Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752964AbbDDOOk (ORCPT ); Sat, 4 Apr 2015 10:14:40 -0400 Received: from mail-wi0-f178.google.com ([209.85.212.178]:33882 "EHLO mail-wi0-f178.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752650AbbDDOOi (ORCPT ); Sat, 4 Apr 2015 10:14:38 -0400 Date: Sat, 4 Apr 2015 16:14:34 +0200 From: Ingo Molnar To: Brian Gerst Cc: "H. Peter Anvin" , Andy Lutomirski , Denys Vlasenko , Linus Torvalds , Borislav Petkov , x86@kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] x86/signal: Remove pax argument from restore_sigcontext Message-ID: <20150404141434.GC22756@gmail.com> References: <1428152303-17154-1-git-send-email-brgerst@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1428152303-17154-1-git-send-email-brgerst@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: 2494 Lines: 71 * Brian Gerst wrote: > The pax argument is unnecesary. Instead, store the RAX value directly > in regs. > > Signed-off-by: Brian Gerst > Cc: Ingo Molnar > Cc: "H. Peter Anvin" > Cc: Andy Lutomirski > Cc: Denys Vlasenko > Cc: Linus Torvalds > Cc: Borislav Petkov > Cc: x86@kernel.org > Cc: linux-kernel@vger.kernel.org > --- > arch/x86/ia32/ia32_signal.c | 17 ++++++----------- > arch/x86/include/asm/sighandling.h | 4 +--- > arch/x86/kernel/signal.c | 22 ++++++++-------------- > 3 files changed, 15 insertions(+), 28 deletions(-) > > diff --git a/arch/x86/ia32/ia32_signal.c b/arch/x86/ia32/ia32_signal.c > index 1f5e2b0..c81d35e6 100644 > --- a/arch/x86/ia32/ia32_signal.c > +++ b/arch/x86/ia32/ia32_signal.c > @@ -161,8 +161,7 @@ int copy_siginfo_from_user32(siginfo_t *to, compat_siginfo_t __user *from) > } > > static int ia32_restore_sigcontext(struct pt_regs *regs, > - struct sigcontext_ia32 __user *sc, > - unsigned int *pax) > + struct sigcontext_ia32 __user *sc) > { > unsigned int tmpflags, err = 0; > void __user *buf; > @@ -184,7 +183,7 @@ static int ia32_restore_sigcontext(struct pt_regs *regs, > RELOAD_SEG(es); > > COPY(di); COPY(si); COPY(bp); COPY(sp); COPY(bx); > - COPY(dx); COPY(cx); COPY(ip); > + COPY(dx); COPY(cx); COPY(ip); COPY(ax); > /* Don't touch extended registers */ > > COPY_SEG_CPL3(cs); > @@ -197,8 +196,6 @@ static int ia32_restore_sigcontext(struct pt_regs *regs, > > get_user_ex(tmp, &sc->fpstate); > buf = compat_ptr(tmp); > - > - get_user_ex(*pax, &sc->ax); > } get_user_catch(err); Note that arch/x86/kernel/signal.c appears to have a similar pattern - and there it could be removed as well? I'm wondering what the original reason for adding the extra handling of regs->ax was. Maybe something changed regs->ax - but I cannot find such code path anymore. It would be nice to try to do a bit of Git archeology to figure out the origins of this complication - maybe it's something subtle - or it's something that has changed meanwhile. Thanks, Ingo -- 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/