/* Find debugging and symbol information for a module in libdwfl.
- Copyright (C) 2005, 2006, 2007 Red Hat, Inc.
- This file is part of Red Hat elfutils.
+ Copyright (C) 2005-2012, 2014, 2015 Red Hat, Inc.
+ This file is part of 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.
+ This file is free software; you can redistribute it and/or modify
+ it under the terms of either
- Red Hat elfutils is distributed in the hope that it will be useful, but
+ * the GNU Lesser General Public License as published by the Free
+ Software Foundation; either version 3 of the License, or (at
+ your option) any later version
+
+ or
+
+ * the GNU General Public License as published by the Free
+ Software Foundation; either version 2 of the License, or (at
+ your option) any later version
+
+ or both in parallel, as here.
+
+ 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>. */
+ You should have received copies of the GNU General Public License and
+ the GNU Lesser General Public License along with this program. If
+ not, see <http://www.gnu.org/licenses/>. */
#include "libdwflP.h"
+#include <inttypes.h>
#include <fcntl.h>
#include <string.h>
#include <unistd.h>
#include "../libdw/libdwP.h" /* DWARF_E_* values are here. */
+#include "../libelf/libelfP.h"
+#include "system.h"
-
-/* Open libelf FILE->fd and compute the load base of ELF as loaded in MOD.
- When we return success, FILE->elf and FILE->bias are set up. */
static inline Dwfl_Error
-open_elf (Dwfl_Module *mod, struct dwfl_file *file)
+open_elf_file (Elf **elf, int *fd, char **name)
{
- if (file->elf == NULL)
+ if (*elf == NULL)
{
- if (file->fd < 0)
+ /* CBFAIL uses errno if it's set, so clear it first in case we don't
+ set it with an open failure below. */
+ errno = 0;
+
+ /* If there was a pre-primed file name left that the callback left
+ behind, try to open that file name. */
+ if (*fd < 0 && *name != NULL)
+ *fd = TEMP_FAILURE_RETRY (open (*name, O_RDONLY));
+
+ if (*fd < 0)
return CBFAIL;
- file->elf = elf_begin (file->fd, ELF_C_READ_MMAP_PRIVATE, NULL);
+ return __libdw_open_file (fd, elf, true, false);
}
+ else if (unlikely (elf_kind (*elf) != ELF_K_ELF))
+ {
+ elf_end (*elf);
+ *elf = NULL;
+ close (*fd);
+ *fd = -1;
+ return DWFL_E_BADELF;
+ }
+
+ /* Elf file already open and looks fine. */
+ return DWFL_E_NOERROR;
+}
+
+/* Open libelf FILE->fd and compute the load base of ELF as loaded in MOD.
+ When we return success, FILE->elf and FILE->vaddr are set up. */
+static inline Dwfl_Error
+open_elf (Dwfl_Module *mod, struct dwfl_file *file)
+{
+ Dwfl_Error error = open_elf_file (&file->elf, &file->fd, &file->name);
+ if (error != DWFL_E_NOERROR)
+ return error;
GElf_Ehdr ehdr_mem, *ehdr = gelf_getehdr (file->elf, &ehdr_mem);
if (ehdr == NULL)
{
elf_error:
+ elf_end (file->elf);
+ file->elf = NULL;
close (file->fd);
file->fd = -1;
- return DWFL_E_LIBELF;
+ return DWFL_E (LIBELF, elf_errno ());
}
- file->bias = 0;
- for (uint_fast16_t i = 0; i < ehdr->e_phnum; ++i)
+ if (ehdr->e_type != ET_REL)
{
- GElf_Phdr ph_mem;
- GElf_Phdr *ph = gelf_getphdr (file->elf, i, &ph_mem);
- if (ph == NULL)
+ /* In any non-ET_REL file, we compute the "synchronization address".
+
+ We start with the address at the end of the first PT_LOAD
+ segment. When prelink converts REL to RELA in an ET_DYN
+ file, it expands the space between the beginning of the
+ segment and the actual code/data addresses. Since that
+ change wasn't made in the debug file, the distance from
+ p_vaddr to an address of interest (in an st_value or DWARF
+ data) now differs between the main and debug files. The
+ distance from address_sync to an address of interest remains
+ consistent.
+
+ If there are no section headers at all (full stripping), then
+ the end of the first segment is a valid synchronization address.
+ This cannot happen in a prelinked file, since prelink itself
+ relies on section headers for prelinking and for undoing it.
+ (If you do full stripping on a prelinked file, then you get what
+ you deserve--you can neither undo the prelinking, nor expect to
+ line it up with a debug file separated before prelinking.)
+
+ However, when prelink processes an ET_EXEC file, it can do
+ something different. There it juggles the "special" sections
+ (SHT_DYNSYM et al) to make space for the additional prelink
+ special sections. Sometimes it will do this by moving a special
+ section like .dynstr after the real program sections in the first
+ PT_LOAD segment--i.e. to the end. That changes the end address of
+ the segment, so it no longer lines up correctly and is not a valid
+ synchronization address to use. Because of this, we need to apply
+ a different prelink-savvy means to discover the synchronization
+ address when there is a separate debug file and a prelinked main
+ file. That is done in find_debuginfo, below. */
+
+ size_t phnum;
+ if (unlikely (elf_getphdrnum (file->elf, &phnum) != 0))
goto elf_error;
- if (ph->p_type == PT_LOAD)
+
+ file->vaddr = file->address_sync = 0;
+ for (size_t i = 0; i < phnum; ++i)
{
- file->bias = ((mod->low_addr & -ph->p_align)
- - (ph->p_vaddr & -ph->p_align));
- break;
+ GElf_Phdr ph_mem;
+ GElf_Phdr *ph = gelf_getphdr (file->elf, i, &ph_mem);
+ if (unlikely (ph == NULL))
+ goto elf_error;
+ if (ph->p_type == PT_LOAD)
+ {
+ file->vaddr = ph->p_vaddr & -ph->p_align;
+ file->address_sync = ph->p_vaddr + ph->p_memsz;
+ break;
+ }
}
}
- mod->e_type = ehdr->e_type;
+ /* We only want to set the module e_type explictly once, derived from
+ the main ELF file. (It might be changed for the kernel, because
+ that is special - see below.) open_elf is always called first for
+ the main ELF file, because both find_dw and find_symtab call
+ __libdwfl_getelf first to open the main file. So don't let debug
+ or aux files override the module e_type. The kernel heuristic
+ below could otherwise trigger for non-kernel/non-main files, since
+ their phdrs might not match the actual load addresses. */
+ if (file == &mod->main)
+ {
+ mod->e_type = ehdr->e_type;
- /* Relocatable Linux kernels are ET_EXEC but act like ET_DYN. */
- if (mod->e_type == ET_EXEC && file->bias != 0)
- mod->e_type = ET_DYN;
+ /* Relocatable Linux kernels are ET_EXEC but act like ET_DYN. */
+ if (mod->e_type == ET_EXEC && file->vaddr != mod->low_addr)
+ mod->e_type = ET_DYN;
+ }
+ else
+ assert (mod->main.elf != NULL);
return DWFL_E_NOERROR;
}
+/* We have an authoritative build ID for this module MOD, so don't use
+ a file by name that doesn't match that ID. */
+static void
+mod_verify_build_id (Dwfl_Module *mod)
+{
+ assert (mod->build_id_len > 0);
+
+ switch (__builtin_expect (__libdwfl_find_build_id (mod, false,
+ mod->main.elf), 2))
+ {
+ case 2:
+ /* Build ID matches as it should. */
+ return;
+
+ case -1: /* ELF error. */
+ mod->elferr = INTUSE(dwfl_errno) ();
+ break;
+
+ case 0: /* File has no build ID note. */
+ case 1: /* FIle has a build ID that does not match. */
+ mod->elferr = DWFL_E_WRONG_ID_ELF;
+ break;
+
+ default:
+ abort ();
+ }
+
+ /* We get here when it was the right ELF file. Clear it out. */
+ elf_end (mod->main.elf);
+ mod->main.elf = NULL;
+ if (mod->main.fd >= 0)
+ {
+ close (mod->main.fd);
+ mod->main.fd = -1;
+ }
+}
+
/* Find the main ELF file for this module and open libelf on it.
