1 /* Report modules by examining dynamic linker data structures.
2 Copyright (C) 2008-2014 Red Hat, Inc.
3 This file is part of elfutils.
5 This file is free software; you can redistribute it and/or modify
6 it under the terms of either
8 * the GNU Lesser General Public License as published by the Free
9 Software Foundation; either version 3 of the License, or (at
10 your option) any later version
14 * the GNU General Public License as published by the Free
15 Software Foundation; either version 2 of the License, or (at
16 your option) any later version
18 or both in parallel, as here.
20 elfutils is distributed in the hope that it will be useful, but
21 WITHOUT ANY WARRANTY; without even the implied warranty of
22 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
23 General Public License for more details.
25 You should have received copies of the GNU General Public License and
26 the GNU Lesser General Public License along with this program. If
27 not, see <http://www.gnu.org/licenses/>. */
31 #include "../libdw/memory-access.h"
38 /* This element is always provided and always has a constant value.
39 This makes it an easy thing to scan for to discern the format. */
40 #define PROBE_TYPE AT_PHENT
41 #define PROBE_VAL32 sizeof (Elf32_Phdr)
42 #define PROBE_VAL64 sizeof (Elf64_Phdr)
45 /* Examine an auxv data block and determine its format.
46 Return true iff we figured it out. */
48 auxv_format_probe (const void *auxv, size_t size,
49 uint_fast8_t *elfclass, uint_fast8_t *elfdata)
54 Elf32_auxv_t a32[size / sizeof (Elf32_auxv_t)];
55 Elf64_auxv_t a64[size / sizeof (Elf64_auxv_t)];
58 inline bool check64 (size_t i)
60 /* The AUXV pointer might not even be naturally aligned for 64-bit
61 data, because note payloads in a core file are not aligned.
62 But we assume the data is 32-bit aligned. */
64 uint64_t type = read_8ubyte_unaligned_noncvt (&u->a64[i].a_type);
65 uint64_t val = read_8ubyte_unaligned_noncvt (&u->a64[i].a_un.a_val);
67 if (type == BE64 (PROBE_TYPE)
68 && val == BE64 (PROBE_VAL64))
70 *elfdata = ELFDATA2MSB;
74 if (type == LE64 (PROBE_TYPE)
75 && val == LE64 (PROBE_VAL64))
77 *elfdata = ELFDATA2LSB;
84 inline bool check32 (size_t i)
86 if (u->a32[i].a_type == BE32 (PROBE_TYPE)
87 && u->a32[i].a_un.a_val == BE32 (PROBE_VAL32))
89 *elfdata = ELFDATA2MSB;
93 if (u->a32[i].a_type == LE32 (PROBE_TYPE)
94 && u->a32[i].a_un.a_val == LE32 (PROBE_VAL32))
96 *elfdata = ELFDATA2LSB;
103 for (size_t i = 0; i < size / sizeof (Elf64_auxv_t); ++i)
107 *elfclass = ELFCLASS64;
111 if (check32 (i * 2) || check32 (i * 2 + 1))
113 *elfclass = ELFCLASS32;
121 /* This is a Dwfl_Memory_Callback that wraps another memory callback.
122 If the underlying callback cannot fill the data, then this will
123 fall back to fetching data from module files. */
125 struct integrated_memory_callback
127 Dwfl_Memory_Callback *memory_callback;
128 void *memory_callback_arg;
133 integrated_memory_callback (Dwfl *dwfl, int ndx,
134 void **buffer, size_t *buffer_available,
139 struct integrated_memory_callback *info = arg;
143 /* Called for cleanup. */
144 if (info->buffer != NULL)
146 /* The last probe buffer came from the underlying callback.
