From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-9.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 5A9E3C282C8 for ; Mon, 28 Jan 2019 15:45:52 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 2C67921741 for ; Mon, 28 Jan 2019 15:45:52 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1548690352; bh=oH1gZkQ/G18Qc3EHxve7AHAYVITaIL9CZNEFG+msbcw=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=bmyLEReIgeHPPDO4shJ2LchvQdnsx8bLgSpn2w/Z4ATiER5wQql1fD0VHJN4l5QNr WJU4PQ9QjrNNlo03NgUn3JLzmPSRdyZvgmutI+aN72p9GUYs9GBQNzMdPsRg6DHKXs 02GicxxmUAiYkSM+VmlaP0XBTr5RgNh5QUKOcvoU= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727866AbfA1Ppu (ORCPT ); Mon, 28 Jan 2019 10:45:50 -0500 Received: from mail.kernel.org ([198.145.29.99]:59180 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727853AbfA1Ppr (ORCPT ); Mon, 28 Jan 2019 10:45:47 -0500 Received: from sasha-vm.mshome.net (c-73-47-72-35.hsd1.nh.comcast.net [73.47.72.35]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 3EC2421741; Mon, 28 Jan 2019 15:45:44 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1548690346; bh=oH1gZkQ/G18Qc3EHxve7AHAYVITaIL9CZNEFG+msbcw=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=W5VgS4lDrzBiPXlaeLDamQfqUwzumbNzdpWzbQNoau4nHtvQRLg4hkYV0yJ5EUrc0 Jxonv7wNsINz9amoOD49dGr2fPvxz0jyg8a9nhVpYRn9RabLIDcltDvDj3fE+5FCRB VVumDiHDZPz6pM+85UIDdnw1BUbzNfd70phig/1M= From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Sami Tolvanen , Masahiro Yamada , Sasha Levin , linux-kbuild@vger.kernel.org Subject: [PATCH AUTOSEL 4.20 059/304] modpost: validate symbol names also in find_elf_symbol Date: Mon, 28 Jan 2019 10:39:36 -0500 Message-Id: <20190128154341.47195-59-sashal@kernel.org> X-Mailer: git-send-email 2.19.1 In-Reply-To: <20190128154341.47195-1-sashal@kernel.org> References: <20190128154341.47195-1-sashal@kernel.org> MIME-Version: 1.0 X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Sami Tolvanen [ Upstream commit 5818c683a619c534c113e1f66d24f636defc29bc ] If an ARM mapping symbol shares an address with a valid symbol, find_elf_symbol can currently return the mapping symbol instead, as the symbol is not validated. This can result in confusing warnings: WARNING: vmlinux.o(.text+0x18f4028): Section mismatch in reference from the function set_reset_devices() to the variable .init.text:$x.0 This change adds a call to is_valid_name to find_elf_symbol, similarly to how it's already used in find_elf_symbol2. Signed-off-by: Sami Tolvanen Signed-off-by: Masahiro Yamada Signed-off-by: Sasha Levin --- scripts/mod/modpost.c | 50 ++++++++++++++++++++++--------------------- 1 file changed, 26 insertions(+), 24 deletions(-) diff --git a/scripts/mod/modpost.c b/scripts/mod/modpost.c index 5a5b3780456f..5a77efd39b3f 100644 --- a/scripts/mod/modpost.c +++ b/scripts/mod/modpost.c @@ -1204,6 +1204,30 @@ static int secref_whitelist(const struct sectioncheck *mismatch, return 1; } +static inline int is_arm_mapping_symbol(const char *str) +{ + return str[0] == '$' && strchr("axtd", str[1]) + && (str[2] == '\0' || str[2] == '.'); +} + +/* + * If there's no name there, ignore it; likewise, ignore it if it's + * one of the magic symbols emitted used by current ARM tools. + * + * Otherwise if find_symbols_between() returns those symbols, they'll + * fail the whitelist tests and cause lots of false alarms ... fixable + * only by merging __exit and __init sections into __text, bloating + * the kernel (which is especially evil on embedded platforms). + */ +static inline int is_valid_name(struct elf_info *elf, Elf_Sym *sym) +{ + const char *name = elf->strtab + sym->st_name; + + if (!name || !strlen(name)) + return 0; + return !is_arm_mapping_symbol(name); +} + /** * Find symbol based on relocation record info. * In some cases the symbol supplied is a valid symbol so @@ -1229,6 +1253,8 @@ static Elf_Sym *find_elf_symbol(struct elf_info *elf, Elf64_Sword addr, continue; if (ELF_ST_TYPE(sym->st_info) == STT_SECTION) continue; + if (!is_valid_name(elf, sym)) + continue; if (sym->st_value == addr) return sym; /* Find a symbol nearby - addr are maybe negative */ @@ -1247,30 +1273,6 @@ static Elf_Sym *find_elf_symbol(struct elf_info *elf, Elf64_Sword addr, return NULL; } -static inline int is_arm_mapping_symbol(const char *str) -{ - return str[0] == '$' && strchr("axtd", str[1]) - && (str[2] == '\0' || str[2] == '.'); -} - -/* - * If there's no name there, ignore it; likewise, ignore it if it's - * one of the magic symbols emitted used by current ARM tools. - * - * Otherwise if find_symbols_between() returns those symbols, they'll - * fail the whitelist tests and cause lots of false alarms ... fixable - * only by merging __exit and __init sections into __text, bloating - * the kernel (which is especially evil on embedded platforms). - */ -static inline int is_valid_name(struct elf_info *elf, Elf_Sym *sym) -{ - const char *name = elf->strtab + sym->st_name; - - if (!name || !strlen(name)) - return 0; - return !is_arm_mapping_symbol(name); -} - /* * Find symbols before or equal addr and after addr - in the section sec. * If we find two symbols with equal offset prefer one with a valid name. -- 2.19.1