Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753878AbbDBOhU (ORCPT ); Thu, 2 Apr 2015 10:37:20 -0400 Received: from mx1.redhat.com ([209.132.183.28]:55738 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753863AbbDBOhP (ORCPT ); Thu, 2 Apr 2015 10:37:15 -0400 From: Denys Vlasenko To: Ingo Molnar Cc: Denys Vlasenko , 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 Subject: [PATCH 8/9] x86/asm/entry/64: simplify jumps in ret_from_fork Date: Thu, 2 Apr 2015 16:36:17 +0200 Message-Id: <1427985378-4287-8-git-send-email-dvlasenk@redhat.com> In-Reply-To: <1427985378-4287-1-git-send-email-dvlasenk@redhat.com> References: <1427985378-4287-1-git-send-email-dvlasenk@redhat.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1847 Lines: 65 Replace test jz 1f jmp label 1: with test jnz label Run-tested. Signed-off-by: Denys Vlasenko CC: Linus Torvalds CC: Steven Rostedt CC: Ingo Molnar CC: Borislav Petkov CC: "H. Peter Anvin" CC: Andy Lutomirski CC: Oleg Nesterov CC: Frederic Weisbecker CC: Alexei Starovoitov CC: Will Drewry CC: Kees Cook CC: x86@kernel.org CC: linux-kernel@vger.kernel.org --- arch/x86/kernel/entry_64.S | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) diff --git a/arch/x86/kernel/entry_64.S b/arch/x86/kernel/entry_64.S index 36a360a..0124f6f 100644 --- a/arch/x86/kernel/entry_64.S +++ b/arch/x86/kernel/entry_64.S @@ -512,18 +512,18 @@ ENTRY(ret_from_fork) RESTORE_EXTRA_REGS testl $3,CS(%rsp) # from kernel_thread? - jz 1f /* * By the time we get here, we have no idea whether our pt_regs, * ti flags, and ti status came from the 64-bit SYSCALL fast path, * the slow path, or one of the ia32entry paths. - * Use int_ret_from_sys_call to return, since it can safely handle + * Use IRET code path to return, since it can safely handle * all of the above. */ - jmp int_ret_from_sys_call + jnz int_ret_from_sys_call -1: + /* We came from from kernel_thread */ + /* nb: we depend on RESTORE_EXTRA_REGS above */ movq %rbp, %rdi call *%rbx xorl %eax, %eax -- 1.8.1.4 -- 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/