diff options
Diffstat (limited to 'src/third_party/unwind/dist/src/dwarf/Gfind_unwind_table.c')
| -rw-r--r-- | src/third_party/unwind/dist/src/dwarf/Gfind_unwind_table.c | 230 |
1 files changed, 230 insertions, 0 deletions
diff --git a/src/third_party/unwind/dist/src/dwarf/Gfind_unwind_table.c b/src/third_party/unwind/dist/src/dwarf/Gfind_unwind_table.c new file mode 100644 index 00000000000..6a2ad504078 --- /dev/null +++ b/src/third_party/unwind/dist/src/dwarf/Gfind_unwind_table.c @@ -0,0 +1,230 @@ +/* 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 <fcntl.h> +#include <string.h> +#include <unistd.h> + +#include <sys/mman.h> + +#include "libunwind_i.h" +#include "dwarf-eh.h" +#include "dwarf_i.h" + +#define to_unw_word(p) ((unw_word_t) (uintptr_t) (p)) + +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 = to_unw_word (-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_int (unw_local_addr_space); + addr = to_unw_word (&hdr->eh_frame); + + /* 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 - to_unw_word (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) + + (to_unw_word (hdr) - + to_unw_word (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 = to_unw_word (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->di_debug, ip, load_base, path, + start_ip, end_ip); +#endif + + return found; +} |