From nobody Fri Sep 25 00:41:19 2026 Received: from galois.linutronix.de (Galois.linutronix.de [193.142.43.55]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id D992D4657C2; Fri, 18 Sep 2026 10:16:21 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=193.142.43.55 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789726586; cv=none; b=HoVMq3MTLXV1M1eaHIQDrBzeYeLeKBllP/eey/uHSFdJ2V7OKoYlshtHwbrYIFfGGHJBAM+g5jDrw2E0LEQf3ipLh/os6An/ytUeGjZKuAHOPZodMm9OF6c84hWgW3/0OJqSuTX1yh0ceAdThQ0Xe0I1tIv6oo6mCvPOcQXvP/M= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789726586; c=relaxed/simple; bh=iHoF4PzSLG/w5sTLE8nMJAdwlBSV75/P9cCWR5lZ+DE=; h=Date:From:To:Subject:Cc:In-Reply-To:References:MIME-Version: Message-ID:Content-Type; b=jTii4i5daZODKU0gZHXsb/Q+bSf4AbkpUoSUxPB8v2Oq5bC0he3pe805WHzNmg0bpD9TpV5C4OR3oEj0erR+zwIIqM2GeRUU6+UT5w/pX4fgmRP0STBAZfJGQWQ712DBwXrFHjT53rd2k2N3HU1A/PexUTajSpeRXpS5h3HHCVA= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linutronix.de; spf=pass smtp.mailfrom=linutronix.de; dkim=pass (2048-bit key) header.d=linutronix.de header.i=@linutronix.de header.b=dbjePgNv; dkim=permerror (0-bit key) header.d=linutronix.de header.i=@linutronix.de header.b=OpSjjJfd; arc=none smtp.client-ip=193.142.43.55 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linutronix.de Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linutronix.de Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=linutronix.de header.i=@linutronix.de header.b="dbjePgNv"; dkim=permerror (0-bit key) header.d=linutronix.de header.i=@linutronix.de header.b="OpSjjJfd" Date: Fri, 18 Sep 2026 10:16:16 -0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1789726578; h=from:from:sender:sender:reply-to:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=0d09WdomnVQlBAyISYcYvl4ddWm/ZZKdQMwp/SfAdr8=; b=dbjePgNvBMEr90wpoyd11XIMo80XTkdpg2liPmjnBqoyilMH0S6d5zVentUgE8wnG/9tIO e6jjK609Q5ZTwHXskp3oiskMEQhouxGlAgA9KrlJRuGCXCyUz8U7fWQeS52EVTLmmjOOTr ntNivLEuWfFjtf48HgYyYMKrkLHgV27xl+OXHc1ugTzAPeDc+wBLhVD7f2f//7iXMax2L0 MyByFsXED/mt7OHDQxtTnbPCY4COm6rjifakSpavp3xsPqWJ0+CkOonXNgLbW+QWrL99ot xxXZ1qmWJu1wKJHcV0cWgrd9BSXqIisznVY6xCG1BHnsGUl4eYOaJbqfp2T3aA== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1789726578; h=from:from:sender:sender:reply-to:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=0d09WdomnVQlBAyISYcYvl4ddWm/ZZKdQMwp/SfAdr8=; b=OpSjjJfdtvtmJYFzfS9V/r0Z9OBkfkSE9lnrTVUJAaKm7rWke5RLwwHMu1/9FcnUl+Jfxv UdEB49PYPFrjrHBA== From: "tip-bot2 for Song Liu" Sender: tip-bot2@linutronix.de Reply-to: linux-kernel@vger.kernel.org To: linux-tip-commits@vger.kernel.org Subject: [tip: objtool/core] objtool/klp: Check the klp test environment once, before any test Cc: Song Liu , Josh Poimboeuf , x86@kernel.org, linux-kernel@vger.kernel.org In-Reply-To: <20260916184351.2720310-3-song@kernel.org> References: <20260916184351.2720310-3-song@kernel.org> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Message-ID: <178972657651.1720534.2125510828136115648.tip-bot2@tip-bot2> Robot-ID: Robot-Unsubscribe: Contact to get blacklisted from these emails Precedence: bulk Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable The following commit has been merged into the objtool/core branch of tip: Commit-ID: c03a4cf88206163f9a78abdd798ffdba9671ae5d Gitweb: https://git.kernel.org/tip/c03a4cf88206163f9a78abdd798ffdba9= 671ae5d Author: Song Liu AuthorDate: Wed, 16 Sep 2026 11:42:55 -07:00 Committer: Josh Poimboeuf CommitterDate: Wed, 16 Sep 2026 17:13:26 -07:00 objtool/klp: Check the klp test environment once, before any test Every test checked for itself that objtool exists, was built with klp support, and that $CC runs. Three problems with that: it is the same work done 40 times, a missing objtool reads as a per-test skip rather than as a suite which cannot run, and