Squashed 'third_party/elfutils/' content from commit 555e15e
Change-Id: I61cde98949e47e5c8c09c33260de17f30921be79
git-subtree-dir: third_party/elfutils
git-subtree-split: 555e15ebe8bf1eb33d00747173cfc80cc65648a4
diff --git a/src/strip.c b/src/strip.c
new file mode 100644
index 0000000..773ed54
--- /dev/null
+++ b/src/strip.c
@@ -0,0 +1,2427 @@
+/* Discard section not used at runtime from object files.
+ Copyright (C) 2000-2012, 2014, 2015, 2016, 2017 Red Hat, Inc.
+ This file is part of elfutils.
+ Written by Ulrich Drepper <drepper@redhat.com>, 2000.
+
+ This file 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.
+
+ 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 this program. If not, see <http://www.gnu.org/licenses/>. */
+
+#ifdef HAVE_CONFIG_H
+# include <config.h>
+#endif
+
+#include <argp.h>
+#include <assert.h>
+#include <byteswap.h>
+#include <endian.h>
+#include <error.h>
+#include <fcntl.h>
+#include <fnmatch.h>
+#include <gelf.h>
+#include <libelf.h>
+#include <libintl.h>
+#include <locale.h>
+#include <stdbool.h>
+#include <stdio.h>
+#include <stdio_ext.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+#include <sys/stat.h>
+#include <sys/time.h>
+
+#include <elf-knowledge.h>
+#include <libebl.h>
+#include "libdwelf.h"
+#include <libeu.h>
+#include <system.h>
+#include <printversion.h>
+
+typedef uint8_t GElf_Byte;
+
+/* Name and version of program. */
+ARGP_PROGRAM_VERSION_HOOK_DEF = print_version;
+
+/* Bug report address. */
+ARGP_PROGRAM_BUG_ADDRESS_DEF = PACKAGE_BUGREPORT;
+
+
+/* Values for the parameters which have no short form. */
+#define OPT_REMOVE_COMMENT 0x100
+#define OPT_PERMISSIVE 0x101
+#define OPT_STRIP_SECTIONS 0x102
+#define OPT_RELOC_DEBUG 0x103
+#define OPT_KEEP_SECTION 0x104
+
+
+/* Definitions of arguments for argp functions. */
+static const struct argp_option options[] =
+{
+ { NULL, 0, NULL, 0, N_("Output selection:"), 0 },
+ { "output", 'o', "FILE", 0, N_("Place stripped output into FILE"), 0 },
+ { NULL, 'f', "FILE", 0, N_("Extract the removed sections into FILE"), 0 },
+ { NULL, 'F', "FILE", 0, N_("Embed name FILE instead of -f argument"), 0 },
+
+ { NULL, 0, NULL, 0, N_("Output options:"), 0 },
+ { "strip-all", 's', NULL, OPTION_HIDDEN, NULL, 0 },
+ { "strip-debug", 'g', NULL, 0, N_("Remove all debugging symbols"), 0 },
+ { NULL, 'd', NULL, OPTION_ALIAS, NULL, 0 },
+ { NULL, 'S', NULL, OPTION_ALIAS, NULL, 0 },
+ { "strip-sections", OPT_STRIP_SECTIONS, NULL, 0,
+ N_("Remove section headers (not recommended)"), 0 },
+ { "preserve-dates", 'p', NULL, 0,
+ N_("Copy modified/access timestamps to the output"), 0 },
+ { "reloc-debug-sections", OPT_RELOC_DEBUG, NULL, 0,
+ N_("Resolve all trivial relocations between debug sections if the removed sections are placed in a debug file (only relevant for ET_REL files, operation is not reversable, needs -f)"), 0 },
+ { "remove-comment", OPT_REMOVE_COMMENT, NULL, 0,
+ N_("Remove .comment section"), 0 },
+ { "remove-section", 'R', "SECTION", 0, N_("Remove the named section. SECTION is an extended wildcard pattern. May be given more than once. Only non-allocated sections can be removed."), 0 },
+ { "keep-section", OPT_KEEP_SECTION, "SECTION", 0, N_("Keep the named section. SECTION is an extended wildcard pattern. May be given more than once."), 0 },
+ { "permissive", OPT_PERMISSIVE, NULL, 0,
+ N_("Relax a few rules to handle slightly broken ELF files"), 0 },
+ { NULL, 0, NULL, 0, NULL, 0 }
+};
+
+/* Short description of program. */
+static const char doc[] = N_("Discard symbols from object files.");
+
+/* Strings for arguments in help texts. */
+static const char args_doc[] = N_("[FILE...]");
+
+/* Prototype for option handler. */
+static error_t parse_opt (int key, char *arg, struct argp_state *state);
+
+/* Data structure to communicate with argp functions. */
+static struct argp argp =
+{
+ options, parse_opt, args_doc, doc, NULL, NULL, NULL
+};
+
+
+/* Print symbols in file named FNAME. */
+static int process_file (const char *fname);
+
+/* Handle one ELF file. */
+static int handle_elf (int fd, Elf *elf, const char *prefix,
+ const char *fname, mode_t mode, struct timespec tvp[2]);
+
+/* Handle all files contained in the archive. */
+static int handle_ar (int fd, Elf *elf, const char *prefix, const char *fname,
+ struct timespec tvp[2]) __attribute__ ((unused));
+
+static int debug_fd = -1;
+static char *tmp_debug_fname = NULL;
+
+/* Close debug file descriptor, if opened. And remove temporary debug file. */
+static void cleanup_debug (void);
+
+#define INTERNAL_ERROR(fname) \
+ do { \
+ cleanup_debug (); \
+ error (EXIT_FAILURE, 0, gettext ("%s: INTERNAL ERROR %d (%s): %s"), \
+ fname, __LINE__, PACKAGE_VERSION, elf_errmsg (-1)); \
+ } while (0)
+
+
+/* Name of the output file. */
+static const char *output_fname;
+
+/* Name of the debug output file. */
+static const char *debug_fname;
+
+/* Name to pretend the debug output file has. */
+static const char *debug_fname_embed;
+
+/* If true output files shall have same date as the input file. */
+static bool preserve_dates;
+
+/* If true .comment sections will be removed. */
+static bool remove_comment;
+
+/* If true remove all debug sections. */
+static bool remove_debug;
+
+/* If true remove all section headers. */
+static bool remove_shdrs;
+
+/* If true relax some ELF rules for input files. */
+static bool permissive;
+
+/* If true perform relocations between debug sections. */
+static bool reloc_debug;
+
+/* Sections the user explicitly wants to keep or remove. */
+struct section_pattern
+{
+ char *pattern;
+ struct section_pattern *next;
+};
+
+static struct section_pattern *keep_secs = NULL;
+static struct section_pattern *remove_secs = NULL;
+
+static void
+add_pattern (struct section_pattern **patterns, const char *pattern)
+{
+ struct section_pattern *p = xmalloc (sizeof *p);
+ p->pattern = xstrdup (pattern);
+ p->next = *patterns;
+ *patterns = p;
+}
+
+static void
+free_sec_patterns (struct section_pattern *patterns)
+{
+ struct section_pattern *pattern = patterns;
+ while (pattern != NULL)
+ {
+ struct section_pattern *p = pattern;
+ pattern = p->next;
+ free (p->pattern);
+ free (p);
+ }
+}
+
+static void
+free_patterns (void)
+{
+ free_sec_patterns (keep_secs);
+ free_sec_patterns (remove_secs);
+}
+
+static bool
+section_name_matches (struct section_pattern *patterns, const char *name)
+{
+ struct section_pattern *pattern = patterns;
+ while (pattern != NULL)
+ {
+ if (fnmatch (pattern->pattern, name, FNM_EXTMATCH) == 0)
+ return true;
+ pattern = pattern->next;
+ }
+ return false;
+}
+
+
+int
+main (int argc, char *argv[])
+{
+ int remaining;
+ int result = 0;
+
+ /* We use no threads here which can interfere with handling a stream. */
+ __fsetlocking (stdin, FSETLOCKING_BYCALLER);
+ __fsetlocking (stdout, FSETLOCKING_BYCALLER);
+ __fsetlocking (stderr, FSETLOCKING_BYCALLER);
+
+ /* Set locale. */
+ setlocale (LC_ALL, "");
+
+ /* Make sure the message catalog can be found. */
+ bindtextdomain (PACKAGE_TARNAME, LOCALEDIR);
+
+ /* Initialize the message catalog. */
+ textdomain (PACKAGE_TARNAME);
+
+ /* Parse and process arguments. */
+ if (argp_parse (&argp, argc, argv, 0, &remaining, NULL) != 0)
+ return EXIT_FAILURE;
+
+ if (reloc_debug && debug_fname == NULL)
+ error (EXIT_FAILURE, 0,
+ gettext ("--reloc-debug-sections used without -f"));
+
+ /* Tell the library which version we are expecting. */
+ elf_version (EV_CURRENT);
+
+ if (remaining == argc)
+ /* The user didn't specify a name so we use a.out. */
+ result = process_file ("a.out");
+ else
+ {
+ /* If we have seen the '-o' or '-f' option there must be exactly one
+ input file. */
+ if ((output_fname != NULL || debug_fname != NULL)
+ && remaining + 1 < argc)
+ error (EXIT_FAILURE, 0, gettext ("\
+Only one input file allowed together with '-o' and '-f'"));
+
+ /* Process all the remaining files. */
+ do
+ result |= process_file (argv[remaining]);
+ while (++remaining < argc);
+ }
+
+ free_patterns ();
+ return result;
+}
+
+
+/* Handle program arguments. */
+static error_t
+parse_opt (int key, char *arg, struct argp_state *state)
+{
+ switch (key)
+ {
+ case 'f':
+ if (debug_fname != NULL)
+ {
+ error (0, 0, gettext ("-f option specified twice"));
+ return EINVAL;
+ }
+ debug_fname = arg;
+ break;
+
+ case 'F':
+ if (debug_fname_embed != NULL)
+ {
+ error (0, 0, gettext ("-F option specified twice"));
+ return EINVAL;
+ }
+ debug_fname_embed = arg;
+ break;
+
+ case 'o':
+ if (output_fname != NULL)
+ {
+ error (0, 0, gettext ("-o option specified twice"));
+ return EINVAL;
+ }
+ output_fname = arg;
+ break;
+
+ case 'p':
+ preserve_dates = true;
+ break;
+
+ case OPT_RELOC_DEBUG:
+ reloc_debug = true;
+ break;
+
+ case OPT_REMOVE_COMMENT:
+ remove_comment = true;
+ break;
+
+ case 'R':
+ if (fnmatch (arg, ".comment", FNM_EXTMATCH) == 0)
+ remove_comment = true;
+ add_pattern (&remove_secs, arg);
+ break;
+
+ case OPT_KEEP_SECTION:
+ add_pattern (&keep_secs, arg);
+ break;
+
+ case 'g':
+ case 'd':
+ case 'S':
+ remove_debug = true;
+ break;
+
+ case OPT_STRIP_SECTIONS:
+ remove_shdrs = true;
+ break;
+
+ case OPT_PERMISSIVE:
+ permissive = true;
+ break;
+
+ case 's': /* Ignored for compatibility. */
+ break;
+
+ case ARGP_KEY_SUCCESS:
+ if (remove_comment == true
+ && section_name_matches (keep_secs, ".comment"))
+ {
+ argp_error (state,
+ gettext ("cannot both keep and remove .comment section"));
+ return EINVAL;
+ }
+ break;
+
+ default:
+ return ARGP_ERR_UNKNOWN;
+ }
+ return 0;
+}
+
+
+static int
+process_file (const char *fname)
+{
+ /* If we have to preserve the modify and access timestamps get them
+ now. We cannot use fstat() after opening the file since the open
+ would change the access time. */
+ struct stat pre_st;
+ struct timespec tv[2];
+ again:
+ if (preserve_dates)
+ {
+ if (stat (fname, &pre_st) != 0)
+ {
+ error (0, errno, gettext ("cannot stat input file '%s'"), fname);
+ return 1;
+ }
+
+ /* If we have to preserve the timestamp, we need it in the
+ format utimes() understands. */
+ tv[0] = pre_st.st_atim;
+ tv[1] = pre_st.st_mtim;
+ }
+
+ /* Open the file. */
+ int fd = open (fname, output_fname == NULL ? O_RDWR : O_RDONLY);
+ if (fd == -1)
+ {
+ error (0, errno, gettext ("while opening '%s'"), fname);
+ return 1;
+ }
+
+ /* We always use fstat() even if we called stat() before. This is
+ done to make sure the information returned by stat() is for the
+ same file. */
+ struct stat st;
+ if (fstat (fd, &st) != 0)
+ {
+ error (0, errno, gettext ("cannot stat input file '%s'"), fname);
+ return 1;
+ }
+ /* Paranoid mode on. */
+ if (preserve_dates
+ && (st.st_ino != pre_st.st_ino || st.st_dev != pre_st.st_dev))
+ {
+ /* We detected a race. Try again. */
+ close (fd);
+ goto again;
+ }
+
+ /* Now get the ELF descriptor. */
+ Elf *elf = elf_begin (fd, output_fname == NULL ? ELF_C_RDWR : ELF_C_READ,
+ NULL);
+ int result;
+ switch (elf_kind (elf))
+ {
+ case ELF_K_ELF:
+ result = handle_elf (fd, elf, NULL, fname, st.st_mode & ACCESSPERMS,
+ preserve_dates ? tv : NULL);
+ break;
+
+ case ELF_K_AR:
+ /* It is not possible to strip the content of an archive direct
+ the output to a specific file. */
+ if (unlikely (output_fname != NULL || debug_fname != NULL))
+ {
+ error (0, 0, gettext ("%s: cannot use -o or -f when stripping archive"),
+ fname);
+ result = 1;
+ }
+ else
+ {
+ /* We would like to support ar archives, but currently it just
+ doesn't work at all since we call elf_clone on the members
+ which doesn't really support ar members.
