| /* libunwind - a platform-independent unwind library |
| Copyright (C) 2003-2004 Hewlett-Packard Co |
| Contributed by David Mosberger-Tang <davidm@hpl.hp.com> |
| |
| This file is part of libunwind. |
| |
| Permission is hereby granted, free of charge, to any person obtaining |
| a copy of this software and associated documentation files (the |
| "Software"), to deal in the Software without restriction, including |
| without limitation the rights to use, copy, modify, merge, publish, |
| distribute, sublicense, and/or sell copies of the Software, and to |
| permit persons to whom the Software is furnished to do so, subject to |
| the following conditions: |
| |
| The above copyright notice and this permission notice shall be |
| included in all copies or substantial portions of the Software. |
| |
| THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, |
| EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF |
| MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND |
| NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE |
| LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION |
| OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION |
| WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. */ |
| #include <elf.h> |
| #include <fcntl.h> |
| #include <string.h> |
| #include <unistd.h> |
| |
| #include <sys/mman.h> |
| |
| #include "libunwind_i.h" |
| #include "elf64.h" |
| |
| static unw_word_t |
| find_gp (struct elf_dyn_info *edi, Elf64_Phdr *pdyn, Elf64_Addr load_base) |
| { |
| Elf64_Off soff, str_soff; |
| Elf64_Ehdr *ehdr = edi->ei.image; |
| Elf64_Shdr *shdr; |
| Elf64_Shdr *str_shdr; |
| Elf64_Addr gp = 0; |
| char *strtab; |
| int i; |
| |
| if (pdyn) |
| { |
| /* If we have a PT_DYNAMIC program header, fetch the gp-value |
| from the DT_PLTGOT entry. */ |
| Elf64_Dyn *dyn = (Elf64_Dyn *) (pdyn->p_offset + (char *) edi->ei.image); |
| for (; dyn->d_tag != DT_NULL; ++dyn) |
| if (dyn->d_tag == DT_PLTGOT) |
| { |
| gp = (Elf64_Addr) dyn->d_un.d_ptr + load_base; |
| goto done; |
| } |
| } |
| |
| /* Without a PT_DYAMIC header, lets try to look for a non-empty .opd |
| section. If there is such a section, we know it's full of |
| function descriptors, and we can simply pick up the gp from the |
| second word of the first entry in this table. */ |
| |
| soff = ehdr->e_shoff; |
| str_soff = soff + (ehdr->e_shstrndx * ehdr->e_shentsize); |
| |
| if (soff + ehdr->e_shnum * ehdr->e_shentsize > edi->ei.size) |
| { |
| Debug (1, "section table outside of image? (%lu > %lu)", |
| soff + ehdr->e_shnum * ehdr->e_shentsize, |
| edi->ei.size); |
| goto done; |
| } |
| |
| shdr = (Elf64_Shdr *) ((char *) edi->ei.image + soff); |
| str_shdr = (Elf64_Shdr *) ((char *) edi->ei.image + str_soff); |
| strtab = (char *) edi->ei.image + str_shdr->sh_offset; |
| for (i = 0; i < ehdr->e_shnum; ++i) |
| { |
| if (strcmp (strtab + shdr->sh_name, ".opd") == 0 |
| && shdr->sh_size >= 16) |
| { |
| gp = ((Elf64_Addr *) ((char *) edi->ei.image + shdr->sh_offset))[1]; |
| goto done; |
| } |
| shdr = (Elf64_Shdr *) (((char *) shdr) + ehdr->e_shentsize); |
| } |
| |
| done: |
| Debug (16, "image at %p, gp = %lx\n", edi->ei.image, gp); |
| return gp; |
| } |
| |
| int |
| ia64_find_unwind_table (struct elf_dyn_info *edi, unw_addr_space_t as, |
| char *path, unw_word_t segbase, unw_word_t mapoff, |
| unw_word_t ip) |
| { |
| Elf64_Phdr *phdr, *ptxt = NULL, *punw = NULL, *pdyn = NULL; |
| Elf64_Ehdr *ehdr; |
| int i; |
| |
| if (!_Uelf64_valid_object (&edi->ei)) |
| return -UNW_ENOINFO; |
| |
| ehdr = edi->ei.image; |
| phdr = (Elf64_Phdr *) ((char *) edi->ei.image + ehdr->e_phoff); |
| |
| for (i = 0; i < ehdr->e_phnum; ++i) |
| { |
| switch (phdr[i].p_type) |
| { |
| case PT_LOAD: |
| if (phdr[i].p_offset == mapoff) |
| ptxt = phdr + i; |
| break; |
| |
| case PT_IA_64_UNWIND: |
| punw = phdr + i; |
| break; |
| |
| case PT_DYNAMIC: |
| pdyn = phdr + i; |
| break; |
| |
| default: |
| break; |
| } |
| } |
| if (!ptxt || !punw) |
| return 0; |
| |
| edi->di_cache.start_ip = segbase; |
| edi->di_cache.end_ip = edi->di_cache.start_ip + ptxt->p_memsz; |
| edi->di_cache.gp = find_gp (edi, pdyn, segbase - ptxt->p_vaddr); |
| edi->di_cache.format = UNW_INFO_FORMAT_TABLE; |
| edi->di_cache.u.ti.name_ptr = 0; |
| edi->di_cache.u.ti.segbase = segbase; |
| edi->di_cache.u.ti.table_len = punw->p_memsz / sizeof (unw_word_t); |
| edi->di_cache.u.ti.table_data = (unw_word_t *) |
| ((char *) edi->ei.image + (punw->p_vaddr - ptxt->p_vaddr)); |
| return 1; |
| } |