a run in which everything skipped still exits 0. Do it once, before any test, in klp_preflight() in lib.sh, and export the answers where the tests can read them. If the suite cannot run the whole run fails and says why; a test which gets as far as running can assume its environment. Nothing is written down, so nothing can go stale. Sourcing lib.sh runs the checks, which means a test run by hand establishes its own answers rather than inheriting those of some earlier run with a different CC, and a test is never handed an empty value for where objtool is or which architecture it is on: either the exports are set or the run has already failed. preflight answers only whether the suite can run at all -- not what the compiler is capable of. A test needing a particular compiler feature probes for it and skips; that costs one compile and keeps the reason next to the test that has to justify it. Assisted-by: Claude:claude-opus-5 Signed-off-by: Song Liu Link: https://patch.msgid.link/20260916184351.2720310-3-song@kernel.org Signed-off-by: Josh Poimboeuf --- tools/objtool/Makefile | 3 +- tools/objtool/tests/lib.sh | 124 ++++++++++++++++++++++++------ tools/objtool/tests/run-tests.sh | 7 ++- 3 files changed, 112 insertions(+), 22 deletions(-) diff --git a/tools/objtool/Makefile b/tools/objtool/Makefile index f4ec9f8..2c200d0 100644 --- a/tools/objtool/Makefile +++ b/tools/objtool/Makefile @@ -152,7 +152,8 @@ mrproper: clean $(call QUIET_CLEAN, objtool) $(RM) $(OBJTOOL) =20 tests: $(OBJTOOL) - $(Q)OBJTOOL=3D$(abspath $(OBJTOOL)) $(srctree)/tools/objtool/tests/run-te= sts.sh + $(Q)OBJTOOL=3D$(abspath $(OBJTOOL)) ARCH=3D$(ARCH) CROSS_COMPILE=3D$(CROS= S_COMPILE) \ + $(srctree)/tools/objtool/tests/run-tests.sh =20 FORCE: =20 diff --git a/tools/objtool/tests/lib.sh b/tools/objtool/tests/lib.sh index 7b29db7..46bdb98 100644 --- a/tools/objtool/tests/lib.sh +++ b/tools/objtool/tests/lib.sh @@ -11,8 +11,104 @@ TESTS_DIR=3D"$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)" FIXTURES_DIR=3D"$TESTS_DIR/fixtures" =20 +# The kernel's convention: CROSS_COMPILE is the one knob, with per-tool +# overrides for what it does not cover. objtool itself is always a host b= inary +# -- it is built with HOSTCC and only reads ELF -- so an arm64 machine can= run +# the x86 tests against x86 objects given a compiler that emits them. +# +# readelf reads any target, so it rarely needs overriding, and either GNU +# readelf or llvm-readelf will do: the assertions match on fields rather t= han +# on columns, and where the two spell something differently -- "OS [0xff20= ]" +# against "OS[0xff20]" for SHN_LIVEPATCH -- they accept both. BFD's objco= py is +# usually built for the host's target alone, and llvm-objcopy is the +# target-agnostic replacement. +CROSS_COMPILE=3D"${CROSS_COMPILE:-}" +CC=3D"${CC:-${CROSS_COMPILE}gcc}" +LD=3D"${LD:-${CROSS_COMPILE}ld}" +READELF=3D"${READELF:-${CROSS_COMPILE}readelf}" +OBJCOPY=3D"${OBJCOPY:-${CROSS_COMPILE}objcopy}" + OBJTOOL=3D"${OBJTOOL:-$TESTS_DIR/../objtool}" -CC=3D"${CC:-gcc}" + +# klp_preflight +# +# Check the environment once, before any test runs, and report what was fo= und. +# +klp_preflight() +{ + local tmp tool cc_version host cc_arch + + bail() { echo "Bail out! $*" >&2; exit 1; } + + # A relative $OBJTOOL is relative to the objtool directory, not tests/. + [ -x "$OBJTOOL" ] || [ ! -x "$TESTS_DIR/../$OBJTOOL" ] || + OBJTOOL=3D"$TESTS_DIR/../$OBJTOOL" + + [ -x "$OBJTOOL" ] || + bail "objtool not found at '$OBJTOOL' -- build it first" + + # run_diff() runs objtool from inside the test's working directory, so + # a relative path would resolve against that instead. + OBJTOOL=3D"$(realpath "$OBJTOOL")" + + "$OBJTOOL" klp 2>&1 | grep -q checksum || + bail "objtool was built without klp support; install libxxhash (>=3D 