+ result = handle_ar (fd, elf, NULL, fname,
+ preserve_dates ? tv : NULL);
+ */
+ error (0, 0, gettext ("%s: no support for stripping archive"),
+ fname);
+ result = 1;
+ }
+ break;
+
+ default:
+ error (0, 0, gettext ("%s: File format not recognized"), fname);
+ result = 1;
+ break;
+ }
+
+ if (unlikely (elf_end (elf) != 0))
+ INTERNAL_ERROR (fname);
+
+ close (fd);
+
+ return result;
+}
+
+
+/* Maximum size of array allocated on stack. */
+#define MAX_STACK_ALLOC (400 * 1024)
+
+static int
+handle_elf (int fd, Elf *elf, const char *prefix, const char *fname,
+ mode_t mode, struct timespec tvp[2])
+{
+ size_t prefix_len = prefix == NULL ? 0 : strlen (prefix);
+ size_t fname_len = strlen (fname) + 1;
+ char *fullname = alloca (prefix_len + 1 + fname_len);
+ char *cp = fullname;
+ Elf *debugelf = NULL;
+ tmp_debug_fname = NULL;
+ int result = 0;
+ size_t shdridx = 0;
+ size_t shstrndx;
+ struct shdr_info
+ {
+ Elf_Scn *scn;
+ GElf_Shdr shdr;
+ Elf_Data *data;
+ Elf_Data *debug_data;
+ const char *name;
+ Elf32_Word idx; /* Index in new file. */
+ Elf32_Word old_sh_link; /* Original value of shdr.sh_link. */
+ Elf32_Word symtab_idx;
+ Elf32_Word version_idx;
+ Elf32_Word group_idx;
+ Elf32_Word group_cnt;
+ Elf_Scn *newscn;
+ Dwelf_Strent *se;
+ Elf32_Word *newsymidx;
+ } *shdr_info = NULL;
+ Elf_Scn *scn;
+ size_t cnt;
+ size_t idx;
+ bool changes;
+ GElf_Ehdr newehdr_mem;
+ GElf_Ehdr *newehdr;
+ GElf_Ehdr debugehdr_mem;
+ GElf_Ehdr *debugehdr;
+ Dwelf_Strtab *shst = NULL;
+ Elf_Data debuglink_crc_data;
+ bool any_symtab_changes = false;
+ Elf_Data *shstrtab_data = NULL;
+ void *debuglink_buf = NULL;
+
+ /* Create the full name of the file. */
+ if (prefix != NULL)
+ {
+ cp = mempcpy (cp, prefix, prefix_len);
+ *cp++ = ':';
+ }
+ memcpy (cp, fname, fname_len);
+
+ /* If we are not replacing the input file open a new file here. */
+ if (output_fname != NULL)
+ {
+ fd = open (output_fname, O_RDWR | O_CREAT, mode);
+ if (unlikely (fd == -1))
+ {
+ error (0, errno, gettext ("cannot open '%s'"), output_fname);
+ return 1;
+ }
+ }
+
+ debug_fd = -1;
+
+ /* Get the EBL handling. Removing all debugging symbols with the -g
+ option or resolving all relocations between debug sections with
+ the --reloc-debug-sections option are currently the only reasons
+ we need EBL so don't open the backend unless necessary. */
+ Ebl *ebl = NULL;
+ if (remove_debug || reloc_debug)
+ {
+ ebl = ebl_openbackend (elf);
+ if (ebl == NULL)
+ {
+ error (0, errno, gettext ("cannot open EBL backend"));
+ result = 1;
+ goto fail;
+ }
+ }
+
+ /* Open the additional file the debug information will be stored in. */
+ if (debug_fname != NULL)
+ {
+ /* Create a temporary file name. We do not want to overwrite
+ the debug file if the file would not contain any
+ information. */
+ size_t debug_fname_len = strlen (debug_fname);
+ tmp_debug_fname = (char *) xmalloc (debug_fname_len + sizeof (".XXXXXX"));
+ strcpy (mempcpy (tmp_debug_fname, debug_fname, debug_fname_len),
+ ".XXXXXX");
+
+ debug_fd = mkstemp (tmp_debug_fname);
+ if (unlikely (debug_fd == -1))
+ {
+ error (0, errno, gettext ("cannot open '%s'"), debug_fname);
+ result = 1;
+ goto fail;
+ }
+ }
+
+ /* Get the information from the old file. */
+ GElf_Ehdr ehdr_mem;
+ GElf_Ehdr *ehdr = gelf_getehdr (elf, &ehdr_mem);
+ if (ehdr == NULL)
+ INTERNAL_ERROR (fname);
+
+ /* Get the section header string table index. */
+ if (unlikely (elf_getshdrstrndx (elf, &shstrndx) < 0))
+ {
+ cleanup_debug ();
+ error (EXIT_FAILURE, 0,
+ gettext ("cannot get section header string table index"));
+ }
+
+ /* Get the number of phdrs in the old file. */
+ size_t phnum;
+ if (elf_getphdrnum (elf, &phnum) != 0)
+ {
+ cleanup_debug ();
+ error (EXIT_FAILURE, 0, gettext ("cannot get number of phdrs"));
+ }
+
+ /* We now create a new ELF descriptor for the same file. We
+ construct it almost exactly in the same way with some information
+ dropped. */
+ Elf *newelf;
+ if (output_fname != NULL)
+ newelf = elf_begin (fd, ELF_C_WRITE_MMAP, NULL);
+ else
+ newelf = elf_clone (elf, ELF_C_EMPTY);
+
+ if (unlikely (gelf_newehdr (newelf, gelf_getclass (elf)) == 0)
+ || (ehdr->e_type != ET_REL
+ && unlikely (gelf_newphdr (newelf, phnum) == 0)))
+ {
+ error (0, 0, gettext ("cannot create new file '%s': %s"),
+ output_fname ?: fname, elf_errmsg (-1));
+ goto fail;
+ }
+
+ /* Copy over the old program header if needed. */
+ if (ehdr->e_type != ET_REL)
+ for (cnt = 0; cnt < phnum; ++cnt)
+ {
+ GElf_Phdr phdr_mem;
+ GElf_Phdr *phdr = gelf_getphdr (elf, cnt, &phdr_mem);
+ if (phdr == NULL
+ || unlikely (gelf_update_phdr (newelf, cnt, phdr) == 0))
+ INTERNAL_ERROR (fname);
+ }
+
+ if (debug_fname != NULL)
+ {
+ /* Also create an ELF descriptor for the debug file */
+ debugelf = elf_begin (debug_fd, ELF_C_WRITE_MMAP, NULL);
+ if (unlikely (gelf_newehdr (debugelf, gelf_getclass (elf)) == 0)
+ || (ehdr->e_type != ET_REL
+ && unlikely (gelf_newphdr (debugelf, phnum) == 0)))
+ {
+ error (0, 0, gettext ("cannot create new file '%s': %s"),
+ debug_fname, elf_errmsg (-1));
+ goto fail_close;
+ }
+
+ /* Copy over the old program header if needed. */
+ if (ehdr->e_type != ET_REL)
+ for (cnt = 0; cnt < phnum; ++cnt)
+ {
+ GElf_Phdr phdr_mem;
+ GElf_Phdr *phdr = gelf_getphdr (elf, cnt, &phdr_mem);
+ if (phdr == NULL
+ || unlikely (gelf_update_phdr (debugelf, cnt, phdr) == 0))
+ INTERNAL_ERROR (fname);
+ }
+ }
+
+ /* Number of sections. */
+ size_t shnum;
+ if (unlikely (elf_getshdrnum (elf, &shnum) < 0))
+ {
+ error (0, 0, gettext ("cannot determine number of sections: %s"),
+ elf_errmsg (-1));
+ goto fail_close;
+ }
+
+ if (shstrndx >= shnum)
+ goto illformed;
+
+#define elf_assert(test) do { if (!(test)) goto illformed; } while (0)
+
+ /* Storage for section information. We leave room for two more
+ entries since we unconditionally create a section header string
+ table. Maybe some weird tool created an ELF file without one.
