| /* Report modules by examining dynamic linker data structures. |
| Copyright (C) 2008, 2009 Red Hat, Inc. |
| This file is part of Red Hat elfutils. |
| |
| Red Hat elfutils 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; version 2 of the License. |
| |
| Red Hat elfutils 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 Red Hat elfutils; if not, write to the Free Software Foundation, |
| Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301 USA. |
| |
| In addition, as a special exception, Red Hat, Inc. gives You the |
| additional right to link the code of Red Hat elfutils with code licensed |
| under any Open Source Initiative certified open source license |
| (http://www.opensource.org/licenses/index.php) which requires the |
| distribution of source code with any binary distribution and to |
| distribute linked combinations of the two. Non-GPL Code permitted under |
| this exception must only link to the code of Red Hat elfutils through |
| those well defined interfaces identified in the file named EXCEPTION |
| found in the source code files (the "Approved Interfaces"). The files |
| of Non-GPL Code may instantiate templates or use macros or inline |
| functions from the Approved Interfaces without causing the resulting |
| work to be covered by the GNU General Public License. Only Red Hat, |
| Inc. may make changes or additions to the list of Approved Interfaces. |
| Red Hat's grant of this exception is conditioned upon your not adding |
| any new exceptions. If you wish to add a new Approved Interface or |
| exception, please contact Red Hat. You must obey the GNU General Public |
| License in all respects for all of the Red Hat elfutils code and other |
| code used in conjunction with Red Hat elfutils except the Non-GPL Code |
| covered by this exception. If you modify this file, you may extend this |
| exception to your version of the file, but you are not obligated to do |
| so. If you do not wish to provide this exception without modification, |
| you must delete this exception statement from your version and license |
| this file solely under the GPL without exception. |
| |
| Red Hat elfutils is an included package of the Open Invention Network. |
| An included package of the Open Invention Network is a package for which |
| Open Invention Network licensees cross-license their patents. No patent |
| license is granted, either expressly or impliedly, by designation as an |
| included package. Should you wish to participate in the Open Invention |
| Network licensing program, please visit www.openinventionnetwork.com |
| <http://www.openinventionnetwork.com>. */ |
| |
| #include <config.h> |
| #include "libdwflP.h" |
| |
| #include <byteswap.h> |
| #include <endian.h> |
| |
| /* This element is always provided and always has a constant value. |
| This makes it an easy thing to scan for to discern the format. */ |
| #define PROBE_TYPE AT_PHENT |
| #define PROBE_VAL32 sizeof (Elf32_Phdr) |
| #define PROBE_VAL64 sizeof (Elf64_Phdr) |
| |
| #if BYTE_ORDER == BIG_ENDIAN |
| # define BE32(x) (x) |
| # define BE64(x) (x) |
