locking/atomics: Check atomic headers with sha1sum
We currently check the atomic headers at build-time to ensure they
haven't been modified directly, and these checks require regenerating
the headers in full. As this takes a few seconds, even when
parallelized, this is too slow to run for every kernel build.
Instead, we can generate a hash of each header as we generate them,
which we can cheaply check at build time (~0.16s for all headers).
This patch does so, updating headers with their hashes using the new
gen-atomics.sh script. As some users apparently build the kernel wihout
coreutils, lacking sha1sum, the checks are skipped in this case.
Presumably, most developers have a working coreutils installation.
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Acked-by: Will Deacon <will.deacon@arm.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Boqun Feng <boqun.feng@gmail.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: anders.roxell@linaro.org
Cc: linux-kernel@vger.kernel.rg
Cc: naresh.kamboju@linaro.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
diff --git a/scripts/atomic/check-atomics.sh b/scripts/atomic/check-atomics.sh
index c30101c..cfa0c2f 100755
--- a/scripts/atomic/check-atomics.sh
+++ b/scripts/atomic/check-atomics.sh
@@ -7,13 +7,27 @@
ATOMICTBL=${ATOMICDIR}/atomics.tbl
LINUXDIR=${ATOMICDIR}/../..
+echo '' | sha1sum - > /dev/null 2>&1
+if [ $? -ne 0 ]; then
+ printf "sha1sum not available, skipping atomic header checks.\n"
+ exit 0
+fi
+
cat <<EOF |
-gen-atomic-instrumented.sh asm-generic/atomic-instrumented.h
-gen-atomic-long.sh asm-generic/atomic-long.h
-gen-atomic-fallback.sh linux/atomic-fallback.h
+asm-generic/atomic-instrumented.h
+asm-generic/atomic-long.h
+linux/atomic-fallback.h
EOF
-while read script header; do
- if ! (${ATOMICDIR}/${script} ${ATOMICTBL} | diff - ${LINUXDIR}/include/${header} > /dev/null); then
- printf "warning: include/${header} is out-of-date.\n"
+while read header; do
+ OLDSUM="$(tail -n 1 ${LINUXDIR}/include/${header})"
+ OLDSUM="${OLDSUM#// }"
+
+ NEWSUM="$(head -n -1 ${LINUXDIR}/include/${header} | sha1sum)"
+ NEWSUM="${NEWSUM%% *}"
+
+ if [ "${OLDSUM}" != "${NEWSUM}" ]; then
+ printf "warning: generated include/${header} has been modified.\n"
fi
done
+
+exit 0