+ The other one is used for the debug link section. */
+ if ((shnum + 2) * sizeof (struct shdr_info) > MAX_STACK_ALLOC)
+ shdr_info = (struct shdr_info *) xcalloc (shnum + 2,
+ sizeof (struct shdr_info));
+ else
+ {
+ shdr_info = (struct shdr_info *) alloca ((shnum + 2)
+ * sizeof (struct shdr_info));
+ memset (shdr_info, '\0', (shnum + 2) * sizeof (struct shdr_info));
+ }
+
+ /* Prepare section information data structure. */
+ scn = NULL;
+ cnt = 1;
+ while ((scn = elf_nextscn (elf, scn)) != NULL)
+ {
+ /* This should always be true (i.e., there should not be any
+ holes in the numbering). */
+ elf_assert (elf_ndxscn (scn) == cnt);
+
+ shdr_info[cnt].scn = scn;
+
+ /* Get the header. */
+ if (gelf_getshdr (scn, &shdr_info[cnt].shdr) == NULL)
+ INTERNAL_ERROR (fname);
+
+ /* Get the name of the section. */
+ shdr_info[cnt].name = elf_strptr (elf, shstrndx,
+ shdr_info[cnt].shdr.sh_name);
+ if (shdr_info[cnt].name == NULL)
+ {
+ illformed:
+ error (0, 0, gettext ("illformed file '%s'"), fname);
+ goto fail_close;
+ }
+
+ /* Sanity check the user. */
+ if (section_name_matches (remove_secs, shdr_info[cnt].name))
+ {
+ if ((shdr_info[cnt].shdr.sh_flags & SHF_ALLOC) != 0)
+ {
+ error (0, 0,
+ gettext ("Cannot remove allocated section '%s'"),
+ shdr_info[cnt].name);
+ result = 1;
+ goto fail_close;
+ }
+
+ if (section_name_matches (keep_secs, shdr_info[cnt].name))
+ {
+ error (0, 0,
+ gettext ("Cannot both keep and remove section '%s'"),
+ shdr_info[cnt].name);
+ result = 1;
+ goto fail_close;
+ }
+ }
+
+ /* Mark them as present but not yet investigated. */
+ shdr_info[cnt].idx = 1;
+
+ /* Remember the shdr.sh_link value. */
+ shdr_info[cnt].old_sh_link = shdr_info[cnt].shdr.sh_link;
+ if (shdr_info[cnt].old_sh_link >= shnum)
+ goto illformed;
+
+ /* Sections in files other than relocatable object files which
+ not loaded can be freely moved by us. In theory we can also
+ freely move around allocated nobits sections. But we don't
+ to keep the layout of all allocated sections as similar as
+ possible to the original file. In relocatable object files
+ everything can be moved. */
+ if (ehdr->e_type == ET_REL
+ || (shdr_info[cnt].shdr.sh_flags & SHF_ALLOC) == 0)
+ shdr_info[cnt].shdr.sh_offset = 0;
+
+ /* If this is an extended section index table store an
+ appropriate reference. */
+ if (unlikely (shdr_info[cnt].shdr.sh_type == SHT_SYMTAB_SHNDX))
+ {
+ elf_assert (shdr_info[shdr_info[cnt].shdr.sh_link].symtab_idx == 0);
+ shdr_info[shdr_info[cnt].shdr.sh_link].symtab_idx = cnt;
+ }
+ else if (unlikely (shdr_info[cnt].shdr.sh_type == SHT_GROUP))
+ {
+ /* Cross-reference the sections contained in the section
+ group. */
+ shdr_info[cnt].data = elf_getdata (shdr_info[cnt].scn, NULL);
+ if (shdr_info[cnt].data == NULL
+ || shdr_info[cnt].data->d_size < sizeof (Elf32_Word))
+ INTERNAL_ERROR (fname);
+
+ /* XXX Fix for unaligned access. */
+ Elf32_Word *grpref = (Elf32_Word *) shdr_info[cnt].data->d_buf;
+ size_t inner;
+ for (inner = 1;
+ inner < shdr_info[cnt].data->d_size / sizeof (Elf32_Word);
+ ++inner)
+ {
+ if (grpref[inner] < shnum)
+ shdr_info[grpref[inner]].group_idx = cnt;
+ else
+ goto illformed;
+ }
+
+ if (inner == 1 || (inner == 2 && (grpref[0] & GRP_COMDAT) == 0))
+ /* If the section group contains only one element and this
+ is n COMDAT section we can drop it right away. */
+ shdr_info[cnt].idx = 0;
+ else
+ shdr_info[cnt].group_cnt = inner - 1;
+ }
+ else if (unlikely (shdr_info[cnt].shdr.sh_type == SHT_GNU_versym))
+ {
+ elf_assert (shdr_info[shdr_info[cnt].shdr.sh_link].version_idx == 0);
+ shdr_info[shdr_info[cnt].shdr.sh_link].version_idx = cnt;
+ }
+
+ /* If this section is part of a group make sure it is not
+ discarded right away. */
+ if ((shdr_info[cnt].shdr.sh_flags & SHF_GROUP) != 0)
+ {
+ elf_assert (shdr_info[cnt].group_idx != 0);
+
+ if (shdr_info[shdr_info[cnt].group_idx].idx == 0)
+ {
+ /* The section group section will be removed. */
+ shdr_info[cnt].group_idx = 0;
+ shdr_info[cnt].shdr.sh_flags &= ~SHF_GROUP;
+ }
+ }
+
+ /* Increment the counter. */
+ ++cnt;
+ }
+
+ /* Now determine which sections can go away. The general rule is that
+ all sections which are not used at runtime are stripped out. But
+ there are a few exceptions:
+
+ - special sections named ".comment" and ".note" are kept
+ - OS or architecture specific sections are kept since we might not
+ know how to handle them
+ - if a section is referred to from a section which is not removed
+ in the sh_link or sh_info element it cannot be removed either
+ - the user might have explicitly said to remove or keep a section
+ */
+ for (cnt = 1; cnt < shnum; ++cnt)
+ /* Check whether the section can be removed. Since we will create
+ a new .shstrtab assume it will be removed too. */
+ if (remove_shdrs ? !(shdr_info[cnt].shdr.sh_flags & SHF_ALLOC)
+ : (ebl_section_strip_p (ebl, ehdr, &shdr_info[cnt].shdr,
+ shdr_info[cnt].name, remove_comment,
+ remove_debug)
+ || cnt == ehdr->e_shstrndx
+ || section_name_matches (remove_secs, shdr_info[cnt].name)))
+ {
+ /* The user might want to explicitly keep this one. */
+ if (section_name_matches (keep_secs, shdr_info[cnt].name))
+ continue;
+
+ /* For now assume this section will be removed. */
+ shdr_info[cnt].idx = 0;
+
+ idx = shdr_info[cnt].group_idx;
+ while (idx != 0)
+ {
+ /* The section group data is already loaded. */
+ elf_assert (shdr_info[idx].data != NULL
+ && shdr_info[idx].data->d_buf != NULL
+ && shdr_info[idx].data->d_size >= sizeof (Elf32_Word));
+
+ /* If the references section group is a normal section
+ group and has one element remaining, or if it is an
+ empty COMDAT section group it is removed. */
+ bool is_comdat = (((Elf32_Word *) shdr_info[idx].data->d_buf)[0]
+ & GRP_COMDAT) != 0;
+
+ --shdr_info[idx].group_cnt;
+ if ((!is_comdat && shdr_info[idx].group_cnt == 1)
+ || (is_comdat && shdr_info[idx].group_cnt == 0))
+ {
+ shdr_info[idx].idx = 0;
+ /* Continue recursively. */
+ idx = shdr_info[idx].group_idx;
+ }
+ else
+ break;
+ }
+ }
+
+ /* Mark the SHT_NULL section as handled. */
+ shdr_info[0].idx = 2;
+
+
+ /* Handle exceptions: section groups and cross-references. We might
+ have to repeat this a few times since the resetting of the flag
+ might propagate. */
+ do
+ {
+ changes = false;
+
+ for (cnt = 1; cnt < shnum; ++cnt)
+ {
+ if (shdr_info[cnt].idx == 0)
+ {
+ /* If a relocation section is marked as being removed make
+ sure the section it is relocating is removed, too. */
+ if (shdr_info[cnt].shdr.sh_type == SHT_REL
+ || shdr_info[cnt].shdr.sh_type == SHT_RELA)
+ {
+ if (shdr_info[cnt].shdr.sh_info >= shnum)
+ goto illformed;
+ else if (shdr_info[shdr_info[cnt].shdr.sh_info].idx != 0)
+ shdr_info[cnt].idx = 1;
+ }
+
+ /* If a group section is marked as being removed make
+ sure all the sections it contains are being removed, too. */
+ if (shdr_info[cnt].shdr.sh_type == SHT_GROUP)
+ {
+ Elf32_Word *grpref;
+ grpref = (Elf32_Word *) shdr_info[cnt].data->d_buf;
+ for (size_t in = 1;
+ in < shdr_info[cnt].data->d_size / sizeof (Elf32_Word);
+ ++in)
+ if (grpref[in] < shnum)
+ {
+ if (shdr_info[grpref[in]].idx != 0)
+ {
+ shdr_info[cnt].idx = 1;
+ break;
+ }
+ }
+ else
+ goto illformed;
+ }
+ }
+
+ if (shdr_info[cnt].idx == 1)
+ {
+ /* The content of symbol tables we don't remove must not
+ reference any section which we do remove. Otherwise
+ we cannot remove the section. */
+ if (debug_fname != NULL
+ && shdr_info[cnt].debug_data == NULL
+ && (shdr_info[cnt].shdr.sh_type == SHT_DYNSYM
+ || shdr_info[cnt].shdr.sh_type == SHT_SYMTAB))
+ {
+ /* Make sure the data is loaded. */
+ if (shdr_info[cnt].data == NULL)
+ {
+ shdr_info[cnt].data
+ = elf_getdata (shdr_info[cnt].scn, NULL);
+ if (shdr_info[cnt].data == NULL)
+ INTERNAL_ERROR (fname);
+ }
+ Elf_Data *symdata = shdr_info[cnt].data;
+
+ /* If there is an extended section index table load it
+ as well. */
+ if (shdr_info[cnt].symtab_idx != 0
+ && shdr_info[shdr_info[cnt].symtab_idx].data == NULL)
+ {
+ elf_assert (shdr_info[cnt].shdr.sh_type == SHT_SYMTAB);
+
+ shdr_info[shdr_info[cnt].symtab_idx].data
+ = elf_getdata (shdr_info[shdr_info[cnt].symtab_idx].scn,
+ NULL);
+ if (shdr_info[shdr_info[cnt].symtab_idx].data == NULL)
+ INTERNAL_ERROR (fname);
+ }
+ Elf_Data *xndxdata
+ = shdr_info[shdr_info[cnt].symtab_idx].data;
+
+ /* Go through all symbols and make sure the section they
+ reference is not removed. */
+ size_t elsize = gelf_fsize (elf, ELF_T_SYM, 1, EV_CURRENT);
+
+ for (size_t inner = 0;
+ inner < shdr_info[cnt].data->d_size / elsize;
+ ++inner)
+ {
+ GElf_Sym sym_mem;
+ Elf32_Word xndx;
+ GElf_Sym *sym = gelf_getsymshndx (symdata, xndxdata,
+ inner, &sym_mem,
+ &xndx);
+ if (sym == NULL)
+ INTERNAL_ERROR (fname);
+
+ size_t scnidx = sym->st_shndx;
+ if (scnidx == SHN_UNDEF || scnidx >= shnum
+ || (scnidx >= SHN_LORESERVE
+ && scnidx <= SHN_HIRESERVE
+ && scnidx != SHN_XINDEX)
+ /* Don't count in the section symbols. */
+ || GELF_ST_TYPE (sym->st_info) == STT_SECTION)
+ /* This is no section index, leave it alone. */
+ continue;
+ else if (scnidx == SHN_XINDEX)
+ scnidx = xndx;
+
+ if (scnidx >= shnum)
+ goto illformed;
+
+ if (shdr_info[scnidx].idx == 0)
+ /* This symbol table has a real symbol in
+ a discarded section. So preserve the
+ original table in the debug file. Unless
+ it is a redundant data marker to a debug
+ (data only) section. */
+ if (! (ebl_section_strip_p (ebl, ehdr,
+ &shdr_info[scnidx].shdr,
+ shdr_info[scnidx].name,
+ remove_comment,
+ remove_debug)
+ && ebl_data_marker_symbol (ebl, sym,
+ elf_strptr (elf,
+ shdr_info[cnt].shdr.sh_link,
+ sym->st_name))))
+ shdr_info[cnt].debug_data = symdata;
+ }
+ }
+
+ /* Cross referencing happens:
+ - for the cases the ELF specification says. That are
+ + SHT_DYNAMIC in sh_link to string table
+ + SHT_HASH in sh_link to symbol table
+ + SHT_REL and SHT_RELA in sh_link to symbol table
+ + SHT_SYMTAB and SHT_DYNSYM in sh_link to string table
+ + SHT_GROUP in sh_link to symbol table
+ + SHT_SYMTAB_SHNDX in sh_link to symbol table
+ Other (OS or architecture-specific) sections might as
+ well use this field so we process it unconditionally.