| # define LE32(x) bswap_32 (x) |
| # define LE64(x) bswap_64 (x) |
| #else |
| # define LE32(x) (x) |
| # define LE64(x) (x) |
| # define BE32(x) bswap_32 (x) |
| # define BE64(x) bswap_64 (x) |
| #endif |
| |
| |
| /* Examine an auxv data block and determine its format. |
| Return true iff we figured it out. */ |
| static bool |
| auxv_format_probe (const void *auxv, size_t size, |
| uint_fast8_t *elfclass, uint_fast8_t *elfdata) |
| { |
| const union |
| { |
| char buf[size]; |
| Elf32_auxv_t a32[size / sizeof (Elf32_auxv_t)]; |
| Elf64_auxv_t a64[size / sizeof (Elf64_auxv_t)]; |
| } *u = auxv; |
| |
| inline bool check64 (size_t i) |
| { |
| if (u->a64[i].a_type == BE64 (PROBE_TYPE) |
| && u->a64[i].a_un.a_val == BE64 (PROBE_VAL64)) |
| { |
| *elfdata = ELFDATA2MSB; |
| return true; |
| } |
| |
| if (u->a64[i].a_type == LE64 (PROBE_TYPE) |
| && u->a64[i].a_un.a_val == LE64 (PROBE_VAL64)) |
| { |
| *elfdata = ELFDATA2LSB; |
| return true; |
| } |
| |
| return false; |
| } |
| |
| inline bool check32 (size_t i) |
| { |
| if (u->a32[i].a_type == BE32 (PROBE_TYPE) |
| && u->a32[i].a_un.a_val == BE32 (PROBE_VAL32)) |
| { |
| *elfdata = ELFDATA2MSB; |
| return true; |
| } |
| |
| if (u->a32[i].a_type == LE32 (PROBE_TYPE) |
| && u->a32[i].a_un.a_val == LE32 (PROBE_VAL32)) |
| { |
| *elfdata = ELFDATA2LSB; |
| return true; |
| } |
| |
| return false; |
| } |
| |
| size_t i; |
| for (i = 0; i < size / sizeof (Elf64_auxv_t); ++i) |
| { |
| if (check64 (i)) |
| { |
| *elfclass = ELFCLASS64; |
| return true; |
| } |
| |
| if (check32 (i)) |
| { |
| *elfclass = ELFCLASS32; |
| return true; |
| } |
| } |
| for (; i < size / sizeof (Elf64_auxv_t); ++i) |
| if (check32 (i)) |
| { |
| *elfclass = ELFCLASS32; |
| return true; |
| } |
| |
| return false; |
| } |
| |
| /* This is a Dwfl_Memory_Callback that wraps another memory callback. |
| If the underlying callback cannot fill the data, then this will |
| fall back to fetching data from module files. */ |
| |
| struct integrated_memory_callback |
| { |
| Dwfl_Memory_Callback *memory_callback; |
| void *memory_callback_arg; |
| void *buffer; |
| }; |
| |
| static bool |
| integrated_memory_callback (Dwfl *dwfl, int ndx, |
| void **buffer, size_t *buffer_available, |
| GElf_Addr vaddr, |
| size_t minread, |
| void *arg) |
| { |
| struct integrated_memory_callback *info = arg; |
| |
| if (ndx == -1) |
| { |
| /* Called for cleanup. */ |
| if (info->buffer != NULL) |
| { |
| /* The last probe buffer came from the underlying callback. |
| Let it do its cleanup. */ |
| assert (*buffer == info->buffer); /* XXX */ |
| *buffer = info->buffer; |
| info->buffer = NULL; |
| return (*info->memory_callback) (dwfl, ndx, buffer, buffer_available, |
| vaddr, minread, |
| info->memory_callback_arg); |
| } |
| *buffer = NULL; |
| *buffer_available = 0; |
| return false; |
| } |
| |
| if (*buffer != NULL) |
| /* For a final-read request, we only use the underlying callback. */ |
| return (*info->memory_callback) (dwfl, ndx, buffer, buffer_available, |
| vaddr, minread, info->memory_callback_arg); |
| |