147 Let it do its cleanup. */
148 assert (*buffer == info->buffer); /* XXX */
149 *buffer = info->buffer;
151 return (*info->memory_callback) (dwfl, ndx, buffer, buffer_available,
153 info->memory_callback_arg);
156 *buffer_available = 0;
161 /* For a final-read request, we only use the underlying callback. */
162 return (*info->memory_callback) (dwfl, ndx, buffer, buffer_available,
163 vaddr, minread, info->memory_callback_arg);
165 /* Let the underlying callback try to fill this request. */
166 if ((*info->memory_callback) (dwfl, ndx, &info->buffer, buffer_available,
167 vaddr, minread, info->memory_callback_arg))
169 *buffer = info->buffer;
173 /* Now look for module text covering this address. */
176 (void) INTUSE(dwfl_addrsegment) (dwfl, vaddr, &mod);
181 Elf_Scn *scn = INTUSE(dwfl_module_address_section) (mod, &vaddr, &bias);
182 if (unlikely (scn == NULL))
184 #if 0 // XXX would have to handle ndx=-1 cleanup calls passed down.
185 /* If we have no sections we can try to fill it from the module file
186 based on its phdr mappings. */
187 if (likely (mod->e_type != ET_REL) && mod->main.elf != NULL)
188 return INTUSE(dwfl_elf_phdr_memory_callback)
189 (dwfl, 0, buffer, buffer_available,
190 vaddr - mod->main.bias, minread, mod->main.elf);
195 Elf_Data *data = elf_rawdata (scn, NULL);
196 if (unlikely (data == NULL))
200 if (unlikely (data->d_size < vaddr))
203 /* Provide as much data as we have. */
204 void *contents = data->d_buf + vaddr;
205 size_t avail = data->d_size - vaddr;
206 if (unlikely (avail < minread))
209 /* If probing for a string, make sure it's terminated. */
210 if (minread == 0 && unlikely (memchr (contents, '\0', avail) == NULL))
215 *buffer_available = avail;
220 addrsize (uint_fast8_t elfclass)
225 /* Report a module for each struct link_map in the linked list at r_map
226 in the struct r_debug at R_DEBUG_VADDR. For r_debug_info description
227 see dwfl_link_map_report in libdwflP.h. If R_DEBUG_INFO is not NULL then no
228 modules get added to DWFL, caller has to add them from filled in
231 For each link_map entry, if an existing module resides at its address,
232 this just modifies that module's name and suggested file name. If
233 no such module exists, this calls dwfl_report_elf on the l_name string.
235 Returns the number of modules found, or -1 for errors. */
238 report_r_debug (uint_fast8_t elfclass, uint_fast8_t elfdata,
239 Dwfl *dwfl, GElf_Addr r_debug_vaddr,
240 Dwfl_Memory_Callback *memory_callback,
241 void *memory_callback_arg,
242 struct r_debug_info *r_debug_info)
244 /* Skip r_version, to aligned r_map field. */
245 GElf_Addr read_vaddr = r_debug_vaddr + addrsize (elfclass);
248 size_t buffer_available = 0;
249 inline int release_buffer (int result)
252 (void) (*memory_callback) (dwfl, -1, &buffer, &buffer_available, 0, 0,
253 memory_callback_arg);
258 inline bool read_addrs (GElf_Addr vaddr, size_t n)
260 size_t nb = n * addrsize (elfclass); /* Address words -> bytes to read. */
262 /* Read a new buffer if the old one doesn't cover these words. */
264 || vaddr < read_vaddr
265 || vaddr - read_vaddr + nb > buffer_available)
270 int segndx = INTUSE(dwfl_addrsegment) (dwfl, vaddr, NULL);
271 if (unlikely (segndx < 0)
272 || unlikely (! (*memory_callback) (dwfl, segndx,
273 &buffer, &buffer_available,
274 vaddr, nb, memory_callback_arg)))
282 } *in = vaddr - read_vaddr + buffer;
284 if (elfclass == ELFCLASS32)
286 if (elfdata == ELFDATA2MSB)
287 for (size_t i = 0; i < n; ++i)
288 addrs[i] = BE32 (in->a32[i]);
290 for (size_t i = 0; i < n; ++i)
291 addrs[i] = LE32 (in->a32[i]);
295 if (elfdata == ELFDATA2MSB)
296 for (size_t i = 0; i < n; ++i)
297 addrs[i] = BE64 (in->a64[i]);
299 for (size_t i = 0; i < n; ++i)
300 addrs[i] = LE64 (in->a64[i]);
