FreeChainXenon/binutils-gdb
1
0
Fork 0
Code Issues Pull requests Projects Releases Packages Wiki Activity Actions

Add support for displaying and merging GNU_BUILD_NOTEs.

Browse source 
include	* elf/common.h (SHF_GNU_BUILD_NOTE): Define.
	(NT_GNU_PROPERTY_TYPE_0): Define.
	(NT_GNU_BUILD_ATTRIBUTE_OPEN): Define.
	(NT_GNU_BUILD_ATTRIBUTE_FUN): Define.
	(GNU_BUILD_ATTRIBUTE_TYPE_NUMERIC): Define.
	(GNU_BUILD_ATTRIBUTE_TYPE_STRING): Define.
	(GNU_BUILD_ATTRIBUTE_TYPE_BOOL_TRUE): Define.
	(GNU_BUILD_ATTRIBUTE_TYPE_BOOL_FALSE): Define.
	(GNU_BUILD_ATTRIBUTE_VERSION): Define.
	(GNU_BUILD_ATTRIBUTE_STACK_PROT): Define.
	(GNU_BUILD_ATTRIBUTE_RELRO): Define.
	(GNU_BUILD_ATTRIBUTE_STACK_SIZE): Define.
	(GNU_BUILD_ATTRIBUTE_TOOL): Define.
	(GNU_BUILD_ATTRIBUTE_ABI): Define.
	(GNU_BUILD_ATTRIBUTE_PIC): Define.
	(NOTE_GNU_PROPERTY_SECTION_NAME): Define.
	(GNU_BUILD_ATTRS_SECTION_NAME): Define.
	(GNU_PROPERTY_STACK_SIZE): Define.
	(GNU_PROPERTY_NO_COPY_ON_PROTECTED): Define.
	(GNU_PROPERTY_X86_ISA_1_USED): Define.
	(GNU_PROPERTY_X86_ISA_1_NEEDED): Define.
	(GNU_PROPERTY_X86_ISA_1_486): Define.
	(GNU_PROPERTY_X86_ISA_1_586): Define.
	(GNU_PROPERTY_X86_ISA_1_686): Define.
	(GNU_PROPERTY_X86_ISA_1_SSE): Define.
	(GNU_PROPERTY_X86_ISA_1_SSE2): Define.
	(GNU_PROPERTY_X86_ISA_1_SSE3): Define.
	(GNU_PROPERTY_X86_ISA_1_SSSE3): Define.
	(GNU_PROPERTY_X86_ISA_1_SSE4_1): Define.
	(GNU_PROPERTY_X86_ISA_1_SSE4_2): Define.
	(GNU_PROPERTY_X86_ISA_1_AVX): Define.
	(GNU_PROPERTY_X86_ISA_1_AVX2): Define.
	(GNU_PROPERTY_X86_ISA_1_AVX512F): Define.
	(GNU_PROPERTY_X86_ISA_1_AVX512CD): Define.
	(GNU_PROPERTY_X86_ISA_1_AVX512ER): Define.
	(GNU_PROPERTY_X86_ISA_1_AVX512PF): Define.
	(GNU_PROPERTY_X86_ISA_1_AVX512VL): Define.
	(GNU_PROPERTY_X86_ISA_1_AVX512DQ): Define.
	(GNU_PROPERTY_X86_ISA_1_AVX512BW): Define.

binutils* readelf.c (get_note_type): Add support for GNU_BUILD_NOTEs.
	(get_gnu_elf_note_type): Add support for GNU_PROPERTY_NOTEs.
	(decode_x86_isa): New function.
	(print_gnu_property_note): New function.
	(print_gnu_note): Handle GNU_PROPERTY_NOTEs.
	(print_gnu_build_attribute_description): New function.
	(print_gnu_build_attribute_name): New function.
	(process_note): Add support for GNU_BUILD_NOTEs.
	* objcopy.c (--merge-notes): New command line option.
	(copy_options): Add merge-notes.
	(copy_usage): Likewise.
	(is_merge_note_section): New function.
	(merge_gnu_build_notes): New function.
	(copy_object): Merge note sections if asked to do so.
	(skip_section): Add skip_copy parameter.  Add support for skipping
	merged note sections.
