Adding upstream version 4.19.249.upstream/4.19.249upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 78 insertions, 0 deletions

diff --git a/arch/powerpc/tools/head_check.sh b/arch/powerpc/tools/head_check.sh
new file mode 100644
index 000000000..ad9e57209
--- /dev/null
+++ b/arch/powerpc/tools/head_check.sh
@@ -0,0 +1,78 @@
+# Copyright © 2016 IBM Corporation
+
+# This program is free software; you can redistribute it and/or
+# modify it under the terms of the GNU General Public License
+# as published by the Free Software Foundation; either version
+# 2 of the License, or (at your option) any later version.
+
+# This script checks the head of a vmlinux for linker stubs that
+# break our placement of fixed-location code for 64-bit.
+
+# based on relocs_check.pl
+# Copyright © 2009 IBM Corporation
+
+# NOTE!
+#
+# If the build dies here, it's likely code in head_64.S/exception-64*.S or
+# nearby, is branching to labels it can't reach directly, which results in the
+# linker inserting branch stubs. This can move code around in ways that break
+# the fixed section calculations (head-64.h). To debug this, disassemble the
+# vmlinux and look for branch stubs (long_branch, plt_branch, etc.) in the
+# fixed section region (0 - 0x8000ish). Check what code is calling those stubs,
+# and perhaps change so a direct branch can reach.
+#
+# A ".linker_stub_catch" section is used to catch some stubs generated by
+# early .text code, which tend to get placed at the start of the section.
+# If there are too many such stubs, they can overflow this section. Expanding
+# it may help (or reducing the number of stub branches).
+#
+# Linker stubs use the TOC pointer, so even if fixed section code could
+# tolerate them being inserted into head code, they can't be allowed in low
+# level entry code (boot, interrupt vectors, etc) until r2 is set up. This
+# could cause the kernel to die in early boot.
+
+# Turn this on if you want more debug output:
+# set -x
+
+if [ $# -lt 2 ]; then
+	echo "$0 [path to nm] [path to vmlinux]" 1>&2
+	exit 1
+fi
+
+# Have Kbuild supply the path to nm so we handle cross compilation.
+nm="$1"
+vmlinux="$2"
+
+# gcc-4.6-era toolchain make _stext an A (absolute) symbol rather than T
+$nm "$vmlinux" | grep -e " [TA] _stext$" -e " t start_first_256B$" -e " a text_start$" -e " t start_text$" -m4 > .tmp_symbols.txt
+
+
+vma=$(cat .tmp_symbols.txt | grep -e " [TA] _stext$" | cut -d' ' -f1)
+
+expected_start_head_addr=$vma
+
+start_head_addr=$(cat .tmp_symbols.txt | grep " t start_first_256B$" | cut -d' ' -f1)
+
+if [ "$start_head_addr" != "$expected_start_head_addr" ]; then
+	echo "ERROR: head code starts at $start_head_addr, should be $expected_start_head_addr"
+	echo "ERROR: try to enable LD_HEAD_STUB_CATCH config option"
+	echo "ERROR: see comments in arch/powerpc/tools/head_check.sh"
+
+	exit 1
+fi
+
+top_vma=$(echo $vma | cut -d'0' -f1)
+
+expected_start_text_addr=$(cat .tmp_symbols.txt | grep " a text_start$" | cut -d' ' -f1 | sed "s/^0/$top_vma/")
+
+start_text_addr=$(cat .tmp_symbols.txt | grep " t start_text$" | cut -d' ' -f1)
+
+if [ "$start_text_addr" != "$expected_start_text_addr" ]; then
+	echo "ERROR: start_text address is $start_text_addr, should be $expected_start_text_addr"
+	echo "ERROR: try to enable LD_HEAD_STUB_CATCH config option"
+	echo "ERROR: see comments in arch/powerpc/tools/head_check.sh"
+
+	exit 1
+fi
+
+rm -f .tmp_symbols.txt