When we return success, MOD->main.elf and MOD->main.bias are set up. */
-static void
-find_file (Dwfl_Module *mod)
+void
+internal_function
+__libdwfl_getelf (Dwfl_Module *mod)
{
if (mod->main.elf != NULL /* Already done. */
|| mod->elferr != DWFL_E_NOERROR) /* Cached failure. */
mod->main.fd = (*mod->dwfl->callbacks->find_elf) (MODCB_ARGS (mod),
&mod->main.name,
&mod->main.elf);
+ const bool fallback = mod->main.elf == NULL && mod->main.fd < 0;
mod->elferr = open_elf (mod, &mod->main);
+ if (mod->elferr != DWFL_E_NOERROR)
+ return;
+
+ if (!mod->main.valid)
+ {
+ /* Clear any explicitly reported build ID, just in case it was wrong.
+ We'll fetch it from the file when asked. */
+ free (mod->build_id_bits);
+ mod->build_id_bits = NULL;
+ mod->build_id_len = 0;
+ }
+ else if (fallback)
+ mod_verify_build_id (mod);
+
+ mod->main_bias = mod->e_type == ET_REL ? 0 : mod->low_addr - mod->main.vaddr;
}
-/* Search an ELF file for a ".gnu_debuglink" section. */
-static const char *
-find_debuglink (Elf *elf, GElf_Word *crc)
+static inline void
+consider_shdr (GElf_Addr interp,
+ GElf_Word sh_type,
+ GElf_Xword sh_flags,
+ GElf_Addr sh_addr,
+ GElf_Xword sh_size,
+ GElf_Addr *phighest)
{
+ if ((sh_flags & SHF_ALLOC)
+ && ((sh_type == SHT_PROGBITS && sh_addr != interp)
+ || sh_type == SHT_NOBITS))
+ {
+ const GElf_Addr sh_end = sh_addr + sh_size;
+ if (sh_end > *phighest)
+ *phighest = sh_end;
+ }
+}
+
+/* If the main file might have been prelinked, then we need to
+ discover the correct synchronization address between the main and
+ debug files. Because of prelink's section juggling, we cannot rely
+ on the address_sync computed from PT_LOAD segments (see open_elf).
+
+ We will attempt to discover a synchronization address based on the
+ section headers instead. But finding a section address that is
+ safe to use requires identifying which sections are SHT_PROGBITS.
+ We can do that in the main file, but in the debug file all the
+ allocated sections have been transformed into SHT_NOBITS so we have
+ lost the means to match them up correctly.
+
+ The only method left to us is to decode the .gnu.prelink_undo
+ section in the prelinked main file. This shows what the sections
+ looked like before prelink juggled them--when they still had a
+ direct correspondence to the debug file. */
+static Dwfl_Error
+find_prelink_address_sync (Dwfl_Module *mod, struct dwfl_file *file)
+{
+ /* The magic section is only identified by name. */
size_t shstrndx;
- if (elf_getshstrndx (elf, &shstrndx) < 0)
- return NULL;
+ if (elf_getshdrstrndx (mod->main.elf, &shstrndx) < 0)
+ return DWFL_E_LIBELF;
Elf_Scn *scn = NULL;
- while ((scn = elf_nextscn (elf, scn)) != NULL)
+ while ((scn = elf_nextscn (mod->main.elf, scn)) != NULL)
{
GElf_Shdr shdr_mem;
GElf_Shdr *shdr = gelf_getshdr (scn, &shdr_mem);
- if (shdr == NULL)
- return NULL;
-
- const char *name = elf_strptr (elf, shstrndx, shdr->sh_name);
- if (name == NULL)
- return NULL;
-
- if (!strcmp (name, ".gnu_debuglink"))
- break;
+ if (unlikely (shdr == NULL))
+ return DWFL_E_LIBELF;
+ if (shdr->sh_type == SHT_PROGBITS
+ && !(shdr->sh_flags & SHF_ALLOC)
+ && shdr->sh_name != 0)
+ {
+ const char *secname = elf_strptr (mod->main.elf, shstrndx,
+ shdr->sh_name);
+ if (unlikely (secname == NULL))
+ return DWFL_E_LIBELF;
+ if (!strcmp (secname, ".gnu.prelink_undo"))
+ break;
+ }
}
if (scn == NULL)
- return NULL;
+ /* There was no .gnu.prelink_undo section. */
+ return DWFL_E_NOERROR;
- /* Found the .gnu_debuglink section. Extract its contents. */
- Elf_Data *rawdata = elf_rawdata (scn, NULL);
- if (rawdata == NULL)
- return NULL;
+ Elf_Data *undodata = elf_rawdata (scn, NULL);
+ if (unlikely (undodata == NULL))
+ return DWFL_E_LIBELF;
- Elf_Data crcdata =
+ /* Decode the section. It consists of the original ehdr, phdrs,
+ and shdrs (but omits section 0). */
+
+ union
+ {
+ Elf32_Ehdr e32;
+ Elf64_Ehdr e64;
+ } ehdr;
+ Elf_Data dst =
{
- .d_type = ELF_T_WORD,
- .d_buf = crc,
- .d_size = sizeof *crc,
- .d_version = EV_CURRENT,
+ .d_buf = &ehdr,
+ .d_size = sizeof ehdr,
+ .d_type = ELF_T_EHDR,
+ .d_version = EV_CURRENT
};
- Elf_Data conv =
+ Elf_Data src = *undodata;
+ src.d_size = gelf_fsize (mod->main.elf, ELF_T_EHDR, 1, EV_CURRENT);
+ src.d_type = ELF_T_EHDR;
+ if (unlikely (gelf_xlatetom (mod->main.elf, &dst, &src,
+ elf_getident (mod->main.elf, NULL)[EI_DATA])
+ == NULL))
+ return DWFL_E_LIBELF;
+
+ size_t shentsize = gelf_fsize (mod->main.elf, ELF_T_SHDR, 1, EV_CURRENT);
+ size_t phentsize = gelf_fsize (mod->main.elf, ELF_T_PHDR, 1, EV_CURRENT);
+
+ uint_fast16_t phnum;
+ uint_fast16_t shnum;
