123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120121122123124125126127128129130131132133134135136137138139140141142143144145146147148149150151152153154155156157158159160161162163164165166167168169170171172173174175176177178179180181182183184185186187188189190191192193194195196197198199200201202203204205206207208209210211212213214215216217218219220221222223224225226227228 |
- /* 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 "dwarf-eh.h"
- #include "dwarf_i.h"
- int
- dwarf_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)
- {
- Elf_W(Phdr) *phdr, *ptxt = NULL, *peh_hdr = NULL, *pdyn = NULL;
- unw_word_t addr, eh_frame_start, fde_count, load_base;
- unw_word_t max_load_addr = 0;
- unw_word_t start_ip = (unw_word_t) -1;
- unw_word_t end_ip = 0;
- struct dwarf_eh_frame_hdr *hdr;
- unw_proc_info_t pi;
- unw_accessors_t *a;
- Elf_W(Ehdr) *ehdr;
- #if UNW_TARGET_ARM
- const Elf_W(Phdr) *parm_exidx = NULL;
- #endif
- int i, ret, found = 0;
- /* XXX: Much of this code is Linux/LSB-specific. */
- if (!elf_w(valid_object) (&edi->ei))
- return -UNW_ENOINFO;
- ehdr = edi->ei.image;
- phdr = (Elf_W(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_vaddr < start_ip)
- start_ip = phdr[i].p_vaddr;
- if (phdr[i].p_vaddr + phdr[i].p_memsz > end_ip)
- end_ip = phdr[i].p_vaddr + phdr[i].p_memsz;
- if (phdr[i].p_offset == mapoff)
- ptxt = phdr + i;
- if ((uintptr_t) edi->ei.image + phdr->p_filesz > max_load_addr)
- max_load_addr = (uintptr_t) edi->ei.image + phdr->p_filesz;
- break;
- case PT_GNU_EH_FRAME:
- peh_hdr = phdr + i;
- break;
- case PT_DYNAMIC:
- pdyn = phdr + i;
- break;
- #if UNW_TARGET_ARM
- case PT_ARM_EXIDX:
- parm_exidx = phdr + i;
- break;
- #endif
- default:
- break;
- }
- }
- if (!ptxt)
- return 0;
- load_base = segbase - ptxt->p_vaddr;
- start_ip += load_base;
- end_ip += load_base;
- if (peh_hdr)
- {
- if (pdyn)
- {
- /* For dynamicly linked executables and shared libraries,
- DT_PLTGOT is the value that data-relative addresses are
- relative to for that object. We call this the "gp". */
- Elf_W(Dyn) *dyn = (Elf_W(Dyn) *)(pdyn->p_offset
- + (char *) edi->ei.image);
- for (; dyn->d_tag != DT_NULL; ++dyn)
- if (dyn->d_tag == DT_PLTGOT)
- {
- /* Assume that _DYNAMIC is writable and GLIBC has
- relocated it (true for x86 at least). */
- edi->di_cache.gp = dyn->d_un.d_ptr;
- break;
- }
- }
- else
- /* Otherwise this is a static executable with no _DYNAMIC. Assume
- that data-relative addresses are relative to 0, i.e.,
- absolute. */
- edi->di_cache.gp = 0;
- hdr = (struct dwarf_eh_frame_hdr *) (peh_hdr->p_offset
- + (char *) edi->ei.image);
- if (hdr->version != DW_EH_VERSION)
- {
- Debug (1, "table `%s' has unexpected version %d\n",
- path, hdr->version);
- return -UNW_ENOINFO;
- }
- a = unw_get_accessors (unw_local_addr_space);
- addr = (unw_word_t) (hdr + 1);
- /* Fill in a dummy proc_info structure. We just need to fill in
- enough to ensure that dwarf_read_encoded_pointer() can do it's
- job. Since we don't have a procedure-context at this point, all
- we have to do is fill in the global-pointer. */
- memset (&pi, 0, sizeof (pi));
- pi.gp = edi->di_cache.gp;
- /* (Optionally) read eh_frame_ptr: */
- if ((ret = dwarf_read_encoded_pointer (unw_local_addr_space, a,
- &addr, hdr->eh_frame_ptr_enc, &pi,
- &eh_frame_start, NULL)) < 0)
- return -UNW_ENOINFO;
- /* (Optionally) read fde_count: */
- if ((ret = dwarf_read_encoded_pointer (unw_local_addr_space, a,
- &addr, hdr->fde_count_enc, &pi,
- &fde_count, NULL)) < 0)
- return -UNW_ENOINFO;
- if (hdr->table_enc != (DW_EH_PE_datarel | DW_EH_PE_sdata4))
- {
- #if 1
- abort ();
- #else
- unw_word_t eh_frame_end;
- /* If there is no search table or it has an unsupported
- encoding, fall back on linear search. */
- if (hdr->table_enc == DW_EH_PE_omit)
- Debug (4, "EH lacks search table; doing linear search\n");
- else
- Debug (4, "EH table has encoding 0x%x; doing linear search\n",
- hdr->table_enc);
- eh_frame_end = max_load_addr; /* XXX can we do better? */
- if (hdr->fde_count_enc == DW_EH_PE_omit)
- fde_count = ~0UL;
- if (hdr->eh_frame_ptr_enc == DW_EH_PE_omit)
- abort ();
- return linear_search (unw_local_addr_space, ip,
- eh_frame_start, eh_frame_end, fde_count,
- pi, need_unwind_info, NULL);
- #endif
- }
- edi->di_cache.start_ip = start_ip;
- edi->di_cache.end_ip = end_ip;
- edi->di_cache.format = UNW_INFO_FORMAT_REMOTE_TABLE;
- edi->di_cache.u.rti.name_ptr = 0;
- /* two 32-bit values (ip_offset/fde_offset) per table-entry: */
- edi->di_cache.u.rti.table_len = (fde_count * 8) / sizeof (unw_word_t);
- edi->di_cache.u.rti.table_data = ((load_base + peh_hdr->p_vaddr)
- + (addr - (unw_word_t) edi->ei.image
- - peh_hdr->p_offset));
- /* For the binary-search table in the eh_frame_hdr, data-relative
- means relative to the start of that section... */
- edi->di_cache.u.rti.segbase = ((load_base + peh_hdr->p_vaddr)
- + ((unw_word_t) hdr - (unw_word_t) edi->ei.image
- - peh_hdr->p_offset));
- found = 1;
- }
- #if UNW_TARGET_ARM
- if (parm_exidx)
- {
- edi->di_arm.format = UNW_INFO_FORMAT_ARM_EXIDX;
- edi->di_arm.start_ip = start_ip;
- edi->di_arm.end_ip = end_ip;
- edi->di_arm.u.rti.name_ptr = (unw_word_t) path;
- edi->di_arm.u.rti.table_data = load_base + parm_exidx->p_vaddr;
- edi->di_arm.u.rti.table_len = parm_exidx->p_memsz;
- found = 1;
- }
- #endif
- #ifdef CONFIG_DEBUG_FRAME
- /* Try .debug_frame. */
- found = dwarf_find_debug_frame (found, &edi->edi.di_debug, ip, segbase, path,
- start_ip, end_ip);
- #endif
- return found;
- }
|