	(copy_relocations_in_section): Update call to skip_section.
	(copy_section): Likewise.
	(copy_main): Add support for merge-notes option.
	* doc/binutils.texi: Document the new option to objcopy.
	* NEWS: Mention the new feature.
	* testsuite/binutils-all/note-2-32.d: New test.  Checks note
	merging on 32-bit targets.
	* testsuite/binutils-all/note-2-32.s: New test source file.
	* testsuite/binutils-all/note-2-64.d: New test.  Like note-2-32.d
	but for 64-bit targets.
	* testsuite/binutils-all/note-2-64.s: New test source file.
	* testsuite/binutils-all/objcopy.exp: Run the new test.
This commit is contained in:
Nick Clifton 2017-03-01 11:09:46 +00:00
parent a7e8b06b89
commit 9ef920e933
12 changed files with 1141 additions and 34 deletions
Download patch file Download diff file Expand all files Collapse all files

393
binutils/objcopy.c
View file

@ -30,6 +30,7 @@
#include "elf-bfd.h"
#include "coff/internal.h"
#include "libcoff.h"
#include "safe-ctype.h"
/* FIXME: See bfd/peXXigen.c for why we include an architecture specific
header in generic PE code. */
@ -94,7 +95,11 @@ static int copy_width = 1;
static bfd_boolean verbose; /* Print file and target names. */
static bfd_boolean preserve_dates; /* Preserve input file timestamp. */
static int deterministic = -1; /* Enable deterministic archives. */
static int status = 0; /* Exit status. */
static int status = 0; /* Exit status. */
static bfd_boolean merge_notes = FALSE; /* Merge note sections. */
static bfd_byte * merged_notes = NULL; /* Contents on note section undergoing a merge. */
static bfd_size_type merged_size = 0; /* New, smaller size of the merged note section. */
enum strip_action
{
@ -315,6 +320,7 @@ enum command_line_switch
OPTION_LOCALIZE_HIDDEN,
OPTION_LOCALIZE_SYMBOLS,
OPTION_LONG_SECTION_NAMES,
OPTION_MERGE_NOTES,
OPTION_NO_CHANGE_WARNINGS,
OPTION_ONLY_KEEP_DEBUG,
OPTION_PAD_TO,
@ -436,6 +442,7 @@ static struct option copy_options[] =
{"localize-symbol", required_argument, 0, 'L'},
{"localize-symbols", required_argument, 0, OPTION_LOCALIZE_SYMBOLS},
{"long-section-names", required_argument, 0, OPTION_LONG_SECTION_NAMES},
{"merge-notes", no_argument, 0, 'M'},
{"no-adjust-warnings", no_argument, 0, OPTION_NO_CHANGE_WARNINGS},
{"no-change-warnings", no_argument, 0, OPTION_NO_CHANGE_WARNINGS},
{"only-keep-debug", no_argument, 0, OPTION_ONLY_KEEP_DEBUG},
@ -634,6 +641,7 @@ copy_usage (FILE *stream, int exit_status)
--decompress-debug-sections Decompress DWARF debug sections using zlib\n\
--elf-stt-common=[yes|no] Generate ELF common symbols with STT_COMMON\n\
type\n\
-M --merge-notes Remove redundant entries in note sections\n\
-v --verbose List all object files modified\n\
@<file> Read options from <file>\n\
-V --version Display this program's version number\n\
@ -1201,6 +1209,20 @@ is_update_section (bfd *abfd ATTRIBUTE_UNUSED, asection *sec)
return FALSE;
}
static bfd_boolean
is_merged_note_section (bfd * abfd, asection * sec)
{
if (merge_notes
&& bfd_get_flavour (abfd) == bfd_target_elf_flavour
&& elf_section_data (sec)->this_hdr.sh_type == SHT_NOTE
/* FIXME: We currently only support merging GNU_BUILD_NOTEs.
We should add support for more note types. */
&& elf_section_data (sec)->this_hdr.sh_flags & SHF_GNU_BUILD_NOTE)
return TRUE;
return FALSE;
}
/* See if a non-group section is being removed. */
static bfd_boolean
@ -1818,6 +1840,255 @@ copy_unknown_object (bfd *ibfd, bfd *obfd)
return TRUE;
}
/* Merge the notes on SEC, removing redundant entries.