+ if (ehdr.e32.e_ident[EI_CLASS] == ELFCLASS32)
{
- .d_type = ELF_T_WORD,
- .d_buf = rawdata->d_buf + rawdata->d_size - sizeof *crc,
- .d_size = sizeof *crc,
- .d_version = EV_CURRENT,
- };
+ if (ehdr.e32.e_shentsize != shentsize
+ || ehdr.e32.e_phentsize != phentsize)
+ return DWFL_E_BAD_PRELINK;
+ phnum = ehdr.e32.e_phnum;
+ shnum = ehdr.e32.e_shnum;
+ }
+ else
+ {
+ if (ehdr.e64.e_shentsize != shentsize
+ || ehdr.e64.e_phentsize != phentsize)
+ return DWFL_E_BAD_PRELINK;
+ phnum = ehdr.e64.e_phnum;
+ shnum = ehdr.e64.e_shnum;
+ }
- GElf_Ehdr ehdr_mem;
- GElf_Ehdr *ehdr = gelf_getehdr (elf, &ehdr_mem);
- if (ehdr == NULL)
- return NULL;
+ /* Since prelink does not store the zeroth section header in the undo
+ section, it cannot support SHN_XINDEX encoding. */
+ if (unlikely (shnum >= SHN_LORESERVE)
+ || unlikely (undodata->d_size != (src.d_size
+ + phnum * phentsize
+ + (shnum - 1) * shentsize)))
+ return DWFL_E_BAD_PRELINK;
+
+ /* We look at the allocated SHT_PROGBITS (or SHT_NOBITS) sections. (Most
+ every file will have some SHT_PROGBITS sections, but it's possible to
+ have one with nothing but .bss, i.e. SHT_NOBITS.) The special sections
+ that can be moved around have different sh_type values--except for
+ .interp, the section that became the PT_INTERP segment. So we exclude
+ the SHT_PROGBITS section whose address matches the PT_INTERP p_vaddr.
+ For this reason, we must examine the phdrs first to find PT_INTERP. */
+
+ GElf_Addr main_interp = 0;
+ {
+ size_t main_phnum;
+ if (unlikely (elf_getphdrnum (mod->main.elf, &main_phnum)))
+ return DWFL_E_LIBELF;
+ for (size_t i = 0; i < main_phnum; ++i)
+ {
+ GElf_Phdr phdr;
+ if (unlikely (gelf_getphdr (mod->main.elf, i, &phdr) == NULL))
+ return DWFL_E_LIBELF;
+ if (phdr.p_type == PT_INTERP)
+ {
+ main_interp = phdr.p_vaddr;
+ break;
+ }
+ }
+ }
+
+ src.d_buf += src.d_size;
+ src.d_type = ELF_T_PHDR;
+ src.d_size = phnum * phentsize;
+
+ GElf_Addr undo_interp = 0;
+ bool class32 = ehdr.e32.e_ident[EI_CLASS] == ELFCLASS32;
+ {
+ size_t phdr_size = class32 ? sizeof (Elf32_Phdr) : sizeof (Elf64_Phdr);
+ if (unlikely (phnum > SIZE_MAX / phdr_size))
+ return DWFL_E_NOMEM;
+ const size_t phdrs_bytes = phnum * phdr_size;
+ void *phdrs = malloc (phdrs_bytes);
+ if (unlikely (phdrs == NULL))
+ return DWFL_E_NOMEM;
+ dst.d_buf = phdrs;
+ dst.d_size = phdrs_bytes;
+ if (unlikely (gelf_xlatetom (mod->main.elf, &dst, &src,
+ ehdr.e32.e_ident[EI_DATA]) == NULL))
+ {
+ free (phdrs);
+ return DWFL_E_LIBELF;
+ }
+ if (class32)
+ {
+ Elf32_Phdr (*p32)[phnum] = phdrs;
+ for (uint_fast16_t i = 0; i < phnum; ++i)
+ if ((*p32)[i].p_type == PT_INTERP)
+ {
+ undo_interp = (*p32)[i].p_vaddr;
+ break;
+ }
+ }
+ else
+ {
+ Elf64_Phdr (*p64)[phnum] = phdrs;
+ for (uint_fast16_t i = 0; i < phnum; ++i)
+ if ((*p64)[i].p_type == PT_INTERP)
+ {
+ undo_interp = (*p64)[i].p_vaddr;
+ break;
+ }
+ }
+ free (phdrs);
+ }
+
+ if (unlikely ((main_interp == 0) != (undo_interp == 0)))
+ return DWFL_E_BAD_PRELINK;
+
+ src.d_buf += src.d_size;
+ src.d_type = ELF_T_SHDR;
+ src.d_size = gelf_fsize (mod->main.elf, ELF_T_SHDR, shnum - 1, EV_CURRENT);
+
+ size_t shdr_size = class32 ? sizeof (Elf32_Shdr) : sizeof (Elf64_Shdr);
+ if (unlikely (shnum - 1 > SIZE_MAX / shdr_size))
+ return DWFL_E_NOMEM;
+ const size_t shdrs_bytes = (shnum - 1) * shdr_size;
+ void *shdrs = malloc (shdrs_bytes);
+ if (unlikely (shdrs == NULL))
+ return DWFL_E_NOMEM;
+ dst.d_buf = shdrs;
+ dst.d_size = shdrs_bytes;
+ if (unlikely (gelf_xlatetom (mod->main.elf, &dst, &src,
+ ehdr.e32.e_ident[EI_DATA]) == NULL))
+ {
+ free (shdrs);
+ return DWFL_E_LIBELF;
+ }
- Elf_Data *d = gelf_xlatetom (elf, &crcdata, &conv, ehdr->e_ident[EI_DATA]);
- if (d == NULL)
- return NULL;
- assert (d == &crcdata);
+ /* Now we can look at the original section headers of the main file
+ before it was prelinked. First we'll apply our method to the main
+ file sections as they are after prelinking, to calculate the
+ synchronization address of the main file. Then we'll apply that
+ same method to the saved section headers, to calculate the matching
+ synchronization address of the debug file.
+
+ The method is to consider SHF_ALLOC sections that are either
+ SHT_PROGBITS or SHT_NOBITS, excluding the section whose sh_addr
+ matches the PT_INTERP p_vaddr. The special sections that can be
+ moved by prelink have other types, except for .interp (which
+ becomes PT_INTERP). The "real" sections cannot move as such, but
+ .bss can be split into .dynbss and .bss, with the total memory
+ image remaining the same but being spread across the two sections.