| /* Let the underlying callback try to fill this request. */ |
| if ((*info->memory_callback) (dwfl, ndx, &info->buffer, buffer_available, |
| vaddr, minread, info->memory_callback_arg)) |
| { |
| *buffer = info->buffer; |
| return true; |
| } |
| |
| /* Now look for module text covering this address. */ |
| |
| Dwfl_Module *mod; |
| (void) INTUSE(dwfl_addrsegment) (dwfl, vaddr, &mod); |
| if (mod == NULL) |
| return false; |
| |
| Dwarf_Addr bias; |
| Elf_Scn *scn = INTUSE(dwfl_module_address_section) (mod, &vaddr, &bias); |
| if (unlikely (scn == NULL)) |
| { |
| #if 0 // XXX would have to handle ndx=-1 cleanup calls passed down. |
| /* If we have no sections we can try to fill it from the module file |
| based on its phdr mappings. */ |
| if (likely (mod->e_type != ET_REL) && mod->main.elf != NULL) |
| return INTUSE(dwfl_elf_phdr_memory_callback) |
| (dwfl, 0, buffer, buffer_available, |
| vaddr - mod->main.bias, minread, mod->main.elf); |
| #endif |
| return false; |
| } |
| |
| Elf_Data *data = elf_rawdata (scn, NULL); |
| if (unlikely (data == NULL)) |
| // XXX throw error? |
| return false; |
| |
| if (unlikely (data->d_size < vaddr)) |
| return false; |
| |
| /* Provide as much data as we have. */ |
| void *contents = data->d_buf + vaddr; |
| size_t avail = data->d_size - vaddr; |
| if (unlikely (avail < minread)) |
| return false; |
| |
| /* If probing for a string, make sure it's terminated. */ |
| if (minread == 0 && unlikely (memchr (contents, '\0', avail) == NULL)) |
| return false; |
| |
| /* We have it! */ |
| *buffer = contents; |
| *buffer_available = avail; |
| return true; |
| } |
| |
| static size_t |
| addrsize (uint_fast8_t elfclass) |
| { |
| return elfclass * 4; |
| } |
| |
| /* Report a module for each struct link_map in the linked list at r_map |
| in the struct r_debug at R_DEBUG_VADDR. |
| |
| For each link_map entry, if an existing module resides at its address, |
| this just modifies that module's name and suggested file name. If |
| no such module exists, this calls dwfl_report_elf on the l_name string. |
| |
| Returns the number of modules found, or -1 for errors. */ |
| |
| static int |
| report_r_debug (uint_fast8_t elfclass, uint_fast8_t elfdata, |
| Dwfl *dwfl, GElf_Addr r_debug_vaddr, |
| Dwfl_Memory_Callback *memory_callback, |
| void *memory_callback_arg) |
| { |
| /* Skip r_version, to aligned r_map field. */ |
| GElf_Addr read_vaddr = r_debug_vaddr + addrsize (elfclass); |
| |
| void *buffer = NULL; |
| size_t buffer_available = 0; |
| inline int release_buffer (int result) |
| { |
| if (buffer != NULL) |
| (void) (*memory_callback) (dwfl, -1, &buffer, &buffer_available, 0, 0, |
| memory_callback_arg); |
| return result; |
| } |
| |
| GElf_Addr addrs[4]; |
| inline bool read_addrs (GElf_Addr vaddr, size_t n) |
| { |
| size_t nb = n * addrsize (elfclass); /* Address words -> bytes to read. */ |
| |
| /* Read a new buffer if the old one doesn't cover these words. */ |
| if (buffer == NULL |
| || vaddr < read_vaddr |
| || vaddr - read_vaddr + nb > buffer_available) |
| { |
| release_buffer (0); |
| |
