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/gen-atomics.sh b/scripts/atomic/gen-atomics.sh
new file mode 100644
index 0000000..27400b0
--- /dev/null
+++ b/scripts/atomic/gen-atomics.sh
@@ -0,0 +1,20 @@
+#!/bin/sh
+# SPDX-License-Identifier: GPL-2.0
+#
+# Generate atomic headers
+
+ATOMICDIR=$(dirname $0)
+ATOMICTBL=${ATOMICDIR}/atomics.tbl
+LINUXDIR=${ATOMICDIR}/../..
+
+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
+EOF
+while read script header; do
+ ${ATOMICDIR}/${script} ${ATOMICTBL} > ${LINUXDIR}/include/${header}
+ HASH="$(sha1sum ${LINUXDIR}/include/${header})"
+ HASH="${HASH%% *}"
+ printf "// %s\n" "${HASH}" >> ${LINUXDIR}/include/${header}
+done