From mboxrd@z Thu Jan  1 00:00:00 1970
Return-Path: <linux-kernel-owner@vger.kernel.org>
Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand
	id S1752853AbbCHUtr (ORCPT <rfc822;w@1wt.eu>);
	Sun, 8 Mar 2015 16:49:47 -0400
Received: from mx1.redhat.com ([209.132.183.28]:39792 "EHLO mx1.redhat.com"
	rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP
	id S1751735AbbCHUtq (ORCPT <rfc822;linux-kernel@vger.kernel.org>);
	Sun, 8 Mar 2015 16:49:46 -0400
From: Denys Vlasenko <dvlasenk@redhat.com>
To: Andy Lutomirski <luto@amacapital.net>
Cc: Denys Vlasenko <dvlasenk@redhat.com>,
        Linus Torvalds <torvalds@linux-foundation.org>,
        Steven Rostedt <rostedt@goodmis.org>, Ingo Molnar <mingo@kernel.org>,
        Borislav Petkov <bp@alien8.de>, "H. Peter Anvin" <hpa@zytor.com>,
        Oleg Nesterov <oleg@redhat.com>,
        Frederic Weisbecker <fweisbec@gmail.com>,
        Alexei Starovoitov <ast@plumgrid.com>, Will Drewry <wad@chromium.org>,
        Kees Cook <keescook@chromium.org>, x86@kernel.org,
        linux-kernel@vger.kernel.org
Subject: [PATCH 0/2] x86: entry_64.S: steps towards simpler iret frame handling
Date: Sun,  8 Mar 2015 21:49:08 +0100
Message-Id: <1425847750-23362-1-git-send-email-dvlasenk@redhat.com>
Sender: linux-kernel-owner@vger.kernel.org
List-ID: <linux-kernel.vger.kernel.org>
X-Mailing-List: linux-kernel@vger.kernel.org

These changes make SYSENTER64 code path save flags and user's
stack pointer in pt_regs->flags and pt_regs->sp, where they belong.

As a result, we can drop stub_iopl() and thread_struct::usersp.

Usage of PER_CPU(old_rsp) is reduced to bare minimum.

FIXUP/RESTORE_TOP_OF_STACK macros are on diet too.

(This is a resend. Previous version was on top of KERNEL_STACK_OFFSET
removal patch. This one is on top of Andy's current git. Patch is run-tested.)

CC: Linus Torvalds <torvalds@linux-foundation.org>
CC: Steven Rostedt <rostedt@goodmis.org>
CC: Ingo Molnar <mingo@kernel.org>
CC: Borislav Petkov <bp@alien8.de>
CC: "H. Peter Anvin" <hpa@zytor.com>
CC: Andy Lutomirski <luto@amacapital.net>
CC: Oleg Nesterov <oleg@redhat.com>
CC: Frederic Weisbecker <fweisbec@gmail.com>
CC: Alexei Starovoitov <ast@plumgrid.com>
CC: Will Drewry <wad@chromium.org>
CC: Kees Cook <keescook@chromium.org>
CC: x86@kernel.org
CC: linux-kernel@vger.kernel.org

Denys Vlasenko (2):
  x86: save r11 into pt_regs->flags on SYSCALL64 fastpath
  x86: save user %rsp in pt_regs->sp on SYSCALL64 fastpath

 arch/x86/include/asm/calling.h   | 20 +++++++++-----
 arch/x86/include/asm/compat.h    |  2 +-
 arch/x86/include/asm/processor.h |  6 -----
 arch/x86/include/asm/ptrace.h    |  8 ++----
 arch/x86/kernel/entry_64.S       | 57 ++++++++++++++--------------------------
 arch/x86/kernel/perf_regs.c      |  2 +-
 arch/x86/kernel/process_64.c     |  8 +-----
 arch/x86/syscalls/syscall_64.tbl |  2 +-
 arch/x86/um/sys_call_table_64.c  |  2 +-
 9 files changed, 40 insertions(+), 67 deletions(-)

-- 
1.8.1.4