From patchwork Wed Feb 16 16:39:38 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Joe Lawrence X-Patchwork-Id: 12748785 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id EF375C4332F for ; Wed, 16 Feb 2022 16:40:09 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236647AbiBPQkU (ORCPT ); Wed, 16 Feb 2022 11:40:20 -0500 Received: from mxb-00190b01.gslb.pphosted.com ([23.128.96.19]:42260 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S236569AbiBPQkK (ORCPT ); Wed, 16 Feb 2022 11:40:10 -0500 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id 2539D25D24E for ; Wed, 16 Feb 2022 08:39:56 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1645029595; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=bg4c13PG3YFA4cx/URObt9BCO2JrLpJ9gS9DNhRWcCM=; b=GhDXhsGWiEdT7vVdAwyadIdQNPvQGtVrDQCYdPLd2bXc13NYMXl49QXqhth34KIgKuECbI vD6srnMX5dAMfMV6EcuxLuNQqKHCbbNYuLVFDNoO0bWLMryeTMZLmFaT1RX6nxovwCBz+R eGWp76wSikiHfVabdX/y/MHbQTSO1o0= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-187-ONL6tvcJN0mMHq0_Z0wugg-1; Wed, 16 Feb 2022 11:39:50 -0500 X-MC-Unique: ONL6tvcJN0mMHq0_Z0wugg-1 Received: from smtp.corp.redhat.com (int-mx01.intmail.prod.int.phx2.redhat.com [10.5.11.11]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id EE486814243; Wed, 16 Feb 2022 16:39:48 +0000 (UTC) Received: from jlaw-desktop.redhat.com (unknown [10.22.8.49]) by smtp.corp.redhat.com (Postfix) with ESMTP id 7C619753CD; Wed, 16 Feb 2022 16:39:48 +0000 (UTC) From: Joe Lawrence To: live-patching@vger.kernel.org, linux-kernel@vger.kernel.org, linux-kbuild@vger.kernel.org Subject: [RFC PATCH v6 10/12] livepatch/selftests: add __asm__ symbol renaming examples Date: Wed, 16 Feb 2022 11:39:38 -0500 Message-Id: <20220216163940.228309-11-joe.lawrence@redhat.com> In-Reply-To: <20220216163940.228309-1-joe.lawrence@redhat.com> References: <20220216163940.228309-1-joe.lawrence@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.11 Precedence: bulk List-ID: X-Mailing-List: linux-kbuild@vger.kernel.org GCC can rename symbols like static data and optimized functions, adding a suffix that includes illegal C characters. Extend the klp-convert examples to demonstrate how to use __asm__ renaming from C code to create klp-relocations to such renamed symbols. Signed-off-by: Joe Lawrence --- lib/livepatch/test_klp_convert.h | 2 ++ lib/livepatch/test_klp_convert1.c | 8 ++++++++ lib/livepatch/test_klp_convert_mod_a.c | 6 ++++++ lib/livepatch/test_klp_convert_mod_b.c | 6 ++++++ tools/testing/selftests/livepatch/test-livepatch.sh | 4 ++++ 5 files changed, 26 insertions(+) diff --git a/lib/livepatch/test_klp_convert.h b/lib/livepatch/test_klp_convert.h index 5d97bc546d6e..42befbfd63cb 100644 --- a/lib/livepatch/test_klp_convert.h +++ b/lib/livepatch/test_klp_convert.h @@ -10,5 +10,7 @@ extern char driver_name[]; extern char homonym_string[]; extern const char *get_homonym_string(void); extern const char *test_klp_get_driver_name(void); +extern char klp_string_a[] __asm__("klp_string.12345"); +extern char klp_string_b[] __asm__("klp_string.67890"); #endif diff --git a/lib/livepatch/test_klp_convert1.c b/lib/livepatch/test_klp_convert1.c index cd2d3c638258..06926cf1c609 100644 --- a/lib/livepatch/test_klp_convert1.c +++ b/lib/livepatch/test_klp_convert1.c @@ -25,6 +25,12 @@ void print_homonym_string(void) pr_info("get_homonym_string(), 1: %s\n", get_homonym_string()); } +void