Add support for v3 binary annotation notes.

I am checking in the attached patch which updates the binutils
  support for version 3 binary annotation notes.  (Version 3 adds
  an end address to the ranges covered by the notes, so that it
  is possible to detect gaps in the coverage).

  This patch also stops the note merging feature of objcopy from
  executing if the notes have relocations against them.  This makes the
  code simpler, and prevents the problems with architectures which have
  unusual relocation management issues.

	* objcopy.c (objcopy_internal_note): New structure.
	(gap_exists): New function.
	(is_open_note): New function.
	(is_func_note): New function.
	(is_64bit): New function.
	(merge_gnu_build_notes): Handle v3 notes.  Do not merge
	if there are relocations against the notes.
	* readelf.c (get_note_type): Use short names for build attribute
	notes.
	(print_symbol_for_build_attribute): Rename to
	get_symbol_for_build_attribute.  Returns the found symbol rather
	than printing it.
	(print_gnu_build_attribute_description): Maintain address ranges
	for function notes as well as global notes.  Handle v3 notes.
	(print_gnu_build_attribute_name): Use more space for printing the
	name in wide mode.
	* testsuite/binutils-all/note-2-32.s: Use .dc.l instead of .word.
	Eliminate symbol references in order to remove the need for
	relocations.
	* testsuite/binutils-all/note-2-64.s: Likewise.
	* testsuite/binutils-all/note-3-32.s: Add a size to the note_1
	symbol.
	* testsuite/binutils-all/note-3-64.s: Likewise.
	* testsuite/binutils-all/mips/mips-note-2r-n32.d: Update expected
	output.
	* testsuite/binutils-all/mips/mips-note-2r-n64.d: Likewise.
	* testsuite/binutils-all/mips/mips-note-2r.d: Likewise.
	* testsuite/binutils-all/note-2-32.d: Likewise.
	* testsuite/binutils-all/note-2-64.d: Likewise.
	* testsuite/binutils-all/note-3-32.d: Likewise.
	* testsuite/binutils-all/note-3-64.d: Likewise.
	* testsuite/binutils-all/note-4-64.s: New test.  Checks v3 notes.
	* testsuite/binutils-all/note-4-32.s: New test.
	* testsuite/binutils-all/note-4-64.d: New test result file.
	* testsuite/binutils-all/note-4-32.d: New test result file.
This commit is contained in:
Nick Clifton 2018-01-03 10:28:33 +00:00
parent 9f757bf7fc
commit 6f156d7a4a
19 changed files with 745 additions and 282 deletions

View file

@ -1905,84 +1905,229 @@ num_bytes (unsigned long val)
return count;
}
typedef struct objcopy_internal_note
{
Elf_Internal_Note note;
bfd_vma start;
bfd_vma end;
bfd_boolean modified;
} objcopy_internal_note;
/* Returns TRUE if a gap does, or could, exist between the address range
covered by PNOTE1 and PNOTE2. */
static bfd_boolean
gap_exists (objcopy_internal_note * pnote1,
objcopy_internal_note * pnote2)
{
/* Without range end notes, we assume that a gap might exist. */
if (pnote1->end == 0 || pnote2->end == 0)
return TRUE;
/* FIXME: Alignment of 16 bytes taken from x86_64 binaries.
Really we should extract the alignment of the section covered by the notes. */
return BFD_ALIGN (pnote1->end, 16) < pnote2->start;
}
static bfd_boolean
is_open_note (objcopy_internal_note * pnote)
{
return (pnote->note.type == NT_GNU_BUILD_ATTRIBUTE_OPEN);
}
static bfd_boolean
is_func_note (objcopy_internal_note * pnote)
{
return (pnote->note.type == NT_GNU_BUILD_ATTRIBUTE_FUNC);
}
static bfd_boolean
is_64bit (bfd * abfd)
{
/* Should never happen, but let's be paranoid. */
if (bfd_get_flavour (abfd) != bfd_target_elf_flavour)
return FALSE;
return elf_elfheader (abfd)->e_ident[EI_CLASS] == ELFCLASS64;
}
/* 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;
objcopy_internal_note * pnotes_end;
objcopy_internal_note * pnotes = NULL;
objcopy_internal_note * pnote;
bfd_size_type remain = size;
unsigned version_1_seen = 0;
unsigned version_2_seen = 0;
unsigned version_3_seen = 0;
bfd_boolean duplicate_found = FALSE;
const char * err = NULL;
bfd_byte * in = contents;
int attribute_type_byte;
int val_start;
unsigned long previous_func_start = 0;
unsigned long previous_open_start = 0;
unsigned long previous_func_end = 0;
unsigned long previous_open_end = 0;
long relsize;
/* Make a copy of the notes.
