Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932797AbcDNQl1 (ORCPT ); Thu, 14 Apr 2016 12:41:27 -0400 Received: from mx1.redhat.com ([209.132.183.28]:58348 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754957AbcDNQlZ (ORCPT ); Thu, 14 Apr 2016 12:41:25 -0400 Date: Thu, 14 Apr 2016 11:41:22 -0500 From: Josh Poimboeuf To: Torsten Duwe Cc: Michael Ellerman , Jiri Kosina , Miroslav Benes , linuxppc-dev@ozlabs.org, bsingharora@gmail.com, linux-kernel@vger.kernel.org, rostedt@goodmis.org, kamalesh@linux.vnet.ibm.com, pmladek@suse.com, jeyu@redhat.com, live-patching@vger.kernel.org Subject: Re: [PATCH 0/5] Live patching for powerpc Message-ID: <20160414164122.7ubcqqm43advdscb@treble> References: <1460552003-15409-1-git-send-email-mpe@ellerman.id.au> <1460616590.2754.6.camel@ellerman.id.au> <20160414125735.GA20296@lst.de> <1460639282.21066.5.camel@ellerman.id.au> <20160414152029.GA24525@lst.de> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <20160414152029.GA24525@lst.de> User-Agent: Mutt/1.6.0.1 (2016-04-01) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 4074 Lines: 105 On Thu, Apr 14, 2016 at 05:20:29PM +0200, Torsten Duwe wrote: > On Thu, Apr 14, 2016 at 11:08:02PM +1000, Michael Ellerman wrote: > > On Thu, 2016-04-14 at 14:57 +0200, Torsten Duwe wrote: > > > > > FTR: then I still have a few ppc64 hunks floating around to support certain consistency > > > models... > > > > OK. I'm not quite sure what you mean but post them and we'll see I guess :) > > It's *roughly* the ppc64 equivalent of Josh Poimboeuf's Mar 25 > | [RFC PATCH v1.9 14/14] livepatch: update task universe when exiting kernel > which only considers x86. > > It's forward ported from an earlier code base; there's some glue missing, > but here it is, for reference. > > Signed-off-by: Torsten Duwe Hi Torsten, Thanks for sharing. This is quite fortuitous as Miroslav just today mentioned to me that we would need something like this. If you don't mind, I may pull this patch or some variant of it into v2 of the consistency model. > > > diff --git a/arch/powerpc/include/asm/thread_info.h b/arch/powerpc/include/asm/thread_info.h > index b034ecd..3e749f4 100644 > --- a/arch/powerpc/include/asm/thread_info.h > +++ b/arch/powerpc/include/asm/thread_info.h > @@ -92,6 +92,7 @@ static inline struct thread_info *current_thread_info(void) > TIF_NEED_RESCHED */ > #define TIF_32BIT 4 /* 32 bit binary */ > #define TIF_RESTORE_TM 5 /* need to restore TM FP/VEC/VSX */ > +#define TIF_KLP_NEED_UPDATE 6 /* kGraft patching in progress */ > #define TIF_SYSCALL_AUDIT 7 /* syscall auditing active */ > #define TIF_SINGLESTEP 8 /* singlestepping active */ > #define TIF_NOHZ 9 /* in adaptive nohz mode */ > @@ -115,8 +116,10 @@ static inline struct thread_info *current_thread_info(void) > #define _TIF_POLLING_NRFLAG (1< #define _TIF_32BIT (1< #define _TIF_RESTORE_TM (1< +#define _TIF_KLP_NEED_UPDATE (1< #define _TIF_SYSCALL_AUDIT (1< #define _TIF_SINGLESTEP (1< +#define _TIF_NOHZ (1< #define _TIF_SECCOMP (1< #define _TIF_RESTOREALL (1< #define _TIF_NOERROR (1< @@ -124,7 +127,7 @@ static inline struct thread_info *current_thread_info(void) > #define _TIF_UPROBE (1< #define _TIF_SYSCALL_TRACEPOINT (1< #define _TIF_EMULATE_STACK_STORE (1< -#define _TIF_NOHZ (1< + > #define _TIF_SYSCALL_DOTRACE (_TIF_SYSCALL_TRACE | _TIF_SYSCALL_AUDIT | \ > _TIF_SECCOMP | _TIF_SYSCALL_TRACEPOINT | \ > _TIF_NOHZ) > @@ -132,7 +135,8 @@ static inline struct thread_info *current_thread_info(void) > #define _TIF_USER_WORK_MASK (_TIF_SIGPENDING | _TIF_NEED_RESCHED | \ > _TIF_NOTIFY_RESUME | _TIF_UPROBE | \ > _TIF_RESTORE_TM) > -#define _TIF_PERSYSCALL_MASK (_TIF_RESTOREALL|_TIF_NOERROR) > + > +#define _TIF_PERSYSCALL_MASK (_TIF_RESTOREALL|_TIF_NOERROR|_TIF_KLP_NEED_UPDATE) > > /* Bits in local_flags */ > /* Don't move TLF_NAPPING without adjusting the code in entry_32.S */ > diff --git a/arch/powerpc/kernel/entry_64.S b/arch/powerpc/kernel/entry_64.S > index 5bbd1bc..17f8a18 100644 > --- a/arch/powerpc/kernel/entry_64.S > +++ b/arch/powerpc/kernel/entry_64.S > @@ -151,8 +151,8 @@ END_FW_FTR_SECTION_IFSET(FW_FEATURE_SPLPAR) > > CURRENT_THREAD_INFO(r11, r1) > ld r10,TI_FLAGS(r11) > - andi. r11,r10,_TIF_SYSCALL_DOTRACE > - bne syscall_dotrace /* does not return */ > + andi. r10,r10,(_TIF_SYSCALL_DOTRACE|_TIF_KLP_NEED_UPDATE) > + bne- syscall_precall /* does not return */ > cmpldi 0,r0,NR_syscalls > bge- syscall_enosys > > @@ -245,6 +245,17 @@ syscall_error: > neg r3,r3 > std r5,_CCR(r1) > b .Lsyscall_error_cont > + > +syscall_precall: > + andi. r10,r10,(_TIF_KLP_NEED_UPDATE) > + beq+ syscall_dotrace > + > + addi r11,r11,TI_FLAGS > +1: ldarx r12,0,r11 > + andc r12,r12,r10 > + stdcx. r12,0,r11 > + bne- 1b > + subi r11,r11,TI_FLAGS > > /* Traced system call support */ > syscall_dotrace: -- Josh