print_static_strings(void) +{ + pr_info("klp_string.12345 = %s\n", klp_string_a); + pr_info("klp_string.67890 = %s\n", klp_string_b); +} + /* provide a sysfs handle to invoke debug functions */ static int print_debug; static int print_debug_set(const char *val, const struct kernel_param *kp) @@ -32,6 +38,7 @@ static int print_debug_set(const char *val, const struct kernel_param *kp) print_saved_command_line(); print_driver_name(); print_homonym_string(); + print_static_strings(); return 0; } @@ -67,6 +74,7 @@ KLP_MODULE_RELOC(test_klp_convert_mod) test_klp_convert_mod_relocs_a[] = { KLP_SYMPOS(homonym_string, 1), KLP_SYMPOS(get_homonym_string, 1), KLP_SYMPOS(test_klp_get_driver_name, 0), + KLP_SYMPOS(klp_string_b, 1), }; static struct klp_func funcs[] = { diff --git a/lib/livepatch/test_klp_convert_mod_a.c b/lib/livepatch/test_klp_convert_mod_a.c index ae5e911fbb9b..9af0fcab0c8d 100644 --- a/lib/livepatch/test_klp_convert_mod_a.c +++ b/lib/livepatch/test_klp_convert_mod_a.c @@ -20,6 +20,12 @@ __used static const char *get_homonym_string(void) return homonym_string; } +__used static void static_string_function(void) +{ + __used static char klp_string[] __asm__("klp_string.12345") = + __FILE__ " static string"; +} + MODULE_LICENSE("GPL"); MODULE_AUTHOR("Joe Lawrence "); MODULE_DESCRIPTION("Livepatch test: klp-convert module"); diff --git a/lib/livepatch/test_klp_convert_mod_b.c b/lib/livepatch/test_klp_convert_mod_b.c index 5eca8a4cae38..0a68e898fe03 100644 --- a/lib/livepatch/test_klp_convert_mod_b.c +++ b/lib/livepatch/test_klp_convert_mod_b.c @@ -11,3 +11,9 @@ __used static const char *get_homonym_string(void) { return homonym_string; } + +__used static void static_string_function(void) +{ + __used static char klp_string[] __asm__("klp_string.67890") = + __FILE__ " static string"; +} diff --git a/tools/testing/selftests/livepatch/test-livepatch.sh b/tools/testing/selftests/livepatch/test-livepatch.sh index bcb8b468b80a..ec3b6c919b01 100755 --- a/tools/testing/selftests/livepatch/test-livepatch.sh +++ b/tools/testing/selftests/livepatch/test-livepatch.sh @@ -200,6 +200,8 @@ $MOD_KLP_CONVERT1: driver_name, 0: $MOD_KLP_CONVERT_MOD $MOD_KLP_CONVERT1: test_klp_get_driver_name(), 0: $MOD_KLP_CONVERT_MOD $MOD_KLP_CONVERT1: homonym_string, 1: homonym string A $MOD_KLP_CONVERT1: get_homonym_string(), 1: homonym string A +test_klp_convert1: klp_string.12345 = lib/livepatch/test_klp_convert_mod_a.c static string +test_klp_convert1: klp_string.67890 = lib/livepatch/test_klp_convert_mod_b.c static string % echo 0 > /sys/kernel/livepatch/$MOD_KLP_CONVERT1/enabled livepatch: '$MOD_KLP_CONVERT1': initializing unpatching transition livepatch: '$MOD_KLP_CONVERT1': starting unpatching transition @@ -265,6 +267,8 @@ $MOD_KLP_CONVERT1: driver_name, 0: $MOD_KLP_CONVERT_MOD $MOD_KLP_CONVERT1: test_klp_get_driver_name(), 0: $MOD_KLP_CONVERT_MOD $MOD_KLP_CONVERT1: homonym_string, 1: homonym string A $MOD_KLP_CONVERT1: get_homonym_string(), 1: homonym string A +test_klp_convert1: klp_string.12345 = lib/livepatch/test_klp_convert_mod_a.c static string +test_klp_convert1: klp_string.67890 = lib/livepatch/test_klp_convert_mod_b.c static string % echo 0 > /sys/kernel/livepatch/$MOD_KLP_CONVERT1/enabled livepatch: '$MOD_KLP_CONVERT1': initializing unpatching transition livepatch: '$MOD_KLP_CONVERT1': starting unpatching transition