From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 F0E3336CE05; Wed, 17 Sep 2025 16:04:58 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1758125099; cv=none; b=Q4CCAf1p07KRcJrtqr618iKkUVJBHKbAZ9KZ4GI6ZzGkTw09n5ZBQb6UfcvBHlwyBz73YQjOEzEYcolxLcLBxYTWbxyc3Be+/vlm5qSmgzl0GIcNcpWyIz5LLtz3UMYI2h+GDV1JZMQQj8GB6YMi8OWpCA6vWWuaRXs9irceLkM= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1758125099; c=relaxed/simple; bh=6+AHs6jxK6kYVAmSPda/p78+Aru2RlpjwG8zJ/p1Dv4=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=Orc7dDraEa0hAkXHtsQRblzJArfxqCayGSLdtH4arHoaV5BF4Cjc5zqbxNBHSW10iipFGRw3YaMB5fkxSrc0aWOXxk1AaiiB7PXJdSOaJIbjyThQZkugCIDJdWKk0HhUvX5znAo+4qmcpXSjU7NJExyde89XRnivUpstZ67MEHQ= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=W69E0M3p; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="W69E0M3p" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 25AFFC4CEF7; Wed, 17 Sep 2025 16:04:58 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1758125098; bh=6+AHs6jxK6kYVAmSPda/p78+Aru2RlpjwG8zJ/p1Dv4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=W69E0M3p8l2ch0GO06yxF4+nHvfW14WXAOgNfXvvUgZHhPvDY6sIKkpmFbVsOrzMI Lughmly3rZM4s6giTr6ghWFdp9OZ7ye9JtgTRnVj8vBPePfEwZcrqvvgHJNM3k8PWv xTj2GFJoFQUPEN5s7XTnSx9ckhUZ8tyyU/cpAIYVWQRHPBiF3ajtbiLFolKlaVnffh Q1fBqhmOAJx7/9wobQ6X9Cg3ISMFHDSpYFpLvWOUN6+VU0c43XFkB3X28Ai28qghOe dCtX/x9909nohhJcGFeSnvnCd3oXJaHZT0GNAYdYGBYEH/rr/GenezlVmA9trBNb7e ay21Ba5DDGXXg== From: Josh Poimboeuf To: x86@kernel.org Cc: linux-kernel@vger.kernel.org, Petr Mladek , Miroslav Benes , Joe Lawrence , live-patching@vger.kernel.org, Song Liu , laokz , Jiri Kosina , Marcos Paulo de Souza , Weinan Liu , Fazla Mehrab , Chen Zhongjin , Puranjay Mohan , Dylan Hatch , Peter Zijlstra Subject: [PATCH v4 59/63] livepatch/klp-build: Add stub init code for livepatch modules Date: Wed, 17 Sep 2025 09:04:07 -0700 Message-ID: <702710bf41d72163d494d8cf2e8c5a95dc98ef75.1758067943.git.jpoimboe@kernel.org> X-Mailer: git-send-email 2.50.0 In-Reply-To: References: Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Add a module initialization stub which can be linked with binary diff objects to produce a livepatch module. Signed-off-by: Josh Poimboeuf --- scripts/livepatch/init.c | 108 +++++++++++++++++++++++++++++++++++++++ 1 file changed, 108 insertions(+) create mode 100644 scripts/livepatch/init.c diff --git a/scripts/livepatch/init.c b/scripts/livepatch/init.c new file mode 100644 index 0000000000000..2274d8f5a4826 --- /dev/null +++ b/scripts/livepatch/init.c @@ -0,0 +1,108 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Init code for a livepatch kernel module + */ + +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt + +#include +#include +#include + +extern struct klp_object_ext __start_klp_objects[]; +extern struct klp_object_ext __stop_klp_objects[]; + +static struct klp_patch *patch; + +static int __init livepatch_mod_init(void) +{ + struct klp_object *objs; + unsigned int nr_objs; + int ret; + + nr_objs = __stop_klp_objects - __start_klp_objects; + + if (!nr_objs) { + pr_err("nothing to patch!\n"); + ret = -EINVAL; + goto err; + } + + patch = kzalloc(sizeof(*patch), GFP_KERNEL); + if (!patch) { + ret = -ENOMEM; + goto err; + } + + objs = kzalloc(sizeof(struct klp_object) * (nr_objs + 1), GFP_KERNEL); + if (!objs) { + ret = -ENOMEM; + goto err_free_patch; + } + + for (int i = 0; i < nr_objs; i++) { + struct klp_object_ext *obj_ext = __start_klp_objects + i; + struct klp_func_ext *funcs_ext = obj_ext->funcs; + unsigned int nr_funcs = obj_ext->nr_funcs; + struct klp_func *funcs = objs[i].funcs; + struct klp_object *obj = objs + i; + + funcs = kzalloc(sizeof(struct klp_func) * (nr_funcs + 1), GFP_KERNEL); + if (!funcs) { + ret = -ENOMEM; + for (int j = 0; j < i; j++) + kfree(objs[i].funcs); + goto err_free_objs; + } + + for (int j = 0; j < nr_funcs; j++) { + funcs[j].old_name = funcs_ext[j].old_name; + funcs[j].new_func = funcs_ext[j].new_func; + funcs[j].old_sympos = funcs_ext[j].sympos; + } + + obj->name = obj_ext->name; + obj->funcs = funcs; + + memcpy(&obj->callbacks, &obj_ext->callbacks, sizeof(struct klp_callbacks)); + } + + patch->mod = THIS_MODULE; + patch->objs = objs; + + /* TODO patch->states */ + +#ifdef KLP_NO_REPLACE + patch->replace = false; +#else + patch->replace = true; +#endif + + return klp_enable_patch(patch); + +err_free_objs: + kfree(objs); +err_free_patch: + kfree(patch); +err: + return ret; +} + +static void __exit livepatch_mod_exit(void) +{ + unsigned int nr_objs; + + nr_objs = __stop_klp_objects - __start_klp_objects; + + for (int i = 0; i < nr_objs; i++) + kfree(patch->objs[i].funcs); + + kfree(patch->objs); + kfree(patch); +} + +module_init(livepatch_mod_init); +module_exit(livepatch_mod_exit); +MODULE_LICENSE("GPL"); +MODULE_INFO(livepatch, "Y"); +MODULE_DESCRIPTION("Livepatch module"); -- 2.50.0