306 if (unlikely (read_addrs (read_vaddr, 1)))
307 return release_buffer (-1);
309 GElf_Addr next = addrs[0];
311 Dwfl_Module **lastmodp = &dwfl->modulelist;
314 /* There can't be more elements in the link_map list than there are
315 segments. DWFL->lookup_elts is probably twice that number, so it
316 is certainly above the upper bound. If we iterate too many times,
317 there must be a loop in the pointers due to link_map clobberation. */
318 size_t iterations = 0;
319 while (next != 0 && ++iterations < dwfl->lookup_elts)
321 if (read_addrs (next, 4))
322 return release_buffer (-1);
324 /* Unused: l_addr is the difference between the address in memory
325 and the ELF file when the core was created. We need to
326 recalculate the difference below because the ELF file we use
327 might be differently pre-linked. */
328 // GElf_Addr l_addr = addrs[0];
329 GElf_Addr l_name = addrs[1];
330 GElf_Addr l_ld = addrs[2];
333 /* If a clobbered or truncated memory image has no useful pointer,
334 just skip this element. */
338 /* Fetch the string at the l_name address. */
339 const char *name = NULL;
341 && read_vaddr <= l_name
342 && l_name + 1 - read_vaddr < buffer_available
343 && memchr (l_name - read_vaddr + buffer, '\0',
344 buffer_available - (l_name - read_vaddr)) != NULL)
345 name = l_name - read_vaddr + buffer;
350 int segndx = INTUSE(dwfl_addrsegment) (dwfl, l_name, NULL);
351 if (likely (segndx >= 0)
352 && (*memory_callback) (dwfl, segndx,
353 &buffer, &buffer_available,
354 l_name, 0, memory_callback_arg))
358 if (name != NULL && name[0] == '\0')
361 if (iterations == 1 && dwfl->executable_for_core != NULL)
362 name = dwfl->executable_for_core;
364 struct r_debug_info_module *r_debug_info_module = NULL;
365 if (r_debug_info != NULL)
367 /* Save link map information about valid shared library (or
368 executable) which has not been found on disk. */
369 const char *name1 = name == NULL ? "" : name;
370 r_debug_info_module = malloc (sizeof (*r_debug_info_module)
371 + strlen (name1) + 1);
372 if (r_debug_info_module == NULL)
373 return release_buffer (result);
374 r_debug_info_module->fd = -1;
375 r_debug_info_module->elf = NULL;
376 r_debug_info_module->l_ld = l_ld;
377 r_debug_info_module->start = 0;
378 r_debug_info_module->end = 0;
379 r_debug_info_module->disk_file_has_build_id = false;
380 strcpy (r_debug_info_module->name, name1);
381 r_debug_info_module->next = r_debug_info->module;
382 r_debug_info->module = r_debug_info_module;
385 Dwfl_Module *mod = NULL;
388 /* This code is mostly inlined dwfl_report_elf. */
389 // XXX hook for sysroot
390 int fd = open64 (name, O_RDONLY);
394 Dwfl_Error error = __libdw_open_file (&fd, &elf, true, false);
395 GElf_Addr elf_dynamic_vaddr;
396 if (error == DWFL_E_NOERROR
397 && __libdwfl_dynamic_vaddr_get (elf, &elf_dynamic_vaddr))
399 const void *build_id_bits;
400 GElf_Addr build_id_elfaddr;
404 if (__libdwfl_find_elf_build_id (NULL, elf, &build_id_bits,
407 && build_id_elfaddr != 0)
409 if (r_debug_info_module != NULL)
410 r_debug_info_module->disk_file_has_build_id = true;
411 GElf_Addr build_id_vaddr = (build_id_elfaddr
412 - elf_dynamic_vaddr + l_ld);
415 int segndx = INTUSE(dwfl_addrsegment) (dwfl,
418 if (! (*memory_callback) (dwfl, segndx,
419 &buffer, &buffer_available,
420 build_id_vaddr, build_id_len,
421 memory_callback_arg))
423 /* File has valid build-id which cannot be read from
424 memory. This happens for core files without bit 4
425 (0x10) set in Linux /proc/PID/coredump_filter. */
429 if (memcmp (build_id_bits, buffer, build_id_len) != 0)
430 /* File has valid build-id which does not match
431 the one in memory. */
439 // It is like l_addr but it handles differently prelinked
440 // files at core dumping vs. core loading time.
