From 364acaae455b465201f4467809edb7384a6c2bda Mon Sep 17 00:00:00 2001
From: Andre Heider
Date: Sun, 5 Sep 2010 22:00:19 +0000
Subject: PLUGINS: Remove spurious extra allocation.

Elf32_Phdr.p_align is to align the memory location of the loaded
segment, not to extend its size. The size of the scratch area
(like .bss and .sbss) is p_memsz-p_filesz, which has to be set to
zero by the loader.

svn-id: r52576
---
 backends/plugins/elf/elf-loader.cpp  | 10 +++-------
 backends/plugins/elf/mips-loader.cpp | 17 ++++++++++-------
 2 files changed, 13 insertions(+), 14 deletions(-)

(limited to 'backends')

diff --git a/backends/plugins/elf/elf-loader.cpp b/backends/plugins/elf/elf-loader.cpp
index 7bdec22508..a6e20a7f6d 100644
--- a/backends/plugins/elf/elf-loader.cpp
+++ b/backends/plugins/elf/elf-loader.cpp
@@ -157,11 +157,7 @@ bool DLObject::readProgramHeaders(Elf32_Ehdr *ehdr, Elf32_Phdr *phdr, Elf32_Half
 }
 
 bool DLObject::loadSegment(Elf32_Phdr *phdr) {
-	// Attempt to allocate memory for segment
-	uint32 extra = phdr->p_vaddr % phdr->p_align;	// Get extra length TODO: check logic here
-	debug(2, "elfloader: Extra mem is %x", extra);
-
-	_segment = (byte *)allocSegment(phdr->p_align, phdr->p_memsz + extra);
+	_segment = (byte *)allocSegment(phdr->p_align, phdr->p_memsz);
 
 	if (!_segment) {
 		warning("elfloader: Out of memory.");
@@ -171,10 +167,10 @@ bool DLObject::loadSegment(Elf32_Phdr *phdr) {
 	debug(2, "elfloader: Allocated segment @ %p", _segment);
 
 	// Get offset to load segment into
-	_segmentSize = phdr->p_memsz + extra;
+	_segmentSize = phdr->p_memsz;
 	_segmentVMA = phdr->p_vaddr;
 
-	// Set bss segment to 0 if necessary (assumes bss is at the end)
+	// Set .bss segment to 0 if necessary
 	if (phdr->p_memsz > phdr->p_filesz) {
 		debug(2, "elfloader: Setting %p to %p to 0 for bss",
 				_segment + phdr->p_filesz, _segment + phdr->p_memsz);
diff --git a/backends/plugins/elf/mips-loader.cpp b/backends/plugins/elf/mips-loader.cpp
index 6ad608556e..0fc1ca8728 100644
--- a/backends/plugins/elf/mips-loader.cpp
+++ b/backends/plugins/elf/mips-loader.cpp
@@ -273,14 +273,10 @@ bool MIPSDLObject::loadSegment(Elf32_Phdr *phdr) {
 
 	// We need to take account of non-allocated segment for shorts
 	if (phdr->p_flags & PF_X) {	// This is a relocated segment
-		// Attempt to allocate memory for segment
-		uint32 extra = phdr->p_vaddr % phdr->p_align;	// Get extra length TODO: check logic here
-		debug(2, "elfloader: Extra mem is %x", extra);
-
 		if (phdr->p_align < 0x10000)
 			phdr->p_align = 0x10000;	// Fix for wrong alignment on e.g. AGI
 
-		_segment = (byte *)allocSegment(phdr->p_align, phdr->p_memsz + extra);
+		_segment = (byte *)allocSegment(phdr->p_align, phdr->p_memsz);
 
 		if (!_segment) {
 			warning("elfloader: Out of memory.");
@@ -291,7 +287,14 @@ bool MIPSDLObject::loadSegment(Elf32_Phdr *phdr) {
 
 		// Get offset to load segment into
 		baseAddress = _segment + phdr->p_vaddr;
-		_segmentSize = phdr->p_memsz + extra;
+		_segmentSize = phdr->p_memsz;
+
+		// Set .bss segment to 0 if necessary
+		if (phdr->p_memsz > phdr->p_filesz) {
+			debug(2, "elfloader: Setting %p to %p to 0 for bss",
+					_segment + phdr->p_filesz, _segment + phdr->p_memsz);
+			memset(_segment + phdr->p_filesz, 0, phdr->p_memsz - phdr->p_filesz);
+		}
 	} else {						// This is a shorts section.
 		_shortsSegment = ShortsMan.newSegment(phdr->p_memsz, (char *)phdr->p_vaddr);
 
@@ -301,7 +304,7 @@ bool MIPSDLObject::loadSegment(Elf32_Phdr *phdr) {
 				_shortsSegment->getOffset());
 	}
 
-	// Set bss segment to 0 if necessary (assumes bss is at the end)
+	// Set .sbss segment to 0 if necessary
 	if (phdr->p_memsz > phdr->p_filesz) {
 		debug(2, "elfloader: Setting %p to %p to 0 for bss", baseAddress + phdr->p_filesz,
 				baseAddress + phdr->p_memsz);
-- 
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