+ - references inside section groups
+ - specially marked references in sh_info if the SHF_INFO_LINK
+ flag is set
+ */
+
+ if (shdr_info[shdr_info[cnt].shdr.sh_link].idx == 0)
+ {
+ shdr_info[shdr_info[cnt].shdr.sh_link].idx = 1;
+ changes |= shdr_info[cnt].shdr.sh_link < cnt;
+ }
+
+ /* Handle references through sh_info. */
+ if (SH_INFO_LINK_P (&shdr_info[cnt].shdr))
+ {
+ if (shdr_info[cnt].shdr.sh_info >= shnum)
+ goto illformed;
+ else if ( shdr_info[shdr_info[cnt].shdr.sh_info].idx == 0)
+ {
+ shdr_info[shdr_info[cnt].shdr.sh_info].idx = 1;
+ changes |= shdr_info[cnt].shdr.sh_info < cnt;
+ }
+ }
+
+ /* Mark the section as investigated. */
+ shdr_info[cnt].idx = 2;
+ }
+
+ if (debug_fname != NULL
+ && (shdr_info[cnt].idx == 0 || shdr_info[cnt].debug_data != NULL))
+ {
+ /* This section is being preserved in the debug file.
+ Sections it refers to must be preserved there too.
+
+ In this pass we mark sections to be preserved in both
+ files by setting the .debug_data pointer to the original
+ file's .data pointer. Below, we'll copy the section
+ contents. */
+
+ inline void check_preserved (size_t i)
+ {
+ if (i != 0 && i < shnum + 2 && shdr_info[i].idx != 0
+ && shdr_info[i].debug_data == NULL)
+ {
+ if (shdr_info[i].data == NULL)
+ shdr_info[i].data = elf_getdata (shdr_info[i].scn, NULL);
+ if (shdr_info[i].data == NULL)
+ INTERNAL_ERROR (fname);
+
+ shdr_info[i].debug_data = shdr_info[i].data;
+ changes |= i < cnt;
+ }
+ }
+
+ check_preserved (shdr_info[cnt].shdr.sh_link);
+ if (SH_INFO_LINK_P (&shdr_info[cnt].shdr))
+ check_preserved (shdr_info[cnt].shdr.sh_info);
+ }
+ }
+ }
+ while (changes);
+
+ /* Copy the removed sections to the debug output file.
+ The ones that are not removed in the stripped file are SHT_NOBITS. */
+ if (debug_fname != NULL)
+ {
+ for (cnt = 1; cnt < shnum; ++cnt)
+ {
+ scn = elf_newscn (debugelf);
+ if (scn == NULL)
+ {
+ cleanup_debug ();
+ error (EXIT_FAILURE, 0,
+ gettext ("while generating output file: %s"),
+ elf_errmsg (-1));
+ }
+
+ bool discard_section = (shdr_info[cnt].idx > 0
+ && shdr_info[cnt].debug_data == NULL
+ && shdr_info[cnt].shdr.sh_type != SHT_NOTE
+ && shdr_info[cnt].shdr.sh_type != SHT_GROUP
+ && cnt != ehdr->e_shstrndx);
+
+ /* Set the section header in the new file. */
+ GElf_Shdr debugshdr = shdr_info[cnt].shdr;
+ if (discard_section)
+ debugshdr.sh_type = SHT_NOBITS;
+
+ if (unlikely (gelf_update_shdr (scn, &debugshdr) == 0))
+ /* There cannot be any overflows. */
+ INTERNAL_ERROR (fname);
+
+ /* Get the data from the old file if necessary. */
+ if (shdr_info[cnt].data == NULL)
+ {
+ shdr_info[cnt].data = elf_getdata (shdr_info[cnt].scn, NULL);
+ if (shdr_info[cnt].data == NULL)
+ INTERNAL_ERROR (fname);
+ }
+
+ /* Set the data. This is done by copying from the old file. */
+ Elf_Data *debugdata = elf_newdata (scn);
+ if (debugdata == NULL)
+ INTERNAL_ERROR (fname);
+
+ /* Copy the structure. This data may be modified in place
+ before we write out the file. */
+ *debugdata = *shdr_info[cnt].data;
+ if (discard_section)
+ debugdata->d_buf = NULL;
+ else if (shdr_info[cnt].debug_data != NULL
+ || shdr_info[cnt].shdr.sh_type == SHT_GROUP)
+ {
+ /* Copy the original data before it gets modified. */
+ shdr_info[cnt].debug_data = debugdata;
+ if (debugdata->d_buf == NULL)
+ INTERNAL_ERROR (fname);
+ debugdata->d_buf = memcpy (xmalloc (debugdata->d_size),
+ debugdata->d_buf, debugdata->d_size);
+ }
+ }
+
+ /* Finish the ELF header. Fill in the fields not handled by
+ libelf from the old file. */
+ debugehdr = gelf_getehdr (debugelf, &debugehdr_mem);
+ if (debugehdr == NULL)
+ INTERNAL_ERROR (fname);
+
+ memcpy (debugehdr->e_ident, ehdr->e_ident, EI_NIDENT);
+ debugehdr->e_type = ehdr->e_type;
+ debugehdr->e_machine = ehdr->e_machine;
+ debugehdr->e_version = ehdr->e_version;
+ debugehdr->e_entry = ehdr->e_entry;
+ debugehdr->e_flags = ehdr->e_flags;
+ debugehdr->e_shstrndx = ehdr->e_shstrndx;
+
+ if (unlikely (gelf_update_ehdr (debugelf, debugehdr) == 0))
+ {
+ error (0, 0, gettext ("%s: error while creating ELF header: %s"),
+ debug_fname, elf_errmsg (-1));
+ result = 1;
+ goto fail_close;
+ }
+ }
+
+ /* Although we always create a new section header string table we
+ don't explicitly mark the existing one as unused. It can still
+ be used through a symbol table section we are keeping. If not it
+ will already be marked as unused. */
+
+ /* We need a string table for the section headers. */
+ shst = dwelf_strtab_init (true);
+ if (shst == NULL)
+ {
+ cleanup_debug ();
+ error (EXIT_FAILURE, errno, gettext ("while preparing output for '%s'"),
+ output_fname ?: fname);
+ }
+
+ /* Assign new section numbers. */
+ shdr_info[0].idx = 0;
+ for (cnt = idx = 1; cnt < shnum; ++cnt)
+ if (shdr_info[cnt].idx > 0)
+ {
+ shdr_info[cnt].idx = idx++;
+
+ /* Create a new section. */
+ shdr_info[cnt].newscn = elf_newscn (newelf);
+ if (shdr_info[cnt].newscn == NULL)
+ {
+ cleanup_debug ();
+ error (EXIT_FAILURE, 0,
+ gettext ("while generating output file: %s"),
+ elf_errmsg (-1));
+ }
+
+ elf_assert (elf_ndxscn (shdr_info[cnt].newscn) == shdr_info[cnt].idx);
+
+ /* Add this name to the section header string table. */
+ shdr_info[cnt].se = dwelf_strtab_add (shst, shdr_info[cnt].name);
+ }
+
+ /* Test whether we are doing anything at all. Either all removable
+ sections are already gone. Or the only section we would remove is
+ the .shstrtab section which we would add again. */
+ bool removing_sections = !(cnt == idx
+ || (cnt == idx + 1
+ && shdr_info[ehdr->e_shstrndx].idx == 0));
+ if (output_fname == NULL && !removing_sections)
+ goto fail_close;
+
+ /* Create the reference to the file with the debug info (if any). */
+ if (debug_fname != NULL && !remove_shdrs && removing_sections)
+ {
+ /* Add the section header string table section name. */
+ shdr_info[cnt].se = dwelf_strtab_add_len (shst, ".gnu_debuglink", 15);
+ shdr_info[cnt].idx = idx++;
+
+ /* Create the section header. */
+ shdr_info[cnt].shdr.sh_type = SHT_PROGBITS;
+ shdr_info[cnt].shdr.sh_flags = 0;
+ shdr_info[cnt].shdr.sh_addr = 0;
+ shdr_info[cnt].shdr.sh_link = SHN_UNDEF;
+ shdr_info[cnt].shdr.sh_info = SHN_UNDEF;
+ shdr_info[cnt].shdr.sh_entsize = 0;
+ shdr_info[cnt].shdr.sh_addralign = 4;
+ /* We set the offset to zero here. Before we write the ELF file the
+ field must have the correct value. This is done in the final
+ loop over all section. Then we have all the information needed. */
+ shdr_info[cnt].shdr.sh_offset = 0;
+
+ /* Create the section. */
+ shdr_info[cnt].newscn = elf_newscn (newelf);
+ if (shdr_info[cnt].newscn == NULL)
+ {
+ cleanup_debug ();
+ error (EXIT_FAILURE, 0,
+ gettext ("while create section header section: %s"),
+ elf_errmsg (-1));
+ }
+ elf_assert (elf_ndxscn (shdr_info[cnt].newscn) == shdr_info[cnt].idx);
+
+ shdr_info[cnt].data = elf_newdata (shdr_info[cnt].newscn);
+ if (shdr_info[cnt].data == NULL)
+ {
+ cleanup_debug ();
+ error (EXIT_FAILURE, 0, gettext ("cannot allocate section data: %s"),
+ elf_errmsg (-1));
+ }
+
+ char *debug_basename = basename (debug_fname_embed ?: debug_fname);
+ off_t crc_offset = strlen (debug_basename) + 1;
+ /* Align to 4 byte boundary */
+ crc_offset = ((crc_offset - 1) & ~3) + 4;
+
+ shdr_info[cnt].data->d_align = 4;
+ shdr_info[cnt].shdr.sh_size = shdr_info[cnt].data->d_size
+ = crc_offset + 4;
+ debuglink_buf = xcalloc (1, shdr_info[cnt].data->d_size);
+ shdr_info[cnt].data->d_buf = debuglink_buf;
+
+ strcpy (shdr_info[cnt].data->d_buf, debug_basename);
+
+ /* Cache this Elf_Data describing the CRC32 word in the section.