441 GElf_Addr base = l_ld - elf_dynamic_vaddr;
442 if (r_debug_info_module == NULL)
444 // XXX hook for sysroot
445 mod = __libdwfl_report_elf (dwfl, basename (name),
454 else if (__libdwfl_elf_address_range (elf, base, true,
456 &r_debug_info_module->start,
457 &r_debug_info_module->end,
460 r_debug_info_module->elf = elf;
461 r_debug_info_module->fd = fd;
478 /* Move this module to the end of the list, so that we end
479 up with a list in the same order as the link_map chain. */
480 if (mod->next != NULL)
482 if (*lastmodp != mod)
484 lastmodp = &dwfl->modulelist;
485 while (*lastmodp != mod)
486 lastmodp = &(*lastmodp)->next;
488 *lastmodp = mod->next;
490 while (*lastmodp != NULL)
491 lastmodp = &(*lastmodp)->next;
495 lastmodp = &mod->next;
499 return release_buffer (result);
503 consider_executable (Dwfl_Module *mod, GElf_Addr at_phdr, GElf_Addr at_entry,
504 uint_fast8_t *elfclass, uint_fast8_t *elfdata,
505 Dwfl_Memory_Callback *memory_callback,
506 void *memory_callback_arg)
509 if (unlikely (gelf_getehdr (mod->main.elf, &ehdr) == NULL))
514 /* If we have an AT_ENTRY value, reject this executable if
515 its entry point address could not have supplied that. */
517 if (ehdr.e_entry == 0)
520 if (mod->e_type == ET_EXEC)
522 if (ehdr.e_entry != at_entry)
527 /* It could be a PIE. */
531 // XXX this could be saved in the file cache: phdr vaddr, DT_DEBUG d_val vaddr
532 /* Find the vaddr of the DT_DEBUG's d_ptr. This is the memory
533 address where &r_debug was written at runtime. */
534 GElf_Xword align = mod->dwfl->segment_align;
535 GElf_Addr d_val_vaddr = 0;
537 if (elf_getphdrnum (mod->main.elf, &phnum) != 0)
540 for (size_t i = 0; i < phnum; ++i)
543 GElf_Phdr *phdr = gelf_getphdr (mod->main.elf, i, &phdr_mem);
547 if (phdr->p_align > 1 && (align == 0 || phdr->p_align < align))
548 align = phdr->p_align;
551 && phdr->p_type == PT_LOAD
552 && (phdr->p_offset & -align) == (ehdr.e_phoff & -align))
554 /* This is the segment that would map the phdrs.
555 If we have an AT_PHDR value, reject this executable
556 if its phdr mapping could not have supplied that. */
557 if (mod->e_type == ET_EXEC)
559 if (ehdr.e_phoff - phdr->p_offset + phdr->p_vaddr != at_phdr)
564 /* It could be a PIE. If the AT_PHDR value and our
565 phdr address don't match modulo ALIGN, then this
566 could not have been the right PIE. */
567 if (((ehdr.e_phoff - phdr->p_offset + phdr->p_vaddr) & -align)
568 != (at_phdr & -align))
571 /* Calculate the bias applied to the PIE's p_vaddr values. */
572 GElf_Addr bias = (at_phdr - (ehdr.e_phoff - phdr->p_offset
575 /* Final sanity check: if we have an AT_ENTRY value,
576 reject this PIE unless its biased e_entry matches. */
577 if (at_entry != 0 && at_entry != ehdr.e_entry + bias)
580 /* If we're changing the module's address range,
581 we've just invalidated the module lookup table. */
582 GElf_Addr mod_bias = dwfl_adjusted_address (mod, 0);
583 if (bias != mod_bias)
585 mod->low_addr -= mod_bias;
586 mod->high_addr -= mod_bias;
587 mod->low_addr += bias;
588 mod->high_addr += bias;
590 free (mod->dwfl->lookup_module);
