Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933259AbbHIUTk (ORCPT ); Sun, 9 Aug 2015 16:19:40 -0400 Received: from ozlabs.org ([103.22.144.67]:59530 "EHLO ozlabs.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933210AbbHIUTj (ORCPT ); Sun, 9 Aug 2015 16:19:39 -0400 From: Rusty Russell To: Takashi Iwai Cc: linux-kernel@vger.kernel.org Subject: Re: [PATCH v2] modpost: abort if a module symbol is too long In-Reply-To: <1438930547-32663-1-git-send-email-tiwai@suse.de> References: <1438930547-32663-1-git-send-email-tiwai@suse.de> User-Agent: Notmuch/0.17 (http://notmuchmail.org) Emacs/24.4.1 (x86_64-pc-linux-gnu) Date: Sat, 08 Aug 2015 15:17:35 +0930 Message-ID: <87io8qbabs.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: 2157 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. Thanks, applied! Cheers, Rusty. > > This patch adds the check of the symbol length in modpost and stops > the build properly. > > Currently MODULE_NAME_LEN is defined in modpost.c instead of referring > to the definition in kernel header because including linux/module.h is > messy and we must cover cross-compilation. > > Signed-off-by: Takashi Iwai > --- > v1->v2: Fix MODULE_NAME_LEN to use Elf_Addr > > scripts/mod/modpost.c | 11 +++++++++++ > 1 file changed, 11 insertions(+) > > diff --git a/scripts/mod/modpost.c b/scripts/mod/modpost.c > index 12d3db3bd46b..d583c98fde31 100644 > --- a/scripts/mod/modpost.c > +++ b/scripts/mod/modpost.c > @@ -2133,6 +2133,11 @@ static void add_staging_flag(struct buffer *b, const char *name) > buf_printf(b, "\nMODULE_INFO(staging, \"Y\");\n"); > } > > +/* In kernel, this size is defined in linux/module.h; > + * here we use Elf_Addr instead of long for covering cross-compile > + */ > +#define MODULE_NAME_LEN (64 - sizeof(Elf_Addr)) > + > /** > * Record CRCs for unresolved symbols > **/ > @@ -2177,6 +2182,12 @@ 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/