Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933330AbbLHJzO (ORCPT ); Tue, 8 Dec 2015 04:55:14 -0500 Received: from mail.skyhub.de ([78.46.96.112]:37882 "EHLO mail.skyhub.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933004AbbLHJzI (ORCPT ); Tue, 8 Dec 2015 04:55:08 -0500 Date: Tue, 8 Dec 2015 10:54:55 +0100 From: Borislav Petkov To: Andy Lutomirski Cc: x86@kernel.org, linux-kernel@vger.kernel.org, Brian Gerst , =?utf-8?B?RnLDqWTDqXJpYw==?= Weisbecker , Denys Vlasenko , Linus Torvalds Subject: Re: [PATCH 02/12] selftests/x86: Add check_initial_reg_state Message-ID: <20151208095455.GC27180@pd.tnic> References: MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.23 (2014-03-12) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3472 Lines: 83 On Mon, Dec 07, 2015 at 01:51:27PM -0800, Andy Lutomirski wrote: > This checks that ELF binaries are started with an appropriately > blank register state. > > (There's currently a nasty special case in the entry asm to arrange > for this. I'm planning on removing the special case, and this will > help make sure I don't break it.) > > Signed-off-by: Andy Lutomirski > --- > tools/testing/selftests/x86/Makefile | 8 +- > .../selftests/x86/check_initial_reg_state.c | 108 +++++++++++++++++++++ > 2 files changed, 115 insertions(+), 1 deletion(-) > create mode 100644 tools/testing/selftests/x86/check_initial_reg_state.c > > diff --git a/tools/testing/selftests/x86/Makefile b/tools/testing/selftests/x86/Makefile > index a460fe7c5365..b82409421fa6 100644 > --- a/tools/testing/selftests/x86/Makefile > +++ b/tools/testing/selftests/x86/Makefile > @@ -4,7 +4,7 @@ include ../lib.mk > > .PHONY: all all_32 all_64 warn_32bit_failure clean > > -TARGETS_C_BOTHBITS := single_step_syscall sysret_ss_attrs ldt_gdt syscall_nt ptrace_syscall > +TARGETS_C_BOTHBITS := single_step_syscall sysret_ss_attrs ldt_gdt syscall_nt ptrace_syscall check_initial_reg_state > TARGETS_C_32BIT_ONLY := entry_from_vm86 syscall_arg_fault sigreturn test_syscall_vdso unwind_vdso > > TARGETS_C_32BIT_ALL := $(TARGETS_C_BOTHBITS) $(TARGETS_C_32BIT_ONLY) > @@ -63,3 +63,9 @@ endif > sysret_ss_attrs_64: thunks.S > ptrace_syscall_32: raw_syscall_helper_32.S > test_syscall_vdso_32: thunks_32.S > + > +# check_initial_reg_state is special: it needs a custom entry, and it > +# needs to be static so that its interpreter doesn't destroy its initial > +# state. > +check_initial_reg_state_32: CFLAGS += -Wl,-ereal_start -static > +check_initial_reg_state_64: CFLAGS += -Wl,-ereal_start -static > diff --git a/tools/testing/selftests/x86/check_initial_reg_state.c b/tools/testing/selftests/x86/check_initial_reg_state.c > new file mode 100644 > index 000000000000..0cb565f7786d > --- /dev/null > +++ b/tools/testing/selftests/x86/check_initial_reg_state.c > @@ -0,0 +1,108 @@ > +/* > + * check_initial_reg_state.c - check that execve sets the correct state > + * Copyright (c) 2014-2015 Andrew Lutomirski > + * > + * This program is free software; you can redistribute it and/or modify > + * it under the terms and conditions of the GNU General Public License, > + * version 2, as published by the Free Software Foundation. > + * > + * This program is distributed in the hope it will be useful, but > + * WITHOUT ANY WARRANTY; without even the implied warranty of > + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU > + * General Public License for more details. > + */ > + > +#define _GNU_SOURCE > + > +#include > + > +unsigned long ax, bx, cx, dx, si, di, bp, sp, flags; > +unsigned long r8, r9, r10, r11, r12, r13, r14, r15; > + > +asm (".pushsection .text\n\t" WARNING: please, no spaces at the start of a line #82: FILE: tools/testing/selftests/x86/check_initial_reg_state.c:23: + ".type real_start, @function\n\t"$ Something trampled over the preceding tabs in that whole asm(). -- Regards/Gruss, Boris. ECO tip #101: Trim your mails when you reply. -- 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/