gnu-efi/0032-Make-our-dummy-.reloc-sections-not-depend-on-section.patch

From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: Peter Jones <pjones@redhat.com>
Date: Mon, 30 Sep 2019 14:29:45 -0400
Subject: [PATCH] Make our dummy .reloc sections not depend on section order.

Currently on x64 we manually build a dummy .reloc table entry by using a
symbol in .text and subtracting its address from another symbol that's
inside the .reloc section.  On ia32 we just use its location.  In either
case, if the linker puts either section in a location we're not
expecting, the .reloc table winds up having invalid values, and the PE
loader will fail to load the binary.

This changes it to be two symbols that are both in .text, making the
result unrelated to the section order or location.

It's not clear to me that these .reloc entries are actually necessary at
all, but I'm going to leave them in place for now, in case they are.

Signed-off-by: Peter Jones <pjones@redhat.com>
---
 gnuefi/crt0-efi-ia32.S | 17 +++++++++--------
 gnuefi/crt0-efi-x64.S  | 16 ++++++++--------
 2 files changed, 17 insertions(+), 16 deletions(-)

diff --git a/gnuefi/crt0-efi-ia32.S b/gnuefi/crt0-efi-ia32.S
index 8e8e372f551..031a592ab35 100644
--- a/gnuefi/crt0-efi-ia32.S
+++ b/gnuefi/crt0-efi-ia32.S
@@ -64,13 +64,14 @@ _start:
 .exit:	leave
 	ret
  
- 	// hand-craft a dummy .reloc section so EFI knows it's a relocatable executable:
- 
- 	.data
-dummy:	.long	0
+	// hand-craft a dummy .reloc section so EFI knows it's a relocatable executable:
+	.data
+.dummy0:
+.dummy1:
+	.long	0
 
 #define IMAGE_REL_ABSOLUTE	0
- 	.section .reloc
- 	.long	dummy					// Page RVA
- 	.long	10					// Block Size (2*4+2)
- 	.word	(IMAGE_REL_ABSOLUTE<<12) +  0		// reloc for dummy
+	.section .reloc, "a"
+	.long	.dummy1-.dummy0				// Page RVA
+	.long	10					// Block Size (2*4+2)
+	.word	(IMAGE_REL_ABSOLUTE<<12) +  0		// reloc for dummy
diff --git a/gnuefi/crt0-efi-x64.S b/gnuefi/crt0-efi-x64.S
index 3fe361b7ffd..5c86cde12e8 100644
--- a/gnuefi/crt0-efi-x64.S
+++ b/gnuefi/crt0-efi-x64.S
@@ -62,15 +62,15 @@ _start:
 .exit:	
   	ret
 
- 	// hand-craft a dummy .reloc section so EFI knows it's a relocatable executable:
- 
- 	.data
-dummy:	.long	0
+	// hand-craft a dummy .reloc section so EFI knows it's a relocatable executable:
+	.data
+.dummy0:
+.dummy1:
+	.long	0
 
 #define IMAGE_REL_ABSOLUTE	0
- 	.section .reloc, "a"
-label1:
-	.long	dummy-label1				// Page RVA
- 	.long	10					// Block Size (2*4+2)
+	.section .reloc, "a"
+	.long	.dummy1-.dummy0				// Page RVA
+	.long	10					// Block Size (2*4+2)
 	.word	(IMAGE_REL_ABSOLUTE<<12) +  0		// reloc for dummy