From fa71cc4400924859467812705749ee9b98b3eec6 Mon Sep 17 00:00:00 2001

From: Oscar Salvador <osalvador@suse.de>

Date: Wed, 5 Oct 2022 18:09:21 +0200

Subject: [PATCH] arm64: Discard .note.GNU-stack section

Patch-mainline: Never, SUSE specific

References: bsc#1203693

Commit "Makefile: link with -z noexecstack --no-warn-rwx-segments: ddbd47d2219a"

creates a new section .note.GNU-stack, which is not discarded by arm64.

This changes the ELF layout and causes the build to fail on arm64.

Quoting Michal Matz:

 "The .note.GNU-stack section in head.o is created by 'ld -r -z noexecstack',

  when relinking head.o into head.o (for various reasons).  That section is created

  with SHT_PROGBITS, and as the kernel linker script doesn't discard those

  it also makes the output ".notes" section (which

  collects all .note* sections) SHT_PROGBITS, which in turn makes ld not generate

  a PT_NOTE segment covering all these.

  Now, I initially thought the linker with 'ld -r', when generating a

  .note.GNU-stack section because of a command line option should simply create it

  with the type SHT_NOTE and all would be well.  That somewhat works, but is actually

  wrong: a SHT_NOTE section has a specific layout per the gABI (at least

  it must contain a header), but .note.GNU-stack is empty.  So it really can't

  be SHT_NOTE but must remain either SHT_PROGBITS or SHT_NOBITS."

Fix it for now by discarding that section.

Signed-off-by: Oscar Salvador <osalvador@suse.de>

Suggested-by: Michael Matz 

---

 arch/arm64/kernel/vmlinux.lds.S | 1 +

 1 file changed, 1 insertion(+)

diff --git a/arch/arm64/kernel/vmlinux.lds.S b/arch/arm64/kernel/vmlinux.lds.S

index 1a40822bbbc5..cd061a9f135d 100644

--- a/arch/arm64/kernel/vmlinux.lds.S

+++ b/arch/arm64/kernel/vmlinux.lds.S

@@ -139,6 +139,7 @@ SECTIONS

 	/DISCARD/ : {

 		*(.interp .dynamic)

 		*(.dynsym .dynstr .hash .gnu.hash)

+		*(.note.GNU-stack)

 	}

 	. = KIMAGE_VADDR;

-- 

2.35.3