+ We'll fill this in when we have written the debug file. */
+ debuglink_crc_data = *shdr_info[cnt].data;
+ debuglink_crc_data.d_buf = ((char *) debuglink_crc_data.d_buf
+ + crc_offset);
+ debuglink_crc_data.d_size = 4;
+
+ /* One more section done. */
+ ++cnt;
+ }
+
+ /* Index of the section header table in the shdr_info array. */
+ shdridx = cnt;
+
+ /* Add the section header string table section name. */
+ shdr_info[cnt].se = dwelf_strtab_add_len (shst, ".shstrtab", 10);
+ shdr_info[cnt].idx = idx;
+
+ /* Create the section header. */
+ shdr_info[cnt].shdr.sh_type = SHT_STRTAB;
+ shdr_info[cnt].shdr.sh_flags = 0;
+ shdr_info[cnt].shdr.sh_addr = 0;
+ shdr_info[cnt].shdr.sh_link = SHN_UNDEF;
+ shdr_info[cnt].shdr.sh_info = SHN_UNDEF;
+ shdr_info[cnt].shdr.sh_entsize = 0;
+ /* We set the offset to zero here. Before we write the ELF file the
+ field must have the correct value. This is done in the final
+ loop over all section. Then we have all the information needed. */
+ shdr_info[cnt].shdr.sh_offset = 0;
+ shdr_info[cnt].shdr.sh_addralign = 1;
+
+ /* Create the section. */
+ shdr_info[cnt].newscn = elf_newscn (newelf);
+ if (shdr_info[cnt].newscn == NULL)
+ {
+ cleanup_debug ();
+ error (EXIT_FAILURE, 0,
+ gettext ("while create section header section: %s"),
+ elf_errmsg (-1));
+ }
+ elf_assert (elf_ndxscn (shdr_info[cnt].newscn) == idx);
+
+ /* Finalize the string table and fill in the correct indices in the
+ section headers. */
+ shstrtab_data = elf_newdata (shdr_info[cnt].newscn);
+ if (shstrtab_data == NULL)
+ {
+ cleanup_debug ();
+ error (EXIT_FAILURE, 0,
+ gettext ("while create section header string table: %s"),
+ elf_errmsg (-1));
+ }
+ if (dwelf_strtab_finalize (shst, shstrtab_data) == NULL)
+ {
+ cleanup_debug ();
+ error (EXIT_FAILURE, 0,
+ gettext ("no memory to create section header string table"));
+ }
+
+ /* We have to set the section size. */
+ shdr_info[cnt].shdr.sh_size = shstrtab_data->d_size;
+
+ /* Update the section information. */
+ GElf_Off lastoffset = 0;
+ for (cnt = 1; cnt <= shdridx; ++cnt)
+ if (shdr_info[cnt].idx > 0)
+ {
+ Elf_Data *newdata;
+
+ scn = elf_getscn (newelf, shdr_info[cnt].idx);
+ elf_assert (scn != NULL);
+
+ /* Update the name. */
+ shdr_info[cnt].shdr.sh_name = dwelf_strent_off (shdr_info[cnt].se);
+
+ /* Update the section header from the input file. Some fields
+ might be section indeces which now have to be adjusted. Keep
+ the index to the "current" sh_link in case we need it to lookup
+ symbol table names. */
+ size_t sh_link = shdr_info[cnt].shdr.sh_link;
+ if (shdr_info[cnt].shdr.sh_link != 0)
+ shdr_info[cnt].shdr.sh_link =
+ shdr_info[shdr_info[cnt].shdr.sh_link].idx;
+
+ if (shdr_info[cnt].shdr.sh_type == SHT_GROUP)
+ {
+ elf_assert (shdr_info[cnt].data != NULL
+ && shdr_info[cnt].data->d_buf != NULL);
+
+ Elf32_Word *grpref = (Elf32_Word *) shdr_info[cnt].data->d_buf;
+ for (size_t inner = 0;
+ inner < shdr_info[cnt].data->d_size / sizeof (Elf32_Word);
+ ++inner)
+ if (grpref[inner] < shnum)
+ grpref[inner] = shdr_info[grpref[inner]].idx;
+ else
+ goto illformed;
+ }
+
+ /* Handle the SHT_REL, SHT_RELA, and SHF_INFO_LINK flag. */
+ if (SH_INFO_LINK_P (&shdr_info[cnt].shdr))
+ shdr_info[cnt].shdr.sh_info =
+ shdr_info[shdr_info[cnt].shdr.sh_info].idx;
+
+ /* Get the data from the old file if necessary. We already
+ created the data for the section header string table. */
+ if (cnt < shnum)
+ {
+ if (shdr_info[cnt].data == NULL)
+ {
+ shdr_info[cnt].data = elf_getdata (shdr_info[cnt].scn, NULL);
+ if (shdr_info[cnt].data == NULL)
+ INTERNAL_ERROR (fname);
+ }
+
+ /* Set the data. This is done by copying from the old file. */
+ newdata = elf_newdata (scn);
+ if (newdata == NULL)
+ INTERNAL_ERROR (fname);
+
+ /* Copy the structure. */
+ *newdata = *shdr_info[cnt].data;
+
+ /* We know the size. */
+ shdr_info[cnt].shdr.sh_size = shdr_info[cnt].data->d_size;
+
+ /* We have to adjust symbol tables. The st_shndx member might
+ have to be updated. */
+ if (shdr_info[cnt].shdr.sh_type == SHT_DYNSYM
+ || shdr_info[cnt].shdr.sh_type == SHT_SYMTAB)
+ {
+ Elf_Data *versiondata = NULL;
+ Elf_Data *shndxdata = NULL;
+
+ size_t elsize = gelf_fsize (elf, ELF_T_SYM, 1, EV_CURRENT);
+
+ if (shdr_info[cnt].symtab_idx != 0)
+ {
+ elf_assert (shdr_info[cnt].shdr.sh_type == SHT_SYMTAB_SHNDX);
+ /* This section has extended section information.
+ We have to modify that information, too. */
+ shndxdata = elf_getdata (shdr_info[shdr_info[cnt].symtab_idx].scn,
+ NULL);
+
+ elf_assert (shndxdata != NULL
+ && shndxdata->d_buf != NULL
+ && ((shndxdata->d_size / sizeof (Elf32_Word))
+ >= shdr_info[cnt].data->d_size / elsize));
+ }
+
+ if (shdr_info[cnt].version_idx != 0)
+ {
+ elf_assert (shdr_info[cnt].shdr.sh_type == SHT_DYNSYM);
+ /* This section has associated version
+ information. We have to modify that
+ information, too. */
+ versiondata = elf_getdata (shdr_info[shdr_info[cnt].version_idx].scn,
+ NULL);
+
+ elf_assert (versiondata != NULL
+ && versiondata->d_buf != NULL
+ && ((versiondata->d_size / sizeof (GElf_Versym))
+ >= shdr_info[cnt].data->d_size / elsize));
+ }
+
+ shdr_info[cnt].newsymidx
+ = (Elf32_Word *) xcalloc (shdr_info[cnt].data->d_size
+ / elsize, sizeof (Elf32_Word));
+
+ bool last_was_local = true;
+ size_t destidx;
+ size_t inner;
+ for (destidx = inner = 1;
+ inner < shdr_info[cnt].data->d_size / elsize;
+ ++inner)
+ {
+ Elf32_Word sec;
+ GElf_Sym sym_mem;
+ Elf32_Word xshndx;
+ GElf_Sym *sym = gelf_getsymshndx (shdr_info[cnt].data,
+ shndxdata, inner,
+ &sym_mem, &xshndx);
+ if (sym == NULL)
+ INTERNAL_ERROR (fname);
+
+ if (sym->st_shndx == SHN_UNDEF
+ || (sym->st_shndx >= shnum
+ && sym->st_shndx != SHN_XINDEX))
+ {
+ /* This is no section index, leave it alone
+ unless it is moved. */
+ if (destidx != inner
+ && gelf_update_symshndx (shdr_info[cnt].data,
+ shndxdata,
+ destidx, sym,
+ xshndx) == 0)
+ INTERNAL_ERROR (fname);
+
+ shdr_info[cnt].newsymidx[inner] = destidx++;
+
+ if (last_was_local
+ && GELF_ST_BIND (sym->st_info) != STB_LOCAL)
+ {
+ last_was_local = false;
+ shdr_info[cnt].shdr.sh_info = destidx - 1;
+ }
+
+ continue;
+ }
+
+ /* Get the full section index, if necessary from the
+ XINDEX table. */
+ if (sym->st_shndx == SHN_XINDEX)
+ elf_assert (shndxdata != NULL
+ && shndxdata->d_buf != NULL);
+ size_t sidx = (sym->st_shndx != SHN_XINDEX
+ ? sym->st_shndx : xshndx);
+ sec = shdr_info[sidx].idx;
+
+ if (sec != 0)
+ {
+ GElf_Section nshndx;
+ Elf32_Word nxshndx;
+
+ if (sec < SHN_LORESERVE)
+ {
+ nshndx = sec;
+ nxshndx = 0;
+ }
+ else
+ {
+ nshndx = SHN_XINDEX;
+ nxshndx = sec;
+ }
+
+ elf_assert (sec < SHN_LORESERVE || shndxdata != NULL);
+
+ if ((inner != destidx || nshndx != sym->st_shndx
+ || (shndxdata != NULL && nxshndx != xshndx))
+ && (sym->st_shndx = nshndx,
+ gelf_update_symshndx (shdr_info[cnt].data,
+ shndxdata,
+ destidx, sym,
+ nxshndx) == 0))
+ INTERNAL_ERROR (fname);
+
+ shdr_info[cnt].newsymidx[inner] = destidx++;
+
+ if (last_was_local
+ && GELF_ST_BIND (sym->st_info) != STB_LOCAL)
+ {
+ last_was_local = false;
+ shdr_info[cnt].shdr.sh_info = destidx - 1;
+ }
+ }
+ else if ((shdr_info[cnt].shdr.sh_flags & SHF_ALLOC) != 0
+ && GELF_ST_TYPE (sym->st_info) != STT_SECTION
+ && shdr_info[sidx].shdr.sh_type != SHT_GROUP)
+ {
+ /* Removing a real symbol from an allocated
+ symbol table is hard and probably a
+ mistake. Really removing it means
+ rewriting the dynamic segment and hash
+ sections. Just warn and set the symbol
+ section to UNDEF. */
+ error (0, 0,
+ gettext ("Cannot remove symbol [%zd] from allocated symbol table [%zd]"), inner, cnt);
+ sym->st_shndx = SHN_UNDEF;
+ if (gelf_update_sym (shdr_info[cnt].data, destidx,
+ sym) == 0)
+ INTERNAL_ERROR (fname);
+ shdr_info[cnt].newsymidx[inner] = destidx++;
+ }
+ else if (debug_fname != NULL
+ && shdr_info[cnt].debug_data == NULL)
+ /* The symbol points to a section that is discarded
+ but isn't preserved in the debug file. Check that
+ this is a section or group signature symbol
+ for a section which has been removed. Or a special
+ data marker symbol to a debug section. */
+ {
+ elf_assert (GELF_ST_TYPE (sym->st_info) == STT_SECTION
+ || ((shdr_info[sidx].shdr.sh_type
+ == SHT_GROUP)
+ && (shdr_info[sidx].shdr.sh_info
+ == inner))
+ || ebl_data_marker_symbol (ebl, sym,
+ elf_strptr (elf, sh_link,
+ sym->st_name)));
+ }
+ }
+
+ if (destidx != inner)
+ {
+ /* The size of the symbol table changed. */
+ shdr_info[cnt].shdr.sh_size = newdata->d_size
+ = destidx * elsize;
+ any_symtab_changes = true;
+ }
+ else
+ {
+ /* The symbol table didn't really change. */
+ free (shdr_info[cnt].newsymidx);
+ shdr_info[cnt].newsymidx = NULL;
+ }
+ }
+ }
+
+ /* If we have to, compute the offset of the section. */
+ if (shdr_info[cnt].shdr.sh_offset == 0)
+ shdr_info[cnt].shdr.sh_offset
+ = ((lastoffset + shdr_info[cnt].shdr.sh_addralign - 1)
+ & ~((GElf_Off) (shdr_info[cnt].shdr.sh_addralign - 1)));
+
+ /* Set the section header in the new file. */
+ if (unlikely (gelf_update_shdr (scn, &shdr_info[cnt].shdr) == 0))
+ /* There cannot be any overflows. */
+ INTERNAL_ERROR (fname);
+
+ /* Remember the last section written so far. */
+ GElf_Off filesz = (shdr_info[cnt].shdr.sh_type != SHT_NOBITS
+ ? shdr_info[cnt].shdr.sh_size : 0);
+ if (lastoffset < shdr_info[cnt].shdr.sh_offset + filesz)
+ lastoffset = shdr_info[cnt].shdr.sh_offset + filesz;
+ }
+
+ /* Adjust symbol references if symbol tables changed. */
+ if (any_symtab_changes)
+ /* Find all relocation sections which use this symbol table. */
+ for (cnt = 1; cnt <= shdridx; ++cnt)
+ {
+ /* Update section headers when the data size has changed.
