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 112AF4D9F64 for ; Wed, 16 Sep 2026 18:45:41 +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=1789584371; cv=none; b=kURSJdsDc5Rw0hms4G65ZLr109EOoRdBBSzCIOXmUgnRldy00hdeo6e6wr+hTfumgnAgkFwPR/BvDsJF/1Q3wnr2irhMPlrxWtrMMJAbEundPFUklqz0yHzHlricRw/zi5pibYhLbfoUjzcRJJs2muJjmqtFuTNvth1PY9ykd1s= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789584371; c=relaxed/simple; bh=8wTVcLx30eXO7S4A2Igmj0Gjyz8HAXZlzTJQhpZ6EaY=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=WW/1vf3iOuqxenWV/2mH7WTnhsvKuH9CGkWvC2F1BIOXutPVNmJCq3c8qe5ibnBmbhB1jU3/JTOotTdDp9xFfZmfaDZsMK1hRZMt+ZC0eTQTmMd4FDKrBt0A+LTFFhSFkUvPrMEvSJmhtLKdbYku9bSn4aRmpWsSXuNPuKrmH84= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=QopA6InZ; 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="QopA6InZ" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 0BC491F0089C; Wed, 16 Sep 2026 18:45:37 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1789584339; bh=3T0EfzRwSX2m193d+Ks4ysPXshEdCV6mslo6m1k1bRs=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=QopA6InZIJDfW9w+Q4Sj8hAWu6SWfC7afINjeQtzpX5cpwkVNdDRFGWatUJwQrZ5r Pf9moiIwWjABv6RZclEWlHsE/m8fB/LflVF09LQ0Mgl09LDmWoOtfTqSE8oxq0KuZS cEE8yaahHKOpKTmDOa+woXKB8+LM26uVG+pyemsNMQOKo3WztJKYwOMKhVnGNTaDhD tNV5LrhPCQm6iCtS3Tq3eNh16VRPv1LDRvQS117QI9LeyIxQrryslwuWG2MbowJnRw JtMguPP+/YXoWNL5h5rCoefOI7v0fLejMQn1iBwbwe0qxdlMZqomvTQeInIx5qVhj2 5L0esR20u3kuw== 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 21/58] objtool/klp: Add test for rejecting module-owned static call keys Date: Wed, 16 Sep 2026 11:43:14 -0700 Message-ID: <20260916184351.2720310-22-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 From: Puranjay Mohan Static calls carry the same constraint as static branches. Check that a vmlinux-owned key is accepted and a module-owned one is refused. Signed-off-by: Puranjay Mohan Assisted-by: Claude:claude-opus-5 Signed-off-by: Song Liu --- .../tests/generic/fixtures/static_call.c | 59 +++++++++++++++++++ .../generic/test-static-call-module-key.sh | 36 +++++++++++ 2 files changed, 95 insertions(+) create mode 100644 tools/objtool/tests/generic/fixtures/static_call.c create mode 100755 tools/objtool/tests/generic/test-static-call-module-key.sh diff --git a/tools/objtool/tests/generic/fixtures/static_call.c b/tools/objtool/tests/generic/fixtures/static_call.c new file mode 100644 index 000000000000..4a0c4c25321e --- /dev/null +++ b/tools/objtool/tests/generic/fixtures/static_call.c @@ -0,0 +1,59 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Static call site in a patched function, laid out by hand as for + * jump_label.c. MODNAME selects whether the key belongs to vmlinux or a + * module. + * + * objtool's check pass would emit the site, and klp-write-tests.txt says to + * let it. Not here: it does not emit the ANNOTATE_DATA_SPECIAL describing + * the entry boundaries -- in the kernel that comes from the static_call + * macros -- and NO_ANNOTATE below has to be able to take it away. A fixture + * which varies the annotation has to write the entry that goes with it. + * + * NO_ANNOTATE drops the ANNOTATE_DATA_SPECIAL block from the patched build, + * leaving .static_call_sites with no annotation to describe its entry + * boundaries. The section carries no entsize either, so klp diff has to fall + * back on the annotations it can still see -- and when the patched object is + * the only one that lost them, the two sides disagree about how the section is + * divided up. + * + * NEW_CALL puts the call site behind PATCHED, so the patch introduces one + * where the original had none. The .static_call_sites entry is then new, with + * nothing in the original to correlate it against. + */ + +#ifndef MODNAME +#define MODNAME "vmlinux" +#endif + +static const char __modinfo[] + __attribute__((section(".modinfo"), used, aligned(1))) = "\0name=" MODNAME; + +long __SCK__klp_test_call; + +int target(int x) +{ +#if defined(NEW_CALL) && !defined(PATCHED) + /* The original has no static call at all. */ + return x + 1; +#else + __asm__ volatile( + "1: nop\n\t" + ".pushsection .static_call_sites, \"aw\"\n\t" + ".balign 8\n\t" + "912:\n\t" +#if !(defined(PATCHED) && defined(NO_ANNOTATE)) + ".pushsection .discard.annotate_data, \"M\", @progbits, 8\n\t" + ".long 912b - ., 1\n\t" + ".popsection\n\t" +#endif + ".long 1b - ., %c0 - .\n\t" + ".popsection\n\t" + :: "i" (&__SCK__klp_test_call)); +#endif +#ifdef PATCHED + return x + 2; +#else + return x + 1; +#endif +} diff --git a/tools/objtool/tests/generic/test-static-call-module-key.sh b/tools/objtool/tests/generic/test-static-call-module-key.sh new file mode 100755 index 000000000000..260c4af72e05 --- /dev/null +++ b/tools/objtool/tests/generic/test-static-call-module-key.sh @@ -0,0 +1,36 @@ +#!/bin/bash +# SPDX-License-Identifier: GPL-2.0 +# +# As for static branches, a static call key owned by a module must be rejected +# while a vmlinux-owned one is accepted. + +. "$(dirname "$0")/../lib.sh" + +setup +build_pair static_call.c + +has_input_section orig.o .static_call_sites || + probe_skip "fixture produced no .static_call_sites on this arch" + +run_diff +assert_patched target + +# The accepted half has to show the entry was carried, not just that the +# function was: dropping the section silently would leave the patched call +# unregistered, and "target was cloned" cannot tell the two apart. +assert_section .static_call_sites +assert_reloc_sym .static_call_sites target + +rm -f "$workdir/out.o" +build_pair static_call.c -DMODNAME='"klp_testmod"' +run_diff 255 + +diff_log | grep -q 'unsupported static call key __SCK__klp_test_call' || + fail "expected rejection, got: $(diff_log | tail -1)" + +# A rejection has to leave nothing behind. out.o was removed above, so +# anything here was written by the run which was supposed to refuse. +[ -e "$workdir/out.o" ] && + fail "output object produced for a rejected input" + +pass "module-owned static call key rejected, vmlinux-owned accepted" -- 2.53.0-Meta