Commit-ID: 0cf264b3133dce56a60ca8b4335d1f76fe26870a
Gitweb: https://git.kernel.org/tip/0cf264b3133dce56a60ca8b4335d1f76fe26870a
Author: Mark Rutland <mark.rutland@xxxxxxx>
AuthorDate: Mon, 11 Feb 2019 13:20:35 +0000
Committer: Ingo Molnar <mingo@xxxxxxxxxx>
CommitDate: Wed, 13 Feb 2019 08:07:31 +0100
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@xxxxxxx>
Acked-by: Will Deacon <will.deacon@xxxxxxx>
Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Cc: Boqun Feng <boqun.feng@xxxxxxxxx>
Cc: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: anders.roxell@xxxxxxxxxx
Cc: linux-kernel@xxxxxxxxxxxxxx
Cc: naresh.kamboju@xxxxxxxxxx
Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx>
---
include/asm-generic/atomic-instrumented.h | 1 +
include/asm-generic/atomic-long.h | 1 +
include/linux/atomic-fallback.h | 1 +
scripts/atomic/check-atomics.sh | 26 +++++++++++++++++-----
.../atomic/{check-atomics.sh => gen-atomics.sh} | 9 ++++----
5 files changed, 28 insertions(+), 10 deletions(-)
diff --git a/include/asm-generic/atomic-instrumented.h b/include/asm-generic/atomic-instrumented.h
index b8f5b35216e1..e8730c6b9fe2 100644
--- a/include/asm-generic/atomic-instrumented.h
+++ b/include/asm-generic/atomic-instrumented.h
@@ -1785,3 +1785,4 @@ atomic64_dec_if_positive(atomic64_t *v)
})
#endif /* _ASM_GENERIC_ATOMIC_INSTRUMENTED_H */
+// b29b625d5de9280f680e42c7be859b55b15e5f6a
diff --git a/include/asm-generic/atomic-long.h b/include/asm-generic/atomic-long.h
index a833d385a70b..881c7e27af28 100644
--- a/include/asm-generic/atomic-long.h
+++ b/include/asm-generic/atomic-long.h
@@ -1010,3 +1010,4 @@ atomic_long_dec_if_positive(atomic_long_t *v)
#endif /* CONFIG_64BIT */
#endif /* _ASM_GENERIC_ATOMIC_LONG_H */
+// 77558968132ce4f911ad53f6f52ce423006f6268
diff --git a/include/linux/atomic-fallback.h b/include/linux/atomic-fallback.h
index 1c02c0112fbb..a7d240e465c0 100644
--- a/include/linux/atomic-fallback.h
+++ b/include/linux/atomic-fallback.h
@@ -2292,3 +2292,4 @@ atomic64_dec_if_positive(atomic64_t *v)
#define atomic64_cond_read_relaxed(v, c) smp_cond_load_relaxed(&(v)->counter, (c))
#endif /* _LINUX_ATOMIC_FALLBACK_H */
+// 25de4a2804d70f57e994fe3b419148658bb5378a
diff --git a/scripts/atomic/check-atomics.sh b/scripts/atomic/check-atomics.sh
index c30101cddf2d..cfa0c2f71c84 100755
--- a/scripts/atomic/check-atomics.sh
+++ b/scripts/atomic/check-atomics.sh
@@ -7,13 +7,27 @@ ATOMICDIR=$(dirname $0)
ATOMICTBL=${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
diff --git a/scripts/atomic/check-atomics.sh b/scripts/atomic/gen-atomics.sh
old mode 100755
new mode 100644
similarity index 61%
copy from scripts/atomic/check-atomics.sh
copy to scripts/atomic/gen-atomics.sh
index c30101cddf2d..27400b0cd732
--- a/scripts/atomic/check-atomics.sh
+++ b/scripts/atomic/gen-atomics.sh
@@ -1,7 +1,7 @@
#!/bin/sh
# SPDX-License-Identifier: GPL-2.0
#
-# Check if atomic headers are up-to-date
+# Generate atomic headers
ATOMICDIR=$(dirname $0)
ATOMICTBL=${ATOMICDIR}/atomics.tbl
@@ -13,7 +13,8 @@ gen-atomic-long.sh asm-generic/atomic-long.h
gen-atomic-fallback.sh 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"
- fi
+ ${ATOMICDIR}/${script} ${ATOMICTBL} > ${LINUXDIR}/include/${header}
+ HASH="$(sha1sum ${LINUXDIR}/include/${header})"
+ HASH="${HASH%% *}"
+ printf "// %s\n" "${HASH}" >> ${LINUXDIR}/include/${header}
done
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