From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (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 ADE1D4BF930 for ; Wed, 16 Sep 2026 18:48:00 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789584496; cv=none; b=Py52Shn3qoX9H61HAXSTsXQqkzog6NCjHllOXLKyeexg3JR3LkTwYEsEFIChYwyOUUzZqrm9ycAVFDfN30XvedsTWsnMLqYAOzJTAmufD2Jb0ZZpVWmFvRtC89Lv6ktCkwJbcmDzU/v8nkFQQ1EW3s/8rYBcnhBhLVnErBky/cE= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789584496; c=relaxed/simple; bh=LkInyhU4QZkMyaBVr4spacs2W/gBANQ3CPaNQ+jOfmw=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=C9pScCagP90BRZd9FS+7iDTkMYyoul3r6AOgxG2KM08Hu8fM9Tyx8XIADJ0vtDx80p0L844zuBby+c9x8jboruUbRkVRwMa49id77Ae+hZb5ITN0dSVDEogwP1PakiTe9fRDoHG15SpGg6e3+n1v09nHKFDbqUn+Zoan8qoN+u4= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=X52EIQRA; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="X52EIQRA" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 3312F1F00898; Wed, 16 Sep 2026 18:47:57 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1789584478; bh=alxai34FQdFaIrkf9TH48GWWK77DSl+25RcxFbyvZTg=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=X52EIQRAZC7dP1Zn5RLNcBBKh9VisIFS41BXVKvceO8fQnXfHjjmO52rC5VSYJvNY lvVQCJix4EY5FIbVn3aNvXMrahTnp3AzsnLc9ET46gRHEUIcQwr7msX5luN+11yBup 7SZXWaKlRNteMqojy6qdUL8BdcDDJGOcMqkKm/nE03z7hmZIRZDWM5Jni8gnnSRyTx 4WGYwWzazM1YMZQtD0hLllsQHCwWAC7GJTMniSWhOJqRrqg8EcjhIgdhouhPG+DAo8 +/zzqQiuW6m32nbUfvrjeoDRMsVgd4v2qJaZa2cl4EC7Pj0IYGeS5y4lcVI7RaNk7i 30xm4vvqXB+Ig== From: Song Liu To: live-patching@vger.kernel.org Cc: jpoimboe@kernel.org, peterz@infradead.org, jikos@kernel.org, mbenes@suse.cz, pmladek@suse.com, joe.lawrence@redhat.com, puranjay@kernel.org, kernel-team@meta.com, Song Liu Subject: [PATCH v5 50/58] objtool/klp: Add test for a static call introduced by the patch Date: Wed, 16 Sep 2026 11:43:43 -0700 Message-ID: <20260916184351.2720310-51-song@kernel.org> X-Mailer: git-send-email 2.53.0 In-Reply-To: <20260916184351.2720310-1-song@kernel.org> References: <20260916184351.2720310-1-song@kernel.org> Precedence: bulk X-Mailing-List: live-patching@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit The counterpart to the static branch case: a patch may add a static call to a function which had none, so the .static_call_sites entry is new and there is nothing in the original to correlate it against. Where the key lives still decides whether that is allowed. A vmlinux key is reachable; a module-owned one is not, for the same reason an existing module key is not -- late module patching lets the livepatch load first and the unresolved entry is dereferenced when the module arrives. Both halves are here because they fail in opposite directions: dropping the new entry leaves a static call the kernel never patches, and accepting a new module-owned one is the corruption the check exists to prevent. Both halves are one test over one fixture: built with -DNEW_CALL the key is vmlinux's and the new entry has to be carried in; built with -DMODNAME as well the key belongs to a module, klp diff has to reject it, and no output object may be left behind. The premise is asserted first -- the original must have no .static_call_sites at all -- since otherwise this is a second copy of test-static-call-module-key. Covers the same ground as corpus/x86_64/static-call-vmlinux-new and corpus/x86_64/static-call-module-new in Joe Lawrence's klp-build unit test corpus. Assisted-by: Claude:claude-opus-4 Based-on-test-by: Joe Lawrence Assisted-by: Claude:claude-opus-5 Signed-off-by: Song Liu --- .../tests/generic/test-static-call-new.sh | 45 +++++++++++++++++++ 1 file changed, 45 insertions(+) create mode 100755 tools/objtool/tests/generic/test-static-call-new.sh diff --git a/tools/objtool/tests/generic/test-static-call-new.sh b/tools/objtool/tests/generic/test-static-call-new.sh new file mode 100755 index 000000000000..f7d2b39c0fec --- /dev/null +++ b/tools/objtool/tests/generic/test-static-call-new.sh @@ -0,0 +1,45 @@ +#!/bin/bash +# SPDX-License-Identifier: GPL-2.0 +# +# A patch may introduce a static call where the original function had none. +# +# The .static_call_sites entry is then new, with nothing in the original to +# correlate it against, so klp diff has to carry it into the patch from +# scratch. Where the key lives still decides whether that is allowed: a +# vmlinux key is reachable, and a module-owned one is not, for the same reason +# an existing module key is not -- late module patching lets the livepatch load +# first, and the unresolved entry is dereferenced when the module arrives. +# +# Both halves are here because they fail in opposite directions. Dropping the +# new entry leaves a static call the kernel never patches; accepting a new +# module-owned one is the corruption the check exists to prevent. +# +# Covers the same ground as corpus/x86_64/static-call-vmlinux-new and +# static-call-module-new in Joe Lawrence's klp-build unit test corpus. + +. "$(dirname "$0")/../lib.sh" + +setup +build_pair static_call.c -DNEW_CALL + +# The premise: the original really has no static call, the patched one does. +has_input_section orig.o .static_call_sites && + fail "fixture put a .static_call_sites in the original; nothing new to add" +has_input_section patched.o .static_call_sites || + probe_skip "compiler produced no .static_call_sites on this arch" + +run_diff +assert_patched target +assert_section .static_call_sites +assert_reloc_sym .static_call_sites target + +# The same new call, with the key owned by a module: not reachable, so the +# build has to stop rather than emit a relocation nothing will resolve. +rm -f "$workdir/out.o" +build_pair static_call.c -DNEW_CALL -DMODNAME='"klp_testmod"' +run_diff 255 +assert_diff_log 'unsupported static call key __SCK__klp_test_call' +[ -e "$workdir/out.o" ] && + fail "output object produced for a rejected input" + +pass "static call introduced by the patch carried in, or rejected for a module key" -- 2.53.0-Meta