| /* ELF emulation code for targets using elf.em. |
| Copyright (C) 1991-2024 Free Software Foundation, Inc. |
| |
| This file is part of the GNU Binutils. |
| |
| This program 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; either version 3 of the License, or |
| (at your option) any later version. |
| |
| This program 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 this program; if not, write to the Free Software |
| Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston, |
| MA 02110-1301, USA. */ |
| |
| #include "sysdep.h" |
| #include "bfd.h" |
| #include "libiberty.h" |
| #include "filenames.h" |
| #include "safe-ctype.h" |
| #include "bfdlink.h" |
| #include "ctf-api.h" |
| #include "ld.h" |
| #include "ldmain.h" |
| #include "ldmisc.h" |
| #include "ldexp.h" |
| #include "ldlang.h" |
| #include "ldfile.h" |
| #include "ldemul.h" |
| #include "ldbuildid.h" |
| #include <ldgram.h> |
| #include "elf-bfd.h" |
| #ifdef HAVE_GLOB |
| #include <glob.h> |
| #endif |
| #include "ldelf.h" |
| #ifdef HAVE_JANSSON |
| #include <jansson.h> |
| #endif |
| |
| struct dt_needed |
| { |
| bfd *by; |
| const char *name; |
| }; |
| |
| /* Style of .note.gnu.build-id section. */ |
| const char *ldelf_emit_note_gnu_build_id; |
| |
| /* Content of .note.package section. */ |
| const char *ldelf_emit_note_fdo_package_metadata; |
| |
| /* These variables are required to pass information back and forth |
| between after_open and check_needed and stat_needed and vercheck. */ |
| |
| static struct bfd_link_needed_list *global_needed; |
| static lang_input_statement_type *global_found; |
| static struct stat global_stat; |
| static struct bfd_link_needed_list *global_vercheck_needed; |
| static bool global_vercheck_failed; |
| |
| void |
| ldelf_after_parse (void) |
| { |
| if (bfd_link_pie (&link_info)) |
| link_info.flags_1 |= (bfd_vma) DF_1_PIE; |
| |
| if (bfd_link_executable (&link_info) |
| && link_info.nointerp) |
| { |
| if (link_info.dynamic_undefined_weak > 0) |
| queue_unknown_cmdline_warning ("-z dynamic-undefined-weak"); |
| link_info.dynamic_undefined_weak = 0; |
| } |
| |
| /* Disable DT_RELR if not building PIE nor shared library. */ |
| if (!bfd_link_pic (&link_info)) |
| link_info.enable_dt_relr = 0; |
| |
| /* Add 3 spare tags for DT_RELR, DT_RELRSZ and DT_RELRENT. */ |
| if (link_info.enable_dt_relr) |
| link_info.spare_dynamic_tags += 3; |
| |
| after_parse_default (); |
| if (link_info.commonpagesize > link_info.maxpagesize) |
| { |
| if (!link_info.commonpagesize_is_set) |
| link_info.commonpagesize = link_info.maxpagesize; |
| else if (!link_info.maxpagesize_is_set) |
| link_info.maxpagesize = link_info.commonpagesize; |
| else |
| einfo (_("%F%P: common page size (0x%v) > maximum page size (0x%v)\n"), |
| link_info.commonpagesize, link_info.maxpagesize); |
| } |
| } |
| |
| /* Handle the generation of DT_NEEDED tags. */ |
| |
| bool |
| ldelf_load_symbols (lang_input_statement_type *entry) |
| { |
| int link_class = 0; |
| |
| /* Tell the ELF linker that we don't want the output file to have a |
| DT_NEEDED entry for this file, unless it is used to resolve |
| references in a regular object. */ |
| if (entry->flags.add_DT_NEEDED_for_regular) |
| link_class = DYN_AS_NEEDED; |
| |
| /* Tell the ELF linker that we don't want the output file to have a |
| DT_NEEDED entry for any dynamic library in DT_NEEDED tags from |
| this file at all. */ |
| if (!entry->flags.add_DT_NEEDED_for_dynamic) |
| link_class |= DYN_NO_ADD_NEEDED; |
| |
| if (entry->flags.just_syms |
| && (bfd_get_file_flags (entry->the_bfd) & DYNAMIC) != 0) |
| einfo (_("%F%P: %pB: --just-symbols may not be used on DSO\n"), |
| entry->the_bfd); |
| |
| if (link_class == 0 |
| || (bfd_get_file_flags (entry->the_bfd) & DYNAMIC) == 0) |
| return false; |
| |
| bfd_elf_set_dyn_lib_class (entry->the_bfd, |
| (enum dynamic_lib_link_class) link_class); |
| |
| /* Continue on with normal load_symbols processing. */ |
| return false; |
| } |
| |
| /* On Linux, it's possible to have different versions of the same |
| shared library linked against different versions of libc. The |
| dynamic linker somehow tags which libc version to use in |
| /etc/ld.so.cache, and, based on the libc that it sees in the |
| executable, chooses which version of the shared library to use. |
| |
| We try to do a similar check here by checking whether this shared |
| library needs any other shared libraries which may conflict with |
| libraries we have already included in the link. If it does, we |
| skip it, and try to find another shared library farther on down the |
| link path. |
| |
| This is called via lang_for_each_input_file. |
| GLOBAL_VERCHECK_NEEDED is the list of objects needed by the object |
| which we are checking. This sets GLOBAL_VERCHECK_FAILED if we find |
| a conflicting version. */ |
| |
| static void |
| ldelf_vercheck (lang_input_statement_type *s) |
| { |
| const char *soname; |
| struct bfd_link_needed_list *l; |
| |
| if (global_vercheck_failed) |
| return; |
| if (s->the_bfd == NULL |
| || (bfd_get_file_flags (s->the_bfd) & DYNAMIC) == 0) |
| return; |
| |
| soname = bfd_elf_get_dt_soname (s->the_bfd); |
| if (soname == NULL) |
| soname = lbasename (bfd_get_filename (s->the_bfd)); |
| |
| for (l = global_vercheck_needed; l != NULL; l = l->next) |
| { |
| const char *suffix; |
| |
| if (filename_cmp (soname, l->name) == 0) |
| { |
| /* Probably can't happen, but it's an easy check. */ |
| continue; |
| } |
| |
| if (strchr (l->name, '/') != NULL) |
| continue; |
| |
| suffix = strstr (l->name, ".so."); |
| if (suffix == NULL) |
| continue; |
| |
| suffix += sizeof ".so." - 1; |
| |
| if (filename_ncmp (soname, l->name, suffix - l->name) == 0) |
| { |
| /* Here we know that S is a dynamic object FOO.SO.VER1, and |
| the object we are considering needs a dynamic object |
| FOO.SO.VER2, and VER1 and VER2 are different. This |
| appears to be a version mismatch, so we tell the caller |
| to try a different version of this library. */ |
| global_vercheck_failed = true; |
| return; |
| } |
| } |
| } |
| |
| |
| /* See if an input file matches a DT_NEEDED entry by running stat on |
| the file. */ |
| |
| static void |
| ldelf_stat_needed (lang_input_statement_type *s) |
| { |
| struct stat st; |
| const char *suffix; |
| const char *soname; |
| |
| if (global_found != NULL) |
| return; |
| if (s->the_bfd == NULL) |
| return; |
| |
| /* If this input file was an as-needed entry, and wasn't found to be |
| needed at the stage it was linked, then don't say we have loaded it. */ |
| if ((bfd_elf_get_dyn_lib_class (s->the_bfd) & DYN_AS_NEEDED) != 0) |
| return; |
| |
| if (bfd_stat (s->the_bfd, &st) != 0) |
| { |
| einfo (_("%P: %pB: bfd_stat failed: %E\n"), s->the_bfd); |
| return; |
| } |
| |
| /* Some operating systems, e.g. Windows, do not provide a meaningful |
| st_ino; they always set it to zero. (Windows does provide a |
| meaningful st_dev.) Do not indicate a duplicate library in that |
| case. While there is no guarantee that a system that provides |
| meaningful inode numbers will never set st_ino to zero, this is |
| merely an optimization, so we do not need to worry about false |
| negatives. */ |
| if (st.st_dev == global_stat.st_dev |
| && st.st_ino == global_stat.st_ino |
| && st.st_ino != 0) |
| { |
| global_found = s; |
| return; |
| } |
| |
| /* We issue a warning if it looks like we are including two |
| different versions of the same shared library. For example, |
| there may be a problem if -lc picks up libc.so.6 but some other |
| shared library has a DT_NEEDED entry of libc.so.5. This is a |
| heuristic test, and it will only work if the name looks like |
| NAME.so.VERSION. FIXME: Depending on file names is error-prone. |
| If we really want to issue warnings about mixing version numbers |
| of shared libraries, we need to find a better way. */ |
| |
| if (strchr (global_needed->name, '/') != NULL) |
| return; |
| suffix = strstr (global_needed->name, ".so."); |
| if (suffix == NULL) |
| return; |
| suffix += sizeof ".so." - 1; |
| |
| soname = bfd_elf_get_dt_soname (s->the_bfd); |
| if (soname == NULL) |
| soname = lbasename (s->filename); |
| |
| if (filename_ncmp (soname, global_needed->name, |
| suffix - global_needed->name) == 0) |
| einfo (_("%P: warning: %s, needed by %pB, may conflict with %s\n"), |
| global_needed->name, global_needed->by, soname); |
| } |
| |
| /* This function is called for each possible name for a dynamic object |
| named by a DT_NEEDED entry. The FORCE parameter indicates whether |
| to skip the check for a conflicting version. */ |
| |
| static bool |
| ldelf_try_needed (struct dt_needed *needed, int force, int is_linux) |
| { |
| bfd *abfd; |
| const char *name = needed->name; |
| const char *soname; |
| int link_class; |