+ So we consider the highest section end, which still matches up. */
+
+ GElf_Addr highest;
+
+ highest = 0;
+ scn = NULL;
+ while ((scn = elf_nextscn (mod->main.elf, scn)) != NULL)
+ {
+ GElf_Shdr sh_mem;
+ GElf_Shdr *sh = gelf_getshdr (scn, &sh_mem);
+ if (unlikely (sh == NULL))
+ {
+ free (shdrs);
+ return DWFL_E_LIBELF;
+ }
+ consider_shdr (main_interp, sh->sh_type, sh->sh_flags,
+ sh->sh_addr, sh->sh_size, &highest);
+ }
+ if (highest > mod->main.vaddr)
+ {
+ mod->main.address_sync = highest;
- return rawdata->d_buf;
-}
+ highest = 0;
+ if (class32)
+ {
+ Elf32_Shdr (*s32)[shnum - 1] = shdrs;
+ for (size_t i = 0; i < shnum - 1; ++i)
+ consider_shdr (undo_interp, (*s32)[i].sh_type,
+ (*s32)[i].sh_flags, (*s32)[i].sh_addr,
+ (*s32)[i].sh_size, &highest);
+ }
+ else
+ {
+ Elf64_Shdr (*s64)[shnum - 1] = shdrs;
+ for (size_t i = 0; i < shnum - 1; ++i)
+ consider_shdr (undo_interp, (*s64)[i].sh_type,
+ (*s64)[i].sh_flags, (*s64)[i].sh_addr,
+ (*s64)[i].sh_size, &highest);
+ }
+ if (highest > file->vaddr)
+ file->address_sync = highest;
+ else
+ {
+ free (shdrs);
+ return DWFL_E_BAD_PRELINK;
+ }
+ }
+
+ free (shdrs);
+
+ return DWFL_E_NOERROR;
+}
/* Find the separate debuginfo file for this module and open libelf on it.
When we return success, MOD->debug is set up. */
return DWFL_E_NOERROR;
GElf_Word debuglink_crc = 0;
- const char *debuglink_file = find_debuglink (mod->main.elf, &debuglink_crc);
+ const char *debuglink_file;
+ debuglink_file = INTUSE(dwelf_elf_gnu_debuglink) (mod->main.elf,
+ &debuglink_crc);
mod->debug.fd = (*mod->dwfl->callbacks->find_debuginfo) (MODCB_ARGS (mod),
mod->main.name,
debuglink_file,
debuglink_crc,
&mod->debug.name);
- return open_elf (mod, &mod->debug);
+ Dwfl_Error result = open_elf (mod, &mod->debug);
+ if (result == DWFL_E_NOERROR && mod->debug.address_sync != 0)
+ result = find_prelink_address_sync (mod, &mod->debug);
+ return result;
}
+/* Try to find the alternative debug link for the given DWARF and set
+ it if found. Only called when mod->dw is already setup but still
+ might need an alternative (dwz multi) debug file. filename is either
+ the main or debug name from which the Dwarf was created. */
+static void
+find_debug_altlink (Dwfl_Module *mod, const char *filename)
+{
+ assert (mod->dw != NULL);
-/* Try to find a symbol table in FILE. */
+ const char *altname;
+ const void *build_id;
+ ssize_t build_id_len = INTUSE(dwelf_dwarf_gnu_debugaltlink) (mod->dw,
+ &altname,
+ &build_id);
+
+ if (build_id_len > 0)
+ {
+ /* We could store altfile in the module, but don't really need it. */
+ char *altfile = NULL;
+ mod->alt_fd = (*mod->dwfl->callbacks->find_debuginfo) (MODCB_ARGS (mod),
+ filename,
+ altname,
+ 0,
+ &altfile);
+
+ /* The (internal) callbacks might just set mod->alt_elf directly
+ because they open the Elf anyway for sanity checking.
+ Otherwise open either the given file name or use the fd
+ returned. */
+ Dwfl_Error error = open_elf_file (&mod->alt_elf, &mod->alt_fd,
+ &altfile);
+ if (error == DWFL_E_NOERROR)
+ {
+ mod->alt = INTUSE(dwarf_begin_elf) (mod->alt_elf,
+ DWARF_C_READ, NULL);
+ if (mod->alt == NULL)
+ {
+ elf_end (mod->alt_elf);
+ mod->alt_elf = NULL;
+ close (mod->alt_fd);
+ mod->alt_fd = -1;
+ }
+ else
+ dwarf_setalt (mod->dw, mod->alt);
+ }
+
+ free (altfile); /* See above, we don't really need it. */
+ }
+}
+
+/* Try to find a symbol table in FILE.
+ Returns DWFL_E_NOERROR if a proper one is found.
+ Returns DWFL_E_NO_SYMTAB if not, but still sets results for SHT_DYNSYM. */
static Dwfl_Error
load_symtab (struct dwfl_file *file, struct dwfl_file **symfile,
Elf_Scn **symscn, Elf_Scn **xndxscn,
- size_t *syments, GElf_Word *strshndx)
+ size_t *syments, int *first_global, GElf_Word *strshndx)
{
+ bool symtab = false;
Elf_Scn *scn = NULL;
while ((scn = elf_nextscn (file->elf, scn)) != NULL)
{
switch (shdr->sh_type)
{
case SHT_SYMTAB:
+ if (shdr->sh_entsize == 0)
+ break;
+ symtab = true;
*symscn = scn;
*symfile = file;
*strshndx = shdr->sh_link;
*syments = shdr->sh_size / shdr->sh_entsize;
- if (*symscn != NULL && *xndxscn != NULL)
+ *first_global = shdr->sh_info;
+ if (*xndxscn != NULL)
return DWFL_E_NOERROR;
break;
case SHT_DYNSYM:
+ if (symtab)
+ break;
/* Use this if need be, but keep looking for SHT_SYMTAB. */
+ if (shdr->sh_entsize == 0)
+ break;
*symscn = scn;
*symfile = file;
*strshndx = shdr->sh_link;
*syments = shdr->sh_size / shdr->sh_entsize;
+ *first_global = shdr->sh_info;
break;
case SHT_SYMTAB_SHNDX:
*xndxscn = scn;
+ if (symtab)
+ return DWFL_E_NOERROR;
break;
default:
break;
}
}
+
+ if (symtab)
+ /* We found one, though no SHT_SYMTAB_SHNDX to go with it. */
+ return DWFL_E_NOERROR;
+
+ /* We found no SHT_SYMTAB, so any SHT_SYMTAB_SHNDX was bogus.
+ We might have found an SHT_DYNSYM and set *SYMSCN et al though. */
+ *xndxscn = NULL;
return DWFL_E_NO_SYMTAB;
}
+
+/* Translate addresses into file offsets.
+ OFFS[*] start out zero and remain zero if unresolved. */
+static void
+find_offsets (Elf *elf, GElf_Addr main_bias, size_t phnum, size_t n,
+ GElf_Addr addrs[n], GElf_Off offs[n])
+{
+ size_t unsolved = n;
+ for (size_t i = 0; i < phnum; ++i)
+ {
+ GElf_Phdr phdr_mem;
+ GElf_Phdr *phdr = gelf_getphdr (elf, i, &phdr_mem);
+ if (phdr != NULL && phdr->p_type == PT_LOAD && phdr->p_memsz > 0)
+ for (size_t j = 0; j < n; ++j)
+ if (offs[j] == 0
+ && addrs[j] >= phdr->p_vaddr + main_bias
+ && addrs[j] - (phdr->p_vaddr + main_bias) < phdr->p_filesz)
+ {
+ offs[j] = addrs[j] - (phdr->p_vaddr + main_bias) + phdr->p_offset;
+ if (--unsolved == 0)
+ break;
+ }
+ }
+}
+
+/* Various addresses we might want to pull from the dynamic segment. */
+enum
+{
+ i_symtab,
+ i_strtab,
+ i_hash,
+ i_gnu_hash,
+ i_max
+};
+
+/* Translate pointers into file offsets. ADJUST is either zero
+ in case the dynamic segment wasn't adjusted or mod->main_bias.
+ Will set mod->symfile if the translated offsets can be used as
+ symbol table. */
+static void
+translate_offs (GElf_Addr adjust,
+ Dwfl_Module *mod, size_t phnum,
+ GElf_Addr addrs[i_max], GElf_Xword strsz,
+ GElf_Ehdr *ehdr)
+{
+ GElf_Off offs[i_max] = { 0, };
+ find_offsets (mod->main.elf, adjust, phnum, i_max, addrs, offs);
+
+ /* Figure out the size of the symbol table. */
+ if (offs[i_hash] != 0)
+ {
+ /* In the original format, .hash says the size of .dynsym. */
+
+ size_t entsz = SH_ENTSIZE_HASH (ehdr);
+ Elf_Data *data = elf_getdata_rawchunk (mod->main.elf,
+ offs[i_hash] + entsz, entsz,
+ (entsz == 4
+ ? ELF_T_WORD : ELF_T_XWORD));
+ if (data != NULL)
+ mod->syments = (entsz == 4
+ ? *(const GElf_Word *) data->d_buf
+ : *(const GElf_Xword *) data->d_buf);
+ }
+ if (offs[i_gnu_hash] != 0 && mod->syments == 0)
+ {
+ /* In the new format, we can derive it with some work. */
+
+ const struct
+ {
+ Elf32_Word nbuckets;
+ Elf32_Word symndx;
+ Elf32_Word maskwords;
+ Elf32_Word shift2;
+ } *header;
+
+ Elf_Data *data = elf_getdata_rawchunk (mod->main.elf, offs[i_gnu_hash],
+ sizeof *header, ELF_T_WORD);
+ if (data != NULL)
+ {
+ header = data->d_buf;
+ Elf32_Word nbuckets = header->nbuckets;
+ Elf32_Word symndx = header->symndx;
+ GElf_Off buckets_at = (offs[i_gnu_hash] + sizeof *header
+ + (gelf_getclass (mod->main.elf)
+ * sizeof (Elf32_Word)
+ * header->maskwords));
+
+ // elf_getdata_rawchunk takes a size_t, make sure it
+ // doesn't overflow.
+#if SIZE_MAX <= UINT32_MAX
+ if (nbuckets > SIZE_MAX / sizeof (Elf32_Word))
+ data = NULL;
+ else
+#endif
+ data = elf_getdata_rawchunk (mod->main.elf, buckets_at,
+ nbuckets * sizeof (Elf32_Word),
+ ELF_T_WORD);
+ if (data != NULL && symndx < nbuckets)
+ {
+ const Elf32_Word *const buckets = data->d_buf;
+ Elf32_Word maxndx = symndx;
+ for (Elf32_Word bucket = 0; bucket < nbuckets; ++bucket)
+ if (buckets[bucket] > maxndx)
+ maxndx = buckets[bucket];
+
+ GElf_Off hasharr_at = (buckets_at
+ + nbuckets * sizeof (Elf32_Word));
+ hasharr_at += (maxndx - symndx) * sizeof (Elf32_Word);
+ do
+ {
+ data = elf_getdata_rawchunk (mod->main.elf,
+ hasharr_at,
+ sizeof (Elf32_Word),
+ ELF_T_WORD);
+ if (data != NULL
+ && (*(const Elf32_Word *) data->d_buf & 1u))
+ {
+ mod->syments = maxndx + 1;
+ break;
+ }
+ ++maxndx;
+ hasharr_at += sizeof (Elf32_Word);
+ }
+ while (data != NULL);
+ }
+ }
+ }
+ if (offs[i_strtab] > offs[i_symtab] && mod->syments == 0)
+ mod->syments = ((offs[i_strtab] - offs[i_symtab])
+ / gelf_fsize (mod->main.elf,
+ ELF_T_SYM, 1, EV_CURRENT));
+
+ if (mod->syments > 0)
+ {
+ mod->symdata = elf_getdata_rawchunk (mod->main.elf,
+ offs[i_symtab],
+ gelf_fsize (mod->main.elf,
+ ELF_T_SYM,
+ mod->syments,
+ EV_CURRENT),
+ ELF_T_SYM);
+ if (mod->symdata != NULL)
+ {
+ mod->symstrdata = elf_getdata_rawchunk (mod->main.elf,
+ offs[i_strtab],
+ strsz,
+ ELF_T_BYTE);
+ if (mod->symstrdata == NULL)
+ mod->symdata = NULL;
+ }
+ if (mod->symdata == NULL)
+ mod->symerr = DWFL_E (LIBELF, elf_errno ());
+ else
+ {
+ mod->symfile = &mod->main;
+ mod->symerr = DWFL_E_NOERROR;
+ }
+ }
+}
+
+/* Try to find a dynamic symbol table via phdrs. */
+static void
+find_dynsym (Dwfl_Module *mod)
+{
+ GElf_Ehdr ehdr_mem;
+ GElf_Ehdr *ehdr = gelf_getehdr (mod->main.elf, &ehdr_mem);
+
+ size_t phnum;
+ if (unlikely (elf_getphdrnum (mod->main.elf, &phnum) != 0))
+ return;
+
+ for (size_t i = 0; i < phnum; ++i)
+ {
+ GElf_Phdr phdr_mem;
+ GElf_Phdr *phdr = gelf_getphdr (mod->main.elf, i, &phdr_mem);
+ if (phdr == NULL)
+ break;
+
+ if (phdr->p_type == PT_DYNAMIC)
+ {
+ /* Examine the dynamic section for the pointers we need. */
+
+ Elf_Data *data = elf_getdata_rawchunk (mod->main.elf,
+ phdr->p_offset, phdr->p_filesz,
+ ELF_T_DYN);
+ if (data == NULL)
+ continue;
+
+ GElf_Addr addrs[i_max] = { 0, };
+ GElf_Xword strsz = 0;
+ size_t n = data->d_size / gelf_fsize (mod->main.elf,
+ ELF_T_DYN, 1, EV_CURRENT);
+ for (size_t j = 0; j < n; ++j)
+ {
+ GElf_Dyn dyn_mem;
+ GElf_Dyn *dyn = gelf_getdyn (data, j, &dyn_mem);
+ if (dyn != NULL)
+ switch (dyn->d_tag)
+ {
+ case DT_SYMTAB:
+ addrs[i_symtab] = dyn->d_un.d_ptr;
+ continue;
+
+ case DT_HASH:
+ addrs[i_hash] = dyn->d_un.d_ptr;
+ continue;
+
+ case DT_GNU_HASH:
+ addrs[i_gnu_hash] = dyn->d_un.d_ptr;
+ continue;
+
+ case DT_STRTAB:
+ addrs[i_strtab] = dyn->d_un.d_ptr;
+ continue;
+
+ case DT_STRSZ:
+ strsz = dyn->d_un.d_val;
+ continue;
+
+ default:
+ continue;
+
+ case DT_NULL:
+ break;
+ }
+ break;
+ }
+
+ /* First try unadjusted, like ELF files from disk, vdso.