Returns the new, smaller size of the section upon success. */
static bfd_size_type
merge_gnu_build_notes (bfd * abfd, asection * sec, bfd_size_type size, bfd_byte * contents)
{
Elf_Internal_Note * pnotes_end;
Elf_Internal_Note * pnotes;
Elf_Internal_Note * pnote;
bfd_size_type remain = size;
unsigned version_notes_seen = 0;
bfd_boolean duplicate_found = FALSE;
const char * err = NULL;
bfd_byte * in = contents;
/* Make a copy of the notes.
Minimum size of a note is 12 bytes. */
pnote = pnotes = (Elf_Internal_Note *) xmalloc ((size / 12) * sizeof (Elf_Internal_Note));
while (remain >= 12)
{
pnote->namesz = (bfd_get_32 (abfd, in ) + 3) & ~3;
pnote->descsz = (bfd_get_32 (abfd, in + 4) + 3) & ~3;
pnote->type = bfd_get_32 (abfd, in + 8);
if (pnote->type != NT_GNU_BUILD_ATTRIBUTE_OPEN
&& pnote->type != NT_GNU_BUILD_ATTRIBUTE_FUNC)
{
err = _("corrupt GNU build attribute note: wrong note type");
goto done;
}
if (pnote->namesz + pnote->descsz + 12 > remain)
{
err = _("corrupt GNU build attribute note: note too big");
goto done;
}
if (pnote->namesz < 2)
{
err = _("corrupt GNU build attribute note: name too small");
goto done;
}
if (pnote->descsz != 0
&& pnote->descsz != 4
&& pnote->descsz != 8)
{
err = _("corrupt GNU build attribute note: bad description size");
goto done;
}
pnote->namedata = (char *)(in + 12);
pnote->descdata = (char *)(in + 12 + pnote->namesz);
remain -= 12 + pnote->namesz + pnote->descsz;
in += 12 + pnote->namesz + pnote->descsz;
if (pnote->namesz > 1 && pnote->namedata[1] == GNU_BUILD_ATTRIBUTE_VERSION)
++ version_notes_seen;
pnote ++;
}
pnotes_end = pnote;
/* Check that the notes are valid. */
if (remain != 0)
{
err = _("corrupt GNU build attribute notes: data at end");
goto done;
}
if (version_notes_seen == 0)
{
err = _("bad GNU build attribute notes: no version note");
goto done;
}
/* Merging is only needed if there is more than one version note... */
if (version_notes_seen == 1)
goto done;
/* The first note should be the first version note. */
if (pnotes[0].namedata[1] != GNU_BUILD_ATTRIBUTE_VERSION)
{
err = _("bad GNU build attribute notes: first note not version note");
goto done;
}
if (pnotes[0].namedata[0] != GNU_BUILD_ATTRIBUTE_TYPE_STRING
|| strcmp (pnotes[0].namedata + 2, "1") != 0)
{
err = _("bad GNU build attribute notes: version note not v1");
goto done;
}
/* Now merge the notes. The rules are:
1. Preserve the ordering of the notes.
2. Preserve any NT_GNU_BUILD_ATTRIBUTE_FUNC notes.
3. Eliminate any NT_GNU_BUILD_ATTRIBUTE_OPEN notes that have the same
full name field as the immediately preceeding note with the same type
of name.