| read_vaddr = vaddr; |
| int segndx = INTUSE(dwfl_addrsegment) (dwfl, vaddr, NULL); |
| if (unlikely (segndx < 0) |
| || unlikely (! (*memory_callback) (dwfl, segndx, |
| &buffer, &buffer_available, |
| vaddr, nb, memory_callback_arg))) |
| return true; |
| } |
| |
| const union |
| { |
| Elf32_Addr a32[n]; |
| Elf64_Addr a64[n]; |
| } *in = vaddr - read_vaddr + buffer; |
| |
| if (elfclass == ELFCLASS32) |
| { |
| if (elfdata == ELFDATA2MSB) |
| for (size_t i = 0; i < n; ++i) |
| addrs[i] = BE32 (in->a32[i]); |
| else |
| for (size_t i = 0; i < n; ++i) |
| addrs[i] = LE32 (in->a32[i]); |
| } |
| else |
| { |
| if (elfdata == ELFDATA2MSB) |
| for (size_t i = 0; i < n; ++i) |
| addrs[i] = BE64 (in->a64[i]); |
| else |
| for (size_t i = 0; i < n; ++i) |
| addrs[i] = LE64 (in->a64[i]); |
| } |
| |
| return false; |
| } |
| |
| if (unlikely (read_addrs (read_vaddr, 1))) |
| return release_buffer (-1); |
| |
| GElf_Addr next = addrs[0]; |
| |
| Dwfl_Module **lastmodp = &dwfl->modulelist; |
| int result = 0; |
| while (next != 0) |
| { |
| if (read_addrs (next, 4)) |
| return release_buffer (-1); |
| |
| GElf_Addr l_addr = addrs[0]; |
| GElf_Addr l_name = addrs[1]; |
| GElf_Addr l_ld = addrs[2]; |
| next = addrs[3]; |
| |
| /* Fetch the string at the l_name address. */ |
| const char *name = NULL; |
| if (buffer != NULL |
| && read_vaddr <= l_name |
| && l_name + 1 - read_vaddr < buffer_available |
| && memchr (l_name - read_vaddr + buffer, '\0', |
| buffer_available - (l_name - read_vaddr)) != NULL) |
| name = l_name - read_vaddr + buffer; |
| else |
| { |
| release_buffer (0); |
| read_vaddr = l_name; |
| int segndx = INTUSE(dwfl_addrsegment) (dwfl, l_name, NULL); |
| if (likely (segndx >= 0) |
| && (*memory_callback) (dwfl, segndx, |
| &buffer, &buffer_available, |
| l_name, 0, memory_callback_arg)) |
| name = buffer; |
| } |
| |
| if (name != NULL && name[0] == '\0') |
| name = NULL; |
| |
| /* If content-sniffing already reported a module covering |
| the same area, find that existing module to adjust. |
| The l_ld address is the only one we know for sure |
| to be within the module's own segments (its .dynamic). */ |
| Dwfl_Module *mod; |
| int segndx = INTUSE(dwfl_addrsegment) (dwfl, l_ld, &mod); |
| if (unlikely (segndx < 0)) |
| return release_buffer (-1); |
| |
| if (mod != NULL) |
| { |
| /* We have a module. We can give it a better name from l_name. */ |
| if (name != NULL && mod->name[0] == '[') |
| { |
| char *newname = strdup (basename (name)); |
| if (newname != NULL) |
| { |
| free (mod->name); |
| mod->name = newname; |
| } |
| } |
| |
| if (name == NULL && mod->name[0] == '/') |
| name = mod->name; |
| |
| /* If we don't have a file for it already, we can pre-install |
| the full file name from l_name. Opening the file by this |
| name will be the fallback when no build ID match is found. |
| XXX hook for sysroot */ |
| if (name != NULL |
| && mod->main.elf == NULL |
| && mod->main.name == NULL) |
| mod->main.name = strdup (name); |
| } |
| else if (name != NULL) |
| { |
| /* We have to find the file's phdrs to compute along with l_addr |
