From nobody Sat Nov 23 22:26:37 2024 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 3EC9E19AD73; Mon, 11 Nov 2024 11:19:00 +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=1731323941; cv=none; b=ceXlq3v81YqHTap6PwAsnWkepTtTHnRmDvAYoZsCEbNlLjMWHUbyKqzX/v10Trg2Sckq6EIVFGlvEqMDbhrD8P4NpO4upN0EVcuN6mnfsm/zvVyY6CP1eJH9OtKYVocGxS/sSDneC/kSA6+eI9cezA0zGmfW7bmvMOxewbVIFq8= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1731323941; c=relaxed/simple; bh=XHnTJHOPYtZIDpwCX8Qj4Gyauad1xJ05yQqNtHbIPkY=; h=Message-Id:Date:From:To:Cc:Subject:References:MIME-Version: Content-Type; b=WfLMbkedPFDzaZQtinM82Woyj65uP5loKJLj8pb6IAtKqrQuTFVIqpnXyZBa3MVPoIV6R1m0a7gBdZAsfOg08ig0rfN0Rj1DllhiTNhAGCnQFruan8UJDIUytHC+E+1B6/YIK8yCJN8Mnw66ZDbSbzNWzOFe1F3f1d+anh8QHRk= 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=Tf4vS9Dl; 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="Tf4vS9Dl" 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=Tf4vS9DlqPq+tWaiyxNstrYCKE quaemMrjgj9A1i/MRz5CAunj225OaYaH53gDtdE4ttBzuVhGSKiWa7aBSsGAJiD64MkmceO9HsX6w +5S5jctlk4Gqjf+2FVagwftbBDgyFa8OIf5aovoY+sfV3l6aIEUb9jgyBZuj2+CyzvC3LR+eNcGDX PxtsxSUZGRLNYNLyvtytUh3XFahx/3vTirrGTNw7D5KuXHiida5sqJ3e4xfBGelk2CLPWz3tfkHoq GYzZzvPo6I1cSEHAqBhCg/ZzR0uMviD3MvA/4+n0TQlAAcnxtoebn339aELra1TFXNmurU+r5YtbN yNcrlTCA==; Received: from j130084.upc-j.chello.nl ([24.132.130.84] helo=noisy.programming.kicks-ass.net) by casper.infradead.org with esmtpsa (Exim 4.98 #2 (Red Hat Linux)) id 1tASRU-0000000CiRC-3Vfh; Mon, 11 Nov 2024 11:18:48 +0000 Received: by noisy.programming.kicks-ass.net (Postfix, from userid 0) id 0D79930122C; Mon, 11 Nov 2024 12:18:47 +0100 (CET) Message-Id: <20241111111817.532312508@infradead.org> User-Agent: quilt/0.65 Date: Mon, 11 Nov 2024 11:54:36 +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: [RFC][PATCH 6/8] module: Add module specific symbol namespace support References: <20241111105430.575636482@infradead.org> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" 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( =20 namespace =3D kernel_symbol_namespace(sym); if (namespace && namespace[0]) { + /* + * Implicitly import MODULE_${mod->name} namespace. + */ + if (strncmp(namespace, "MODULE_", 7) =3D=3D 0 && + strcmp(namespace+7, mod->name) =3D=3D 0) + return 0; + for_each_modinfo_entry(imported_namespace, info, "import_ns") { if (strcmp(namespace, imported_namespace) =3D=3D 0) return 0; @@ -1613,15 +1620,30 @@ static void module_license_taint_check(s } } =20 -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; =20 for (i =3D 0; (attr =3D 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; } =20 static void free_modinfo(struct module *mod) @@ -2935,7 +2957,9 @@ static int load_module(struct load_info goto free_unload; =20 /* Set up MODINFO_ATTR fields */ - setup_modinfo(mod, info); + err =3D setup_modinfo(mod, info); + if (err) + goto free_modinfo; =20 /* Fix up syms, so that st_value is a pointer to location. */ err =3D 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 =20 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 =3D get_next_modinfo(&info, "import_ns", namespace)) add_namespace(&mod->imported_namespaces, namespace); =20 + 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); }