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authorH.J. Lu <hjl.tools@gmail.com>2017-11-24 14:49:36 -0800
committerH.J. Lu <hjl.tools@gmail.com>2017-11-24 14:52:15 -0800
commit276da9b31bd6e3eb8d1dd814c867266f59f29093 (patch)
tree1acbee1595881224123021036356e0d43316ccf3 /bfd/elf.c
parente547c119d043f2ecffb70452020ab9150d083a91 (diff)
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Re-apply "elf: Properly compute offsets of note descriptor and next note"
CORE PT_NOTE segments may have p_align values of 0 or 1. gABI specifies that PT_NOTE alignment should be aligned to 4 bytes for 32-bit objects and to 8 bytes for 64-bit objects. If segment alignment is less than 4, we use 4 byte alignment.
Diffstat (limited to 'bfd/elf.c')
-rw-r--r--bfd/elf.c31
1 files changed, 21 insertions, 10 deletions
diff --git a/bfd/elf.c b/bfd/elf.c
index 8cd67ad..8f6aa53 100644
--- a/bfd/elf.c
+++ b/bfd/elf.c
@@ -52,9 +52,10 @@ static int elf_sort_sections (const void *, const void *);
static bfd_boolean assign_file_positions_except_relocs (bfd *, struct bfd_link_info *);
static bfd_boolean prep_headers (bfd *);
static bfd_boolean swap_out_syms (bfd *, struct elf_strtab_hash **, int) ;
-static bfd_boolean elf_read_notes (bfd *, file_ptr, bfd_size_type) ;
+static bfd_boolean elf_read_notes (bfd *, file_ptr, bfd_size_type,
+ size_t align) ;
static bfd_boolean elf_parse_notes (bfd *abfd, char *buf, size_t size,
- file_ptr offset);
+ file_ptr offset, size_t align);
/* Swap version information in and out. The version information is
currently size independent. If that ever changes, this code will
@@ -1089,7 +1090,8 @@ _bfd_elf_make_section_from_shdr (bfd *abfd,
if (!bfd_malloc_and_get_section (abfd, newsect, &contents))
return FALSE;
- elf_parse_notes (abfd, (char *) contents, hdr->sh_size, hdr->sh_offset);
+ elf_parse_notes (abfd, (char *) contents, hdr->sh_size,
+ hdr->sh_offset, hdr->sh_addralign);
free (contents);
}
@@ -2990,7 +2992,8 @@ bfd_section_from_phdr (bfd *abfd, Elf_Internal_Phdr *hdr, int hdr_index)
case PT_NOTE:
if (! _bfd_elf_make_section_from_phdr (abfd, hdr, hdr_index, "note"))
return FALSE;
- if (! elf_read_notes (abfd, hdr->p_offset, hdr->p_filesz))
+ if (! elf_read_notes (abfd, hdr->p_offset, hdr->p_filesz,
+ hdr->p_align))
return FALSE;
return TRUE;
@@ -10970,14 +10973,21 @@ elfcore_write_register_note (bfd *abfd,
}
static bfd_boolean
-elf_parse_notes (bfd *abfd, char *buf, size_t size, file_ptr offset)
+elf_parse_notes (bfd *abfd, char *buf, size_t size, file_ptr offset,
+ size_t align)
{
char *p;
+ /* NB: CORE PT_NOTE segments may have p_align values of 0 or 1.
+ gABI specifies that PT_NOTE alignment should be aligned to 4
+ bytes for 32-bit objects and to 8 bytes for 64-bit objects. If
+ align is less than 4, we use 4 byte alignment. */
+ if (align < 4)
+ align = 4;
+
p = buf;
while (p < buf + size)
{
- /* FIXME: bad alignment assumption. */
Elf_External_Note *xnp = (Elf_External_Note *) p;
Elf_Internal_Note in;
@@ -10992,7 +11002,7 @@ elf_parse_notes (bfd *abfd, char *buf, size_t size, file_ptr offset)
return FALSE;
in.descsz = H_GET_32 (abfd, xnp->descsz);
- in.descdata = in.namedata + BFD_ALIGN (in.namesz, 4);
+ in.descdata = p + ELF_NOTE_DESC_OFFSET (in.namesz, align);
in.descpos = offset + (in.descdata - buf);
if (in.descsz != 0
&& (in.descdata >= buf + size
@@ -11054,14 +11064,15 @@ elf_parse_notes (bfd *abfd, char *buf, size_t size, file_ptr offset)
break;
}
- p = in.descdata + BFD_ALIGN (in.descsz, 4);
+ p += ELF_NOTE_NEXT_OFFSET (in.namesz, in.descsz, align);
}
return TRUE;
}
static bfd_boolean
-elf_read_notes (bfd *abfd, file_ptr offset, bfd_size_type size)
+elf_read_notes (bfd *abfd, file_ptr offset, bfd_size_type size,
+ size_t align)
{
char *buf;
@@ -11080,7 +11091,7 @@ elf_read_notes (bfd *abfd, file_ptr offset, bfd_size_type size)
buf[size] = 0;
if (bfd_bread (buf, size, abfd) != size
- || !elf_parse_notes (abfd, buf, size, offset))
+ || !elf_parse_notes (abfd, buf, size, offset, align))
{
free (buf);
return FALSE;