From patchwork Mon Dec 2 14:59:50 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Peter Zijlstra X-Patchwork-Id: 13890941 Received: from casper.infradead.org (casper.infradead.org [90.155.50.34]) (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 CB71B1FECDE; Mon, 2 Dec 2024 15:11:36 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=90.155.50.34 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1733152299; cv=none; b=ZTPHsh29Gd2CmBpkXQe42ETFzionB8zG7ImwGDa2SEweWn9yjfTouEOsjKMkxNJfaAnEqF/IFzvSMGMUj/Acu0aPZHqsdGJ9jik02srnwBlGEpMaKp/ovgcEf7HkrT6d6eU2Rl6Ug1LnvhyhV4Hm+GM6F09D4VxFV+WsYHn4Ch8= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1733152299; c=relaxed/simple; bh=XHnTJHOPYtZIDpwCX8Qj4Gyauad1xJ05yQqNtHbIPkY=; h=Message-ID:Date:From:To:Cc:Subject:References:MIME-Version: Content-Type; b=HFJGjNFVaK+2ggPdh3ILHNG9Oa3KHGX6RL7LEB4kjsMIpLibhdCvLdTOkLS9am9r4yHvlmtmi641W9lyjWUpxL9hLL8ZCOLwtwncFLAlTNuCN/2JOClBXEVx82+z52frGdygzdLqHT5ZuI08QJwsq77UObeDEV0lp3ZarbS+6vg= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=infradead.org; spf=none smtp.mailfrom=infradead.org; dkim=pass (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b=TeVV6PeR; arc=none smtp.client-ip=90.155.50.34 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=infradead.org Authentication-Results: smtp.subspace.kernel.org; spf=none smtp.mailfrom=infradead.org Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="TeVV6PeR" DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=casper.20170209; h=Content-Type:MIME-Version:References: Subject:Cc:To:From:Date:Message-ID:Sender:Reply-To:Content-Transfer-Encoding: Content-ID:Content-Description:In-Reply-To; bh=aGjvucfOz39yLyUBScLYaZkWFoL5jwssjx5+IvdVnTE=; b=TeVV6PeRrbodIeRA0Peu2iSy1W 35Kog7wgqiIar7hDxW/FcHmMlEeOx/TMzcoCNTwv4Jc1/RpD5JyNAx/QIftdgHIHBJvuh6Gl1ltjp TRL5nPu8FulMe/y6i2ZLQjRHyrKl8SNLegDXZmDABrmRURXepAdFk2bRknGvTzJfzifVaTt/WnyWz JpKPzUXZ0Ek1dzHkr/elr/roLRZahPI8KEWCyN9lz8LPzsCGHYmSvIbUN8guKFaL2q167p5rA7GNp Nfh4a7OGTXA4VRZpg3wiXt5mCvcZ/NhHgi6KNOC+NryG5mhL6i4xXYj8yIxxSdj96CyX7BIH7q+1l QTfoSYxQ==; Received: from 77-249-17-89.cable.dynamic.v4.ziggo.nl ([77.249.17.89] helo=noisy.programming.kicks-ass.net) by casper.infradead.org with esmtpsa (Exim 4.98 #2 (Red Hat Linux)) id 1tI859-00000008CPm-17Pt; Mon, 02 Dec 2024 15:11:28 +0000 Received: by noisy.programming.kicks-ass.net (Postfix, from userid 0) id C9DFE300731; Mon, 2 Dec 2024 16:11:27 +0100 (CET) Message-ID: <20241202150810.382545529@infradead.org> User-Agent: quilt/0.66 Date: Mon, 02 Dec 2024 15:59:50 +0100 From: Peter Zijlstra To: mcgrof@kernel.org Cc: x86@kernel.org, hpa@zytor.com, petr.pavlu@suse.com, samitolvanen@google.com, da.gomez@samsung.com, masahiroy@kernel.org, nathan@kernel.org, nicolas@fjasle.eu, linux-kernel@vger.kernel.org, linux-modules@vger.kernel.org, linux-kbuild@vger.kernel.org, hch@infradead.org, gregkh@linuxfoundation.org, "Peter Zijlstra (Intel)" Subject: [PATCH -v2 4/7] module: Add module specific symbol namespace support References: <20241202145946.108093528@infradead.org> Precedence: bulk X-Mailing-List: linux-kbuild@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Designate the "MODULE_${modname}" symbol namespace to mean: 'only export to the named module'. Notably, explicit imports of anything in the "MODULE_" space is forbidden. Modules implicitly get the "MODULE_${modname}" namespace added. Signed-off-by: Peter Zijlstra (Intel) --- kernel/module/main.c | 28 ++++++++++++++++++++++++++-- scripts/mod/modpost.c | 5 +++++ 2 files changed, 31 insertions(+), 2 deletions(-) --- a/kernel/module/main.c +++ b/kernel/module/main.c @@ -1070,6 +1070,13 @@ static int verify_namespace_is_imported( namespace = kernel_symbol_namespace(sym); if (namespace && namespace[0]) { + /* + * Implicitly import MODULE_${mod->name} namespace. + */ + if (strncmp(namespace, "MODULE_", 7) == 0 && + strcmp(namespace+7, mod->name) == 0) + return 0; + for_each_modinfo_entry(imported_namespace, info, "import_ns") { if (strcmp(namespace, imported_namespace) == 0) return 0; @@ -1613,15 +1620,30 @@ static void module_license_taint_check(s } } -static void setup_modinfo(struct module *mod, struct load_info *info) +static int setup_modinfo(struct module *mod, struct load_info *info) { struct module_attribute *attr; + char *imported_namespace; int i; for (i = 0; (attr = modinfo_attrs[i]); i++) { if (attr->setup) attr->setup(mod, get_modinfo(info, attr->attr.name)); } + + for_each_modinfo_entry(imported_namespace, info, "import_ns") { + /* + * 'MODULE_' prefixed namespaces are implicit, disallow + * explicit imports. + */ + if (strstarts(imported_namespace, "MODULE_")) { + pr_err("%s: module tries to import module namespace: %s\n", + mod->name, imported_namespace); + return -EPERM; + } + } + + return 0; } static void free_modinfo(struct module *mod) @@ -2935,7 +2957,9 @@ static int load_module(struct load_info goto free_unload; /* Set up MODINFO_ATTR fields */ - setup_modinfo(mod, info); + err = setup_modinfo(mod, info); + if (err) + goto free_modinfo; /* Fix up syms, so that st_value is a pointer to location. */ err = simplify_symbols(mod, info); --- a/scripts/mod/modpost.c +++ b/scripts/mod/modpost.c @@ -1565,6 +1565,7 @@ static const char *mod_basename(const ch static void read_symbols(const char *modname) { + char module_namespace[MODULE_NAME_LEN + 8]; const char *symname; char *version; char *license; @@ -1600,6 +1601,10 @@ static void read_symbols(const char *mod namespace = get_next_modinfo(&info, "import_ns", namespace)) add_namespace(&mod->imported_namespaces, namespace); + snprintf(module_namespace, sizeof(module_namespace), "MODULE_%s", + mod_basename(mod->name)); + add_namespace(&mod->imported_namespaces, module_namespace); + if (extra_warn && !get_modinfo(&info, "description")) warn("missing MODULE_DESCRIPTION() in %s\n", modname); }