| what its runtime address boundaries are. */ |
| |
| // XXX hook for sysroot |
| mod = INTUSE(dwfl_report_elf) (dwfl, basename (name), |
| name, -1, l_addr); |
| } |
| |
| if (mod != NULL) |
| { |
| ++result; |
| |
| /* Move this module to the end of the list, so that we end |
| up with a list in the same order as the link_map chain. */ |
| if (mod->next != NULL) |
| { |
| if (*lastmodp != mod) |
| { |
| lastmodp = &dwfl->modulelist; |
| while (*lastmodp != mod) |
| lastmodp = &(*lastmodp)->next; |
| } |
| *lastmodp = mod->next; |
| mod->next = NULL; |
| while (*lastmodp != NULL) |
| lastmodp = &(*lastmodp)->next; |
| *lastmodp = mod; |
| } |
| |
| lastmodp = &mod->next; |
| } |
| } |
| |
| return release_buffer (result); |
| } |
| |
| static GElf_Addr |
| consider_executable (Dwfl_Module *mod, GElf_Addr at_phdr, GElf_Addr at_entry, |
| uint_fast8_t *elfclass, uint_fast8_t *elfdata, |
| Dwfl_Memory_Callback *memory_callback, |
| void *memory_callback_arg) |
| { |
| GElf_Ehdr ehdr; |
| if (unlikely (gelf_getehdr (mod->main.elf, &ehdr) == NULL)) |
| return 0; |
| |
| if (at_entry != 0) |
| { |
| /* If we have an AT_ENTRY value, reject this executable if |
| its entry point address could not have supplied that. */ |
| |
| if (ehdr.e_entry == 0) |
| return 0; |
| |
| if (mod->e_type == ET_EXEC) |
| { |
| if (ehdr.e_entry != at_entry) |
| return 0; |
| } |
| else |
| { |
| /* It could be a PIE. */ |
| } |
| } |
| |
| // XXX this could be saved in the file cache: phdr vaddr, DT_DEBUG d_val vaddr |
| /* Find the vaddr of the DT_DEBUG's d_ptr. This is the memory |
| address where &r_debug was written at runtime. */ |
| GElf_Xword align = mod->dwfl->segment_align; |
| GElf_Addr d_val_vaddr = 0; |
| for (uint_fast16_t i = 0; i < ehdr.e_phnum; ++i) |
| { |
| GElf_Phdr phdr_mem; |
| GElf_Phdr *phdr = gelf_getphdr (mod->main.elf, i, &phdr_mem); |
| if (phdr == NULL) |
| break; |
| |
| if (phdr->p_align > 1 && (align == 0 || phdr->p_align < align)) |
| align = phdr->p_align; |
| |
| if (at_phdr != 0 |
| && phdr->p_type == PT_LOAD |
| && (phdr->p_offset & -align) == (ehdr.e_phoff & -align)) |
| { |
| /* This is the segment that would map the phdrs. |
| If we have an AT_PHDR value, reject this executable |
| if its phdr mapping could not have supplied that. */ |
| if (mod->e_type == ET_EXEC) |
| { |
| if (ehdr.e_phoff - phdr->p_offset + phdr->p_vaddr != at_phdr) |
| return 0; |
| } |
| else |
| { |
| /* It could be a PIE. If the AT_PHDR value and our |
| phdr address don't match modulo ALIGN, then this |
| could not have been the right PIE. */ |
| if (((ehdr.e_phoff - phdr->p_offset + phdr->p_vaddr) & -align) |
| != (at_phdr & -align)) |
| return 0; |
| |
| /* Calculate the bias applied to the PIE's p_vaddr values. */ |
| GElf_Addr bias = (at_phdr - (ehdr.e_phoff - phdr->p_offset |
| + phdr->p_vaddr)); |
| |
| /* Final sanity check: if we have an AT_ENTRY value, |
| reject this PIE unless its biased e_entry matches. */ |
| if (at_entry != 0 && at_entry != ehdr.e_entry + bias) |
| return 0; |
| |
| /* If we're changing the module's address range, |