591 mod->dwfl->lookup_module = NULL;
596 if (phdr->p_type == PT_DYNAMIC)
598 Elf_Data *data = elf_getdata_rawchunk (mod->main.elf, phdr->p_offset,
599 phdr->p_filesz, ELF_T_DYN);
602 const size_t entsize = gelf_fsize (mod->main.elf,
603 ELF_T_DYN, 1, EV_CURRENT);
604 const size_t n = data->d_size / entsize;
605 for (size_t j = 0; j < n; ++j)
608 GElf_Dyn *dyn = gelf_getdyn (data, j, &dyn_mem);
609 if (dyn != NULL && dyn->d_tag == DT_DEBUG)
611 d_val_vaddr = phdr->p_vaddr + entsize * j + entsize / 2;
618 if (d_val_vaddr != 0)
620 /* Now we have the final address from which to read &r_debug. */
621 d_val_vaddr = dwfl_adjusted_address (mod, d_val_vaddr);
624 size_t buffer_available = addrsize (ehdr.e_ident[EI_CLASS]);
626 int segndx = INTUSE(dwfl_addrsegment) (mod->dwfl, d_val_vaddr, NULL);
628 if ((*memory_callback) (mod->dwfl, segndx,
629 &buffer, &buffer_available,
630 d_val_vaddr, buffer_available,
631 memory_callback_arg))
640 if (ehdr.e_ident[EI_CLASS] == ELFCLASS32)
641 vaddr = (ehdr.e_ident[EI_DATA] == ELFDATA2MSB
642 ? BE32 (u->a32) : LE32 (u->a32));
644 vaddr = (ehdr.e_ident[EI_DATA] == ELFDATA2MSB
645 ? BE64 (u->a64) : LE64 (u->a64));
647 (*memory_callback) (mod->dwfl, -1, &buffer, &buffer_available, 0, 0,
648 memory_callback_arg);
650 if (*elfclass == ELFCLASSNONE)
651 *elfclass = ehdr.e_ident[EI_CLASS];
652 else if (*elfclass != ehdr.e_ident[EI_CLASS])
655 if (*elfdata == ELFDATANONE)
656 *elfdata = ehdr.e_ident[EI_DATA];
657 else if (*elfdata != ehdr.e_ident[EI_DATA])
667 /* Try to find an existing executable module with a DT_DEBUG. */
669 find_executable (Dwfl *dwfl, GElf_Addr at_phdr, GElf_Addr at_entry,
670 uint_fast8_t *elfclass, uint_fast8_t *elfdata,
671 Dwfl_Memory_Callback *memory_callback,
672 void *memory_callback_arg)
674 for (Dwfl_Module *mod = dwfl->modulelist; mod != NULL; mod = mod->next)
675 if (mod->main.elf != NULL)
677 GElf_Addr r_debug_vaddr = consider_executable (mod, at_phdr, at_entry,
680 memory_callback_arg);
681 if (r_debug_vaddr != 0)
682 return r_debug_vaddr;
690 dwfl_link_map_report (Dwfl *dwfl, const void *auxv, size_t auxv_size,
691 Dwfl_Memory_Callback *memory_callback,
692 void *memory_callback_arg,
693 struct r_debug_info *r_debug_info)
695 GElf_Addr r_debug_vaddr = 0;
697 uint_fast8_t elfclass = ELFCLASSNONE;
698 uint_fast8_t elfdata = ELFDATANONE;
699 if (likely (auxv != NULL)
700 && likely (auxv_format_probe (auxv, auxv_size, &elfclass, &elfdata)))
704 GElf_Xword phent = 0;
705 GElf_Xword phnum = 0;
707 #define READ_AUXV32(ptr) read_4ubyte_unaligned_noncvt (ptr)
708 #define READ_AUXV64(ptr) read_8ubyte_unaligned_noncvt (ptr)
709 #define AUXV_SCAN(NN, BL) do \
711 const Elf##NN##_auxv_t *av = auxv; \
712 for (size_t i = 0; i < auxv_size / sizeof av[0]; ++i) \
714 uint##NN##_t type = READ_AUXV##NN (&av[i].a_type); \
715 uint##NN##_t val = BL##NN (READ_AUXV##NN (&av[i].a_un.a_val)); \
716 if (type == BL##NN (AT_ENTRY)) \
718 else if (type == BL##NN (AT_PHDR)) \
720 else if (type == BL##NN (AT_PHNUM)) \
722 else if (type == BL##NN (AT_PHENT)) \
724 else if (type == BL##NN (AT_PAGESZ)) \