+ We also update the SHT_NOBITS section in the debug
+ file so that the section headers match in sh_size. */
+ inline void update_section_size (const Elf_Data *newdata)
+ {
+ GElf_Shdr shdr_mem;
+ GElf_Shdr *shdr = gelf_getshdr (scn, &shdr_mem);
+ shdr->sh_size = newdata->d_size;
+ (void) gelf_update_shdr (scn, shdr);
+ if (debugelf != NULL)
+ {
+ /* libelf will use d_size to set sh_size. */
+ Elf_Data *debugdata = elf_getdata (elf_getscn (debugelf,
+ cnt), NULL);
+ if (debugdata == NULL)
+ INTERNAL_ERROR (fname);
+ debugdata->d_size = newdata->d_size;
+ }
+ }
+
+ if (shdr_info[cnt].idx == 0 && debug_fname == NULL)
+ /* Ignore sections which are discarded. When we are saving a
+ relocation section in a separate debug file, we must fix up
+ the symbol table references. */
+ continue;
+
+ const Elf32_Word symtabidx = shdr_info[cnt].old_sh_link;
+ elf_assert (symtabidx < shnum + 2);
+ const Elf32_Word *const newsymidx = shdr_info[symtabidx].newsymidx;
+ switch (shdr_info[cnt].shdr.sh_type)
+ {
+ inline bool no_symtab_updates (void)
+ {
+ /* If the symbol table hasn't changed, do not do anything. */
+ if (shdr_info[symtabidx].newsymidx == NULL)
+ return true;
+
+ /* If the symbol table is not discarded, but additionally
+ duplicated in the separate debug file and this section
+ is discarded, don't adjust anything. */
+ return (shdr_info[cnt].idx == 0
+ && shdr_info[symtabidx].debug_data != NULL);
+ }
+
+ case SHT_REL:
+ case SHT_RELA:
+ if (no_symtab_updates ())
+ break;
+
+ Elf_Data *d = elf_getdata (shdr_info[cnt].idx == 0
+ ? elf_getscn (debugelf, cnt)
+ : elf_getscn (newelf,
+ shdr_info[cnt].idx),
+ NULL);
+ elf_assert (d != NULL && d->d_buf != NULL
+ && shdr_info[cnt].shdr.sh_entsize != 0);
+ size_t nrels = (shdr_info[cnt].shdr.sh_size
+ / shdr_info[cnt].shdr.sh_entsize);
+
+ size_t symsize = gelf_fsize (elf, ELF_T_SYM, 1, EV_CURRENT);
+ const Elf32_Word symidxn = (shdr_info[symtabidx].data->d_size
+ / symsize);
+ if (shdr_info[cnt].shdr.sh_type == SHT_REL)
+ for (size_t relidx = 0; relidx < nrels; ++relidx)
+ {
+ GElf_Rel rel_mem;
+ if (gelf_getrel (d, relidx, &rel_mem) == NULL)
+ INTERNAL_ERROR (fname);
+
+ size_t symidx = GELF_R_SYM (rel_mem.r_info);
+ elf_assert (symidx < symidxn);
+ if (newsymidx[symidx] != symidx)
+ {
+ rel_mem.r_info
+ = GELF_R_INFO (newsymidx[symidx],
+ GELF_R_TYPE (rel_mem.r_info));
+
+ if (gelf_update_rel (d, relidx, &rel_mem) == 0)
+ INTERNAL_ERROR (fname);
+ }
+ }
+ else
+ for (size_t relidx = 0; relidx < nrels; ++relidx)
+ {
+ GElf_Rela rel_mem;
+ if (gelf_getrela (d, relidx, &rel_mem) == NULL)
+ INTERNAL_ERROR (fname);
+
+ size_t symidx = GELF_R_SYM (rel_mem.r_info);
+ elf_assert (symidx < symidxn);
+ if (newsymidx[symidx] != symidx)
+ {
+ rel_mem.r_info
+ = GELF_R_INFO (newsymidx[symidx],
+ GELF_R_TYPE (rel_mem.r_info));
+
+ if (gelf_update_rela (d, relidx, &rel_mem) == 0)
+ INTERNAL_ERROR (fname);
+ }
+ }
+ break;
+
+ case SHT_HASH:
+ if (no_symtab_updates ())
+ break;
+
+ /* We have to recompute the hash table. */
+
+ elf_assert (shdr_info[cnt].idx > 0);
+
+ /* The hash section in the new file. */
+ scn = elf_getscn (newelf, shdr_info[cnt].idx);
+
+ /* The symbol table data. */
+ Elf_Data *symd = elf_getdata (elf_getscn (newelf,
+ shdr_info[symtabidx].idx),
+ NULL);
+ elf_assert (symd != NULL && symd->d_buf != NULL);
+
+ /* The hash table data. */
+ Elf_Data *hashd = elf_getdata (scn, NULL);
+ elf_assert (hashd != NULL && hashd->d_buf != NULL);
+
+ if (shdr_info[cnt].shdr.sh_entsize == sizeof (Elf32_Word))
+ {
+ /* Sane arches first. */
+ elf_assert (hashd->d_size >= 2 * sizeof (Elf32_Word));
+ Elf32_Word *bucket = (Elf32_Word *) hashd->d_buf;
+
+ size_t strshndx = shdr_info[symtabidx].old_sh_link;
+ size_t elsize = gelf_fsize (elf, ELF_T_SYM, 1, EV_CURRENT);
+
+ Elf32_Word nchain = bucket[1];
+ Elf32_Word nbucket = bucket[0];
+ uint64_t used_buf = ((2ULL + nchain + nbucket)
+ * sizeof (Elf32_Word));
+ elf_assert (used_buf <= hashd->d_size);
+
+ /* Adjust the nchain value. The symbol table size
+ changed. We keep the same size for the bucket array. */
+ bucket[1] = symd->d_size / elsize;
+ bucket += 2;
+ Elf32_Word *chain = bucket + nbucket;
+
+ /* New size of the section. */
+ size_t n_size = ((2 + symd->d_size / elsize + nbucket)
+ * sizeof (Elf32_Word));
+ elf_assert (n_size <= hashd->d_size);
+ hashd->d_size = n_size;
+ update_section_size (hashd);
+
+ /* Clear the arrays. */
+ memset (bucket, '\0',
+ (symd->d_size / elsize + nbucket)
+ * sizeof (Elf32_Word));
+
+ for (size_t inner = shdr_info[symtabidx].shdr.sh_info;
+ inner < symd->d_size / elsize; ++inner)
+ {
+ GElf_Sym sym_mem;
+ GElf_Sym *sym = gelf_getsym (symd, inner, &sym_mem);
+ elf_assert (sym != NULL);
+
+ const char *name = elf_strptr (elf, strshndx,
+ sym->st_name);
+ elf_assert (name != NULL && nbucket != 0);
+ size_t hidx = elf_hash (name) % nbucket;
+
+ if (bucket[hidx] == 0)
+ bucket[hidx] = inner;
+ else
+ {
+ hidx = bucket[hidx];
+
+ while (chain[hidx] != 0 && chain[hidx] < nchain)
+ hidx = chain[hidx];
+
+ chain[hidx] = inner;
+ }
+ }
+ }
+ else
+ {
+ /* Alpha and S390 64-bit use 64-bit SHT_HASH entries. */
+ elf_assert (shdr_info[cnt].shdr.sh_entsize
+ == sizeof (Elf64_Xword));
+
+ Elf64_Xword *bucket = (Elf64_Xword *) hashd->d_buf;
+
+ size_t strshndx = shdr_info[symtabidx].old_sh_link;
+ size_t elsize = gelf_fsize (elf, ELF_T_SYM, 1, EV_CURRENT);
+
+ elf_assert (symd->d_size >= 2 * sizeof (Elf64_Xword));
+ Elf64_Xword nbucket = bucket[0];
+ Elf64_Xword nchain = bucket[1];
+ uint64_t maxwords = hashd->d_size / sizeof (Elf64_Xword);
+ elf_assert (maxwords >= 2
+ && maxwords - 2 >= nbucket
+ && maxwords - 2 - nbucket >= nchain);
+
+ /* Adjust the nchain value. The symbol table size
+ changed. We keep the same size for the bucket array. */
+ bucket[1] = symd->d_size / elsize;
+ bucket += 2;
+ Elf64_Xword *chain = bucket + nbucket;
+
+ /* New size of the section. */
+ size_t n_size = ((2 + symd->d_size / elsize + nbucket)
+ * sizeof (Elf64_Xword));
+ elf_assert (n_size <= hashd->d_size);
+ hashd->d_size = n_size;
+ update_section_size (hashd);
+
+ /* Clear the arrays. */
+ memset (bucket, '\0',
+ (symd->d_size / elsize + nbucket)
+ * sizeof (Elf64_Xword));
+
+ for (size_t inner = shdr_info[symtabidx].shdr.sh_info;
+ inner < symd->d_size / elsize; ++inner)
+ {
+ GElf_Sym sym_mem;
+ GElf_Sym *sym = gelf_getsym (symd, inner, &sym_mem);
+ elf_assert (sym != NULL);
+
+ const char *name = elf_strptr (elf, strshndx,
+ sym->st_name);
+ elf_assert (name != NULL && nbucket != 0);
+ size_t hidx = elf_hash (name) % nbucket;
+
+ if (bucket[hidx] == 0)
+ bucket[hidx] = inner;
+ else
+ {
+ hidx = bucket[hidx];
+
+ while (chain[hidx] != 0 && chain[hidx] < nchain)
+ hidx = chain[hidx];
+
+ chain[hidx] = inner;
+ }
+ }
+ }
+ break;
+
+ case SHT_GNU_versym:
+ /* If the symbol table changed we have to adjust the entries. */
+ if (no_symtab_updates ())
+ break;
+
+ elf_assert (shdr_info[cnt].idx > 0);
+
+ /* The symbol version section in the new file. */
+ scn = elf_getscn (newelf, shdr_info[cnt].idx);
+
+ /* The symbol table data. */
+ symd = elf_getdata (elf_getscn (newelf, shdr_info[symtabidx].idx),
+ NULL);
+ elf_assert (symd != NULL && symd->d_buf != NULL);
+ size_t symz = gelf_fsize (elf, ELF_T_SYM, 1, EV_CURRENT);
+ const Elf32_Word syms = (shdr_info[symtabidx].data->d_size / symz);
+
+ /* The version symbol data. */
+ Elf_Data *verd = elf_getdata (scn, NULL);
+ elf_assert (verd != NULL && verd->d_buf != NULL);
+
+ /* The symbol version array. */
+ GElf_Half *verstab = (GElf_Half *) verd->d_buf;
+
+ /* Walk through the list and */
+ size_t elsize = gelf_fsize (elf, verd->d_type, 1, EV_CURRENT);
+ Elf32_Word vers = verd->d_size / elsize;
+ for (size_t inner = 1; inner < vers && inner < syms; ++inner)
+ if (newsymidx[inner] != 0 && newsymidx[inner] < vers)
+ /* Overwriting the same array works since the
+ reordering can only move entries to lower indices
+ in the array. */
+ verstab[newsymidx[inner]] = verstab[inner];
+
+ /* New size of the section. */
+ verd->d_size = gelf_fsize (newelf, verd->d_type,
+ symd->d_size
+ / gelf_fsize (elf, symd->d_type, 1,
+ EV_CURRENT),
+ EV_CURRENT);
+ update_section_size (verd);
+ break;
+
+ case SHT_GROUP:
+ if (no_symtab_updates ())
+ break;
+
+ /* Yes, the symbol table changed.
