Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752603AbbGQTpG (ORCPT ); Fri, 17 Jul 2015 15:45:06 -0400 Received: from mail-la0-f41.google.com ([209.85.215.41]:34801 "EHLO mail-la0-f41.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751670AbbGQTpE (ORCPT ); Fri, 17 Jul 2015 15:45:04 -0400 MIME-Version: 1.0 In-Reply-To: <20150717194307.GA26757@gmail.com> References: <2ea0f0602978178eafd012e52b8bdb83cfb159d5.1437150175.git.jpoimboe@redhat.com> <20150717194307.GA26757@gmail.com> From: Andy Lutomirski Date: Fri, 17 Jul 2015 12:44:42 -0700 Message-ID: Subject: Re: [RFC PATCH 13/21] x86/asm/crypto: Fix frame pointer usage in aesni-intel_asm.S To: Ingo Molnar Cc: Josh Poimboeuf , Thomas Gleixner , Ingo Molnar , "H. Peter Anvin" , Michal Marek , Peter Zijlstra , Andy Lutomirski , Borislav Petkov , Linus Torvalds , Andi Kleen , Pedro Alves , X86 ML , live-patching@vger.kernel.org, "linux-kernel@vger.kernel.org" Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1460 Lines: 53 On Fri, Jul 17, 2015 at 12:43 PM, Ingo Molnar wrote: > > * Josh Poimboeuf wrote: > >> ENTRY(aesni_set_key) >> + FRAME >> #ifndef __x86_64__ >> pushl KEYP >> movl 8(%esp), KEYP # ctx >> @@ -1905,6 +1907,7 @@ ENTRY(aesni_set_key) >> #ifndef __x86_64__ >> popl KEYP >> #endif >> + ENDFRAME >> ret >> ENDPROC(aesni_set_key) > > So cannot we make this a bit more compact and less fragile? > > Instead of: > > ENTRY(aesni_set_key) > FRAME > ... > ENDFRAME > ret > ENDPROC(aesni_set_key) > > > How about writing this as: > > FUNCTION_ENTRY(aesni_set_key) > ... > FUNCTION_RETURN(aesni_set_key) > > which does the same thing in a short, symmetric construct? > > One potential problem with this approach would be that what 'looks' like an entry > declaration, but it will now generate real code. > > OTOH if people find this intuitive enough then it's a lot harder to mess it up, > and I think 'RETURN' makes it clear enough that there's a real instruction > generated there. > How about FUNCTION_PROLOGUE and FUNCTION_EPILOGUE? -Andy -- 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/