From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.kernel.org ([198.145.29.99]:46640 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1030879AbeEXKBU (ORCPT ); Thu, 24 May 2018 06:01:20 -0400 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Greg Kroah-Hartman , Martin Schwidefsky Subject: [PATCH 4.16 055/161] s390: correct module section names for expoline code revert Date: Thu, 24 May 2018 11:38:00 +0200 Message-Id: <20180524093025.041710235@linuxfoundation.org> In-Reply-To: <20180524093018.331893860@linuxfoundation.org> References: <20180524093018.331893860@linuxfoundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: stable-owner@vger.kernel.org List-ID: 4.16-stable review patch. If anyone has any objections, please let me know. ------------------ From: Martin Schwidefsky [ Upstream commit 6cf09958f32b9667bb3ebadf74367c791112771b ] The main linker script vmlinux.lds.S for the kernel image merges the expoline code patch tables into two section ".nospec_call_table" and ".nospec_return_table". This is *not* done for the modules, there the sections retain their original names as generated by gcc: ".s390_indirect_call", ".s390_return_mem" and ".s390_return_reg". The module_finalize code has to check for the compiler generated section names, otherwise no code patching is done. This slows down the module code in case of "spectre_v2=off". Cc: stable@vger.kernel.org # 4.16 Fixes: f19fbd5ed6 ("s390: introduce execute-trampolines for branches") Signed-off-by: Martin Schwidefsky Signed-off-by: Greg Kroah-Hartman --- arch/s390/kernel/module.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) --- a/arch/s390/kernel/module.c +++ b/arch/s390/kernel/module.c @@ -465,11 +465,11 @@ int module_finalize(const Elf_Ehdr *hdr, apply_alternatives(aseg, aseg + s->sh_size); if (IS_ENABLED(CONFIG_EXPOLINE) && - (!strcmp(".nospec_call_table", secname))) + (!strncmp(".s390_indirect", secname, 14))) nospec_revert(aseg, aseg + s->sh_size); if (IS_ENABLED(CONFIG_EXPOLINE) && - (!strcmp(".nospec_return_table", secname))) + (!strncmp(".s390_return", secname, 12))) nospec_revert(aseg, aseg + s->sh_size); }