From 94c9a77f6504170a6bd38b0aa29039208987650e Mon Sep 17 00:00:00 2001
From: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Date: Wed, 13 Aug 2014 13:35:38 +0200
Subject: [PATCH 52/74] Handle empty .reloc section in PE/COFF loader

On archs where no EFI aware objcopy is available, the generated PE/COFF
header contains a .reloc section which is completely empty. Handle this by
- returning early from relocate_coff() with EFI_SUCCESS,
- ignoring discardable sections in the section loader.

Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
---
 shim.c | 11 ++++++++---
 1 file changed, 8 insertions(+), 3 deletions(-)

diff --git a/shim.c b/shim.c
index ea8eba8..1329212 100644
--- a/shim.c
+++ b/shim.c
@@ -145,6 +145,9 @@ static EFI_STATUS relocate_coff (PE_COFF_LOADER_IMAGE_CONTEXT *context,
 		return EFI_UNSUPPORTED;
 	}
 
+	if (!context->RelocDir->Size)
+		return EFI_SUCCESS;
+
 	RelocBase = ImageAddress(data, size, context->RelocDir->VirtualAddress);
 	RelocBaseEnd = ImageAddress(data, size, context->RelocDir->VirtualAddress + context->RelocDir->Size - 1);
 
@@ -996,7 +999,11 @@ static EFI_STATUS handle_image (void *data, unsigned int datasize,
 	 * Copy the executable's sections to their desired offsets
 	 */
 	Section = context.FirstSection;
-	for (i = 0; i < context.NumberOfSections; i++) {
+	for (i = 0; i < context.NumberOfSections; i++, Section++) {
+		if (Section->Characteristics & 0x02000000)
+			/* section has EFI_IMAGE_SCN_MEM_DISCARDABLE attr set */
+			continue;
+
 		size = Section->Misc.VirtualSize;
 
 		if (size > Section->SizeOfRawData)
@@ -1021,8 +1028,6 @@ static EFI_STATUS handle_image (void *data, unsigned int datasize,
 
 		if (size < Section->Misc.VirtualSize)
 			ZeroMem (base + size, Section->Misc.VirtualSize - size);
-
-		Section += 1;
 	}
 
 	/*
-- 
1.9.3