relsize = bfd_get_reloc_upper_bound (abfd, sec);
if (relsize > 0)
{
arelent ** relpp;
long relcount;
/* If there are relocs associated with this section then we
cannot safely merge it. */
relpp = (arelent **) xmalloc (relsize);
relcount = bfd_canonicalize_reloc (abfd, sec, relpp, isympp);
free (relpp);
if (relcount != 0)
goto done;
}
/* Make a copy of the notes and convert to our internal format.
Minimum size of a note is 12 bytes. */
pnote = pnotes = (Elf_Internal_Note *) xcalloc ((size / 12), sizeof (Elf_Internal_Note));
pnote = pnotes = (objcopy_internal_note *) xcalloc ((size / 12), sizeof (* pnote));
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);
bfd_vma start, end;
if (pnote->type != NT_GNU_BUILD_ATTRIBUTE_OPEN
&& pnote->type != NT_GNU_BUILD_ATTRIBUTE_FUNC)
pnote->note.namesz = (bfd_get_32 (abfd, in ) + 3) & ~3;
pnote->note.descsz = (bfd_get_32 (abfd, in + 4) + 3) & ~3;
pnote->note.type = bfd_get_32 (abfd, in + 8);
if (pnote->note.type != NT_GNU_BUILD_ATTRIBUTE_OPEN
&& pnote->note.type != NT_GNU_BUILD_ATTRIBUTE_FUNC)
{
err = _("corrupt GNU build attribute note: wrong note type");
goto done;
}
if (pnote->namesz + pnote->descsz + 12 > remain)
if (pnote->note.namesz + pnote->note.descsz + 12 > remain)
{
err = _("corrupt GNU build attribute note: note too big");
goto done;
}
if (pnote->namesz < 2)
if (pnote->note.namesz < 2)
{
err = _("corrupt GNU build attribute note: name too small");
goto done;
}
if (pnote->descsz != 0
&& pnote->descsz != 4
&& pnote->descsz != 8)
pnote->note.namedata = (char *)(in + 12);
pnote->note.descdata = (char *)(in + 12 + pnote->note.namesz);
remain -= 12 + pnote->note.namesz + pnote->note.descsz;
in += 12 + pnote->note.namesz + pnote->note.descsz;
if (pnote->note.namesz > 2
&& pnote->note.namedata[0] == '$'
&& pnote->note.namedata[1] == GNU_BUILD_ATTRIBUTE_VERSION
&& pnote->note.namedata[2] == '1')
++ version_1_seen;
else if (pnote->note.namesz > 4
&& pnote->note.namedata[0] == 'G'
&& pnote->note.namedata[1] == 'A'
&& pnote->note.namedata[2] == '$'
&& pnote->note.namedata[3] == GNU_BUILD_ATTRIBUTE_VERSION)
{
if (pnote->note.namedata[4] == '2')
++ version_2_seen;
else if (pnote->note.namedata[4] == '3')
++ version_3_seen;
else
{
err = _("corrupt GNU build attribute note: unsupported version");
goto done;
}
}
switch (pnote->note.descsz)
{
case 0:
start = end = 0;
break;
case 4:
start = bfd_get_32 (abfd, pnote->note.descdata);
/* FIXME: For version 1 and 2 notes we should try to
calculate the end address by finding a symbol whose
value is START, and then adding in its size.
For now though, since v1 and v2 was not intended to
handle gaps, we chose an artificially large end
address. */
end = 0x7ffffffffffffffUL;
break;
case 8:
if (! is_64bit (abfd))
{
start = bfd_get_32 (abfd, pnote->note.descdata);
end = bfd_get_32 (abfd, pnote->note.descdata + 4);
}
else
{
start = bfd_get_64 (abfd, pnote->note.descdata);
/* FIXME: For version 1 and 2 notes we should try to
calculate the end address by finding a symbol whose
value is START, and then adding in its size.