727 && (dwfl->segment_align == 0 \
728 || val < dwfl->segment_align)) \
729 dwfl->segment_align = val; \
735 if (elfclass == ELFCLASS32)
737 if (elfdata == ELFDATA2MSB)
744 if (elfdata == ELFDATA2MSB)
750 /* If we found the phdr dimensions, search phdrs for PT_DYNAMIC. */
751 GElf_Addr dyn_vaddr = 0;
752 GElf_Xword dyn_filesz = 0;
753 GElf_Addr dyn_bias = (GElf_Addr) -1;
755 inline bool consider_phdr (GElf_Word type,
756 GElf_Addr vaddr, GElf_Xword filesz)
761 if (dyn_bias == (GElf_Addr) -1
762 /* Do a sanity check on the putative address. */
763 && ((vaddr & (dwfl->segment_align - 1))
764 == (phdr & (dwfl->segment_align - 1))))
766 dyn_bias = phdr - vaddr;
767 return dyn_vaddr != 0;
774 return dyn_bias != (GElf_Addr) -1;
780 if (phdr != 0 && phnum != 0)
782 Dwfl_Module *phdr_mod;
783 int phdr_segndx = INTUSE(dwfl_addrsegment) (dwfl, phdr, &phdr_mod);
786 .d_type = ELF_T_PHDR,
787 .d_version = EV_CURRENT,
788 .d_size = phnum * phent,
791 bool in_ok = (*memory_callback) (dwfl, phdr_segndx, &in.d_buf,
792 &in.d_size, phdr, phnum * phent,
793 memory_callback_arg);
794 if (! in_ok && dwfl->executable_for_core != NULL)
796 /* AUXV -> PHDR -> DYNAMIC
797 Both AUXV and DYNAMIC should be always present in a core file.
798 PHDR may be missing in core file, try to read it from
799 EXECUTABLE_FOR_CORE to find where DYNAMIC is located in the
802 int fd = open (dwfl->executable_for_core, O_RDONLY);
804 Dwfl_Error error = DWFL_E_ERRNO;
806 error = __libdw_open_file (&fd, &elf, true, false);
807 if (error != DWFL_E_NOERROR)
809 __libdwfl_seterrno (error);
812 GElf_Ehdr ehdr_mem, *ehdr = gelf_getehdr (elf, &ehdr_mem);
817 __libdwfl_seterrno (DWFL_E_LIBELF);
821 if (elf_getphdrnum (elf, &e_phnum) != 0)
825 __libdwfl_seterrno (DWFL_E_LIBELF);
828 if (e_phnum != phnum || ehdr->e_phentsize != phent)
832 __libdwfl_seterrno (DWFL_E_BADELF);
835 off_t off = ehdr->e_phoff;
836 assert (in.d_buf == NULL);
837 assert (in.d_size == phnum * phent);
838 in.d_buf = malloc (in.d_size);
839 if (unlikely (in.d_buf == NULL))
843 __libdwfl_seterrno (DWFL_E_NOMEM);
846 ssize_t nread = pread_retry (fd, in.d_buf, in.d_size, off);
849 if (nread != (ssize_t) in.d_size)
852 __libdwfl_seterrno (DWFL_E_ERRNO);
863 char data[phnum * phent];
867 .d_type = ELF_T_PHDR,
868 .d_version = EV_CURRENT,
869 .d_size = phnum * phent,
872 in.d_size = out.d_size;
873 if (likely ((elfclass == ELFCLASS32
874 ? elf32_xlatetom : elf64_xlatetom)
875 (&out, &in, elfdata) != NULL))
877 /* We are looking for PT_DYNAMIC. */
880 Elf32_Phdr p32[phnum];
881 Elf64_Phdr p64[phnum];
882 } *u = (void *) &buf;
883 if (elfclass == ELFCLASS32)
885 for (size_t i = 0; i < phnum; ++i)
886 if (consider_phdr (u->p32[i].p_type,
893 for (size_t i = 0; i < phnum; ++i)
894 if (consider_phdr (u->p64[i].p_type,
901 (*memory_callback) (dwfl, -1, &in.d_buf, &in.d_size, 0, 0,
902 memory_callback_arg);
905 /* We could not read the executable's phdrs from the
906 memory image. If we have a presupplied executable,
907 we can still use the AT_PHDR and AT_ENTRY values to
908 verify it, and to adjust its bias if it's a PIE.