| we've just invalidated the module lookup table. */ |
| if (bias != mod->main.bias) |
| { |
| mod->low_addr -= mod->main.bias; |
| mod->high_addr -= mod->main.bias; |
| mod->main.bias = bias; |
| mod->low_addr += bias; |
| mod->high_addr += bias; |
| |
| free (mod->dwfl->lookup_module); |
| mod->dwfl->lookup_module = NULL; |
| } |
| } |
| } |
| |
| if (phdr->p_type == PT_DYNAMIC) |
| { |
| Elf_Data *data = elf_getdata_rawchunk (mod->main.elf, phdr->p_offset, |
| phdr->p_filesz, ELF_T_DYN); |
| if (data == NULL) |
| continue; |
| const size_t entsize = gelf_fsize (mod->main.elf, |
| ELF_T_DYN, 1, EV_CURRENT); |
| const size_t n = data->d_size / entsize; |
| for (size_t j = 0; j < n; ++j) |
| { |
| GElf_Dyn dyn_mem; |
| GElf_Dyn *dyn = gelf_getdyn (data, j, &dyn_mem); |
| if (dyn != NULL && dyn->d_tag == DT_DEBUG) |
| { |
| d_val_vaddr = phdr->p_vaddr + entsize * j + entsize / 2; |
| break; |
| } |
| } |
| } |
| } |
| |
| if (d_val_vaddr != 0) |
| { |
| /* Now we have the final address from which to read &r_debug. */ |
| d_val_vaddr += mod->main.bias; |
| |
| void *buffer = NULL; |
| size_t buffer_available = addrsize (ehdr.e_ident[EI_CLASS]); |
| |
| int segndx = INTUSE(dwfl_addrsegment) (mod->dwfl, d_val_vaddr, NULL); |
| |
| if ((*memory_callback) (mod->dwfl, segndx, |
| &buffer, &buffer_available, |
| d_val_vaddr, buffer_available, |
| memory_callback_arg)) |
| { |
| const union |
| { |
| Elf32_Addr a32; |
| Elf64_Addr a64; |
| } *u = buffer; |
| |
| GElf_Addr vaddr; |
| if (ehdr.e_ident[EI_CLASS] == ELFCLASS32) |
| vaddr = (ehdr.e_ident[EI_DATA] == ELFDATA2MSB |
| ? BE32 (u->a32) : LE32 (u->a32)); |
| else |
| vaddr = (ehdr.e_ident[EI_DATA] == ELFDATA2MSB |
| ? BE64 (u->a64) : LE64 (u->a64)); |
| |
| (*memory_callback) (mod->dwfl, -1, &buffer, &buffer_available, 0, 0, |
| memory_callback_arg); |
| |
| if (*elfclass == ELFCLASSNONE) |
| *elfclass = ehdr.e_ident[EI_CLASS]; |
| else if (*elfclass != ehdr.e_ident[EI_CLASS]) |
| return 0; |
| |
| if (*elfdata == ELFDATANONE) |
| *elfdata = ehdr.e_ident[EI_DATA]; |
| else if (*elfdata != ehdr.e_ident[EI_DATA]) |
| return 0; |
| |
| return vaddr; |
| } |
| } |
| |
| return 0; |
| } |
| |
| /* Try to find an existing executable module with a DT_DEBUG. */ |
| static GElf_Addr |
| find_executable (Dwfl *dwfl, GElf_Addr at_phdr, GElf_Addr at_entry, |
| uint_fast8_t *elfclass, uint_fast8_t *elfdata, |
| Dwfl_Memory_Callback *memory_callback, |
| void *memory_callback_arg) |
| { |
| for (Dwfl_Module *mod = dwfl->modulelist; mod != NULL; mod = mod->next) |
| if (mod->main.elf != NULL) |
| { |
| GElf_Addr r_debug_vaddr = consider_executable (mod, at_phdr, at_entry, |
| elfclass, elfdata, |
| memory_callback, |
| memory_callback_arg); |
| if (r_debug_vaddr != 0) |
| return r_debug_vaddr; |
| } |
| |
| return 0; |
| } |
| |
| |
| int |
| dwfl_link_map_report (Dwfl *dwfl, const void *auxv, size_t auxv_size, |
| Dwfl_Memory_Callback *memory_callback, |
| void *memory_callback_arg) |
| { |
| GElf_Addr r_debug_vaddr = 0; |
| |
| uint_fast8_t elfclass = ELFCLASSNONE; |
| uint_fast8_t elfdata = ELFDATANONE; |