For now though, since v1 and v2 was not intended to
handle gaps, we chose an artificially large end
address. */
end = 0x7ffffffffffffffUL;
}
break;
case 16:
start = bfd_get_64 (abfd, pnote->note.descdata);
end = bfd_get_64 (abfd, pnote->note.descdata + 8);
break;
default:
err = _("corrupt GNU build attribute note: bad description size");
goto done;
}
pnote->namedata = (char *)(in + 12);
pnote->descdata = (char *)(in + 12 + pnote->namesz);
if (is_open_note (pnote))
{
if (start)
previous_open_start = start;
remain -= 12 + pnote->namesz + pnote->descsz;
in += 12 + pnote->namesz + pnote->descsz;
pnote->start = previous_open_start;
if (pnote->namedata[pnote->namesz - 1] != 0)
if (end)
previous_open_end = end;
pnote->end = previous_open_end;
}
else
{
if (start)
previous_func_start = start;
pnote->start = previous_func_start;
if (end)
previous_func_end = end;
pnote->end = previous_func_end;
}
if (pnote->note.namedata[pnote->note.namesz - 1] != 0)
{
err = _("corrupt GNU build attribute note: name not NUL terminated");
goto done;
}
if (pnote->namesz > 2
&& pnote->namedata[0] == '$'
&& pnote->namedata[1] == GNU_BUILD_ATTRIBUTE_VERSION
&& pnote->namedata[2] == '1')
++ version_1_seen;
else if (pnote->namesz > 4
&& pnote->namedata[0] == 'G'
&& pnote->namedata[1] == 'A'
&& pnote->namedata[2] == '$'
&& pnote->namedata[3] == GNU_BUILD_ATTRIBUTE_VERSION
&& pnote->namedata[4] == '2')
++ version_2_seen;
pnote ++;
}
@ -1995,27 +2140,29 @@ merge_gnu_build_notes (bfd * abfd, asection * sec, bfd_size_type size, bfd_byte
goto done;
}
if (version_1_seen == 0 && version_2_seen == 0)
if (version_1_seen == 0 && version_2_seen == 0 && version_3_seen == 0)
{
err = _("bad GNU build attribute notes: no known versions detected");
goto done;
}
if (version_1_seen > 0 && version_2_seen > 0)
if ((version_1_seen > 0 && version_2_seen > 0)
|| (version_1_seen > 0 && version_3_seen > 0)
|| (version_2_seen > 0 && version_3_seen > 0))
{
err = _("bad GNU build attribute notes: multiple different versions");
goto done;
}
/* Merging is only needed if there is more than one version note... */
if (version_1_seen == 1 || version_2_seen == 1)
if (version_1_seen == 1 || version_2_seen == 1 || version_3_seen == 1)
goto done;
attribute_type_byte = version_1_seen ? 1 : 3;
val_start = attribute_type_byte + 1;
/* The first note should be the first version note. */
if (pnotes[0].namedata[attribute_type_byte] != GNU_BUILD_ATTRIBUTE_VERSION)
if (pnotes[0].note.namedata[attribute_type_byte] != GNU_BUILD_ATTRIBUTE_VERSION)
{
err = _("bad GNU build attribute notes: first note not version note");
goto done;
@ -2026,7 +2173,9 @@ merge_gnu_build_notes (bfd * abfd, asection * sec, bfd_size_type size, bfd_byte
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.
of name and whose address ranges coincide.
IE - it there are gaps in the coverage of the notes, then these gaps
must be preserved.
4. Combine the numeric value of any NT_GNU_BUILD_ATTRIBUTE_OPEN notes
of type GNU_BUILD_ATTRIBUTE_STACK_SIZE.