| |
| abfd = bfd_openr (name, bfd_get_target (link_info.output_bfd)); |
| if (abfd == NULL) |
| { |
| if (verbose) |
| info_msg (_("attempt to open %s failed\n"), name); |
| return false; |
| } |
| |
| track_dependency_files (name); |
| |
| /* Linker needs to decompress sections. */ |
| abfd->flags |= BFD_DECOMPRESS; |
| |
| if (! bfd_check_format (abfd, bfd_object)) |
| { |
| bfd_close (abfd); |
| return false; |
| } |
| if ((bfd_get_file_flags (abfd) & DYNAMIC) == 0) |
| { |
| bfd_close (abfd); |
| return false; |
| } |
| |
| /* For DT_NEEDED, they have to match. */ |
| if (abfd->xvec != link_info.output_bfd->xvec) |
| { |
| bfd_close (abfd); |
| return false; |
| } |
| |
| /* Check whether this object would include any conflicting library |
| versions. If FORCE is set, then we skip this check; we use this |
| the second time around, if we couldn't find any compatible |
| instance of the shared library. */ |
| |
| if (!force) |
| { |
| struct bfd_link_needed_list *needs; |
| |
| if (! bfd_elf_get_bfd_needed_list (abfd, &needs)) |
| einfo (_("%F%P: %pB: bfd_elf_get_bfd_needed_list failed: %E\n"), abfd); |
| |
| if (needs != NULL) |
| { |
| global_vercheck_needed = needs; |
| global_vercheck_failed = false; |
| lang_for_each_input_file (ldelf_vercheck); |
| if (global_vercheck_failed) |
| { |
| bfd_close (abfd); |
| /* Return FALSE to force the caller to move on to try |
| another file on the search path. */ |
| return false; |
| } |
| |
| /* But wait! It gets much worse. On Linux, if a shared |
| library does not use libc at all, we are supposed to skip |
| it the first time around in case we encounter a shared |
| library later on with the same name which does use the |
| version of libc that we want. This is much too horrible |
| to use on any system other than Linux. */ |
| if (is_linux) |
| { |
| struct bfd_link_needed_list *l; |
| |
| for (l = needs; l != NULL; l = l->next) |
| if (startswith (l->name, "libc.so")) |
| break; |
| if (l == NULL) |
| { |
| bfd_close (abfd); |
| return false; |
| } |
| } |
| } |
| } |
| |
| /* We've found a dynamic object matching the DT_NEEDED entry. */ |
| |
| /* We have already checked that there is no other input file of the |
| same name. We must now check again that we are not including the |
| same file twice. We need to do this because on many systems |
| libc.so is a symlink to, e.g., libc.so.1. The SONAME entry will |
| reference libc.so.1. If we have already included libc.so, we |
| don't want to include libc.so.1 if they are the same file, and we |
| can only check that using stat. */ |
| |
| if (bfd_stat (abfd, &global_stat) != 0) |
| einfo (_("%F%P: %pB: bfd_stat failed: %E\n"), abfd); |
| |
| /* First strip off everything before the last '/'. */ |
| soname = lbasename (bfd_get_filename (abfd)); |
| |
| if (verbose) |
| info_msg (_("found %s at %s\n"), soname, name); |
| |
| global_found = NULL; |
| lang_for_each_input_file (ldelf_stat_needed); |
| if (global_found != NULL) |
| { |
| /* Return TRUE to indicate that we found the file, even though |
| we aren't going to do anything with it. */ |
| return true; |
| } |
| |
| /* Specify the soname to use. */ |
| bfd_elf_set_dt_needed_name (abfd, soname); |
| |
| /* Tell the ELF linker that we don't want the output file to have a |
| DT_NEEDED entry for this file, unless it is used to resolve |
| references in a regular object. */ |
| link_class = DYN_DT_NEEDED; |
| |
| /* Tell the ELF linker that we don't want the output file to have a |
| DT_NEEDED entry for this file at all if the entry is from a file |
| with DYN_NO_ADD_NEEDED. */ |
| if (needed->by != NULL |
| && (bfd_elf_get_dyn_lib_class (needed->by) & DYN_NO_ADD_NEEDED) != 0) |
| link_class |= DYN_NO_NEEDED | DYN_NO_ADD_NEEDED; |
| |
| bfd_elf_set_dyn_lib_class (abfd, (enum dynamic_lib_link_class) link_class); |
| |
| *link_info.input_bfds_tail = abfd; |
| link_info.input_bfds_tail = &abfd->link.next; |
| |
| /* Add this file into the symbol table. */ |
| if (! bfd_link_add_symbols (abfd, &link_info)) |
| einfo (_("%F%P: %pB: error adding symbols: %E\n"), abfd); |
| |
| return true; |
| } |
| |
| /* Search for a needed file in a path. */ |
| |
| static bool |
| ldelf_search_needed (const char *path, struct dt_needed *n, int force, |
| int is_linux, int elfsize) |
| { |
| const char *s; |
| const char *name = n->name; |
| size_t len; |
| struct dt_needed needed; |
| |
| if (name[0] == '/') |
| return ldelf_try_needed (n, force, is_linux); |
| |
| if (path == NULL || *path == '\0') |
| return false; |
| |
| needed.by = n->by; |
| needed.name = n->name; |
| |
| len = strlen (name); |
| while (1) |
| { |
| unsigned offset = 0; |
| char * var; |
| char *filename, *sset; |
| |
| s = strchr (path, config.rpath_separator); |
| if (s == NULL) |
| s = path + strlen (path); |
| |
| #if HAVE_DOS_BASED_FILE_SYSTEM |
| /* Assume a match on the second char is part of drive specifier. */ |
| else if (config.rpath_separator == ':' |
| && s == path + 1 |
| && ISALPHA (*path)) |
| { |
| s = strchr (s + 1, config.rpath_separator); |
| if (s == NULL) |
| s = path + strlen (path); |
| } |
| #endif |
| filename = (char *) xmalloc (s - path + len + 2); |
| if (s == path) |
| sset = filename; |
| else |
| { |
| memcpy (filename, path, s - path); |
| filename[s - path] = '/'; |
| sset = filename + (s - path) + 1; |
| } |
| strcpy (sset, name); |
| |
| /* PR 20535: Support the same pseudo-environment variables that |
| are supported by ld.so. Namely, $ORIGIN, $LIB and $PLATFORM. |
| Since there can be more than one occurrence of these tokens in |
| the path we loop until no more are found. Since we might not |
| be able to substitute some of the tokens we maintain an offset |
| into the filename for where we should begin our scan. */ |
| while ((var = strchr (filename + offset, '$')) != NULL) |
| { |
| /* The ld.so manual page does not say, but I am going to assume that |
| these tokens are terminated by a directory separator character |
| (/) or the end of the string. There is also an implication that |
| $ORIGIN should only be used at the start of a path, but that is |
| not enforced here. |
| |
| The ld.so manual page also states that it allows ${ORIGIN}, |
| ${LIB} and ${PLATFORM}, so these are supported as well. |
| |
| FIXME: The code could be a lot cleverer about allocating space |
| for the processed string. */ |
| char * end = strchr (var, '/'); |
| const char *replacement = NULL; |
| char * v = var + 1; |
| char * freeme = NULL; |
| unsigned flen = strlen (filename); |
| |
| if (end != NULL) |
| /* Temporarily terminate the filename at the end of the token. */ |
| * end = 0; |
| |
| if (*v == '{') |
| ++ v; |
| switch (*v++) |
| { |
| case 'O': |
| if (strcmp (v, "RIGIN") == 0 || strcmp (v, "RIGIN}") == 0) |
| { |
| /* ORIGIN - replace with the full path to the directory |
| containing the program or shared object. */ |
| if (needed.by == NULL) |
| { |
| if (link_info.output_bfd == NULL) |
| { |
| break; |
| } |
| else |
| replacement = bfd_get_filename (link_info.output_bfd); |
| } |
| else |
| replacement = bfd_get_filename (needed.by); |
| |
| if (replacement) |
| { |
| char * slash; |
| |
| if (replacement[0] == '/') |
| freeme = xstrdup (replacement); |
| else |
| { |
| char * current_dir = getpwd (); |
| size_t cdir_len = strlen (current_dir); |
| size_t rep_len = strlen (replacement); |
| freeme = xmalloc (cdir_len + rep_len + 2); |
| memcpy (freeme, current_dir, cdir_len); |
| freeme[cdir_len] = '/'; |
| memcpy (freeme + cdir_len + 1, |
| replacement, rep_len + 1); |
| } |
| |
| replacement = freeme; |
| if ((slash = strrchr (replacement, '/')) != NULL) |
| * slash = 0; |
| } |
| } |
| break; |
| |
| case 'L': |
| if (strcmp (v, "IB") == 0 || strcmp (v, "IB}") == 0) |
| { |
| /* LIB - replace with "lib" in 32-bit environments |
| and "lib64" in 64-bit environments. */ |
| |
| switch (elfsize) |
| { |
| case 32: replacement = "lib"; break; |
| case 64: replacement = "lib64"; break; |
| default: |
| abort (); |
| } |
| } |
| break; |
| |
| case 'P': |
| /* Supporting $PLATFORM in a cross-hosted environment is not |
| possible. Supporting it in a native environment involves |
| loading the <sys/auxv.h> header file which loads the |
| system <elf.h> header file, which conflicts with the |
| "include/elf/mips.h" header file. */ |
| /* Fall through. */ |
| default: |
| break; |
| } |
| |
| if (replacement) |
| { |
| char * filename2 = xmalloc (flen + strlen (replacement)); |
| |
| if (end) |
| { |
| sprintf (filename2, "%.*s%s/%s", |
| (int)(var - filename), filename, |
| replacement, end + 1); |
| offset = (var - filename) + 1 + strlen (replacement); |
| } |
| else |
| { |
| sprintf (filename2, "%.*s%s", |
| (int)(var - filename), filename, |
| replacement); |
| offset = var - filename + strlen (replacement); |