4. If an NT_GNU_BUILD_ATTRIBUTE_OPEN note is going to be preserved and
its description field is empty then the nearest preceeding OPEN note
with a non-empty description field must also be preserved *OR* the
description field of the note must be changed to contain the starting
address to which it refers. */
for (pnote = pnotes + 1; pnote < pnotes_end; pnote ++)
{
Elf_Internal_Note * back;
Elf_Internal_Note * prev_open = NULL;
if (pnote->type == NT_GNU_BUILD_ATTRIBUTE_FUNC)
continue;
/* Scan for duplicates. Clear the type field of any found - but do not
delete them just yet. */
for (back = pnote - 1; back >= pnotes; back --)
{
if (back->descsz > 0
&& back->type != NT_GNU_BUILD_ATTRIBUTE_FUNC
&& prev_open == NULL)
prev_open = back;
if (back->type == pnote->type
&& back->namedata[1] == pnote->namedata[1])
{
if (back->namesz == pnote->namesz
&& memcmp (back->namedata, pnote->namedata, back->namesz) == 0)
{
duplicate_found = TRUE;
pnote->type = 0;
break;
}
/* If we have found an attribute match then stop searching backwards. */
if (! ISPRINT (back->namedata[1])
|| strcmp (back->namedata + 2, pnote->namedata + 2) == 0)
{
/* Since we are keeping this note we must check to see if its
description refers back to an earlier OPEN note. If so
then we must make sure that version note is also preserved. */
if (pnote->descsz == 0
&& prev_open != NULL
&& prev_open->type == 0)
prev_open->type = NT_GNU_BUILD_ATTRIBUTE_FUNC;
break;
}
}
}
}
if (duplicate_found)
{
bfd_byte * new_contents;
bfd_byte * old;
bfd_byte * new;
bfd_size_type new_size;
arelent ** relpp = NULL;
long relsize;
long relcount = 0;
relsize = bfd_get_reloc_upper_bound (abfd, sec);
if (relsize > 0)
{
/* If there are relocs associated with this section then we may
have to adjust them as well, as we remove notes. */
relpp = (arelent **) xmalloc (relsize);
relcount = bfd_canonicalize_reloc (abfd, sec, relpp, isympp);
if (relcount < 0)
/* Do not bother complaining here - copy_relocations_in_section
will do that for us. */
relcount = 0;
}
/* Eliminate the duplicates. */
new = new_contents = xmalloc (size);
for (pnote = pnotes, old = contents;
pnote < pnotes_end;
pnote ++)
{
bfd_size_type note_size = 12 + pnote->namesz + pnote->descsz;
if (pnote->type == 0)
{
if (relcount > 0)
{
arelent ** rel;
/* If there is a reloc at the current offset, delete it.
Adjust the location of any relocs above the current
location downwards by the size of the note being deleted.
FIXME: We could optimize this loop by retaining a pointer to
the last reloc below the current note. */
for (rel = relpp; rel < relpp + relcount; rel ++)
{
if ((* rel)->howto == NULL)
continue;
if ((* rel)->address < (bfd_vma) (new - new_contents))
continue;
if ((* rel)->address >= (bfd_vma) ((new + note_size) - new_contents))
(* rel)->address -= note_size;
else
(* rel)->howto = NULL;
}
}
}
else
{
memcpy (new, old, note_size);
new += note_size;
}
old += note_size;
}
new_size = new - new_contents;
memcpy (contents, new_contents, new_size);
size = new_size;
free (new_contents);
if (relcount > 0)
{
arelent ** rel;
for (rel = relpp; rel < relpp + relcount; rel ++)
if ((* rel)->howto == NULL)
{
/* Delete eliminated relocs.
FIXME: There are better ways to do this. */
memmove (rel, rel + 1, ((relcount - (rel - relpp)) - 1) * sizeof (* rel));
relcount --;
}
bfd_set_reloc (abfd, sec, relpp, relcount);
}
}
done:
if (err)
{
bfd_set_error (bfd_error_bad_value);
bfd_nonfatal_message (NULL, abfd, sec, err);
status = 1;
}
free (pnotes);
return size;
}
/* Copy object file IBFD onto OBFD.