5. If an NT_GNU_BUILD_ATTRIBUTE_OPEN note is going to be preserved and
@ -2036,103 +2185,134 @@ merge_gnu_build_notes (bfd * abfd, asection * sec, bfd_size_type size, bfd_byte
address to which it refers. */
for (pnote = pnotes + 1; pnote < pnotes_end; pnote ++)
{
Elf_Internal_Note * back;
Elf_Internal_Note * prev_open = NULL;
int note_type;
objcopy_internal_note * back;
objcopy_internal_note * prev_open_with_range = NULL;
if (pnote->type == NT_GNU_BUILD_ATTRIBUTE_FUNC)
/* Rule 2 - preserve function notes. */
if (! is_open_note (pnote))
continue;
/* Scan for duplicates. Clear the type field of any found - but do not
delete them just yet. */
note_type = pnote->note.namedata[attribute_type_byte];
/* Scan backwards from pnote, looking 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;
int back_type = back->note.namedata[attribute_type_byte];
if (back->type == pnote->type
&& back->namedata[attribute_type_byte] == pnote->namedata[attribute_type_byte])
/* If this is the first open note with an address
range that we have encountered then record it. */
if (prev_open_with_range == NULL
&& back->note.descsz > 0
&& ! is_func_note (back))
prev_open_with_range = back;
if (! is_open_note (back))
continue;
/* If the two notes are different then keep on searching. */
if (back_type != note_type)
continue;
/* Rule 4 - combine stack size notes. */
if (back_type == GNU_BUILD_ATTRIBUTE_STACK_SIZE)
{
if (back->namedata[attribute_type_byte] == GNU_BUILD_ATTRIBUTE_STACK_SIZE)
unsigned char * name;
unsigned long note_val;
unsigned long back_val;
unsigned int shift;
unsigned int bytes;
unsigned long byte;
for (shift = 0, note_val = 0,
bytes = pnote->note.namesz - val_start,
name = (unsigned char *) pnote->note.namedata + val_start;
bytes--;)
{
unsigned char * name;
unsigned long note_val;
unsigned long back_val;
unsigned int shift;
unsigned int bytes;
unsigned long byte;
for (shift = 0, note_val = 0,
bytes = pnote->namesz - val_start,
name = (unsigned char *) pnote->namedata + val_start;
bytes--;)
{
byte = (* name ++) & 0xff;
note_val |= byte << shift;
shift += 8;
}
for (shift = 0, back_val = 0,
bytes = back->namesz - val_start,
name = (unsigned char *) back->namedata + val_start;
bytes--;)
{
byte = (* name ++) & 0xff;
back_val |= byte << shift;
shift += 8;
}
back_val += note_val;
if (num_bytes (back_val) >= back->namesz - val_start)
{
/* We have a problem - the new value requires more bytes of
storage in the name field than are available. Currently
we have no way of fixing this, so we just preserve both
notes. */
continue;
}
/* Write the new val into back. */
name = (unsigned char *) back->namedata + val_start;
while (name < (unsigned char *) back->namedata + back->namesz)
{
byte = back_val & 0xff;
* name ++ = byte;
if (back_val == 0)
break;
back_val >>= 8;
}
duplicate_found = TRUE;
pnote->type = 0;
break;
}
if (back->namesz == pnote->namesz
&& memcmp (back->namedata, pnote->namedata, back->namesz) == 0)
{
duplicate_found = TRUE;
pnote->type = 0;
break;
byte = (* name ++) & 0xff;
note_val |= byte << shift;
shift += 8;
}
/* If we have found an attribute match then stop searching backwards. */
if (! ISPRINT (back->namedata[attribute_type_byte])
/* Names are NUL terminated, so this is safe. */
|| strcmp (back->namedata + val_start, pnote->namedata + val_start) == 0)
for (shift = 0, back_val = 0,
bytes = back->note.namesz - val_start,
name = (unsigned char *) back->note.namedata + val_start;
bytes--;)
{
/* Since we are keeping this note we must check to see if its
description refers back to an earlier OPEN version 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;
byte = (* name ++) & 0xff;
back_val |= byte << shift;
shift += 8;
}
back_val += note_val;
if (num_bytes (back_val) >= back->note.namesz - val_start)