+ Then try for already adjusted dynamic section, like ELF
+ from remote memory. */
+ translate_offs (0, mod, phnum, addrs, strsz, ehdr);
+ if (mod->symfile == NULL)
+ translate_offs (mod->main_bias, mod, phnum, addrs, strsz, ehdr);
+
+ return;
+ }
+ }
+}
+
+
+#if USE_LZMA
+/* Try to find the offset between the main file and .gnu_debugdata. */
+static bool
+find_aux_address_sync (Dwfl_Module *mod)
+{
+ /* Don't trust the phdrs in the minisymtab elf file to be setup correctly.
+ The address_sync is equal to the main file it is embedded in at first. */
+ mod->aux_sym.address_sync = mod->main.address_sync;
+
+ /* Adjust address_sync for the difference in entry addresses, attempting to
+ account for ELF relocation changes after aux was split. */
+ GElf_Ehdr ehdr_main, ehdr_aux;
+ if (unlikely (gelf_getehdr (mod->main.elf, &ehdr_main) == NULL)
+ || unlikely (gelf_getehdr (mod->aux_sym.elf, &ehdr_aux) == NULL))
+ return false;
+ mod->aux_sym.address_sync += ehdr_aux.e_entry - ehdr_main.e_entry;
+
+ /* The shdrs are setup OK to make find_prelink_address_sync () do the right
+ thing, which is possibly more reliable, but it needs .gnu.prelink_undo. */
+ if (mod->aux_sym.address_sync != 0)
+ return find_prelink_address_sync (mod, &mod->aux_sym) == DWFL_E_NOERROR;
+
+ return true;
+}
+#endif
+
+/* Try to find the auxiliary symbol table embedded in the main elf file
+ section .gnu_debugdata. Only matters if the symbol information comes
+ from the main file dynsym. No harm done if not found. */
+static void
+find_aux_sym (Dwfl_Module *mod __attribute__ ((unused)),
+ Elf_Scn **aux_symscn __attribute__ ((unused)),
+ Elf_Scn **aux_xndxscn __attribute__ ((unused)),
+ GElf_Word *aux_strshndx __attribute__ ((unused)))
+{
+ /* Since a .gnu_debugdata section is compressed using lzma don't do
+ anything unless we have support for that. */
+#if USE_LZMA
+ Elf *elf = mod->main.elf;
+
+ size_t shstrndx;
+ if (elf_getshdrstrndx (elf, &shstrndx) < 0)
+ return;
+
+ Elf_Scn *scn = NULL;
+ while ((scn = elf_nextscn (elf, scn)) != NULL)
+ {
+ GElf_Shdr shdr_mem;
+ GElf_Shdr *shdr = gelf_getshdr (scn, &shdr_mem);
+ if (shdr == NULL)
+ return;
+
+ const char *name = elf_strptr (elf, shstrndx, shdr->sh_name);
+ if (name == NULL)
+ return;
+
+ if (!strcmp (name, ".gnu_debugdata"))
+ break;
+ }
+
+ if (scn == NULL)
+ return;
+
+ /* Found the .gnu_debugdata section. Uncompress the lzma image and
+ turn it into an ELF image. */
+ Elf_Data *rawdata = elf_rawdata (scn, NULL);
+ if (rawdata == NULL)
+ return;
+
+ Dwfl_Error error;
+ void *buffer = NULL;
+ size_t size = 0;
+ error = __libdw_unlzma (-1, 0, rawdata->d_buf, rawdata->d_size,
+ &buffer, &size);
+ if (error == DWFL_E_NOERROR)
+ {
+ if (unlikely (size == 0))
+ free (buffer);
+ else
+ {
+ mod->aux_sym.elf = elf_memory (buffer, size);
+ if (mod->aux_sym.elf == NULL)
+ free (buffer);
+ else
+ {
+ mod->aux_sym.fd = -1;
+ mod->aux_sym.elf->flags |= ELF_F_MALLOCED;
+ if (open_elf (mod, &mod->aux_sym) != DWFL_E_NOERROR)
+ return;
+ if (! find_aux_address_sync (mod))
+ {
+ elf_end (mod->aux_sym.elf);
+ mod->aux_sym.elf = NULL;
+ return;
+ }
+
+ /* So far, so good. Get minisymtab table data and cache it. */
+ bool minisymtab = false;
+ scn = NULL;
+ while ((scn = elf_nextscn (mod->aux_sym.elf, scn)) != NULL)
+ {
+ GElf_Shdr shdr_mem, *shdr = gelf_getshdr (scn, &shdr_mem);
+ if (shdr != NULL)
+ switch (shdr->sh_type)
+ {
+ case SHT_SYMTAB:
+ minisymtab = true;
+ *aux_symscn = scn;
+ *aux_strshndx = shdr->sh_link;
+ mod->aux_syments = shdr->sh_size / shdr->sh_entsize;
+ mod->aux_first_global = shdr->sh_info;
+ if (*aux_xndxscn != NULL)
+ return;
+ break;
+
+ case SHT_SYMTAB_SHNDX:
+ *aux_xndxscn = scn;
+ if (minisymtab)
+ return;
+ break;
+
+ default:
+ break;
+ }
+ }
+
+ if (minisymtab)
+ /* We found one, though no SHT_SYMTAB_SHNDX to go with it. */
+ return;
+
+ /* We found no SHT_SYMTAB, so everything else is bogus. */
+ *aux_xndxscn = NULL;
+ *aux_strshndx = 0;
+ mod->aux_syments = 0;
+ elf_end (mod->aux_sym.elf);
+ mod->aux_sym.elf = NULL;
+ return;
+ }
+ }
+ }
+ else
+ free (buffer);
+#endif
+}
+
/* Try to find a symbol table in either MOD->main.elf or MOD->debug.elf. */
static void
find_symtab (Dwfl_Module *mod)
{
- if (mod->symdata != NULL /* Already done. */
+ if (mod->symdata != NULL || mod->aux_symdata != NULL /* Already done. */
|| mod->symerr != DWFL_E_NOERROR) /* Cached previous failure. */
return;
