From 119e9db233ad0f4cbd4cfb9f9385a7bca378b37d Mon Sep 17 00:00:00 2001
From: Zeng Chi <zengchi@kylinos.cn>
Date: Mon, 21 Sep 2026 18:24:42 +0800
Subject: KVM: Don't pre-reserve xarray entries when storing empty/NULL
 attributes

Skip the xarray reservation loop when clearing all memory attributes, as
storing NULL only erases the entry and never needs to allocate, so no
reservation (and no cleanup of a failed one) is required in that case.

Suggested-by: Sean Christopherson <seanjc@google.com>
Cc: David Ballesteros <davimaba.v@proton.me>
Signed-off-by: Zeng Chi <zengchi@kylinos.cn>
Link: https://patch.msgid.link/20260921102442.1232375-1-zeng_chi911@163.com
[sean: split to separate patch]
Signed-off-by: Sean Christopherson <seanjc@google.com>
---
 scripts/objdiff | 162 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 162 insertions(+)
 create mode 100755 scripts/objdiff

(limited to 'scripts/objdiff')

diff --git a/scripts/objdiff b/scripts/objdiff
new file mode 100755
index 000000000..0685bc3ce
--- /dev/null
+++ b/scripts/objdiff
@@ -0,0 +1,162 @@
+#!/bin/bash
+# SPDX-License-Identifier: GPL-2.0-only
+
+# objdiff - a small script for validating that a commit or series of commits
+# didn't change object code.
+#
+# Copyright 2014, Jason Cooper <jason@lakedaemon.net>
+#
+
+# usage example:
+#
+# $ git checkout COMMIT_A
+# $ <your fancy build command here>
+# $ ./scripts/objdiff record path/to/*.o
+#
+# $ git checkout COMMIT_B
+# $ <your fancy build command here>
+# $ ./scripts/objdiff record path/to/*.o
+#
+# $ ./scripts/objdiff diff COMMIT_A COMMIT_B
+# $
+
+# And to clean up (everything is in .objdiff/*)
+# $ ./scripts/objdiff clean all
+#
+# Note: 'make mrproper' will also remove .objdiff
+
+SRCTREE=$(cd $(git rev-parse --show-toplevel 2>/dev/null); pwd)
+
+if [ -z "$SRCTREE" ]; then
+	echo >&2 "ERROR: Not a git repository."
+	exit 1
+fi
+
+TMPD=$SRCTREE/.objdiff
+
+usage() {
+	echo >&2 "Usage: $0 <command> <args>"
+	echo >&2 "  record    <list of object files or directories>"
+	echo >&2 "  diff      <commitA> <commitB>"
+	echo >&2 "  clean     all | <commit>"
+	exit 1
+}
+
+get_output_dir() {
+	dir=${1%/*}
+
+	if [ "$dir" = "$1" ]; then
+		dir=.
+	fi
+
+	dir=$(cd $dir; pwd)
+
+	echo $TMPD/$CMT${dir#$SRCTREE}
+}
+
+do_objdump() {
+	dir=$(get_output_dir $1)
+	base=${1##*/}
+	stripped=$dir/${base%.o}.stripped
+	dis=$dir/${base%.o}.dis
+
+	[ ! -d "$dir" ] && mkdir -p $dir
+
+	# remove addresses for a cleaner diff
+	# http://dummdida.tumblr.com/post/60924060451/binary-diff-between-libc-from-scientificlinux-and
+	$STRIP -g $1 -R __bug_table -R .note -R .comment -o $stripped
+	$OBJDUMP -D $stripped | sed -e "s/^[[:space:]]\+[0-9a-f]\+//" -e "s:^$stripped:$1:" > $dis
+}
+
+dorecord() {
+	[ $# -eq 0 ] && usage
+
+	FILES="$*"
+
+	CMT="`git rev-parse --short HEAD`"
+
+	STRIP="${CROSS_COMPILE}strip"
+	OBJDUMP="${CROSS_COMPILE}objdump"
+
+	for d in $FILES; do
+		if [ -d "$d" ]; then
+			for f in $(find $d -name '*.o')
+			do
+				do_objdump $f
+			done
+		else
+			do_objdump $d
+		fi
+	done
+}
+
+dodiff() {
+	[ $# -ne 2 ] && [ $# -ne 0 ] && usage
+
+	if [ $# -eq 0 ]; then
+		SRC="`git rev-parse --short HEAD^`"
+		DST="`git rev-parse --short HEAD`"
+	else
+		SRC="`git rev-parse --short $1`"
+		DST="`git rev-parse --short $2`"
+	fi
+
+	DIFF="`which colordiff`"
+
+	if [ ${#DIFF} -eq 0 ] || [ ! -x "$DIFF" ]; then
+		DIFF="`which diff`"
+	fi
+
+	SRCD="$TMPD/$SRC"
+	DSTD="$TMPD/$DST"
+
+	if [ ! -d "$SRCD" ]; then
+		echo >&2 "ERROR: $SRCD doesn't exist"
+		exit 1
+	fi
+
+	if [ ! -d "$DSTD" ]; then
+		echo >&2 "ERROR: $DSTD doesn't exist"
+		exit 1
+	fi
+
+	$DIFF -Nurd $SRCD $DSTD
+}
+
+doclean() {
+	[ $# -eq 0 ] && usage
+	[ $# -gt 1 ] && usage
+
+	if [ "x$1" = "xall" ]; then
+		rm -rf $TMPD/*
+	else
+		CMT="`git rev-parse --short $1`"
+
+		if [ -d "$TMPD/$CMT" ]; then
+			rm -rf $TMPD/$CMT
+		else
+			echo >&2 "$CMT not found"
+		fi
+	fi
+}
+
+[ $# -eq 0 ] &&	usage
+
+case "$1" in
+	record)
+		shift
+		dorecord $*
+		;;
+	diff)
+		shift
+		dodiff $*
+		;;
+	clean)
+		shift
+		doclean $*
+		;;
+	*)
+		echo >&2 "Unrecognized command '$1'"
+		exit 1
+		;;
+esac
-- 
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