{
/* We have a problem - the new value requires more bytes of
storage in the name field than are available. Currently
we have no way of fixing this, so we just preserve both
notes. */
continue;
}
/* Write the new val into back. */
name = (unsigned char *) back->note.namedata + val_start;
while (name < (unsigned char *) back->note.namedata
+ back->note.namesz)
{
byte = back_val & 0xff;
* name ++ = byte;
if (back_val == 0)
break;
back_val >>= 8;
}
duplicate_found = TRUE;
pnote->note.type = 0;
break;
}
/* Rule 3 - combine identical open notes. */
if (back->note.namesz == pnote->note.namesz
&& memcmp (back->note.namedata,
pnote->note.namedata, back->note.namesz) == 0
&& ! gap_exists (back, pnote))
{
duplicate_found = TRUE;
pnote->note.type = 0;
if (pnote->end > back->end)
back->end = pnote->end;
if (version_3_seen)
back->modified = TRUE;
break;
}
/* Rule 5 - Since we are keeping this note we must check to see
if its description refers back to an earlier OPEN version
note that has been scheduled for deletion. If so then we
must make sure that version note is also preserved. */
if (version_3_seen)
{
/* As of version 3 we can just
move the range into the note. */
pnote->modified = TRUE;
pnote->note.type = NT_GNU_BUILD_ATTRIBUTE_FUNC;
back->modified = TRUE;
back->note.type = NT_GNU_BUILD_ATTRIBUTE_FUNC;
}
else
{
if (pnote->note.descsz == 0
&& prev_open_with_range != NULL
&& prev_open_with_range->note.type == 0)
prev_open_with_range->note.type = NT_GNU_BUILD_ATTRIBUTE_OPEN;
}
/* We have found a similar attribute but the details do not match.
Stop searching backwards. */
break;
}
}
@ -2142,22 +2322,8 @@ merge_gnu_build_notes (bfd * abfd, asection * sec, bfd_size_type size, bfd_byte
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;
}
bfd_vma prev_start = 0;
bfd_vma prev_end = 0;
/* Eliminate the duplicates. */
new = new_contents = xmalloc (size);
@ -2165,36 +2331,52 @@ merge_gnu_build_notes (bfd * abfd, asection * sec, bfd_size_type size, bfd_byte
pnote < pnotes_end;
pnote ++)
{
bfd_size_type note_size = 12 + pnote->namesz + pnote->descsz;
bfd_size_type note_size = 12 + pnote->note.namesz + pnote->note.descsz;
if (pnote->type == 0)
if (pnote->note.type != 0)
{
if (relcount > 0)
if (pnote->modified)
{
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 the note has been modified then we must copy it by
hand, potentially adding in a new description field. */
if (pnote->start == prev_start && pnote->end == prev_end)
{
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;
bfd_put_32 (abfd, pnote->note.namesz, new);
bfd_put_32 (abfd, 0, new + 4);
bfd_put_32 (abfd, pnote->note.type, new + 8);
new += 12;
memcpy (new, pnote->note.namedata, pnote->note.namesz);
new += pnote->note.namesz;
}
else
{
bfd_put_32 (abfd, pnote->note.namesz, new);
bfd_put_32 (abfd, is_64bit (abfd) ? 16 : 8, new + 4);
bfd_put_32 (abfd, pnote->note.type, new + 8);
new += 12;
memcpy (new, pnote->note.namedata, pnote->note.namesz);
new += pnote->note.namesz;
if (is_64bit (abfd))
{
bfd_put_64 (abfd, pnote->start, new);
bfd_put_64 (abfd, pnote->end, new + 8);
new += 16;
}
else
(* rel)->howto = NULL;
{
bfd_put_32 (abfd, pnote->start, new);
bfd_put_32 (abfd, pnote->end, new + 4);
new += 8;
}
}
}
}
else
{
memcpy (new, old, note_size);
new += note_size;
else
{
memcpy (new, old, note_size);
new += note_size;
}
prev_start = pnote->start;
prev_end = pnote->end;
}
old += note_size;
@ -2204,24 +2386,6 @@ merge_gnu_build_notes (bfd * abfd, asection * sec, bfd_size_type size, bfd_byte
memcpy (contents, new_contents, new_size);
size = new_size;
free (new_contents);
if (relcount > 0)
{
arelent **rel = relpp;
while (rel < relpp + relcount)
if ((*rel)->howto != NULL)
rel++;
else
{
/* 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: