Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755261AbbGFMqs (ORCPT ); Mon, 6 Jul 2015 08:46:48 -0400 Received: from mail-wi0-f174.google.com ([209.85.212.174]:33877 "EHLO mail-wi0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755007AbbGFMqq (ORCPT ); Mon, 6 Jul 2015 08:46:46 -0400 Date: Mon, 6 Jul 2015 14:46:41 +0200 From: Ingo Molnar To: Denys Vlasenko Cc: Linus Torvalds , Steven Rostedt , Borislav Petkov , "H. Peter Anvin" , Andy Lutomirski , Oleg Nesterov , Frederic Weisbecker , Alexei Starovoitov , Will Drewry , Kees Cook , x86@kernel.org, linux-kernel@vger.kernel.org, Shuah Khan Subject: Re: [PATCH v3 RESEND] x86/asm/entry/32, selftests: Add test_syscall_vdso test Message-ID: <20150706124641.GA12927@gmail.com> References: <1435953772-1446-1-git-send-email-dvlasenk@redhat.com> <20150706124455.GA10784@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20150706124455.GA10784@gmail.com> 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: 3034 Lines: 78 * Ingo Molnar wrote: > > tools/testing/selftests/x86/test_syscall_vdso.c | 401 ++++++++++++++++++++++++ > > tools/testing/selftests/x86/thunks_32.S | 55 ++++ > > 2 files changed, 456 insertions(+) > > create mode 100644 tools/testing/selftests/x86/test_syscall_vdso.c > > create mode 100644 tools/testing/selftests/x86/thunks_32.S > > Hm, what I don't see is any Makefile integration. How am I supposed to build this > test, and how will automated tests pick this testcase up? Note that I prettied up its changelog (attached below), please use this for the next submission. Thanks, Ingo =======================> Subject: x86/asm/entry/32, selftests: Add 'test_syscall_vdso' test From: Denys Vlasenko Date: Fri, 3 Jul 2015 22:02:52 +0200 This new test checks that all x86 registers are preserved across 32-bit syscalls. It tests syscalls through VDSO (if available) and through INT 0x80, normally and under ptrace. If kernel is a 64-bit one, high registers (r8..r15) are poisoned before the syscall is called and are checked afterwards. They must be either preserved, or cleared to zero (but r11 is special); r12..15 must be preserved for INT 0x80. EFLAGS is checked for changes too, but change there is not considered to be a bug (paravirt kernels do not preserve arithmetic flags). Run-tested on 64-bit kernel: $ ./test_syscall_vdso_32 [RUN] Executing 6-argument 32-bit syscall via VDSO [OK] Arguments are preserved across syscall [NOTE] R11 has changed:0000000000200ed7 - assuming clobbered by SYSRET insn [OK] R8..R15 did not leak kernel data [RUN] Executing 6-argument 32-bit syscall via INT 80 [OK] Arguments are preserved across syscall [OK] R8..R15 did not leak kernel data [RUN] Running tests under ptrace [RUN] Executing 6-argument 32-bit syscall via VDSO [OK] Arguments are preserved across syscall [OK] R8..R15 did not leak kernel data [RUN] Executing 6-argument 32-bit syscall via INT 80 [OK] Arguments are preserved across syscall [OK] R8..R15 did not leak kernel data On 32-bit paravirt kernel: $ ./test_syscall_vdso_32 [NOTE] Not a 64-bit kernel, won't test R8..R15 leaks [RUN] Executing 6-argument 32-bit syscall via VDSO [WARN] Flags before=0000000000200ed7 id 0 00 o d i s z 0 a 0 p 1 c [WARN] Flags after=0000000000200246 id 0 00 i z 0 0 p 1 [WARN] Flags change=0000000000000c91 0 00 o d s 0 a 0 0 c [OK] Arguments are preserved across syscall [RUN] Executing 6-argument 32-bit syscall via INT 80 [OK] Arguments are preserved across syscall [RUN] Running tests under ptrace [RUN] Executing 6-argument 32-bit syscall via VDSO [OK] Arguments are preserved across syscall [RUN] Executing 6-argument 32-bit syscall via INT 80 [OK] Arguments are preserved across syscall -- 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/