0.8= ) and rebuild" + + command -v "${CC%% *}" >/dev/null || bail "compiler not found: $CC" + + for tool in "$READELF" "$OBJCOPY" "$LD"; do + command -v "${tool%% *}" >/dev/null || bail "$tool not found" + done + + tmp=3D"$(mktemp -d)" || bail "mktemp failed" + echo 'int probe(void) { return 0; }' > "$tmp/probe.c" + $CC -c -o "$tmp/probe.o" "$tmp/probe.c" 2>/dev/null || + { rm -rf "$tmp"; bail "$CC cannot compile a trivial object"; } + + # $CC, $ARCH and objtool have to agree about the target, and cross runs + # are where they stop agreeing: plain "CC=3Dclang ARCH=3Dx86_64" on an ar= m64 + # box selects the x86 tests and then builds arm64 objects, because clang + # needs --target=3D to emit anything but the host's. + # + # Ask objtool rather than comparing machine names. It rejects an object + # it was not built for -- "unexpected ELF machine type" -- so one check + # covers every way the three can disagree, and says so once instead of + # failing every test for the same reason. + "$OBJTOOL" klp checksum "$tmp/probe.o" >/dev/null 2>&1 || + { rm -rf "$tmp" + bail "objtool rejects an object built by '$CC'; they target" \ + "different architectures (set CROSS_COMPILE, or" \ + "--target=3D for clang)"; } + + # BFD objcopy is usually built for the host's target alone, and + # checksum_of() needs it to read the object under test. + $OBJCOPY -O binary --only-section=3D.text "$tmp/probe.o" "$tmp/probe.bin"= 2>/dev/null || + { rm -rf "$tmp" + bail "$OBJCOPY cannot read objects built by '$CC'; install" \ + "binutils-multiarch or set OBJCOPY=3Dllvm-objcopy"; } + # $ARCH only chooses which directory of tests runs, so it can disagree + # with what $CC builds without objtool noticing -- and the result is the + # wrong set of tests, quietly. + case "$($READELF -hW "$tmp/probe.o" | sed -n 's/.*Machine: *//p')" in + *X86-64*|*Intel*80386*) cc_arch=3Dx86 ;; + *AArch64*) cc_arch=3Darm64 ;; + *) cc_arch=3D ;; + esac + rm -rf "$tmp" + + KLP_TEST_PREFLIGHT=3Ddone + export OBJTOOL CC KLP_TEST_PREFLIGHT + + cc_version=3D"$($CC --version 2>/dev/null | head -1)" + cat <&1 | grep -q checksum || - skip "objtool built without klp support (needs libxxhash)" - command -v "${CC%% *}" >/dev/null || skip "no compiler ($CC)" - + # The environment was checked once when this file was sourced, so there + # is nothing to verify here: objtool exists at the resolved path, has + # klp support, and $CC works. workdir=3D"$(mktemp -d)" || fail "mktemp failed" trap cleanup EXIT =20 @@ -155,9 +237,9 @@ find_thinlto_toolchain() return 1 } =20 -out_sections() { readelf -S -W "$workdir/out.o" 2>/dev/null; } -out_relocs() { readelf -r -W "$workdir/out.o" 2>/dev/null; } -out_symbols() { readelf -s -W "$workdir/out.o" 2>/dev/null; } +out_sections() { $READELF -S -W "$workdir/out.o" 2>/dev/null; } +out_relocs() { $READELF -r -W "$workdir/out.o" 2>/dev/null; } +out_symbols() { $READELF -s -W "$workdir/out.o" 2>/dev/null; } diff_log() { cat "$workdir/diff.log"; } =20 assert_section() diff --git a/tools/objtool/tests/run-tests.sh b/tools/objtool/tests/run-tes= ts.sh index ab1dea5..f6a3e1b 100755 --- a/tools/objtool/tests/run-tests.sh +++ b/tools/objtool/tests/run-tests.sh @@ -2,6 +2,9 @@ # SPDX-License-Identifier: GPL-2.0 # # Run the objtool klp tests. Each test-*.sh prints one TAP result line. +# +# The harness checks the environment once up front and fails the run if the +# suite cannot execute, rather than letting every test skip and exit 0. =20 set -u =20 @@ -10,6 +13,10 @@ cd "$(dirname "$0")" || exit 1 tests=3D( test-*.sh ) [ "${tests[0]}" =3D "test-*.sh" ] && { echo "1..0 # SKIP no tests found"; = exit 0; } =20 +# Sourcing the harness runs its preflight, and exports what it found so the +# tests inherit it rather than working it out again. +. ./lib.sh + echo "1..${#tests[@]}" =20 rc=3D0