| } |
| |
| free (filename); |
| filename = filename2; |
| /* There is no need to restore the path separator (when |
| end != NULL) as we have replaced the entire string. */ |
| } |
| else |
| { |
| if (verbose) |
| /* We only issue an "unrecognised" message in verbose mode |
| as the $<foo> token might be a legitimate component of |
| a path name in the target's file system. */ |
| info_msg (_("unrecognised or unsupported token " |
| "'%s' in search path\n"), var); |
| if (end) |
| /* Restore the path separator. */ |
| * end = '/'; |
| |
| /* PR 20784: Make sure that we resume the scan *after* |
| the token that we could not replace. */ |
| offset = (var + 1) - filename; |
| } |
| |
| free (freeme); |
| } |
| |
| needed.name = filename; |
| |
| if (ldelf_try_needed (&needed, force, is_linux)) |
| return true; |
| |
| free (filename); |
| |
| if (*s == '\0') |
| break; |
| path = s + 1; |
| } |
| |
| return false; |
| } |
| |
| /* Prefix the sysroot to absolute paths in PATH, a string containing |
| paths separated by config.rpath_separator. If running on a DOS |
| file system, paths containing a drive spec won't have the sysroot |
| prefix added, unless the sysroot also specifies the same drive. */ |
| |
| static const char * |
| ldelf_add_sysroot (const char *path) |
| { |
| size_t len, extra; |
| const char *p; |
| char *ret, *q; |
| int dos_drive_sysroot = HAS_DRIVE_SPEC (ld_sysroot); |
| |
| len = strlen (ld_sysroot); |
| for (extra = 0, p = path; ; ) |
| { |
| int dos_drive = HAS_DRIVE_SPEC (p); |
| |
| if (dos_drive) |
| p += 2; |
| if (IS_DIR_SEPARATOR (*p) |
| && (!dos_drive |
| || (dos_drive_sysroot |
| && ld_sysroot[0] == p[-2]))) |
| { |
| if (dos_drive && dos_drive_sysroot) |
| extra += len - 2; |
| else |
| extra += len; |
| } |
| p = strchr (p, config.rpath_separator); |
| if (!p) |
| break; |
| ++p; |
| } |
| |
| ret = xmalloc (strlen (path) + extra + 1); |
| |
| for (q = ret, p = path; ; ) |
| { |
| const char *end; |
| int dos_drive = HAS_DRIVE_SPEC (p); |
| |
| if (dos_drive) |
| { |
| *q++ = *p++; |
| *q++ = *p++; |
| } |
| if (IS_DIR_SEPARATOR (*p) |
| && (!dos_drive |
| || (dos_drive_sysroot |
| && ld_sysroot[0] == p[-2]))) |
| { |
| if (dos_drive && dos_drive_sysroot) |
| { |
| strcpy (q, ld_sysroot + 2); |
| q += len - 2; |
| } |
| else |
| { |
| strcpy (q, ld_sysroot); |
| q += len; |
| } |
| } |
| end = strchr (p, config.rpath_separator); |
| if (end) |
| { |
| size_t n = end - p + 1; |
| strncpy (q, p, n); |
| q += n; |
| p += n; |
| } |
| else |
| { |
| strcpy (q, p); |
| break; |
| } |
| } |
| |
| return ret; |
| } |
| |
| /* Read the system search path the FreeBSD way rather than the Linux way. */ |
| #ifdef HAVE_ELF_HINTS_H |
| #include <elf-hints.h> |
| #else |
| #include "elf-hints-local.h" |
| #endif |
| |
| static bool |
| ldelf_check_ld_elf_hints (const struct bfd_link_needed_list *l, int force, |
| int elfsize) |
| { |
| static bool initialized; |
| static const char *ld_elf_hints; |
| struct dt_needed needed; |
| |
| if (!initialized) |
| { |
| FILE *f; |
| char *tmppath; |
| |
| tmppath = concat (ld_sysroot, _PATH_ELF_HINTS, (const char *) NULL); |
| f = fopen (tmppath, FOPEN_RB); |
| free (tmppath); |
| if (f != NULL) |
| { |
| struct elfhints_hdr hdr; |
| |
| if (fread (&hdr, 1, sizeof (hdr), f) == sizeof (hdr) |
| && hdr.magic == ELFHINTS_MAGIC |
| && hdr.version == 1) |
| { |
| if (fseek (f, hdr.strtab + hdr.dirlist, SEEK_SET) != -1) |
| { |
| char *b; |
| |
| b = xmalloc (hdr.dirlistlen + 1); |
| if (fread (b, 1, hdr.dirlistlen + 1, f) == |
| hdr.dirlistlen + 1) |
| ld_elf_hints = ldelf_add_sysroot (b); |
| |
| free (b); |
| } |
| } |
| fclose (f); |
| } |
| |
| initialized = true; |
| } |
| |
| if (ld_elf_hints == NULL) |
| return false; |
| |
| needed.by = l->by; |
| needed.name = l->name; |
| return ldelf_search_needed (ld_elf_hints, &needed, force, false, elfsize); |
| } |
| |
| /* For a native linker, check the file /etc/ld.so.conf for directories |
| in which we may find shared libraries. /etc/ld.so.conf is really |
| only meaningful on Linux. */ |
| |
| struct ldelf_ld_so_conf |
| { |
| char *path; |
| size_t len, alloc; |
| }; |
| |
| static bool |
| ldelf_parse_ld_so_conf (struct ldelf_ld_so_conf *, const char *); |
| |
| static void |
| ldelf_parse_ld_so_conf_include (struct ldelf_ld_so_conf *info, |
| const char *filename, |
| const char *pattern) |
| { |
| char *newp = NULL; |
| #ifdef HAVE_GLOB |
| glob_t gl; |
| #endif |
| |
| if (pattern[0] != '/') |
| { |
| char *p = strrchr (filename, '/'); |
| size_t patlen = strlen (pattern) + 1; |
| |
| newp = xmalloc (p - filename + 1 + patlen); |
| memcpy (newp, filename, p - filename + 1); |
| memcpy (newp + (p - filename + 1), pattern, patlen); |
| pattern = newp; |
| } |
| |
| #ifdef HAVE_GLOB |
| if (glob (pattern, 0, NULL, &gl) == 0) |
| { |
| size_t i; |
| |
| for (i = 0; i < gl.gl_pathc; ++i) |
| ldelf_parse_ld_so_conf (info, gl.gl_pathv[i]); |
| globfree (&gl); |
| } |
| #else |
| /* If we do not have glob, treat the pattern as a literal filename. */ |
| ldelf_parse_ld_so_conf (info, pattern); |
| #endif |
| |
| free (newp); |
| } |
| |
| static bool |
| ldelf_parse_ld_so_conf (struct ldelf_ld_so_conf *info, const char *filename) |
| { |
| FILE *f = fopen (filename, FOPEN_RT); |
| char *line; |
| size_t linelen; |
| |
| if (f == NULL) |
| return false; |
| |
| linelen = 256; |
| line = xmalloc (linelen); |
| do |
| { |
| char *p = line, *q; |
| |
| /* Normally this would use getline(3), but we need to be portable. */ |
| while ((q = fgets (p, linelen - (p - line), f)) != NULL |
| && strlen (q) == linelen - (p - line) - 1 |
| && line[linelen - 2] != '\n') |
| { |
| line = xrealloc (line, 2 * linelen); |
| p = line + linelen - 1; |
| linelen += linelen; |
| } |
| |
| if (q == NULL && p == line) |
| break; |
| |
| p = strchr (line, '\n'); |
| if (p) |
| *p = '\0'; |
| |
| /* Because the file format does not know any form of quoting we |
| can search forward for the next '#' character and if found |
| make it terminating the line. */ |
| p = strchr (line, '#'); |
| if (p) |
| *p = '\0'; |
| |
| /* Remove leading whitespace. NUL is no whitespace character. */ |
| p = line; |
| while (*p == ' ' || *p == '\f' || *p == '\r' || *p == '\t' || *p == '\v') |
| ++p; |
| |
| /* If the line is blank it is ignored. */ |
| if (p[0] == '\0') |
| continue; |
| |
| if (startswith (p, "include") && (p[7] == ' ' || p[7] == '\t')) |
| { |
| char *dir, c; |
| p += 8; |
| do |
| { |
| while (*p == ' ' || *p == '\t') |
| ++p; |
| |
| if (*p == '\0') |
| break; |
| |
| dir = p; |
| |
| while (*p != ' ' && *p != '\t' && *p) |
| ++p; |
| |
| c = *p; |
| *p++ = '\0'; |
| if (dir[0] != '\0') |
| ldelf_parse_ld_so_conf_include (info, filename, dir); |
| } |
| while (c != '\0'); |
| } |
| else |
| { |
| char *dir = p; |
| while (*p && *p != '=' && *p != ' ' && *p != '\t' && *p != '\f' |
| && *p != '\r' && *p != '\v') |
| ++p; |
| |
| while (p != dir && p[-1] == '/') |
| --p; |
| if (info->path == NULL) |
| { |
| info->alloc = p - dir + 1 + 256; |
| info->path = xmalloc (info->alloc); |
| info->len = 0; |
| } |
| else |
| { |
| if (info->len + 1 + (p - dir) >= info->alloc) |
| { |
| info->alloc += p - dir + 256; |
| info->path = xrealloc (info->path, info->alloc); |
| } |
| info->path[info->len++] = config.rpath_separator; |
| } |
| memcpy (info->path + info->len, dir, p - dir); |
| info->len += p - dir; |
| info->path[info->len] = '\0'; |
| } |
| } |
| while (! feof (f)); |
| free (line); |
| fclose (f); |
| return true; |
| } |
| |
| static bool |
| ldelf_check_ld_so_conf (const struct bfd_link_needed_list *l, int force, |
| int elfsize, const char *prefix) |
| { |
| static bool initialized; |
| static const char *ld_so_conf; |
| struct dt_needed needed; |
| |
| if (! initialized) |
| { |
| char *tmppath; |
| struct ldelf_ld_so_conf info; |
| |
| info.path = NULL; |
| info.len = info.alloc = 0; |
| tmppath = concat (ld_sysroot, prefix, "/etc/ld.so.conf", |
| (const char *) NULL); |
| if (!ldelf_parse_ld_so_conf (&info, tmppath)) |
| { |
| free (tmppath); |
| tmppath = concat (ld_sysroot, "/etc/ld.so.conf", |
| (const char *) NULL); |
| ldelf_parse_ld_so_conf (&info, tmppath); |
| } |
| free (tmppath); |
| |
| if (info.path) |
| { |
| ld_so_conf = ldelf_add_sysroot (info.path); |
| free (info.path); |
| } |
| initialized = true; |
| } |
| |
| if (ld_so_conf == NULL) |
| return false; |
| |
| |
| needed.by = l->by; |
| needed.name = l->name; |
| return ldelf_search_needed (ld_so_conf, &needed, force, true, elfsize); |
| } |
| |
| /* See if an input file matches a DT_NEEDED entry by name. */ |
| |
| static void |
| ldelf_check_needed (lang_input_statement_type *s) |
| { |
| const char *soname; |
| |
| /* Stop looking if we've found a loaded lib. */ |