- find_file (mod);
+ __libdwfl_getelf (mod);
mod->symerr = mod->elferr;
if (mod->symerr != DWFL_E_NOERROR)
return;
/* First see if the main ELF file has the debugging information. */
Elf_Scn *symscn = NULL, *xndxscn = NULL;
- GElf_Word strshndx;
+ Elf_Scn *aux_symscn = NULL, *aux_xndxscn = NULL;
+ GElf_Word strshndx, aux_strshndx = 0;
mod->symerr = load_symtab (&mod->main, &mod->symfile, &symscn,
- &xndxscn, &mod->syments, &strshndx);
+ &xndxscn, &mod->syments, &mod->first_global,
+ &strshndx);
switch (mod->symerr)
{
default:
case DWFL_E_NOERROR:
mod->symerr = load_symtab (&mod->debug, &mod->symfile, &symscn,
- &xndxscn, &mod->syments, &strshndx);
+ &xndxscn, &mod->syments,
+ &mod->first_global, &strshndx);
break;
case DWFL_E_CB: /* The find_debuginfo hook failed. */
break;
case DWFL_E_NO_SYMTAB:
- if (symscn == NULL)
- return;
- /* We still have the dynamic symbol table. */
- mod->symerr = DWFL_E_NOERROR;
- break;
+ /* There might be an auxiliary table. */
+ find_aux_sym (mod, &aux_symscn, &aux_xndxscn, &aux_strshndx);
+
+ if (symscn != NULL)
+ {
+ /* We still have the dynamic symbol table. */
+ mod->symerr = DWFL_E_NOERROR;
+ break;
+ }
+
+ if (aux_symscn != NULL)
+ {
+ /* We still have the auxiliary symbol table. */
+ mod->symerr = DWFL_E_NOERROR;
+ goto aux_cache;
+ }
+
+ /* Last ditch, look for dynamic symbols without section headers. */
+ find_dynsym (mod);
+ return;
}
break;
}
if (elf_strptr (mod->symfile->elf, strshndx, 0) == NULL)
{
elferr:
+ mod->symdata = NULL;
+ mod->syments = 0;
+ mod->first_global = 0;
mod->symerr = DWFL_E (LIBELF, elf_errno ());
- return;
+ goto aux_cleanup; /* This cleans up some more and tries find_dynsym. */
}
- /* Cache the data; MOD->syments was set above. */
+ /* Cache the data; MOD->syments and MOD->first_global were set
+ above. If any of the sections is compressed, uncompress it
+ first. Only the string data setion could theoretically be
+ compressed GNU style (as .zdebug_str). Everything else only ELF
+ gabi style (SHF_COMPRESSED). */
+
+ Elf_Scn *symstrscn = elf_getscn (mod->symfile->elf, strshndx);
+ if (symstrscn == NULL)
+ goto elferr;
+
+ GElf_Shdr shdr_mem;
+ GElf_Shdr *shdr = gelf_getshdr (symstrscn, &shdr_mem);
+ if (shdr == NULL)
+ goto elferr;
+
+ size_t shstrndx;
+ if (elf_getshdrstrndx (mod->symfile->elf, &shstrndx) < 0)
+ goto elferr;
+
+ const char *sname = elf_strptr (mod->symfile->elf, shstrndx, shdr->sh_name);
+ if (sname == NULL)
+ goto elferr;
+
+ if (strncmp (sname, ".zdebug", strlen (".zdebug")) == 0)
+ /* Try to uncompress, but it might already have been, an error
+ might just indicate, already uncompressed. */
+ elf_compress_gnu (symstrscn, 0, 0);
+
+ if ((shdr->sh_flags & SHF_COMPRESSED) != 0)
+ if (elf_compress (symstrscn, 0, 0) < 0)
+ goto elferr;
- mod->symstrdata = elf_getdata (elf_getscn (mod->symfile->elf, strshndx),
- NULL);
- if (mod->symstrdata == NULL)
+ mod->symstrdata = elf_getdata (symstrscn, NULL);
+ if (mod->symstrdata == NULL || mod->symstrdata->d_buf == NULL)
goto elferr;
if (xndxscn == NULL)
mod->symxndxdata = NULL;
else
{
+ shdr = gelf_getshdr (xndxscn, &shdr_mem);
+ if (shdr == NULL)
+ goto elferr;
+
+ if ((shdr->sh_flags & SHF_COMPRESSED) != 0)
+ if (elf_compress (xndxscn, 0, 0) < 0)
+ goto elferr;
+
mod->symxndxdata = elf_getdata (xndxscn, NULL);
- if (mod->symxndxdata == NULL)
+ if (mod->symxndxdata == NULL || mod->symxndxdata->d_buf == NULL)
goto elferr;
}
+ shdr = gelf_getshdr (symscn, &shdr_mem);
+ if (shdr == NULL)
+ goto elferr;
+
+ if ((shdr->sh_flags & SHF_COMPRESSED) != 0)
+ if (elf_compress (symscn, 0, 0) < 0)
+ goto elferr;
+
mod->symdata = elf_getdata (symscn, NULL);
- if (mod->symdata == NULL)
+ if (mod->symdata == NULL || mod->symdata->d_buf == NULL)
+ goto elferr;
+
+ // Sanity check number of symbols.
+ shdr = gelf_getshdr (symscn, &shdr_mem);
+ if (shdr == NULL || shdr->sh_entsize == 0
+ || mod->syments > mod->symdata->d_size / shdr->sh_entsize
+ || (size_t) mod->first_global > mod->syments)
goto elferr;
+
+ /* Cache any auxiliary symbol info, when it fails, just ignore aux_sym. */
+ if (aux_symscn != NULL)
+ {
+ aux_cache:
+ /* This does some sanity checks on the string table section. */
+ if (elf_strptr (mod->aux_sym.elf, aux_strshndx, 0) == NULL)
+ {
+ aux_cleanup:
+ mod->aux_syments = 0;
+ elf_end (mod->aux_sym.elf);
+ mod->aux_sym.elf = NULL;
+ /* We thought we had something through shdrs, but it failed...