Returns TRUE upon success, FALSE otherwise. */
@ -1827,6 +2098,7 @@ copy_object (bfd *ibfd, bfd *obfd, const bfd_arch_info_type *input_arch)
bfd_vma start;
long symcount;
asection **osections = NULL;
asection *osec;
asection *gnu_debuglink_section = NULL;
bfd_size_type *gaps = NULL;
bfd_size_type max_gap = 0;
@ -2127,8 +2399,6 @@ copy_object (bfd *ibfd, bfd *obfd, const bfd_arch_info_type *input_arch)
pupdate != NULL;
pupdate = pupdate->next)
{
asection *osec;
pupdate->section = bfd_get_section_by_name (ibfd, pupdate->name);
if (pupdate->section == NULL)
{
@ -2145,16 +2415,63 @@ copy_object (bfd *ibfd, bfd *obfd, const bfd_arch_info_type *input_arch)
}
}
if (merge_notes)
{
/* This palaver is necessary because we must set the output
section size first, before its contents are ready. */
osec = bfd_get_section_by_name (ibfd, GNU_BUILD_ATTRS_SECTION_NAME);
if (osec && is_merged_note_section (ibfd, osec))
{
bfd_size_type size;
size = bfd_get_section_size (osec);
if (size == 0)
{
bfd_nonfatal_message (NULL, ibfd, osec, _("warning: note section is empty"));
merge_notes = FALSE;
}
else if (! bfd_get_full_section_contents (ibfd, osec, & merged_notes))
{
bfd_nonfatal_message (NULL, ibfd, osec, _("warning: could not load note section"));
free (merged_notes);
merged_notes = NULL;
merge_notes = FALSE;
}
else
{
merged_size = merge_gnu_build_notes (ibfd, osec, size, merged_notes);
if (merged_size == size)
{
/* Merging achieves nothing. */
free (merged_notes);
merged_notes = NULL;
merge_notes = FALSE;
merged_size = 0;
}
else
{
if (osec->output_section == NULL
|| ! bfd_set_section_size (obfd, osec->output_section, merged_size))
{
bfd_nonfatal_message (NULL, obfd, osec, _("warning: failed to set merged notes size"));
free (merged_notes);
merged_notes = NULL;
merge_notes = FALSE;
merged_size = 0;
}
}
}
}
}
if (dump_sections != NULL)
{
struct section_add * pdump;
for (pdump = dump_sections; pdump != NULL; pdump = pdump->next)
{
asection * sec;
sec = bfd_get_section_by_name (ibfd, pdump->name);
if (sec == NULL)
osec = bfd_get_section_by_name (ibfd, pdump->name);
if (osec == NULL)
{
bfd_nonfatal_message (NULL, ibfd, NULL,
_("can't dump section '%s' - it does not exist"),
@ -2162,17 +2479,17 @@ copy_object (bfd *ibfd, bfd *obfd, const bfd_arch_info_type *input_arch)
continue;
}
if ((bfd_get_section_flags (ibfd, sec) & SEC_HAS_CONTENTS) == 0)
if ((bfd_get_section_flags (ibfd, osec) & SEC_HAS_CONTENTS) == 0)
{
bfd_nonfatal_message (NULL, ibfd, sec,
bfd_nonfatal_message (NULL, ibfd, osec,
_("can't dump section - it has no contents"));
continue;
}
bfd_size_type size = bfd_get_section_size (sec);
bfd_size_type size = bfd_get_section_size (osec);
if (size == 0)
{
bfd_nonfatal_message (NULL, ibfd, sec,
bfd_nonfatal_message (NULL, ibfd, osec,
_("can't dump section - it is empty"));
continue;
}
@ -2187,7 +2504,7 @@ copy_object (bfd *ibfd, bfd *obfd, const bfd_arch_info_type *input_arch)
}
bfd_byte * contents = xmalloc (size);
if (bfd_get_section_contents (ibfd, sec, contents, 0, size))
if (bfd_get_section_contents (ibfd, osec, contents, 0, size))
{
if (fwrite (contents, 1, size, f) != size)
{
@ -2198,7 +2515,7 @@ copy_object (bfd *ibfd, bfd *obfd, const bfd_arch_info_type *input_arch)
}
}
else
bfd_nonfatal_message (NULL, ibfd, sec,
bfd_nonfatal_message (NULL, ibfd, osec,
_("could not retrieve section contents"));
fclose (f);
@ -2236,7 +2553,6 @@ copy_object (bfd *ibfd, bfd *obfd, const bfd_arch_info_type *input_arch)
{
bfd_vma debuglink_vma;
asection * highest_section;
asection * sec;