+ Update the section header of the section group. */
+ scn = elf_getscn (newelf, shdr_info[cnt].idx);
+ GElf_Shdr shdr_mem;
+ GElf_Shdr *shdr = gelf_getshdr (scn, &shdr_mem);
+ elf_assert (shdr != NULL);
+
+ size_t symsz = gelf_fsize (elf, ELF_T_SYM, 1, EV_CURRENT);
+ const Elf32_Word symn = (shdr_info[symtabidx].data->d_size
+ / symsz);
+ elf_assert (shdr->sh_info < symn);
+ shdr->sh_info = newsymidx[shdr->sh_info];
+
+ (void) gelf_update_shdr (scn, shdr);
+ break;
+ }
+ }
+
+ /* Remove any relocations between debug sections in ET_REL
+ for the debug file when requested. These relocations are always
+ zero based between the unallocated sections. */
+ if (debug_fname != NULL && removing_sections
+ && reloc_debug && ehdr->e_type == ET_REL)
+ {
+ scn = NULL;
+ cnt = 0;
+ while ((scn = elf_nextscn (debugelf, scn)) != NULL)
+ {
+ cnt++;
+ /* We need the actual section and header from the debugelf
+ not just the cached original in shdr_info because we
+ might want to change the size. */
+ GElf_Shdr shdr_mem;
+ GElf_Shdr *shdr = gelf_getshdr (scn, &shdr_mem);
+ if (shdr->sh_type == SHT_REL || shdr->sh_type == SHT_RELA)
+ {
+ /* Make sure that this relocation section points to a
+ section to relocate with contents, that isn't
+ allocated and that is a debug section. */
+ Elf_Scn *tscn = elf_getscn (debugelf, shdr->sh_info);
+ GElf_Shdr tshdr_mem;
+ GElf_Shdr *tshdr = gelf_getshdr (tscn, &tshdr_mem);
+ if (tshdr->sh_type == SHT_NOBITS
+ || tshdr->sh_size == 0
+ || (tshdr->sh_flags & SHF_ALLOC) != 0)
+ continue;
+
+ const char *tname = elf_strptr (debugelf, shstrndx,
+ tshdr->sh_name);
+ if (! tname || ! ebl_debugscn_p (ebl, tname))
+ continue;
+
+ /* OK, lets relocate all trivial cross debug section
+ relocations. */
+ Elf_Data *reldata = elf_getdata (scn, NULL);
+ if (reldata == NULL || reldata->d_buf == NULL)
+ INTERNAL_ERROR (fname);
+
+ /* Make sure we adjust the uncompressed debug data
+ (and recompress if necessary at the end). */
+ GElf_Chdr tchdr;
+ int tcompress_type = 0;
+ if (gelf_getchdr (tscn, &tchdr) != NULL)
+ {
+ tcompress_type = tchdr.ch_type;
+ if (elf_compress (tscn, 0, 0) != 1)
+ INTERNAL_ERROR (fname);
+ }
+
+ Elf_Data *tdata = elf_getdata (tscn, NULL);
+ if (tdata == NULL || tdata->d_buf == NULL
+ || tdata->d_type != ELF_T_BYTE)
+ INTERNAL_ERROR (fname);
+
+ /* Pick up the symbol table and shndx table to
+ resolve relocation symbol indexes. */
+ Elf64_Word symt = shdr->sh_link;
+ Elf_Data *symdata, *xndxdata;
+ elf_assert (symt < shnum + 2);
+ elf_assert (shdr_info[symt].symtab_idx < shnum + 2);
+ symdata = (shdr_info[symt].debug_data
+ ?: shdr_info[symt].data);
+ xndxdata = (shdr_info[shdr_info[symt].symtab_idx].debug_data
+ ?: shdr_info[shdr_info[symt].symtab_idx].data);
+
+ /* Apply one relocation. Returns true when trivial
+ relocation actually done. */
+ bool relocate (GElf_Addr offset, const GElf_Sxword addend,
+ bool is_rela, int rtype, int symndx)
+ {
+ /* R_*_NONE relocs can always just be removed. */
+ if (rtype == 0)
+ return true;
+
+ /* We only do simple absolute relocations. */
+ Elf_Type type = ebl_reloc_simple_type (ebl, rtype);
+ if (type == ELF_T_NUM)
+ return false;
+
+ /* These are the types we can relocate. */
+#define TYPES DO_TYPE (BYTE, Byte); DO_TYPE (HALF, Half); \
+ DO_TYPE (WORD, Word); DO_TYPE (SWORD, Sword); \
+ DO_TYPE (XWORD, Xword); DO_TYPE (SXWORD, Sxword)
+
+ /* And only for relocations against other debug sections. */
+ GElf_Sym sym_mem;
+ Elf32_Word xndx;
+ GElf_Sym *sym = gelf_getsymshndx (symdata, xndxdata,
+ symndx, &sym_mem,
+ &xndx);
+ Elf32_Word sec = (sym->st_shndx == SHN_XINDEX
+ ? xndx : sym->st_shndx);
+ if (sec >= shnum + 2)
+ INTERNAL_ERROR (fname);
+
+ if (ebl_debugscn_p (ebl, shdr_info[sec].name))
+ {
+ size_t size;
+
+#define DO_TYPE(NAME, Name) GElf_##Name Name;
+ union { TYPES; } tmpbuf;
+#undef DO_TYPE
+
+ switch (type)
+ {
+#define DO_TYPE(NAME, Name) \
+ case ELF_T_##NAME: \
+ size = sizeof (GElf_##Name); \
+ tmpbuf.Name = 0; \
+ break;
+ TYPES;
+#undef DO_TYPE
+ default:
+ return false;
+ }
+
+ if (offset > tdata->d_size
+ || tdata->d_size - offset < size)
+ {
+ cleanup_debug ();
+ error (EXIT_FAILURE, 0, gettext ("bad relocation"));
+ }
+
+ /* When the symbol value is zero then for SHT_REL
+ sections this is all that needs to be checked.
+ The addend is contained in the original data at
+ the offset already. So if the (section) symbol
+ address is zero and the given addend is zero
+ just remove the relocation, it isn't needed
+ anymore. */
+ if (addend == 0 && sym->st_value == 0)
+ return true;
+
+ Elf_Data tmpdata =
+ {
+ .d_type = type,
+ .d_buf = &tmpbuf,
+ .d_size = size,
+ .d_version = EV_CURRENT,
+ };
+ Elf_Data rdata =
+ {
+ .d_type = type,
+ .d_buf = tdata->d_buf + offset,
+ .d_size = size,
+ .d_version = EV_CURRENT,
+ };
+
+ GElf_Addr value = sym->st_value;
+ if (is_rela)
+ {
+ /* For SHT_RELA sections we just take the
+ given addend and add it to the value. */
+ value += addend;
+ }
+ else
+ {
+ /* For SHT_REL sections we have to peek at
+ what is already in the section at the given
+ offset to get the addend. */
+ Elf_Data *d = gelf_xlatetom (debugelf, &tmpdata,
+ &rdata,
+ ehdr->e_ident[EI_DATA]);
+ if (d == NULL)
+ INTERNAL_ERROR (fname);
+ assert (d == &tmpdata);
+ }
+
+ switch (type)
+ {
+#define DO_TYPE(NAME, Name) \
+ case ELF_T_##NAME: \
+ tmpbuf.Name += (GElf_##Name) value; \
+ break;
+ TYPES;
+#undef DO_TYPE
+ default:
+ abort ();
+ }
+
+ /* Now finally put in the new value. */
+ Elf_Data *s = gelf_xlatetof (debugelf, &rdata,
+ &tmpdata,
+ ehdr->e_ident[EI_DATA]);
+ if (s == NULL)
+ INTERNAL_ERROR (fname);
+ assert (s == &rdata);
+
+ return true;
+ }
+ return false;
+ }
+
+ if (shdr->sh_entsize == 0)
+ INTERNAL_ERROR (fname);
+
+ size_t nrels = shdr->sh_size / shdr->sh_entsize;
+ size_t next = 0;
+ if (shdr->sh_type == SHT_REL)
+ for (size_t relidx = 0; relidx < nrels; ++relidx)
+ {
+ GElf_Rel rel_mem;
+ GElf_Rel *r = gelf_getrel (reldata, relidx, &rel_mem);
+ if (! relocate (r->r_offset, 0, false,
+ GELF_R_TYPE (r->r_info),
+ GELF_R_SYM (r->r_info)))
+ {
+ if (relidx != next)
+ gelf_update_rel (reldata, next, r);
+ ++next;
+ }
+ }
+ else
+ for (size_t relidx = 0; relidx < nrels; ++relidx)
+ {
+ GElf_Rela rela_mem;
+ GElf_Rela *r = gelf_getrela (reldata, relidx, &rela_mem);
+ if (! relocate (r->r_offset, r->r_addend, true,
+ GELF_R_TYPE (r->r_info),
+ GELF_R_SYM (r->r_info)))
+ {
+ if (relidx != next)
+ gelf_update_rela (reldata, next, r);
+ ++next;
+ }
+ }
+
+ nrels = next;
+ shdr->sh_size = reldata->d_size = nrels * shdr->sh_entsize;
+ gelf_update_shdr (scn, shdr);
+
+ if (tcompress_type != 0)
+ if (elf_compress (tscn, tcompress_type, ELF_CHF_FORCE) != 1)
+ INTERNAL_ERROR (fname);
+ }
+ }
+ }
+
+ /* Now that we have done all adjustments to the data,
+ we can actually write out the debug file. */
+ if (debug_fname != NULL && removing_sections)
+ {
+ /* Finally write the file. */
+ if (unlikely (elf_update (debugelf, ELF_C_WRITE) == -1))
+ {
+ error (0, 0, gettext ("while writing '%s': %s"),
+ tmp_debug_fname, elf_errmsg (-1));
+ result = 1;
+ goto fail_close;
+ }
+
+ /* Create the real output file. First rename, then change the
+ mode. */
+ if (rename (tmp_debug_fname, debug_fname) != 0
+ || fchmod (debug_fd, mode) != 0)
+ {
+ error (0, errno, gettext ("while creating '%s'"), debug_fname);
+ result = 1;
+ goto fail_close;
+ }
+
+ /* The temporary file does not exist anymore. */
+ free (tmp_debug_fname);
+ tmp_debug_fname = NULL;
+
+ if (!remove_shdrs)
+ {
+ uint32_t debug_crc;
+ Elf_Data debug_crc_data =