| if (global_found != NULL |
| && (bfd_elf_get_dyn_lib_class (global_found->the_bfd) |
| & DYN_AS_NEEDED) == 0) |
| return; |
| |
| if (s->filename == NULL || s->the_bfd == NULL) |
| return; |
| |
| /* Don't look for a second non-loaded as-needed lib. */ |
| if (global_found != NULL |
| && (bfd_elf_get_dyn_lib_class (s->the_bfd) & DYN_AS_NEEDED) != 0) |
| return; |
| |
| if (filename_cmp (s->filename, global_needed->name) == 0) |
| { |
| global_found = s; |
| return; |
| } |
| |
| if (s->flags.search_dirs) |
| { |
| const char *f = strrchr (s->filename, '/'); |
| if (f != NULL |
| && filename_cmp (f + 1, global_needed->name) == 0) |
| { |
| global_found = s; |
| return; |
| } |
| } |
| |
| soname = bfd_elf_get_dt_soname (s->the_bfd); |
| if (soname != NULL |
| && filename_cmp (soname, global_needed->name) == 0) |
| { |
| global_found = s; |
| return; |
| } |
| } |
| |
| static void |
| ldelf_handle_dt_needed (struct elf_link_hash_table *htab, |
| int use_libpath, int native, int is_linux, |
| int is_freebsd, int elfsize, const char *prefix) |
| { |
| struct bfd_link_needed_list *needed, *l; |
| bfd *abfd; |
| bfd **save_input_bfd_tail; |
| |
| /* Get the list of files which appear in DT_NEEDED entries in |
| dynamic objects included in the link (often there will be none). |
| For each such file, we want to track down the corresponding |
| library, and include the symbol table in the link. This is what |
| the runtime dynamic linker will do. Tracking the files down here |
| permits one dynamic object to include another without requiring |
| special action by the person doing the link. Note that the |
| needed list can actually grow while we are stepping through this |
| loop. */ |
| save_input_bfd_tail = link_info.input_bfds_tail; |
| needed = bfd_elf_get_needed_list (link_info.output_bfd, &link_info); |
| for (l = needed; l != NULL; l = l->next) |
| { |
| struct bfd_link_needed_list *ll; |
| struct dt_needed n, nn; |
| int force; |
| |
| /* If the lib that needs this one was --as-needed and wasn't |
| found to be needed, then this lib isn't needed either. */ |
| if (l->by != NULL |
| && (bfd_elf_get_dyn_lib_class (l->by) & DYN_AS_NEEDED) != 0) |
| continue; |
| |
| /* Skip the lib if --no-copy-dt-needed-entries and when we are |
| handling DT_NEEDED entries or --allow-shlib-undefined is in |
| effect. */ |
| if (l->by != NULL |
| && (htab->handling_dt_needed |
| || link_info.unresolved_syms_in_shared_libs == RM_IGNORE) |
| && (bfd_elf_get_dyn_lib_class (l->by) & DYN_NO_ADD_NEEDED) != 0) |
| continue; |
| |
| /* If we've already seen this file, skip it. */ |
| for (ll = needed; ll != l; ll = ll->next) |
| if ((ll->by == NULL |
| || (bfd_elf_get_dyn_lib_class (ll->by) & DYN_AS_NEEDED) == 0) |
| && strcmp (ll->name, l->name) == 0) |
| break; |
| if (ll != l) |
| continue; |
| |
| /* See if this file was included in the link explicitly. */ |
| global_needed = l; |
| global_found = NULL; |
| lang_for_each_input_file (ldelf_check_needed); |
| if (global_found != NULL |
| && (bfd_elf_get_dyn_lib_class (global_found->the_bfd) |
| & DYN_AS_NEEDED) == 0) |
| continue; |
| |
| n.by = l->by; |
| n.name = l->name; |
| nn.by = l->by; |
| if (verbose) |
| info_msg (_("%s needed by %pB\n"), l->name, l->by); |
| |
| /* As-needed libs specified on the command line (or linker script) |
| take priority over libs found in search dirs. */ |
| if (global_found != NULL) |
| { |
| nn.name = global_found->filename; |
| if (ldelf_try_needed (&nn, true, is_linux)) |
| continue; |
| } |
| |
| /* We need to find this file and include the symbol table. We |
| want to search for the file in the same way that the dynamic |
| linker will search. That means that we want to use |
| rpath_link, rpath, then the environment variable |
| LD_LIBRARY_PATH (native only), then the DT_RPATH/DT_RUNPATH |
| entries (native only), then the linker script LIB_SEARCH_DIRS. |
| We do not search using the -L arguments. |
| |
| We search twice. The first time, we skip objects which may |
| introduce version mismatches. The second time, we force |
| their use. See ldelf_vercheck comment. */ |
| for (force = 0; force < 2; force++) |
| { |
| size_t len; |
| search_dirs_type *search; |
| const char *path; |
| struct bfd_link_needed_list *rp; |
| int found; |
| |
| if (ldelf_search_needed (command_line.rpath_link, &n, force, |
| is_linux, elfsize)) |
| break; |
| |
| if (use_libpath) |
| { |
| path = command_line.rpath; |
| if (path) |
| { |
| path = ldelf_add_sysroot (path); |
| found = ldelf_search_needed (path, &n, force, |
| is_linux, elfsize); |
| free ((char *) path); |
| if (found) |
| break; |
| } |
| } |
| if (native) |
| { |
| if (command_line.rpath_link == NULL |
| && command_line.rpath == NULL) |
| { |
| path = (const char *) getenv ("LD_RUN_PATH"); |
| if (path |
| && ldelf_search_needed (path, &n, force, |
| is_linux, elfsize)) |
| break; |
| } |
| path = (const char *) getenv ("LD_LIBRARY_PATH"); |
| if (path |
| && ldelf_search_needed (path, &n, force, |
| is_linux, elfsize)) |
| break; |
| } |
| if (use_libpath) |
| { |
| found = 0; |
| rp = bfd_elf_get_runpath_list (link_info.output_bfd, &link_info); |
| for (; !found && rp != NULL; rp = rp->next) |
| { |
| path = ldelf_add_sysroot (rp->name); |
| found = (rp->by == l->by |
| && ldelf_search_needed (path, &n, force, |
| is_linux, elfsize)); |
| free ((char *) path); |
| } |
| if (found) |
| break; |
| |
| if (is_freebsd |
| && ldelf_check_ld_elf_hints (l, force, elfsize)) |
| break; |
| |
| if (is_linux |
| && ldelf_check_ld_so_conf (l, force, elfsize, prefix)) |
| break; |
| } |
| |
| len = strlen (l->name); |
| for (search = search_head; search != NULL; search = search->next) |
| { |
| char *filename; |
| |
| if (search->source != search_dir_linker_script) |
| continue; |
| filename = (char *) xmalloc (strlen (search->name) + len + 2); |
| sprintf (filename, "%s/%s", search->name, l->name); |
| nn.name = filename; |
| if (ldelf_try_needed (&nn, force, is_linux)) |
| break; |
| free (filename); |
| } |
| if (search != NULL) |
| break; |
| } |
| |
| if (force < 2) |
| continue; |
| |
| einfo (_("%P: warning: %s, needed by %pB, not found " |
| "(try using -rpath or -rpath-link)\n"), |
| l->name, l->by); |
| } |
| |
| /* Don't add DT_NEEDED when loading shared objects from DT_NEEDED for |
| plugin symbol resolution while handling DT_NEEDED entries. */ |
| if (!htab->handling_dt_needed) |
| for (abfd = link_info.input_bfds; abfd; abfd = abfd->link.next) |
| if (bfd_get_format (abfd) == bfd_object |
| && ((abfd->flags) & DYNAMIC) != 0 |
| && bfd_get_flavour (abfd) == bfd_target_elf_flavour |
| && (elf_dyn_lib_class (abfd) & (DYN_AS_NEEDED | DYN_NO_NEEDED)) == 0 |
| && elf_dt_name (abfd) != NULL) |
| { |
| if (bfd_elf_add_dt_needed_tag (abfd, &link_info) < 0) |
| einfo (_("%F%P: failed to add DT_NEEDED dynamic tag\n")); |
| } |
| |
| link_info.input_bfds_tail = save_input_bfd_tail; |
| *save_input_bfd_tail = NULL; |
| } |
| |
| /* This is called before calling plugin 'all symbols read' hook. */ |
| |
| void |
| ldelf_before_plugin_all_symbols_read (int use_libpath, int native, |
| int is_linux, int is_freebsd, |
| int elfsize, const char *prefix) |
| { |
| struct elf_link_hash_table *htab = elf_hash_table (&link_info); |
| |
| if (!link_info.lto_plugin_active |
| || !is_elf_hash_table (&htab->root)) |
| return; |
| |
| htab->handling_dt_needed = true; |
| ldelf_handle_dt_needed (htab, use_libpath, native, is_linux, |
| is_freebsd, elfsize, prefix); |
| htab->handling_dt_needed = false; |
| } |
| |
| /* This is called after all the input files have been opened and all |
| symbols have been loaded. */ |
| |
| void |
| ldelf_after_open (int use_libpath, int native, int is_linux, int is_freebsd, |
| int elfsize, const char *prefix) |
| { |
| struct elf_link_hash_table *htab; |
| asection *s; |
| bfd *abfd; |
| |
| after_open_default (); |
| |
| htab = elf_hash_table (&link_info); |
| if (!is_elf_hash_table (&htab->root)) |
| return; |
| |
| if (command_line.out_implib_filename) |
| { |
| unlink_if_ordinary (command_line.out_implib_filename); |
| link_info.out_implib_bfd |
| = bfd_openw (command_line.out_implib_filename, |
| bfd_get_target (link_info.output_bfd)); |
| |
| if (link_info.out_implib_bfd == NULL) |
| { |
| einfo (_("%F%P: %s: can't open for writing: %E\n"), |
| command_line.out_implib_filename); |
| } |
| } |
| |
| if (ldelf_emit_note_gnu_build_id != NULL |
| || ldelf_emit_note_fdo_package_metadata != NULL) |
| { |
| /* Find an ELF input. */ |
| for (abfd = link_info.input_bfds; |
| abfd != (bfd *) NULL; abfd = abfd->link.next) |
| if (bfd_get_flavour (abfd) == bfd_target_elf_flavour |
| && bfd_count_sections (abfd) != 0 |
| && !bfd_input_just_syms (abfd)) |
| break; |
| |
| /* PR 10555: If there are no ELF input files do not try to |
