[PATCH] xen: Fix EFI buildid alignment

[Marek Marczykowski-Górecki <marmarek@xxxxxxxxxxxxxxxxxxxxxx>]

Old binutils get confused about .buildid overlapping (in VA space) with
earlier section. That confusion results in weird errors down the road,
like this one:

    objcopy: xen.efi: Data Directory size (1c) exceeds space left in section (8)

While the bug is fixed in later binutils version, force alignment of the
buildid to avoid overlapping and make it work with older versions too.
This can be reverted once toolchain base is raised at or above binutils
2.36.

Details at:
https://lore.kernel.org/all/3TMd7J2u5gCA8ouIG_Xfcw7s5JKMG06XsDIesEB3Fi9htUJ43Lfl057wXohlpCHcszqoCmicpIlneEDO26ZqT8QfC2Y39VxBuqD3nS1j5Q4=@trmm.net/

Signed-off-by: Marek Marczykowski-Górecki <marmarek@xxxxxxxxxxxxxxxxxxxxxx>
Fixes: eee5909e9d1e ("x86/EFI: use less crude a way of generating the build ID")
---
While the actual bug apparently is in binutils, the commit mentioned in
Fixes: tag introduced part that triggers that bug.
---
 xen/arch/x86/xen.lds.S | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/xen/arch/x86/xen.lds.S b/xen/arch/x86/xen.lds.S
index 5d02f83a409c..967f9167f757 100644
--- a/xen/arch/x86/xen.lds.S
+++ b/xen/arch/x86/xen.lds.S
@@ -171,6 +171,8 @@ SECTIONS
        __note_gnu_build_id_end = .;
   } PHDR(note) PHDR(text)
 #elif defined(BUILD_ID_EFI)
+  /* Workaround bug in binutils < 2.38 */
+  . = ALIGN(32);
   DECL_SECTION(.buildid) {
        __note_gnu_build_id_start = .;
        *(.buildid)
-- 
2.51.0