Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756313AbbHFV1P (ORCPT ); Thu, 6 Aug 2015 17:27:15 -0400 Received: from ozlabs.org ([103.22.144.67]:36491 "EHLO ozlabs.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756099AbbHFV1O (ORCPT ); Thu, 6 Aug 2015 17:27:14 -0400 From: Rusty Russell To: Takashi Iwai Cc: linux-kernel@vger.kernel.org Subject: Re: [PATCH] modpost: abort if a module symbol is too long In-Reply-To: <1438876428-19911-1-git-send-email-tiwai@suse.de> References: <1438876428-19911-1-git-send-email-tiwai@suse.de> User-Agent: Notmuch/0.17 (http://notmuchmail.org) Emacs/24.4.1 (x86_64-pc-linux-gnu) Date: Fri, 07 Aug 2015 06:39:12 +0930 Message-ID: <871tfgcefb.fsf@rustcorp.com.au> MIME-Version: 1.0 Content-Type: text/plain Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2152 Lines: 65 Takashi Iwai writes: > Module symbols have a limited length, but currently the build system > allows the build finishing even if the driver code contains a too long > symbol name, which eventually overflows the modversion_info[] item. > The compiler may catch at compiling *.mod.c like > CC xxx.mod.o > xxx.mod.c:18:16: warning: initializer-string for array of chars is too long > but it's merely a warning. > > This patch adds the check of the symbol length in modpost and stops > the build properly. > > As of now, MODULE_NAME_LEN is copied in modpost.c. At best, this > should be read directly from kernel headers. But including > linux/module.h is too troublesome for now, so just paper over it. > > Signed-off-by: Takashi Iwai > --- > scripts/mod/modpost.c | 9 +++++++++ > 1 file changed, 9 insertions(+) > > diff --git a/scripts/mod/modpost.c b/scripts/mod/modpost.c > index 12d3db3bd46b..25bda9d2868c 100644 > --- a/scripts/mod/modpost.c > +++ b/scripts/mod/modpost.c > @@ -2133,6 +2133,9 @@ static void add_staging_flag(struct buffer *b, const char *name) > buf_printf(b, "\nMODULE_INFO(staging, \"Y\");\n"); > } > > +/* FIXME: better to be included from kernel header */ > +#define MODULE_NAME_LEN (64 - sizeof(unsigned long)) This isn't quite right, since modpost handles cross-compilation. #define MODULE_NAME_LEN (64 - sizeof(Elf_Addr)) Should work... Thanks! Rusty. > + > /** > * Record CRCs for unresolved symbols > **/ > @@ -2177,6 +2180,12 @@ static int add_versions(struct buffer *b, struct module *mod) > s->name, mod->name); > continue; > } > + if (strlen(s->name) >= MODULE_NAME_LEN) { > + merror("too long symbol \"%s\" [%s.ko]\n", > + s->name, mod->name); > + err = 1; > + break; > + } > buf_printf(b, "\t{ %#8x, __VMLINUX_SYMBOL_STR(%s) },\n", > s->crc, s->name); > } > -- > 2.5.0 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/