From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from ozlabs.org (ozlabs.org [IPv6:2401:3900:2:1::2]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 7C2D01A00A5 for ; Fri, 26 Feb 2016 01:02:07 +1100 (AEDT) Received: from newverein.lst.de (verein.lst.de [213.95.11.211]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id 13F3F140324 for ; Fri, 26 Feb 2016 01:02:07 +1100 (AEDT) Date: Thu, 25 Feb 2016 15:02:04 +0100 From: Torsten Duwe To: Balbir Singh Cc: Michael Ellerman , linuxppc-dev@ozlabs.org, linux-kernel@vger.kernel.org, rostedt@goodmis.org, kamalesh@linux.vnet.ibm.com, pmladek@suse.com, jeyu@redhat.com, jkosina@suse.cz, live-patching@vger.kernel.org, mbenes@suse.cz Subject: Re: [PATCH 05/12] powerpc/ftrace: ftrace_graph_caller() needs to save/restore toc Message-ID: <20160225140204.GG21932@lst.de> References: <1456324115-21144-1-git-send-email-mpe@ellerman.id.au> <1456324115-21144-5-git-send-email-mpe@ellerman.id.au> <56CE4B2E.7070505@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii In-Reply-To: <56CE4B2E.7070505@gmail.com> List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , On Thu, Feb 25, 2016 at 11:30:38AM +1100, Balbir Singh wrote: > On 25/02/16 01:28, Michael Ellerman wrote: > > Signed-off-by: Michael Ellerman > > --- > > arch/powerpc/kernel/entry_64.S | 8 ++++++++ > > 1 file changed, 8 insertions(+) > > Ah, -mprofile-kernel, DYNAMIC_FTRACE but without REGS. Hadn't considered that, thanks! > > > > diff --git a/arch/powerpc/kernel/entry_64.S b/arch/powerpc/kernel/entry_64.S > > index 2a7313cfbc7d..9e77a2c8f218 100644 > > --- a/arch/powerpc/kernel/entry_64.S > > +++ b/arch/powerpc/kernel/entry_64.S > > @@ -1237,6 +1237,11 @@ _GLOBAL(ftrace_graph_caller) > > std r5, 64(r1) > > std r4, 56(r1) > > std r3, 48(r1) > > + > > + /* Save callee's TOC in the ABI compliant location */ > > + std r2, 24(r1) > R2_STACK_OFFSET for readability? I have encountered LRSAVE vs. PPC_LR_STKOFF and STK_GOT vs. R2_STACK_OFFSET, some usable in assembler source, some in C. > > + ld r2, PACATOC(r13) /* get kernel TOC in r2 */ > > + > > mfctr r4 /* ftrace_caller has moved local addr here */ > > std r4, 40(r1) > > mflr r3 /* ftrace_caller has restored LR from stack */ > > @@ -1262,6 +1267,9 @@ _GLOBAL(ftrace_graph_caller) > > ld r4, 56(r1) > > ld r3, 48(r1) > > > > + /* Restore callee's TOC */ > > + ld r2, 24(r1) > > + > > addi r1, r1, 112 > > mflr r0 > > std r0, LRSAVE(r1) > > Reviewed-by: Balbir Singh Reviewed-by: Torsten Duwe Torsten