/* The PE spec requires that all sections be adjacent and sorted
in ascending order of VMA. It also specifies that debug
@ -2248,13 +2564,13 @@ copy_object (bfd *ibfd, bfd *obfd, const bfd_arch_info_type *input_arch)
VMA which makes it contiguous with other debug sections. So
walk the current section list, find the section with the
highest VMA and start the debuglink section after that one. */
for (sec = obfd->sections, highest_section = NULL;
sec != NULL;
sec = sec->next)
if (sec->vma > 0
for (osec = obfd->sections, highest_section = NULL;
osec != NULL;
osec = osec->next)
if (osec->vma > 0
&& (highest_section == NULL
|| sec->vma > highest_section->vma))
highest_section = sec;
|| osec->vma > highest_section->vma))
highest_section = osec;
if (highest_section)
debuglink_vma = BFD_ALIGN (highest_section->vma
@ -2442,8 +2758,6 @@ copy_object (bfd *ibfd, bfd *obfd, const bfd_arch_info_type *input_arch)
pupdate != NULL;
pupdate = pupdate->next)
{
asection *osec;
osec = pupdate->section->output_section;
if (! bfd_set_section_contents (obfd, osec, pupdate->contents,
0, pupdate->size))
@ -2454,6 +2768,24 @@ copy_object (bfd *ibfd, bfd *obfd, const bfd_arch_info_type *input_arch)
}
}
if (merge_notes)
{
osec = bfd_get_section_by_name (obfd, GNU_BUILD_ATTRS_SECTION_NAME);
if (osec && is_merged_note_section (obfd, osec))
{
if (! bfd_set_section_contents (obfd, osec, merged_notes, 0, merged_size))
{
bfd_nonfatal_message (NULL, obfd, osec, _("error: failed to copy merged notes into output"));
return FALSE;
}
}
else
bfd_nonfatal_message (NULL, obfd, osec, _("ICE: lost merged note section"));
free (merged_notes);
merged_notes = NULL;
merge_notes = FALSE;
}
if (gnu_debuglink_filename != NULL)
{
if (! bfd_fill_in_gnu_debuglink_section
@ -3179,7 +3511,7 @@ setup_section (bfd *ibfd, sec_ptr isection, void *obfdarg)
/* Return TRUE if input section ISECTION should be skipped. */
static bfd_boolean
skip_section (bfd *ibfd, sec_ptr isection)
skip_section (bfd *ibfd, sec_ptr isection, bfd_boolean skip_copy)
{
sec_ptr osection;
bfd_size_type size;
@ -3199,6 +3531,11 @@ skip_section (bfd *ibfd, sec_ptr isection)
if (is_update_section (ibfd, isection))
return TRUE;
/* When merging a note section we skip the copying of the contents,
but not the copying of the relocs associated with the contents. */
if (skip_copy && is_merged_note_section (ibfd, isection))
return TRUE;
flags = bfd_get_section_flags (ibfd, isection);
if ((flags & SEC_GROUP) != 0)
return TRUE;
@ -3265,7 +3602,7 @@ copy_relocations_in_section (bfd *ibfd, sec_ptr isection, void *obfdarg)
long relcount;
sec_ptr osection;
if (skip_section (ibfd, isection))
if (skip_section (ibfd, isection, FALSE))
return;
osection = isection->output_section;
@ -3354,7 +3691,7 @@ copy_section (bfd *ibfd, sec_ptr isection, void *obfdarg)
sec_ptr osection;
bfd_size_type size;
if (skip_section (ibfd, isection))
if (skip_section (ibfd, isection, TRUE))
return;
osection = isection->output_section;
@ -4010,7 +4347,7 @@ copy_main (int argc, char *argv[])
struct stat statbuf;
const bfd_arch_info_type *input_arch = NULL;
while ((c = getopt_long (argc, argv, "b:B:i:I:j:K:N:s:O:d:F:L:G:R:SpgxXHhVvW:wDU",
while ((c = getopt_long (argc, argv, "b:B:i:I:j:K:MN:s:O:d:F:L:G:R:SpgxXHhVvW:wDU",
copy_options, (int *) 0)) != EOF)
{
switch (c)
@ -4104,6 +4441,10 @@ copy_main (int argc, char *argv[])
add_specific_symbol (optarg, keep_specific_htab);
break;
case 'M':
merge_notes = TRUE;
break;
case 'N':
add_specific_symbol (optarg, strip_specific_htab);
break;