910 If there was an ET_EXEC module presupplied that contains
911 the AT_PHDR address, then we only consider that one.
912 We'll either accept it if its phdr location and e_entry
913 make sense or reject it if they don't. If there is no
914 presupplied ET_EXEC, then look for a presupplied module,
915 which might be a PIE (ET_DYN) that needs its bias adjusted. */
916 r_debug_vaddr = ((phdr_mod == NULL
917 || phdr_mod->main.elf == NULL
918 || phdr_mod->e_type != ET_EXEC)
919 ? find_executable (dwfl, phdr, entry,
923 : consider_executable (phdr_mod, phdr, entry,
926 memory_callback_arg));
929 /* If we found PT_DYNAMIC, search it for DT_DEBUG. */
932 if (dyn_bias != (GElf_Addr) -1)
933 dyn_vaddr += dyn_bias;
938 .d_version = EV_CURRENT,
939 .d_size = dyn_filesz,
942 int dyn_segndx = dwfl_addrsegment (dwfl, dyn_vaddr, NULL);
943 if ((*memory_callback) (dwfl, dyn_segndx, &in.d_buf, &in.d_size,
944 dyn_vaddr, dyn_filesz, memory_callback_arg))
950 char data[dyn_filesz];
955 .d_version = EV_CURRENT,
956 .d_size = dyn_filesz,
959 in.d_size = out.d_size;
960 if (likely ((elfclass == ELFCLASS32
961 ? elf32_xlatetom : elf64_xlatetom)
962 (&out, &in, elfdata) != NULL))
964 /* We are looking for DT_DEBUG. */
967 Elf32_Dyn d32[dyn_filesz / sizeof (Elf32_Dyn)];
968 Elf64_Dyn d64[dyn_filesz / sizeof (Elf64_Dyn)];
969 } *u = (void *) &buf;
970 if (elfclass == ELFCLASS32)
972 size_t n = dyn_filesz / sizeof (Elf32_Dyn);
973 for (size_t i = 0; i < n; ++i)
974 if (u->d32[i].d_tag == DT_DEBUG)
976 r_debug_vaddr = u->d32[i].d_un.d_val;
982 size_t n = dyn_filesz / sizeof (Elf64_Dyn);
983 for (size_t i = 0; i < n; ++i)
984 if (u->d64[i].d_tag == DT_DEBUG)
986 r_debug_vaddr = u->d64[i].d_un.d_val;
992 (*memory_callback) (dwfl, -1, &in.d_buf, &in.d_size, 0, 0,
993 memory_callback_arg);
998 /* We have to look for a presupplied executable file to determine
999 the vaddr of its dynamic section and DT_DEBUG therein. */
1000 r_debug_vaddr = find_executable (dwfl, 0, 0, &elfclass, &elfdata,
1001 memory_callback, memory_callback_arg);
1003 if (r_debug_vaddr == 0)
1006 /* For following pointers from struct link_map, we will use an
1007 integrated memory access callback that can consult module text
1008 elided from the core file. This is necessary when the l_name
1009 pointer for the dynamic linker's own entry is a pointer into the
1010 executable's .interp section. */
1011 struct integrated_memory_callback mcb =
1013 .memory_callback = memory_callback,
1014 .memory_callback_arg = memory_callback_arg
1017 /* Now we can follow the dynamic linker's library list. */
1018 return report_r_debug (elfclass, elfdata, dwfl, r_debug_vaddr,
1019 &integrated_memory_callback, &mcb, r_debug_info);
1021 INTDEF (dwfl_link_map_report)