seccomp: Make seccomp.sh re-entrancy safe

seccomp.sh generates seccomp.h piece by piece using >> directives.  This
means that if two instances of seccomp.h are run concurrently a corrupted
version of seccomp.h will be generated. Amongst other problems this can
cause spurious failures on clang-tidy.

Alter seccomp.sh to build the output in a temporary file and atomic move it
to seccomp.h, so concurrent invocations will still result in valud output.

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
This commit is contained in:
David Gibson 2023-06-21 13:06:37 +10:00 committed by Stefano Brivio
parent 3c6d1b9bb2
commit db29fd281a

View file

@ -15,7 +15,7 @@
TMP="$(mktemp)" TMP="$(mktemp)"
IN="$@" IN="$@"
OUT="seccomp.h" OUT="$(mktemp)"
[ -z "${ARCH}" ] && ARCH="$(uname -m)" [ -z "${ARCH}" ] && ARCH="$(uname -m)"
[ -z "${CC}" ] && CC="cc" [ -z "${CC}" ] && CC="cc"
@ -53,7 +53,7 @@ BST=' BPF_JUMP(BPF_JMP | BPF_JGE | BPF_K, @NR@, @R@, @L@),'
# cleanup() - Remove temporary file if it exists # cleanup() - Remove temporary file if it exists
cleanup() { cleanup() {
rm -f "${TMP}" rm -f "${TMP}" "${OUT}"
} }
trap "cleanup" EXIT trap "cleanup" EXIT
@ -254,3 +254,5 @@ for __p in ${__profiles}; do
gen_profile "${__p}" ${__calls} gen_profile "${__p}" ${__calls}
done done
mv "${OUT}" seccomp.h