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authorJoel Fernandes (Google) <joel@joelfernandes.org>2019-05-15 17:35:51 -0400
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2019-05-24 20:16:01 +0200
commitf7b101d33046a837c2aa4526cef28a3c785d7af2 (patch)
tree50756746345f4a6ba56994e823d5f60681eb662d /kernel/gen_kheaders.sh
parenta188339ca5a396acc588e5851ed7e19f66b0ebd9 (diff)
kheaders: Move from proc to sysfs
The kheaders archive consisting of the kernel headers used for compiling bpf programs is in /proc. However there is concern that moving it here will make it permanent. Let us move it to /sys/kernel as discussed [1]. [1] https://lore.kernel.org/patchwork/patch/1067310/#1265969 Suggested-by: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Joel Fernandes (Google) <joel@joelfernandes.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'kernel/gen_kheaders.sh')
-rwxr-xr-xkernel/gen_kheaders.sh89
1 files changed, 89 insertions, 0 deletions
diff --git a/kernel/gen_kheaders.sh b/kernel/gen_kheaders.sh
new file mode 100755
index 000000000000..581b83534587
--- /dev/null
+++ b/kernel/gen_kheaders.sh
@@ -0,0 +1,89 @@
+#!/bin/bash
+# SPDX-License-Identifier: GPL-2.0
+
+# This script generates an archive consisting of kernel headers
+# for CONFIG_IKHEADERS.
+set -e
+spath="$(dirname "$(readlink -f "$0")")"
+kroot="$spath/.."
+outdir="$(pwd)"
+tarfile=$1
+cpio_dir=$outdir/$tarfile.tmp
+
+# Script filename relative to the kernel source root
+# We add it to the archive because it is small and any changes
+# to this script will also cause a rebuild of the archive.
+sfile="$(realpath --relative-to $kroot "$(readlink -f "$0")")"
+
+src_file_list="
+include/
+arch/$SRCARCH/include/
+$sfile
+"
+
+obj_file_list="
+include/
+arch/$SRCARCH/include/
+"
+
+# Support incremental builds by skipping archive generation
+# if timestamps of files being archived are not changed.
+
+# This block is useful for debugging the incremental builds.
+# Uncomment it for debugging.
+# iter=1
+# if [ ! -f /tmp/iter ]; then echo 1 > /tmp/iter;
+# else; iter=$(($(cat /tmp/iter) + 1)); fi
+# find $src_file_list -type f | xargs ls -lR > /tmp/src-ls-$iter
+# find $obj_file_list -type f | xargs ls -lR > /tmp/obj-ls-$iter
+
+# include/generated/compile.h is ignored because it is touched even when none
+# of the source files changed. This causes pointless regeneration, so let us
+# ignore them for md5 calculation.
+pushd $kroot > /dev/null
+src_files_md5="$(find $src_file_list -type f |
+ grep -v "include/generated/compile.h" |
+ xargs ls -lR | md5sum | cut -d ' ' -f1)"
+popd > /dev/null
+obj_files_md5="$(find $obj_file_list -type f |
+ grep -v "include/generated/compile.h" |
+ xargs ls -lR | md5sum | cut -d ' ' -f1)"
+
+if [ -f $tarfile ]; then tarfile_md5="$(md5sum $tarfile | cut -d ' ' -f1)"; fi
+if [ -f kernel/kheaders.md5 ] &&
+ [ "$(cat kernel/kheaders.md5|head -1)" == "$src_files_md5" ] &&
+ [ "$(cat kernel/kheaders.md5|head -2|tail -1)" == "$obj_files_md5" ] &&
+ [ "$(cat kernel/kheaders.md5|tail -1)" == "$tarfile_md5" ]; then
+ exit
+fi
+
+if [ "${quiet}" != "silent_" ]; then
+ echo " GEN $tarfile"
+fi
+
+rm -rf $cpio_dir
+mkdir $cpio_dir
+
+pushd $kroot > /dev/null
+for f in $src_file_list;
+ do find "$f" ! -name "*.cmd" ! -name ".*";
+done | cpio --quiet -pd $cpio_dir
+popd > /dev/null
+
+# The second CPIO can complain if files already exist which can
+# happen with out of tree builds. Just silence CPIO for now.
+for f in $obj_file_list;
+ do find "$f" ! -name "*.cmd" ! -name ".*";
+done | cpio --quiet -pd $cpio_dir >/dev/null 2>&1
+
+# Remove comments except SDPX lines
+find $cpio_dir -type f -print0 |
+ xargs -0 -P8 -n1 perl -pi -e 'BEGIN {undef $/;}; s/\/\*((?!SPDX).)*?\*\///smg;'
+
+tar -Jcf $tarfile -C $cpio_dir/ . > /dev/null
+
+echo "$src_files_md5" > kernel/kheaders.md5
+echo "$obj_files_md5" >> kernel/kheaders.md5
+echo "$(md5sum $tarfile | cut -d ' ' -f1)" >> kernel/kheaders.md5
+
+rm -rf $cpio_dir