| create a .note.gnu-build-id section. */ |
| if (abfd == NULL |
| || (ldelf_emit_note_gnu_build_id != NULL |
| && !ldelf_setup_build_id (abfd))) |
| { |
| free ((char *) ldelf_emit_note_gnu_build_id); |
| ldelf_emit_note_gnu_build_id = NULL; |
| } |
| |
| if (abfd == NULL |
| || (ldelf_emit_note_fdo_package_metadata != NULL |
| && !ldelf_setup_package_metadata (abfd))) |
| { |
| free ((char *) ldelf_emit_note_fdo_package_metadata); |
| ldelf_emit_note_fdo_package_metadata = NULL; |
| } |
| } |
| |
| get_elf_backend_data (link_info.output_bfd)->setup_gnu_properties (&link_info); |
| |
| /* Do not allow executable files to be used as inputs to the link. */ |
| for (abfd = link_info.input_bfds; abfd; abfd = abfd->link.next) |
| { |
| /* Discard input .note.gnu.build-id sections. */ |
| s = bfd_get_section_by_name (abfd, ".note.gnu.build-id"); |
| while (s != NULL) |
| { |
| if (s != elf_tdata (link_info.output_bfd)->o->build_id.sec) |
| s->flags |= SEC_EXCLUDE; |
| s = bfd_get_next_section_by_name (NULL, s); |
| } |
| |
| if (abfd->xvec->flavour == bfd_target_elf_flavour |
| && !bfd_input_just_syms (abfd) |
| && elf_tdata (abfd) != NULL |
| /* FIXME: Maybe check for other non-supportable types as well ? */ |
| && (elf_tdata (abfd)->elf_header->e_type == ET_EXEC |
| || (elf_tdata (abfd)->elf_header->e_type == ET_DYN |
| && elf_tdata (abfd)->is_pie))) |
| einfo (_("%F%P: cannot use executable file '%pB' as input to a link\n"), |
| abfd); |
| } |
| |
| if (bfd_link_relocatable (&link_info)) |
| { |
| if (link_info.execstack == !link_info.noexecstack) |
| { |
| /* PR ld/16744: If "-z [no]execstack" has been specified on the |
| command line and we are perfoming a relocatable link then no |
| PT_GNU_STACK segment will be created and so the |
| linkinfo.[no]execstack values set in _handle_option() will have no |
| effect. Instead we create a .note.GNU-stack section in much the |
| same way as the assembler does with its --[no]execstack option. */ |
| flagword flags = SEC_READONLY | (link_info.execstack ? SEC_CODE : 0); |
| (void) bfd_make_section_with_flags (link_info.input_bfds, |
| ".note.GNU-stack", flags); |
| } |
| return; |
| } |
| |
| if (!link_info.traditional_format) |
| { |
| bfd *elfbfd = NULL; |
| bool warn_eh_frame = false; |
| int seen_type = 0; |
| |
| for (abfd = link_info.input_bfds; abfd; abfd = abfd->link.next) |
| { |
| int type = 0; |
| |
| if (bfd_input_just_syms (abfd)) |
| continue; |
| |
| for (s = abfd->sections; s && type < COMPACT_EH_HDR; s = s->next) |
| { |
| const char *name = bfd_section_name (s); |
| |
| if (bfd_is_abs_section (s->output_section)) |
| continue; |
| if (startswith (name, ".eh_frame_entry")) |
| type = COMPACT_EH_HDR; |
| else if (strcmp (name, ".eh_frame") == 0 && s->size > 8) |
| type = DWARF2_EH_HDR; |
| } |
| |
| if (type != 0) |
| { |
| if (seen_type == 0) |
| { |
| seen_type = type; |
| } |
| else if (seen_type != type) |
| { |
| einfo (_("%F%P: compact frame descriptions incompatible with" |
| " DWARF2 .eh_frame from %pB\n"), |
| type == DWARF2_EH_HDR ? abfd : elfbfd); |
| break; |
| } |
| |
| if (!elfbfd |
| && (type == COMPACT_EH_HDR |
| || link_info.eh_frame_hdr_type != 0)) |
| { |
| if (bfd_get_flavour (abfd) == bfd_target_elf_flavour) |
| elfbfd = abfd; |
| |
| warn_eh_frame = true; |
| } |
| } |
| |
| if (seen_type == COMPACT_EH_HDR) |
| link_info.eh_frame_hdr_type = COMPACT_EH_HDR; |
| } |
| if (elfbfd) |
| { |
| const struct elf_backend_data *bed; |
| |
| bed = get_elf_backend_data (elfbfd); |
| s = bfd_make_section_with_flags (elfbfd, ".eh_frame_hdr", |
| bed->dynamic_sec_flags |
| | SEC_READONLY); |
| if (s != NULL |
| && bfd_set_section_alignment (s, 2)) |
| { |
| htab->eh_info.hdr_sec = s; |
| warn_eh_frame = false; |
| } |
| } |
| if (warn_eh_frame) |
| einfo (_("%P: warning: cannot create .eh_frame_hdr section," |
| " --eh-frame-hdr ignored\n")); |
| } |
| |
| if (link_info.eh_frame_hdr_type == COMPACT_EH_HDR) |
| if (!bfd_elf_parse_eh_frame_entries (NULL, &link_info)) |
| einfo (_("%F%P: failed to parse EH frame entries\n")); |
| |
| ldelf_handle_dt_needed (htab, use_libpath, native, is_linux, |
| is_freebsd, elfsize, prefix); |
| } |
| |
| static bfd_size_type |
| id_note_section_size (bfd *abfd ATTRIBUTE_UNUSED) |
| { |
| const char *style = ldelf_emit_note_gnu_build_id; |
| bfd_size_type size; |
| bfd_size_type build_id_size; |
| |
| size = offsetof (Elf_External_Note, name[sizeof "GNU"]); |
| size = (size + 3) & -(bfd_size_type) 4; |
| |
| build_id_size = compute_build_id_size (style); |
| if (build_id_size) |
| size += build_id_size; |
| else |
| size = 0; |
| |
| return size; |
| } |
| |
| static bool |
| write_build_id (bfd *abfd) |
| { |
| const struct elf_backend_data *bed = get_elf_backend_data (abfd); |
| struct elf_obj_tdata *t = elf_tdata (abfd); |
| const char *style; |
| asection *asec; |
| Elf_Internal_Shdr *i_shdr; |
| unsigned char *contents, *id_bits; |
| bfd_size_type size; |
| file_ptr position; |
| Elf_External_Note *e_note; |
| |
| style = t->o->build_id.style; |
| asec = t->o->build_id.sec; |
| if (bfd_is_abs_section (asec->output_section)) |
| { |
| einfo (_("%P: warning: .note.gnu.build-id section discarded," |
| " --build-id ignored\n")); |
| return true; |
| } |
| i_shdr = &elf_section_data (asec->output_section)->this_hdr; |
| |
| if (i_shdr->contents == NULL) |
| { |
| if (asec->contents == NULL) |
| asec->contents = (unsigned char *) xmalloc (asec->size); |
| contents = asec->contents; |
| } |
| else |
| contents = i_shdr->contents + asec->output_offset; |
| |
| e_note = (Elf_External_Note *) contents; |
| size = offsetof (Elf_External_Note, name[sizeof "GNU"]); |
| size = (size + 3) & -(bfd_size_type) 4; |
| id_bits = contents + size; |
| size = asec->size - size; |
| |
| /* Clear the build ID field. */ |
| memset (id_bits, 0, size); |
| |
| bfd_h_put_32 (abfd, sizeof "GNU", &e_note->namesz); |
| bfd_h_put_32 (abfd, size, &e_note->descsz); |
| bfd_h_put_32 (abfd, NT_GNU_BUILD_ID, &e_note->type); |
| memcpy (e_note->name, "GNU", sizeof "GNU"); |
| |
| generate_build_id (abfd, style, bed->s->checksum_contents, id_bits, size); |
| |
| position = i_shdr->sh_offset + asec->output_offset; |
| size = asec->size; |
| return (bfd_seek (abfd, position, SEEK_SET) == 0 |
| && bfd_write (contents, size, abfd) == size); |
| } |
| |
| /* Make .note.gnu.build-id section, and set up elf_tdata->build_id. */ |
| |
| bool |
| ldelf_setup_build_id (bfd *ibfd) |
| { |
| asection *s; |
| bfd_size_type size; |
| flagword flags; |
| |
| size = id_note_section_size (ibfd); |
| if (size == 0) |
| { |
| einfo (_("%P: warning: unrecognized --build-id style ignored\n")); |
| return false; |
| } |
| |
| flags = (SEC_ALLOC | SEC_LOAD | SEC_IN_MEMORY |
| | SEC_LINKER_CREATED | SEC_READONLY | SEC_DATA); |
| s = bfd_make_section_anyway_with_flags (ibfd, ".note.gnu.build-id", |
| flags); |
| if (s != NULL && bfd_set_section_alignment (s, 2)) |
| { |
| struct elf_obj_tdata *t = elf_tdata (link_info.output_bfd); |
| t->o->build_id.after_write_object_contents = &write_build_id; |
| t->o->build_id.style = ldelf_emit_note_gnu_build_id; |
| t->o->build_id.sec = s; |
| elf_section_type (s) = SHT_NOTE; |
| s->size = size; |
| return true; |
| } |
| |
| einfo (_("%P: warning: cannot create .note.gnu.build-id section," |
| " --build-id ignored\n")); |
| return false; |
| } |
| |
| static bool |
| write_package_metadata (bfd *abfd) |
| { |
| struct elf_obj_tdata *t = elf_tdata (abfd); |
| const char *json; |
| asection *asec; |
| Elf_Internal_Shdr *i_shdr; |
| unsigned char *contents, *json_bits; |
| bfd_size_type size; |
| file_ptr position; |
| Elf_External_Note *e_note; |
| |
| json = t->o->package_metadata.json; |
| asec = t->o->package_metadata.sec; |
| if (bfd_is_abs_section (asec->output_section)) |
| { |
| einfo (_("%P: warning: .note.package section discarded," |
| " --package-metadata ignored\n")); |
| return true; |
| } |
| i_shdr = &elf_section_data (asec->output_section)->this_hdr; |
| |
| if (i_shdr->contents == NULL) |
| { |
| if (asec->contents == NULL) |
| asec->contents = (unsigned char *) xmalloc (asec->size); |
| contents = asec->contents; |
| } |
| else |
| contents = i_shdr->contents + asec->output_offset; |
| |
| e_note = (Elf_External_Note *) contents; |
| size = offsetof (Elf_External_Note, name[sizeof "FDO"]); |
| size = (size + 3) & -(bfd_size_type) 4; |
| json_bits = contents + size; |
| size = asec->size - size; |
| |
| /* Clear the package metadata field. */ |
| memset (json_bits, 0, size); |
| |
| bfd_h_put_32 (abfd, sizeof "FDO", &e_note->namesz); |
| bfd_h_put_32 (abfd, size, &e_note->descsz); |
| bfd_h_put_32 (abfd, FDO_PACKAGING_METADATA, &e_note->type); |
| memcpy (e_note->name, "FDO", sizeof "FDO"); |
| memcpy (json_bits, json, strlen(json)); |
| |
