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.

1 files changed, 16 insertions, 0 deletions

diff --git a/include/elf/external.h b/include/elf/external.h
index d65bae0..eb0a53a 100644
--- a/include/elf/external.h
+++ b/include/elf/external.h
@@ -183,6 +183,22 @@ typedef struct {
   char		name[1];		/* Start of the name+desc data */
 } Elf_External_Note;
 
+/* Align an address upward to a boundary, expressed as a number of bytes.
+   E.g. align to an 8-byte boundary with argument of 8.  */
+#define ELF_ALIGN_UP(addr, boundary) \
+  (((bfd_vma) (addr) + ((boundary) - 1)) & ~ (bfd_vma) ((boundary) -1))
+
+/* Compute the offset of the note descriptor from size of note entry's
+   owner string and note alignment.  */
+#define ELF_NOTE_DESC_OFFSET(namesz, align) \
+  ELF_ALIGN_UP (offsetof (Elf_External_Note, name) + (namesz), (align))
+
+/* Compute the offset of the next note entry from size of note entry's
+   owner string, size of the note descriptor and note alignment.  */
+#define ELF_NOTE_NEXT_OFFSET(namesz, descsz, align) \
+  ELF_ALIGN_UP (ELF_NOTE_DESC_OFFSET ((namesz), (align)) + (descsz), \
+		(align))
+
 /* Relocation Entries */
 typedef struct {
   unsigned char r_offset[4];	/* Location at which to apply the action */