| if (likely (auxv != NULL) |
| && likely (auxv_format_probe (auxv, auxv_size, &elfclass, &elfdata))) |
| { |
| GElf_Addr entry = 0; |
| GElf_Addr phdr = 0; |
| GElf_Xword phent = 0; |
| GElf_Xword phnum = 0; |
| |
| #define AUXV_SCAN(NN, BL) do \ |
| { \ |
| const Elf##NN##_auxv_t *av = auxv; \ |
| for (size_t i = 0; i < auxv_size / sizeof av[0]; ++i) \ |
| { \ |
| Elf##NN##_Addr val = BL##NN (av[i].a_un.a_val); \ |
| if (av[i].a_type == BL##NN (AT_ENTRY)) \ |
| entry = val; \ |
| else if (av[i].a_type == BL##NN (AT_PHDR)) \ |
| phdr = val; \ |
| else if (av[i].a_type == BL##NN (AT_PHNUM)) \ |
| phnum = val; \ |
| else if (av[i].a_type == BL##NN (AT_PHENT)) \ |
| phent = val; \ |
| else if (av[i].a_type == BL##NN (AT_PAGESZ)) \ |
| { \ |
| if (val > 1 \ |
| && (dwfl->segment_align == 0 \ |
| || val < dwfl->segment_align)) \ |
| dwfl->segment_align = val; \ |
| } \ |
| } \ |
| } \ |
| while (0) |
| |
| if (elfclass == ELFCLASS32) |
| { |
| if (elfdata == ELFDATA2MSB) |
| AUXV_SCAN (32, BE); |
| else |
| AUXV_SCAN (32, LE); |
| } |
| else |
| { |
| if (elfdata == ELFDATA2MSB) |
| AUXV_SCAN (64, BE); |
| else |
| AUXV_SCAN (64, LE); |
| } |
| |
| /* If we found the phdr dimensions, search phdrs for PT_DYNAMIC. */ |
| GElf_Addr dyn_vaddr = 0; |
| GElf_Xword dyn_filesz = 0; |
| if (phdr != 0 && phnum != 0) |
| { |
| Dwfl_Module *phdr_mod; |
| int phdr_segndx = INTUSE(dwfl_addrsegment) (dwfl, phdr, &phdr_mod); |
| Elf_Data in = |
| { |
| .d_type = ELF_T_PHDR, |
| .d_version = EV_CURRENT, |
| .d_size = phnum * phent, |
| .d_buf = NULL |
| }; |
| if ((*memory_callback) (dwfl, phdr_segndx, &in.d_buf, &in.d_size, |
| phdr, phnum * phent, memory_callback_arg)) |
| { |
| union |
| { |
| Elf32_Phdr p32; |
| Elf64_Phdr p64; |
| char data[phnum * phent]; |
| } buf; |
| Elf_Data out = |
| { |
| .d_type = ELF_T_PHDR, |
| .d_version = EV_CURRENT, |
| .d_size = phnum * phent, |
| .d_buf = &buf |
| }; |
| in.d_size = out.d_size; |
| if (likely ((elfclass == ELFCLASS32 |
| ? elf32_xlatetom : elf64_xlatetom) |
| (&out, &in, elfdata) != NULL)) |
| { |
| /* We are looking for PT_DYNAMIC. */ |
| const union |
| { |
| Elf32_Phdr p32[phnum]; |
| Elf64_Phdr p64[phnum]; |
| } *u = (void *) &buf; |
| if (elfclass == ELFCLASS32) |
| { |
| for (size_t i = 0; i < phnum; ++i) |
| if (u->p32[i].p_type == PT_DYNAMIC) |
| { |
| dyn_vaddr = u->p32[i].p_vaddr; |
| dyn_filesz = u->p32[i].p_filesz; |
| break; |
| } |
| } |
| else |
| { |
| for (size_t i = 0; i < phnum; ++i) |
| if (u->p64[i].p_type == PT_DYNAMIC) |
| { |
| dyn_vaddr = u->p64[i].p_vaddr; |
| dyn_filesz = u->p64[i].p_filesz; |
| break; |
| } |
| } |
| } |
| |
| (*memory_callback) (dwfl, -1, &in.d_buf, &in.d_size, 0, 0, |
| memory_callback_arg); |
| } |
| else |
| /* We could not read the executable's phdrs from the |
| memory image. If we have a presupplied executable, |
| we can still use the AT_PHDR and AT_ENTRY values to |
| verify it, and to adjust its bias if it's a PIE. |
| |
| If there was an ET_EXEC module presupplied that contains |
| the AT_PHDR address, then we only consider that one. |