| position = i_shdr->sh_offset + asec->output_offset; |
| size = asec->size; |
| return (bfd_seek (abfd, position, SEEK_SET) == 0 |
| && bfd_write (contents, size, abfd) == size); |
| } |
| |
| /* Make .note.package section. |
| https://systemd.io/ELF_PACKAGE_METADATA/ */ |
| |
| bool |
| ldelf_setup_package_metadata (bfd *ibfd) |
| { |
| asection *s; |
| bfd_size_type size; |
| size_t json_length; |
| flagword flags; |
| |
| /* If the option wasn't specified, silently return. */ |
| if (!ldelf_emit_note_fdo_package_metadata) |
| return false; |
| |
| /* The option was specified, but it's empty, log and return. */ |
| json_length = strlen (ldelf_emit_note_fdo_package_metadata); |
| if (json_length == 0) |
| { |
| einfo (_("%P: warning: --package-metadata is empty, ignoring\n")); |
| return false; |
| } |
| |
| #ifdef HAVE_JANSSON |
| json_error_t json_error; |
| json_t *json = json_loads (ldelf_emit_note_fdo_package_metadata, |
| 0, &json_error); |
| if (!json) |
| { |
| einfo (_("%P: warning: --package-metadata=%s does not contain valid " |
| "JSON, ignoring: %s\n"), |
| ldelf_emit_note_fdo_package_metadata, json_error.text); |
| return false; |
| } |
| else |
| json_decref (json); |
| #endif |
| |
| size = offsetof (Elf_External_Note, name[sizeof "FDO"]); |
| size += json_length + 1; |
| size = (size + 3) & -(bfd_size_type) 4; |
| |
| flags = (SEC_ALLOC | SEC_LOAD | SEC_IN_MEMORY |
| | SEC_LINKER_CREATED | SEC_READONLY | SEC_DATA); |
| s = bfd_make_section_anyway_with_flags (ibfd, ".note.package", |
| flags); |
| if (s != NULL && bfd_set_section_alignment (s, 2)) |
| { |
| struct elf_obj_tdata *t = elf_tdata (link_info.output_bfd); |
| t->o->package_metadata.after_write_object_contents |
| = &write_package_metadata; |
| t->o->package_metadata.json = ldelf_emit_note_fdo_package_metadata; |
| t->o->package_metadata.sec = s; |
| elf_section_type (s) = SHT_NOTE; |
| s->size = size; |
| return true; |
| } |
| |
| einfo (_("%P: warning: cannot create .note.package section," |
| " --package-metadata ignored\n")); |
| return false; |
| } |
| |
| /* Look through an expression for an assignment statement. */ |
| |
| static void |
| ldelf_find_exp_assignment (etree_type *exp) |
| { |
| bool provide = false; |
| |
| switch (exp->type.node_class) |
| { |
| case etree_provide: |
| case etree_provided: |
| provide = true; |
| /* Fallthru */ |
| case etree_assign: |
| /* We call record_link_assignment even if the symbol is defined. |
| This is because if it is defined by a dynamic object, we |
| actually want to use the value defined by the linker script, |
| not the value from the dynamic object (because we are setting |
| symbols like etext). If the symbol is defined by a regular |
| object, then, as it happens, calling record_link_assignment |
| will do no harm. */ |
| if (strcmp (exp->assign.dst, ".") != 0) |
| { |
| if (!bfd_elf_record_link_assignment (link_info.output_bfd, |
| &link_info, |
| exp->assign.dst, provide, |
| exp->assign.hidden)) |
| einfo (_("%F%P: failed to record assignment to %s: %E\n"), |
| exp->assign.dst); |
| } |
| ldelf_find_exp_assignment (exp->assign.src); |
| break; |
| |
| case etree_binary: |
| ldelf_find_exp_assignment (exp->binary.lhs); |
| ldelf_find_exp_assignment (exp->binary.rhs); |
| break; |
| |
| case etree_trinary: |
| ldelf_find_exp_assignment (exp->trinary.cond); |
| ldelf_find_exp_assignment (exp->trinary.lhs); |
| ldelf_find_exp_assignment (exp->trinary.rhs); |
| break; |
| |
| case etree_unary: |
| ldelf_find_exp_assignment (exp->unary.child); |
| break; |
| |
| default: |
| break; |
| } |
| } |
| |
| /* This is called by the before_allocation routine via |
| lang_for_each_statement. It locates any assignment statements, and |
| tells the ELF backend about them, in case they are assignments to |
| symbols which are referred to by dynamic objects. */ |
| |
| static void |
| ldelf_find_statement_assignment (lang_statement_union_type *s) |
| { |
| if (s->header.type == lang_assignment_statement_enum) |
| ldelf_find_exp_assignment (s->assignment_statement.exp); |
| } |
| |
| /* Used by before_allocation and handle_option. */ |
| |
| void |
| ldelf_append_to_separated_string (char **to, char *op_arg) |
| { |
| if (*to == NULL) |
| *to = xstrdup (op_arg); |
| else |
| { |
| size_t to_len = strlen (*to); |
| size_t op_arg_len = strlen (op_arg); |
| char *buf; |
| char *cp = *to; |
| |
| /* First see whether OPTARG is already in the path. */ |
| do |
| { |
| if (strncmp (op_arg, cp, op_arg_len) == 0 |
| && (cp[op_arg_len] == 0 |
| || cp[op_arg_len] == config.rpath_separator)) |
| /* We found it. */ |
| break; |
| |
| /* Not yet found. */ |
| cp = strchr (cp, config.rpath_separator); |
| if (cp != NULL) |
| ++cp; |
| } |
| while (cp != NULL); |
| |
| if (cp == NULL) |
| { |
| buf = xmalloc (to_len + op_arg_len + 2); |
| sprintf (buf, "%s%c%s", *to, |
| config.rpath_separator, op_arg); |
| free (*to); |
| *to = buf; |
| } |
| } |
| } |
| |
| /* This is called after the sections have been attached to output |
| sections, but before any sizes or addresses have been set. */ |
| |
| void |
| ldelf_before_allocation (char *audit, char *depaudit, |
| const char *default_interpreter_name) |
| { |
| const char *rpath; |
| asection *sinterp; |
| bfd *abfd; |
| struct bfd_link_hash_entry *ehdr_start = NULL; |
| unsigned char ehdr_start_save_type = 0; |
| char ehdr_start_save_u[sizeof ehdr_start->u |
| - sizeof ehdr_start->u.def.next] = ""; |
| |
| if (is_elf_hash_table (link_info.hash)) |
| { |
| _bfd_elf_tls_setup (link_info.output_bfd, &link_info); |
| |
| /* Make __ehdr_start hidden if it has been referenced, to |
| prevent the symbol from being dynamic. */ |
| if (!bfd_link_relocatable (&link_info)) |
| { |
| struct elf_link_hash_table *htab = elf_hash_table (&link_info); |
| struct elf_link_hash_entry *h |
| = elf_link_hash_lookup (htab, "__ehdr_start", false, false, true); |
| |
| /* Only adjust the export class if the symbol was referenced |
| and not defined, otherwise leave it alone. */ |
| if (h != NULL |
| && (h->root.type == bfd_link_hash_new |
| || h->root.type == bfd_link_hash_undefined |
| || h->root.type == bfd_link_hash_undefweak |
| || h->root.type == bfd_link_hash_common)) |
| { |
| /* Don't leave the symbol undefined. Undefined hidden |
| symbols typically won't have dynamic relocations, but |
| we most likely will need dynamic relocations for |
| __ehdr_start if we are building a PIE or shared |
| library. */ |
| ehdr_start = &h->root; |
| ehdr_start_save_type = ehdr_start->type; |
| memcpy (ehdr_start_save_u, |
| (char *) &ehdr_start->u + sizeof ehdr_start->u.def.next, |
| sizeof ehdr_start_save_u); |
| ehdr_start->type = bfd_link_hash_defined; |
| /* It will be converted to section-relative later. */ |
| ehdr_start->u.def.section = bfd_abs_section_ptr; |
| ehdr_start->u.def.value = 0; |
| } |
| } |
| |
| /* If we are going to make any variable assignments, we need to |
| let the ELF backend know about them in case the variables are |
| referred to by dynamic objects. */ |
| lang_for_each_statement (ldelf_find_statement_assignment); |
| } |
| |
| /* Let the ELF backend work out the sizes of any sections required |
| by dynamic linking. */ |
| rpath = command_line.rpath; |
| if (rpath == NULL) |
| rpath = (const char *) getenv ("LD_RUN_PATH"); |
| |
| for (abfd = link_info.input_bfds; abfd; abfd = abfd->link.next) |
| if (bfd_get_flavour (abfd) == bfd_target_elf_flavour) |
| { |
| const char *audit_libs = elf_dt_audit (abfd); |
| |
| /* If the input bfd contains an audit entry, we need to add it as |
| a dep audit entry. */ |
| if (audit_libs && *audit_libs != '\0') |
| { |
| char *cp = xstrdup (audit_libs); |
| do |
| { |
| int more = 0; |
| char *cp2 = strchr (cp, config.rpath_separator); |
| |
| if (cp2) |
| { |
| *cp2 = '\0'; |
| more = 1; |
| } |
| |
| if (cp != NULL && *cp != '\0') |
| ldelf_append_to_separated_string (&depaudit, cp); |
| |
| cp = more ? ++cp2 : NULL; |
| } |
| while (cp != NULL); |
| } |
| } |
| |
| if (! (bfd_elf_size_dynamic_sections |
| (link_info.output_bfd, command_line.soname, rpath, |
| command_line.filter_shlib, audit, depaudit, |
| (const char * const *) command_line.auxiliary_filters, |
| &link_info, &sinterp))) |
| einfo (_("%F%P: failed to set dynamic section sizes: %E\n")); |
| |
| if (sinterp != NULL) |
| { |
| /* Let the user override the dynamic linker we are using. */ |
| if (command_line.interpreter != NULL) |
| default_interpreter_name = command_line.interpreter; |
| if (default_interpreter_name != NULL) |
| { |
| sinterp->contents = (bfd_byte *) default_interpreter_name; |
| sinterp->size = strlen ((char *) sinterp->contents) + 1; |
| } |
| } |
| |
| /* Look for any sections named .gnu.warning. As a GNU extensions, |
| we treat such sections as containing warning messages. We print |