+ {
+ .d_type = ELF_T_WORD,
+ .d_buf = &debug_crc,
+ .d_size = sizeof (debug_crc),
+ .d_version = EV_CURRENT
+ };
+
+ /* Compute the checksum which we will add to the executable. */
+ if (crc32_file (debug_fd, &debug_crc) != 0)
+ {
+ error (0, errno, gettext ("\
+while computing checksum for debug information"));
+ unlink (debug_fname);
+ result = 1;
+ goto fail_close;
+ }
+
+ /* Store it in the debuglink section data. */
+ if (unlikely (gelf_xlatetof (newelf, &debuglink_crc_data,
+ &debug_crc_data, ehdr->e_ident[EI_DATA])
+ != &debuglink_crc_data))
+ INTERNAL_ERROR (fname);
+ }
+ }
+
+ /* Finally finish the ELF header. Fill in the fields not handled by
+ libelf from the old file. */
+ newehdr = gelf_getehdr (newelf, &newehdr_mem);
+ if (newehdr == NULL)
+ INTERNAL_ERROR (fname);
+
+ memcpy (newehdr->e_ident, ehdr->e_ident, EI_NIDENT);
+ newehdr->e_type = ehdr->e_type;
+ newehdr->e_machine = ehdr->e_machine;
+ newehdr->e_version = ehdr->e_version;
+ newehdr->e_entry = ehdr->e_entry;
+ newehdr->e_flags = ehdr->e_flags;
+ newehdr->e_phoff = ehdr->e_phoff;
+
+ /* We need to position the section header table. */
+ const size_t offsize = gelf_fsize (elf, ELF_T_OFF, 1, EV_CURRENT);
+ newehdr->e_shoff = ((shdr_info[shdridx].shdr.sh_offset
+ + shdr_info[shdridx].shdr.sh_size + offsize - 1)
+ & ~((GElf_Off) (offsize - 1)));
+ newehdr->e_shentsize = gelf_fsize (elf, ELF_T_SHDR, 1, EV_CURRENT);
+
+ /* The new section header string table index. */
+ if (likely (idx < SHN_HIRESERVE) && likely (idx != SHN_XINDEX))
+ newehdr->e_shstrndx = idx;
+ else
+ {
+ /* The index does not fit in the ELF header field. */
+ shdr_info[0].scn = elf_getscn (elf, 0);
+
+ if (gelf_getshdr (shdr_info[0].scn, &shdr_info[0].shdr) == NULL)
+ INTERNAL_ERROR (fname);
+
+ shdr_info[0].shdr.sh_link = idx;
+ (void) gelf_update_shdr (shdr_info[0].scn, &shdr_info[0].shdr);
+
+ newehdr->e_shstrndx = SHN_XINDEX;
+ }
+
+ if (gelf_update_ehdr (newelf, newehdr) == 0)
+ {
+ error (0, 0, gettext ("%s: error while creating ELF header: %s"),
+ output_fname ?: fname, elf_errmsg (-1));
+ cleanup_debug ();
+ return 1;
+ }
+
+ /* We have everything from the old file. */
+ if (elf_cntl (elf, ELF_C_FDDONE) != 0)
+ {
+ error (0, 0, gettext ("%s: error while reading the file: %s"),
+ fname, elf_errmsg (-1));
+ cleanup_debug ();
+ return 1;
+ }
+
+ /* The ELF library better follows our layout when this is not a
+ relocatable object file. */
+ elf_flagelf (newelf, ELF_C_SET,
+ (ehdr->e_type != ET_REL ? ELF_F_LAYOUT : 0)
+ | (permissive ? ELF_F_PERMISSIVE : 0));
+
+ /* Finally write the file. */
+ if (elf_update (newelf, ELF_C_WRITE) == -1)
+ {
+ error (0, 0, gettext ("while writing '%s': %s"),
+ output_fname ?: fname, elf_errmsg (-1));
+ result = 1;
+ }
+
+ if (remove_shdrs)
+ {
+ /* libelf can't cope without the section headers being properly intact.
+ So we just let it write them normally, and then we nuke them later. */
+
+ if (newehdr->e_ident[EI_CLASS] == ELFCLASS32)
+ {
+ assert (offsetof (Elf32_Ehdr, e_shentsize) + sizeof (Elf32_Half)
+ == offsetof (Elf32_Ehdr, e_shnum));
+ assert (offsetof (Elf32_Ehdr, e_shnum) + sizeof (Elf32_Half)
+ == offsetof (Elf32_Ehdr, e_shstrndx));
+ const Elf32_Off zero_off = 0;
+ const Elf32_Half zero[3] = { 0, 0, SHN_UNDEF };
+ if (pwrite_retry (fd, &zero_off, sizeof zero_off,
+ offsetof (Elf32_Ehdr, e_shoff)) != sizeof zero_off
+ || (pwrite_retry (fd, zero, sizeof zero,
+ offsetof (Elf32_Ehdr, e_shentsize))
+ != sizeof zero)
+ || ftruncate (fd, shdr_info[shdridx].shdr.sh_offset) < 0)
+ {
+ error (0, errno, gettext ("while writing '%s'"),
+ output_fname ?: fname);
+ result = 1;
+ }
+ }
+ else
+ {
+ assert (offsetof (Elf64_Ehdr, e_shentsize) + sizeof (Elf64_Half)
+ == offsetof (Elf64_Ehdr, e_shnum));
+ assert (offsetof (Elf64_Ehdr, e_shnum) + sizeof (Elf64_Half)
+ == offsetof (Elf64_Ehdr, e_shstrndx));
+ const Elf64_Off zero_off = 0;
+ const Elf64_Half zero[3] = { 0, 0, SHN_UNDEF };
+ if (pwrite_retry (fd, &zero_off, sizeof zero_off,
+ offsetof (Elf64_Ehdr, e_shoff)) != sizeof zero_off
+ || (pwrite_retry (fd, zero, sizeof zero,
+ offsetof (Elf64_Ehdr, e_shentsize))
+ != sizeof zero)
+ || ftruncate (fd, shdr_info[shdridx].shdr.sh_offset) < 0)
+ {
+ error (0, errno, gettext ("while writing '%s'"),
+ output_fname ?: fname);
+ result = 1;
+ }
+ }
+ }
+
+ fail_close:
+ if (shdr_info != NULL)
+ {
+ /* For some sections we might have created an table to map symbol
+ table indices. Or we might kept (original) data around to put
+ into the .debug file. */
+ for (cnt = 1; cnt <= shdridx; ++cnt)
+ {
+ free (shdr_info[cnt].newsymidx);
+ if (shdr_info[cnt].debug_data != NULL)
+ free (shdr_info[cnt].debug_data->d_buf);
+ }
+
+ /* Free data we allocated for the .gnu_debuglink section. */
+ free (debuglink_buf);
+
+ /* Free the memory. */
+ if ((shnum + 2) * sizeof (struct shdr_info) > MAX_STACK_ALLOC)
+ free (shdr_info);
+ }
+
+ /* Free other resources. */
+ if (shstrtab_data != NULL)
+ free (shstrtab_data->d_buf);
+ if (shst != NULL)
+ dwelf_strtab_free (shst);
+
+ /* That was it. Close the descriptors. */
+ if (elf_end (newelf) != 0)
+ {
+ error (0, 0, gettext ("error while finishing '%s': %s"),
+ output_fname ?: fname, elf_errmsg (-1));
+ result = 1;
+ }
+
+ if (debugelf != NULL && elf_end (debugelf) != 0)
+ {
+ error (0, 0, gettext ("error while finishing '%s': %s"), debug_fname,
+ elf_errmsg (-1));
+ result = 1;
+ }
+
+ fail:
+ /* Close the EBL backend. */
+ if (ebl != NULL)
+ ebl_closebackend (ebl);
+
+ cleanup_debug ();
+
+ /* If requested, preserve the timestamp. */
+ if (tvp != NULL)
+ {
+ if (futimens (fd, tvp) != 0)
+ {
+ error (0, errno, gettext ("\
+cannot set access and modification date of '%s'"),
+ output_fname ?: fname);
+ result = 1;
+ }
+ }
+
+ /* Close the file descriptor if we created a new file. */
+ if (output_fname != NULL)
+ {
+ close (fd);
+ if (result != 0)
+ unlink (output_fname);
+ }
+
+ return result;
+}
+
+static void
+cleanup_debug (void)
+{
+ if (debug_fd >= 0)
+ {
+ if (tmp_debug_fname != NULL)
+ {
+ unlink (tmp_debug_fname);
+ free (tmp_debug_fname);
+ tmp_debug_fname = NULL;
+ }
+ close (debug_fd);
+ debug_fd = -1;
+ }
+}
+
+static int
+handle_ar (int fd, Elf *elf, const char *prefix, const char *fname,
+ struct timespec tvp[2])
+{
+ size_t prefix_len = prefix == NULL ? 0 : strlen (prefix);
+ size_t fname_len = strlen (fname) + 1;
+ char new_prefix[prefix_len + 1 + fname_len];
+ char *cp = new_prefix;
+
+ /* Create the full name of the file. */
+ if (prefix != NULL)
+ {
+ cp = mempcpy (cp, prefix, prefix_len);
+ *cp++ = ':';
+ }
+ memcpy (cp, fname, fname_len);
+
+
+ /* Process all the files contained in the archive. */
+ Elf *subelf;
+ Elf_Cmd cmd = ELF_C_RDWR;
+ int result = 0;
+ while ((subelf = elf_begin (fd, cmd, elf)) != NULL)
+ {
+ /* The the header for this element. */
+ Elf_Arhdr *arhdr = elf_getarhdr (subelf);
+
+ if (elf_kind (subelf) == ELF_K_ELF)
+ result |= handle_elf (fd, subelf, new_prefix, arhdr->ar_name, 0, NULL);
+ else if (elf_kind (subelf) == ELF_K_AR)
+ result |= handle_ar (fd, subelf, new_prefix, arhdr->ar_name, NULL);
+
+ /* Get next archive element. */
+ cmd = elf_next (subelf);
+ if (unlikely (elf_end (subelf) != 0))
+ INTERNAL_ERROR (fname);
+ }
+
+ if (tvp != NULL)
+ {
+ if (unlikely (futimens (fd, tvp) != 0))
+ {
+ error (0, errno, gettext ("\
+cannot set access and modification date of '%s'"), fname);
+ result = 1;
+ }
+ }
+
+ if (unlikely (close (fd) != 0))
+ error (EXIT_FAILURE, errno, gettext ("while closing '%s'"), fname);
+
+ return result;
+}
+
+
+#include "debugpred.h"