Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755329AbbHGGzu (ORCPT ); Fri, 7 Aug 2015 02:55:50 -0400 Received: from mx2.suse.de ([195.135.220.15]:37786 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754204AbbHGGzt (ORCPT ); Fri, 7 Aug 2015 02:55:49 -0400 From: Takashi Iwai To: Rusty Russell Cc: linux-kernel@vger.kernel.org Subject: [PATCH v2] modpost: abort if a module symbol is too long Date: Fri, 7 Aug 2015 08:55:47 +0200 Message-Id: <1438930547-32663-1-git-send-email-tiwai@suse.de> X-Mailer: git-send-email 2.5.0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1985 Lines: 59 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. 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/