| out the warning message, and then zero out the section size so |
| that it does not get copied into the output file. */ |
| |
| { |
| LANG_FOR_EACH_INPUT_STATEMENT (is) |
| { |
| asection *s; |
| bfd_size_type sz; |
| char *msg; |
| |
| if (is->flags.just_syms) |
| continue; |
| |
| s = bfd_get_section_by_name (is->the_bfd, ".gnu.warning"); |
| if (s == NULL) |
| continue; |
| |
| sz = s->size; |
| msg = (char *) xmalloc ((size_t) (sz + 1)); |
| if (! bfd_get_section_contents (is->the_bfd, s, msg, |
| (file_ptr) 0, sz)) |
| einfo (_("%F%P: %pB: can't read contents of section .gnu.warning: %E\n"), |
| is->the_bfd); |
| msg[sz] = '\0'; |
| (*link_info.callbacks->warning) (&link_info, msg, |
| (const char *) NULL, is->the_bfd, |
| (asection *) NULL, (bfd_vma) 0); |
| free (msg); |
| |
| /* Clobber the section size, so that we don't waste space |
| copying the warning into the output file. If we've already |
| sized the output section, adjust its size. The adjustment |
| is on rawsize because targets that size sections early will |
| have called lang_reset_memory_regions after sizing. */ |
| if (s->output_section != NULL |
| && s->output_section->rawsize >= s->size) |
| s->output_section->rawsize -= s->size; |
| |
| s->size = 0; |
| |
| /* Also set SEC_EXCLUDE, so that local symbols defined in the |
| warning section don't get copied to the output. */ |
| s->flags |= SEC_EXCLUDE | SEC_KEEP; |
| } |
| } |
| |
| before_allocation_default (); |
| |
| if (!bfd_elf_size_dynsym_hash_dynstr (link_info.output_bfd, &link_info)) |
| einfo (_("%F%P: failed to set dynamic section sizes: %E\n")); |
| |
| if (ehdr_start != NULL) |
| { |
| /* If we twiddled __ehdr_start to defined earlier, put it back |
| as it was. */ |
| ehdr_start->type = ehdr_start_save_type; |
| memcpy ((char *) &ehdr_start->u + sizeof ehdr_start->u.def.next, |
| ehdr_start_save_u, |
| sizeof ehdr_start_save_u); |
| } |
| } |
| /* Try to open a dynamic archive. This is where we know that ELF |
| dynamic libraries have an extension of .so (or .sl on oddball systems |
| like hpux). */ |
| |
| bool |
| ldelf_open_dynamic_archive (const char *arch, search_dirs_type *search, |
| lang_input_statement_type *entry) |
| { |
| const char *filename; |
| char *string; |
| size_t len; |
| bool opened = false; |
| |
| if (! entry->flags.maybe_archive) |
| return false; |
| |
| filename = entry->filename; |
| len = strlen (search->name) + strlen (filename); |
| if (entry->flags.full_name_provided) |
| { |
| len += sizeof "/"; |
| string = (char *) xmalloc (len); |
| sprintf (string, "%s/%s", search->name, filename); |
| } |
| else |
| { |
| size_t xlen = 0; |
| |
| len += strlen (arch) + sizeof "/lib.so"; |
| #ifdef EXTRA_SHLIB_EXTENSION |
| xlen = (strlen (EXTRA_SHLIB_EXTENSION) > 3 |
| ? strlen (EXTRA_SHLIB_EXTENSION) - 3 |
| : 0); |
| #endif |
| string = (char *) xmalloc (len + xlen); |
| sprintf (string, "%s/lib%s%s.so", search->name, filename, arch); |
| #ifdef EXTRA_SHLIB_EXTENSION |
| /* Try the .so extension first. If that fails build a new filename |
| using EXTRA_SHLIB_EXTENSION. */ |
| opened = ldfile_try_open_bfd (string, entry); |
| if (!opened) |
| strcpy (string + len - 4, EXTRA_SHLIB_EXTENSION); |
| #endif |
| } |
| |
| if (!opened && !ldfile_try_open_bfd (string, entry)) |
| { |
| free (string); |
| return false; |
| } |
| |
| entry->filename = string; |
| |
| /* We have found a dynamic object to include in the link. The ELF |
| backend linker will create a DT_NEEDED entry in the .dynamic |
| section naming this file. If this file includes a DT_SONAME |
| entry, it will be used. Otherwise, the ELF linker will just use |
| the name of the file. For an archive found by searching, like |
| this one, the DT_NEEDED entry should consist of just the name of |
| the file, without the path information used to find it. Note |
| that we only need to do this if we have a dynamic object; an |
| archive will never be referenced by a DT_NEEDED entry. |
| |
| FIXME: This approach--using bfd_elf_set_dt_needed_name--is not |
| very pretty. I haven't been able to think of anything that is |
| pretty, though. */ |
| if (bfd_check_format (entry->the_bfd, bfd_object) |
| && (entry->the_bfd->flags & DYNAMIC) != 0) |
| { |
| ASSERT (entry->flags.maybe_archive && entry->flags.search_dirs); |
| |
| /* Rather than duplicating the logic above. Just use the |
| filename we recorded earlier. */ |
| |
| if (!entry->flags.full_name_provided) |
| filename = lbasename (entry->filename); |
| bfd_elf_set_dt_needed_name (entry->the_bfd, filename); |
| } |
| |
| return true; |
| } |
| |
| /* A variant of lang_output_section_find used by place_orphan. */ |
| |
| static lang_output_section_statement_type * |
| output_rel_find (int isdyn, int rela) |
| { |
| lang_output_section_statement_type *lookup; |
| lang_output_section_statement_type *last = NULL; |
| lang_output_section_statement_type *last_alloc = NULL; |
| lang_output_section_statement_type *last_ro_alloc = NULL; |
| lang_output_section_statement_type *last_rel = NULL; |
| lang_output_section_statement_type *last_rel_alloc = NULL; |
| |
| for (lookup = (void *) lang_os_list.head; |
| lookup != NULL; |
| lookup = lookup->next) |
| { |
| if (lookup->constraint >= 0 |
| && startswith (lookup->name, ".rel")) |
| { |
| int lookrela = lookup->name[4] == 'a'; |
| |
| /* .rel.dyn must come before all other reloc sections, to suit |
| GNU ld.so. */ |
| if (isdyn) |
| break; |
| |
| /* Don't place after .rel.plt as doing so results in wrong |
| dynamic tags. */ |
| if (strcmp (".plt", lookup->name + 4 + lookrela) == 0) |
| break; |
| |
| if (rela == lookrela || last_rel == NULL) |
| last_rel = lookup; |
| if ((rela == lookrela || last_rel_alloc == NULL) |
| && lookup->bfd_section != NULL |
| && (lookup->bfd_section->flags & SEC_ALLOC) != 0) |
| last_rel_alloc = lookup; |
| } |
| |
| last = lookup; |
| if (lookup->bfd_section != NULL |
| && (lookup->bfd_section->flags & SEC_ALLOC) != 0) |
| { |
| last_alloc = lookup; |
| if ((lookup->bfd_section->flags & SEC_READONLY) != 0) |
| last_ro_alloc = lookup; |
| } |
| } |
| |
| if (last_rel_alloc) |
| return last_rel_alloc; |
| |
| if (last_rel) |
| return last_rel; |
| |
| if (last_ro_alloc) |
| return last_ro_alloc; |
| |
| if (last_alloc) |
| return last_alloc; |
| |
| return last; |
| } |
| |
| /* Return whether IN is suitable to be part of OUT. */ |
| |
| static bool |
| elf_orphan_compatible (asection *in, asection *out) |
| { |
| /* Non-zero sh_info implies a section with SHF_INFO_LINK with |
| unknown semantics for the generic linker, or a SHT_REL/SHT_RELA |
| section where sh_info specifies a symbol table. (We won't see |
| SHT_GROUP, SHT_SYMTAB or SHT_DYNSYM sections here.) We clearly |
| can't merge SHT_REL/SHT_RELA using differing symbol tables, and |
| shouldn't merge sections with differing unknown semantics. */ |
| if (elf_section_data (out)->this_hdr.sh_info |
| != elf_section_data (in)->this_hdr.sh_info) |
| return false; |
| /* We can't merge with a member of an output section group or merge |
| two sections with differing SHF_EXCLUDE or other processor and OS |
| specific flags or with different SHF_LINK_ORDER when doing a |
| relocatable link. */ |
| if (bfd_link_relocatable (&link_info) |
| && (elf_next_in_group (out) != NULL |
| || ((elf_section_flags (in) & SHF_LINK_ORDER) != 0 |
| && (elf_section_flags (out) & SHF_LINK_ORDER) != 0 |
| && (elf_linked_to_section (in)->output_section |
| != elf_linked_to_section (out)->output_section)) |
| || ((elf_section_flags (out) ^ elf_section_flags (in)) |
| & (SHF_MASKPROC | SHF_MASKOS)) != 0)) |
| return false; |
| return _bfd_elf_match_sections_by_type (link_info.output_bfd, out, |
| in->owner, in); |
| } |
| |
| /* Place an orphan section. We use this to put random SHF_ALLOC |
| sections in the right segment. */ |
| |
| lang_output_section_statement_type * |
| ldelf_place_orphan (asection *s, const char *secname, int constraint) |
| { |
| static struct orphan_save hold[] = |
| { |
| { ".text", |
| SEC_HAS_CONTENTS | SEC_ALLOC | SEC_LOAD | SEC_READONLY | SEC_CODE, |
| 0, 0, 0, 0 }, |
| { ".rodata", |
| SEC_HAS_CONTENTS | SEC_ALLOC | SEC_LOAD | SEC_READONLY | SEC_DATA, |
| 0, 0, 0, 0 }, |
| { ".tdata", |
| SEC_HAS_CONTENTS | SEC_ALLOC | SEC_LOAD | SEC_DATA | SEC_THREAD_LOCAL, |
| 0, 0, 0, 0 }, |
| { ".data", |
| SEC_HAS_CONTENTS | SEC_ALLOC | SEC_LOAD | SEC_DATA, |
| 0, 0, 0, 0 }, |
| { ".bss", |
| SEC_ALLOC, |
| 0, 0, 0, 0 }, |
| { 0, |
| SEC_HAS_CONTENTS | SEC_ALLOC | SEC_LOAD | SEC_READONLY | SEC_DATA, |
| 0, 0, 0, 0 }, |
| { ".interp", |
| SEC_HAS_CONTENTS | SEC_ALLOC | SEC_LOAD | SEC_READONLY | SEC_DATA, |
| 0, 0, 0, 0 }, |
| { ".sdata", |
| SEC_HAS_CONTENTS | SEC_ALLOC | SEC_LOAD | SEC_DATA | SEC_SMALL_DATA, |
| 0, 0, 0, 0 }, |
| { ".comment", |
