct unw_table_entry *ret; |
| rt_link_map *map = _r_debug.r_map; /* address of link 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, map, pseg_base, pgp); |
| if (ret) |
| { |
| /* If we're in the main application, use the current GP value. */ |
| register unsigned long gp __asm__("gp"); |
| *pgp = gp; |
| return ret; |
| } |
| |
| /* FIXME need a DSO lock mechanism for AIX here, to ensure shared |
| libraries aren't changed while we're examining them. */ |
| |
| for (map = _r_debug.r_map; map; map = map->l_next) |
| { |
| /* Skip the main application's entry. */ |
| if (!map->l_name) |
| continue; |
| ret = find_fde_for_dso ((Elf64_Addr)pc, map, pseg_base, pgp); |
| if (ret) |
| break; |
| } |
| |
| /* FIXME need a DSO unlock mechanism for AIX here. */ |
| |
| return ret; |
| } |