+ Last ditch, look for dynamic symbols without section headers. */
+ find_dynsym (mod);
+ return;
+ }
+
+ Elf_Scn *aux_strscn = elf_getscn (mod->aux_sym.elf, aux_strshndx);
+ if (aux_strscn == NULL)
+ goto elferr;
+
+ shdr = gelf_getshdr (aux_strscn, &shdr_mem);
+ if (shdr == NULL)
+ goto elferr;
+
+ size_t aux_shstrndx;
+ if (elf_getshdrstrndx (mod->aux_sym.elf, &aux_shstrndx) < 0)
+ goto elferr;
+
+ sname = elf_strptr (mod->aux_sym.elf, aux_shstrndx,
+ shdr->sh_name);
+ if (sname == NULL)
+ goto elferr;
+
+ if (strncmp (sname, ".zdebug", strlen (".zdebug")) == 0)
+ /* Try to uncompress, but it might already have been, an error
+ might just indicate, already uncompressed. */
+ elf_compress_gnu (aux_strscn, 0, 0);
+
+ if ((shdr->sh_flags & SHF_COMPRESSED) != 0)
+ if (elf_compress (aux_strscn, 0, 0) < 0)
+ goto elferr;
+
+ mod->aux_symstrdata = elf_getdata (aux_strscn, NULL);
+ if (mod->aux_symstrdata == NULL || mod->aux_symstrdata->d_buf == NULL)
+ goto aux_cleanup;
+
+ if (aux_xndxscn == NULL)
+ mod->aux_symxndxdata = NULL;
+ else
+ {
+ shdr = gelf_getshdr (aux_xndxscn, &shdr_mem);
+ if (shdr == NULL)
+ goto elferr;
+
+ if ((shdr->sh_flags & SHF_COMPRESSED) != 0)
+ if (elf_compress (aux_xndxscn, 0, 0) < 0)
+ goto elferr;
+
+ mod->aux_symxndxdata = elf_getdata (aux_xndxscn, NULL);
+ if (mod->aux_symxndxdata == NULL
+ || mod->aux_symxndxdata->d_buf == NULL)
+ goto aux_cleanup;
+ }
+
+ shdr = gelf_getshdr (aux_symscn, &shdr_mem);
+ if (shdr == NULL)
+ goto elferr;
+
+ if ((shdr->sh_flags & SHF_COMPRESSED) != 0)
+ if (elf_compress (aux_symscn, 0, 0) < 0)
+ goto elferr;
+
+ mod->aux_symdata = elf_getdata (aux_symscn, NULL);
+ if (mod->aux_symdata == NULL || mod->aux_symdata->d_buf == NULL)
+ goto aux_cleanup;
+
+ // Sanity check number of aux symbols.
+ shdr = gelf_getshdr (aux_symscn, &shdr_mem);
+ if (mod->aux_syments > mod->aux_symdata->d_size / shdr->sh_entsize
+ || (size_t) mod->aux_first_global > mod->aux_syments)
+ goto aux_cleanup;
+ }
}
{
if (mod->ebl == NULL)
{
- find_file (mod);
+ __libdwfl_getelf (mod);
if (mod->elferr != DWFL_E_NOERROR)
return mod->elferr;
static Dwfl_Error
load_dw (Dwfl_Module *mod, struct dwfl_file *debugfile)
{
- if (mod->e_type == ET_REL)
+ if (mod->e_type == ET_REL && !debugfile->relocated)
{
const Dwfl_Callbacks *const cb = mod->dwfl->callbacks;
find_symtab (mod);
Dwfl_Error result = mod->symerr;
if (result == DWFL_E_NOERROR)
- result = __libdwfl_relocate (mod, debugfile->elf);
+ result = __libdwfl_relocate (mod, debugfile->elf, true);
if (result != DWFL_E_NOERROR)
return result;
|| mod->dwerr != DWFL_E_NOERROR) /* Cached previous failure. */
return;
- find_file (mod);
+ __libdwfl_getelf (mod);
mod->dwerr = mod->elferr;
if (mod->dwerr != DWFL_E_NOERROR)
return;
{
case DWFL_E_NOERROR:
mod->debug.elf = mod->main.elf;
- mod->debug.bias = mod->main.bias;
+ mod->debug.address_sync = mod->main.address_sync;
+
+ /* The Dwarf might need an alt debug file, find that now after
+ everything about the debug file has been setup (the
+ find_debuginfo callback might need it). */
+ find_debug_altlink (mod, mod->main.name);
return;
case DWFL_E_NO_DWARF:
{
case DWFL_E_NOERROR:
mod->dwerr = load_dw (mod, &mod->debug);
+ if (mod->dwerr == DWFL_E_NOERROR)
+ {
+ /* The Dwarf might need an alt debug file, find that now after
+ everything about the debug file has been setup (the
+ find_debuginfo callback might need it). */
+ find_debug_altlink (mod, mod->debug.name);
+ return;
+ }
+
break;
case DWFL_E_CB: /* The find_debuginfo hook failed. */
mod->dwerr = __libdwfl_canon_error (mod->dwerr);
}
-
-Elf *
-dwfl_module_getelf (Dwfl_Module *mod, GElf_Addr *loadbase)
-{
- if (mod == NULL)
- return NULL;
-
- find_file (mod);
- if (mod->elferr == DWFL_E_NOERROR)
- {
- *loadbase = mod->main.bias;
- return mod->main.elf;
- }
-
- __libdwfl_seterrno (mod->elferr);
- return NULL;
-}
-INTDEF (dwfl_module_getelf)
-
-
Dwarf *
dwfl_module_getdwarf (Dwfl_Module *mod, Dwarf_Addr *bias)
{
find_dw (mod);
if (mod->dwerr == DWFL_E_NOERROR)
{
- *bias = mod->debug.bias;
+ /* If dwfl_module_getelf was used previously, then partial apply
+ relocation to miscellaneous sections in the debug file too. */
+ if (mod->e_type == ET_REL
+ && mod->main.relocated && ! mod->debug.relocated)
+ {
+ mod->debug.relocated = true;
+ if (mod->debug.elf != mod->main.elf)
+ (void) __libdwfl_relocate (mod, mod->debug.elf, false);
+ }
+
+ *bias = dwfl_adjusted_dwarf_addr (mod, 0);
return mod->dw;
}
find_symtab (mod);
if (mod->symerr == DWFL_E_NOERROR)
- return mod->syments;
+ /* We will skip the auxiliary zero entry if there is another one. */
+ return (mod->syments + mod->aux_syments
+ - (mod->syments > 0 && mod->aux_syments > 0 ? 1 : 0));
__libdwfl_seterrno (mod->symerr);
return -1;
}
INTDEF (dwfl_module_getsymtab)
+
+int
+dwfl_module_getsymtab_first_global (Dwfl_Module *mod)
+{
+ if (mod == NULL)
+ return -1;
+
+ find_symtab (mod);
+ if (mod->symerr == DWFL_E_NOERROR)
+ {
+ /* All local symbols should come before all global symbols. If
+ we have an auxiliary table make sure all the main locals come
+ first, then all aux locals, then all main globals and finally all
+ aux globals. And skip the auxiliary table zero undefined
+ entry. */
+ int skip_aux_zero = (mod->syments > 0 && mod->aux_syments > 0) ? 1 : 0;
+ return mod->first_global + mod->aux_first_global - skip_aux_zero;
+ }
+
+ __libdwfl_seterrno (mod->symerr);
+ return -1;
+}
+INTDEF (dwfl_module_getsymtab_first_global)