| SEC_HAS_CONTENTS, |
| 0, 0, 0, 0 }, |
| }; |
| enum orphan_save_index |
| { |
| orphan_text = 0, |
| orphan_rodata, |
| orphan_tdata, |
| orphan_data, |
| orphan_bss, |
| orphan_rel, |
| orphan_interp, |
| orphan_sdata, |
| orphan_nonalloc |
| }; |
| static int orphan_init_done = 0; |
| struct orphan_save *place; |
| lang_output_section_statement_type *after; |
| lang_output_section_statement_type *os; |
| lang_output_section_statement_type *match_by_name = NULL; |
| int isdyn = 0; |
| int elfinput = s->owner->xvec->flavour == bfd_target_elf_flavour; |
| int elfoutput = link_info.output_bfd->xvec->flavour == bfd_target_elf_flavour; |
| unsigned int sh_type = elfinput ? elf_section_type (s) : SHT_NULL; |
| flagword flags; |
| asection *nexts; |
| |
| if (!bfd_link_relocatable (&link_info) |
| && link_info.combreloc |
| && (s->flags & SEC_ALLOC)) |
| { |
| if (elfinput) |
| switch (sh_type) |
| { |
| case SHT_RELA: |
| secname = ".rela.dyn"; |
| isdyn = 1; |
| break; |
| case SHT_REL: |
| secname = ".rel.dyn"; |
| isdyn = 1; |
| break; |
| default: |
| break; |
| } |
| else if (startswith (secname, ".rel")) |
| { |
| secname = secname[4] == 'a' ? ".rela.dyn" : ".rel.dyn"; |
| isdyn = 1; |
| } |
| } |
| |
| if (!bfd_link_relocatable (&link_info) |
| && elfinput |
| && elfoutput |
| && (s->flags & SEC_ALLOC) != 0 |
| && (elf_tdata (s->owner)->has_gnu_osabi & elf_gnu_osabi_mbind) != 0 |
| && (elf_section_flags (s) & SHF_GNU_MBIND) != 0) |
| { |
| /* Find the output mbind section with the same type, attributes |
| and sh_info field. */ |
| for (os = (void *) lang_os_list.head; |
| os != NULL; |
| os = os->next) |
| if (os->bfd_section != NULL |
| && !bfd_is_abs_section (os->bfd_section) |
| && (elf_section_flags (os->bfd_section) & SHF_GNU_MBIND) != 0 |
| && ((s->flags & (SEC_ALLOC |
| | SEC_LOAD |
| | SEC_HAS_CONTENTS |
| | SEC_READONLY |
| | SEC_CODE)) |
| == (os->bfd_section->flags & (SEC_ALLOC |
| | SEC_LOAD |
| | SEC_HAS_CONTENTS |
| | SEC_READONLY |
| | SEC_CODE))) |
| && (elf_section_data (os->bfd_section)->this_hdr.sh_info |
| == elf_section_data (s)->this_hdr.sh_info)) |
| { |
| lang_add_section (&os->children, s, NULL, NULL, os); |
| return os; |
| } |
| |
| /* Create the output mbind section with the ".mbind." prefix |
| in section name. */ |
| if ((s->flags & (SEC_LOAD | SEC_HAS_CONTENTS)) == 0) |
| secname = ".mbind.bss"; |
| else if ((s->flags & SEC_READONLY) == 0) |
| secname = ".mbind.data"; |
| else if ((s->flags & SEC_CODE) == 0) |
| secname = ".mbind.rodata"; |
| else |
| secname = ".mbind.text"; |
| elf_tdata (link_info.output_bfd)->has_gnu_osabi |= elf_gnu_osabi_mbind; |
| } |
| |
| /* Look through the script to see where to place this section. The |
| script includes entries added by previous lang_insert_orphan |
| calls, so this loop puts multiple compatible orphans of the same |
| name into a single output section. */ |
| if (constraint == 0) |
| for (os = lang_output_section_find (secname); |
| os != NULL; |
| os = next_matching_output_section_statement (os, 0)) |
| { |
| /* If we don't match an existing output section, tell |
| lang_insert_orphan to create a new output section. */ |
| constraint = SPECIAL; |
| |
| /* Check to see if we already have an output section statement |
| with this name, and its bfd section has compatible flags. |
| If the section already exists but does not have any flags |
| set, then it has been created by the linker, possibly as a |
| result of a --section-start command line switch. */ |
| if (os->bfd_section != NULL |
| && !bfd_is_abs_section (os->bfd_section) |
| && (os->bfd_section->flags == 0 |
| || (((s->flags ^ os->bfd_section->flags) |
| & (SEC_LOAD | SEC_ALLOC)) == 0 |
| && (!elfinput |
| || !elfoutput |
| || elf_orphan_compatible (s, os->bfd_section))))) |
| { |
| lang_add_section (&os->children, s, NULL, NULL, os); |
| return os; |
| } |
| |
| /* Save unused output sections in case we can match them |
| against orphans later. */ |
| if (os->bfd_section == NULL) |
| match_by_name = os; |
| } |
| |
| /* If we didn't match an active output section, see if we matched an |
| unused one and use that. */ |
| if (match_by_name) |
| { |
| lang_add_section (&match_by_name->children, s, NULL, NULL, match_by_name); |
| return match_by_name; |
| } |
| |
| if (!orphan_init_done) |
| { |
| struct orphan_save *ho; |
| |
| for (ho = hold; ho < hold + sizeof (hold) / sizeof (hold[0]); ++ho) |
| if (ho->name != NULL) |
| { |
| ho->os = lang_output_section_find (ho->name); |
| if (ho->os != NULL && ho->os->flags == 0) |
| ho->os->flags = ho->flags; |
| } |
| orphan_init_done = 1; |
| } |
| |
| /* If this is a final link, then always put .gnu.warning.SYMBOL |
| sections into the .text section to get them out of the way. */ |
| if (bfd_link_executable (&link_info) |
| && startswith (s->name, ".gnu.warning.") |
| && hold[orphan_text].os != NULL) |
| { |
| os = hold[orphan_text].os; |
| lang_add_section (&os->children, s, NULL, NULL, os); |
| return os; |
| } |
| |
| flags = s->flags; |
| if (!bfd_link_relocatable (&link_info)) |
| { |
| nexts = s; |
| while ((nexts = bfd_get_next_section_by_name (nexts->owner, nexts)) |
| != NULL) |
| if (nexts->output_section == NULL |
| && (nexts->flags & SEC_EXCLUDE) == 0 |
| && ((nexts->flags ^ flags) & (SEC_LOAD | SEC_ALLOC)) == 0 |
| && (nexts->owner->flags & DYNAMIC) == 0 |
| && !bfd_input_just_syms (nexts->owner) |
| && _bfd_elf_match_sections_by_type (nexts->owner, nexts, |
| s->owner, s)) |
| flags = (((flags ^ SEC_READONLY) |
| | (nexts->flags ^ SEC_READONLY)) |
| ^ SEC_READONLY); |
| } |
| |
| /* Decide which segment the section should go in based on the |
| section name and section flags. We put loadable .note sections |
| right after the .interp section, so that the PT_NOTE segment is |
| stored right after the program headers where the OS can read it |
| in the first page. */ |
| |
| place = NULL; |
| if ((flags & (SEC_ALLOC | SEC_DEBUGGING)) == 0) |
| place = &hold[orphan_nonalloc]; |
| else if ((flags & SEC_ALLOC) == 0) |
| ; |
| else if ((flags & SEC_LOAD) != 0 |
| && (elfinput |
| ? sh_type == SHT_NOTE |
| : startswith (secname, ".note"))) |
| place = &hold[orphan_interp]; |
| else if ((flags & (SEC_LOAD | SEC_HAS_CONTENTS | SEC_THREAD_LOCAL)) == 0) |
| place = &hold[orphan_bss]; |
| else if ((flags & SEC_SMALL_DATA) != 0) |
| place = &hold[orphan_sdata]; |
| else if ((flags & SEC_THREAD_LOCAL) != 0) |
| place = &hold[orphan_tdata]; |
| else if ((flags & SEC_READONLY) == 0) |
| place = &hold[orphan_data]; |
| else if ((flags & SEC_LOAD) != 0 |
| && (elfinput |
| ? sh_type == SHT_RELA || sh_type == SHT_REL |
| : startswith (secname, ".rel"))) |
| place = &hold[orphan_rel]; |
| else if ((flags & SEC_CODE) == 0) |
| place = &hold[orphan_rodata]; |
| else |
| place = &hold[orphan_text]; |
| |
| after = NULL; |
| if (place != NULL) |
| { |
| if (place->os == NULL) |
| { |
| if (place->name != NULL) |
| place->os = lang_output_section_find (place->name); |
| else |
| { |
| int rela = elfinput ? sh_type == SHT_RELA : secname[4] == 'a'; |
| place->os = output_rel_find (isdyn, rela); |
| } |
| } |
| after = place->os; |
| if (after == NULL) |
| after |
| = lang_output_section_find_by_flags (s, flags, &place->os, |
| _bfd_elf_match_sections_by_type); |
| if (after == NULL) |
| /* *ABS* is always the first output section statement. */ |
| after = (void *) lang_os_list.head; |
| } |
| |
| return lang_insert_orphan (s, secname, constraint, after, place, NULL, NULL); |
| } |
| |
| void |
| ldelf_before_place_orphans (void) |
| { |
| bfd *abfd; |
| |
| for (abfd = link_info.input_bfds; |
| abfd != (bfd *) NULL; abfd = abfd->link.next) |
| if (bfd_get_flavour (abfd) == bfd_target_elf_flavour |
| && bfd_count_sections (abfd) != 0 |
| && !bfd_input_just_syms (abfd)) |
| { |
| asection *isec; |
| for (isec = abfd->sections; isec != NULL; isec = isec->next) |
| { |
| /* Discard a section if any of its linked-to section has |
| been discarded. */ |
| asection *linked_to_sec; |
| for (linked_to_sec = elf_linked_to_section (isec); |
| linked_to_sec != NULL && !linked_to_sec->linker_mark; |
| linked_to_sec = elf_linked_to_section (linked_to_sec)) |
| { |
| if (discarded_section (linked_to_sec)) |
| { |
| isec->output_section = bfd_abs_section_ptr; |
| isec->flags |= SEC_EXCLUDE; |
| break; |
| } |
| linked_to_sec->linker_mark = 1; |
| } |
| for (linked_to_sec = elf_linked_to_section (isec); |
| linked_to_sec != NULL && linked_to_sec->linker_mark; |
| linked_to_sec = elf_linked_to_section (linked_to_sec)) |
| linked_to_sec->linker_mark = 0; |
| } |
| } |
| } |
| |
| void |
| ldelf_set_output_arch (void) |
| { |
| set_output_arch_default (); |
| if (link_info.output_bfd->xvec->flavour == bfd_target_elf_flavour) |
| elf_link_info (link_info.output_bfd) = &link_info; |
| } |