| We'll either accept it if its phdr location and e_entry |
| make sense or reject it if they don't. If there is no |
| presupplied ET_EXEC, then look for a presupplied module, |
| which might be a PIE (ET_DYN) that needs its bias adjusted. */ |
| r_debug_vaddr = ((phdr_mod == NULL |
| || phdr_mod->main.elf == NULL |
| || phdr_mod->e_type != ET_EXEC) |
| ? find_executable (dwfl, phdr, entry, |
| &elfclass, &elfdata, |
| memory_callback, |
| memory_callback_arg) |
| : consider_executable (phdr_mod, phdr, entry, |
| &elfclass, &elfdata, |
| memory_callback, |
| memory_callback_arg)); |
| } |
| |
| /* If we found PT_DYNAMIC, search it for DT_DEBUG. */ |
| if (dyn_filesz != 0) |
| { |
| Elf_Data in = |
| { |
| .d_type = ELF_T_DYN, |
| .d_version = EV_CURRENT, |
| .d_size = dyn_filesz, |
| .d_buf = NULL |
| }; |
| int dyn_segndx = dwfl_addrsegment (dwfl, dyn_vaddr, NULL); |
| if ((*memory_callback) (dwfl, dyn_segndx, &in.d_buf, &in.d_size, |
| dyn_vaddr, dyn_filesz, memory_callback_arg)) |
| { |
| union |
| { |
| Elf32_Dyn d32; |
| Elf64_Dyn d64; |
| char data[dyn_filesz]; |
| } buf; |
| Elf_Data out = |
| { |
| .d_type = ELF_T_DYN, |
| .d_version = EV_CURRENT, |
| .d_size = dyn_filesz, |
| .d_buf = &buf |
| }; |
| in.d_size = out.d_size; |
| if (likely ((elfclass == ELFCLASS32 |
| ? elf32_xlatetom : elf64_xlatetom) |
| (&out, &in, elfdata) != NULL)) |
| { |
| /* We are looking for PT_DYNAMIC. */ |
| const union |
| { |
| Elf32_Dyn d32[dyn_filesz / sizeof (Elf32_Dyn)]; |
| Elf64_Dyn d64[dyn_filesz / sizeof (Elf64_Dyn)]; |
| } *u = (void *) &buf; |
| if (elfclass == ELFCLASS32) |
| { |
| size_t n = dyn_filesz / sizeof (Elf32_Dyn); |
| for (size_t i = 0; i < n; ++i) |
| if (u->d32[i].d_tag == DT_DEBUG) |
| { |
| r_debug_vaddr = u->d32[i].d_un.d_val; |
| break; |
| } |
| } |
| else |
| { |
| size_t n = dyn_filesz / sizeof (Elf64_Dyn); |
| for (size_t i = 0; i < n; ++i) |
| if (u->d64[i].d_tag == DT_DEBUG) |
| { |
| r_debug_vaddr = u->d64[i].d_un.d_val; |
| break; |
| } |
| } |
| } |
| |
| (*memory_callback) (dwfl, -1, &in.d_buf, &in.d_size, 0, 0, |
| memory_callback_arg); |
| } |
| } |
| } |
| else |
| /* We have to look for a presupplied executable file to determine |
| the vaddr of its dynamic section and DT_DEBUG therein. */ |
| r_debug_vaddr = find_executable (dwfl, 0, 0, &elfclass, &elfdata, |
| memory_callback, memory_callback_arg); |
| |
| if (r_debug_vaddr == 0) |
| return 0; |
| |
| /* For following pointers from struct link_map, we will use an |
| integrated memory access callback that can consult module text |
| elided from the core file. This is necessary when the l_name |
| pointer for the dynamic linker's own entry is a pointer into the |
| executable's .interp section. */ |
| struct integrated_memory_callback mcb = |
| { |
| .memory_callback = memory_callback, |
| .memory_callback_arg = memory_callback_arg |
| }; |
| |
| /* Now we can follow the dynamic linker's library list. */ |
| return report_r_debug (elfclass, elfdata, dwfl, r_debug_vaddr, |
| &integrated_memory_callback, &mcb); |
| } |
| INTDEF (dwfl_link_map_report) |