Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753700AbbH0SQq (ORCPT ); Thu, 27 Aug 2015 14:16:46 -0400 Received: from fieldses.org ([173.255.197.46]:45763 "EHLO fieldses.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751186AbbH0SQo (ORCPT ); Thu, 27 Aug 2015 14:16:44 -0400 Date: Thu, 27 Aug 2015 14:16:43 -0400 From: "J. Bruce Fields" To: Pratyush Anand Cc: linux-nfs@vger.kernel.org, Jeff Layton , Steven Rostedt , Ingo Molnar , "J. Bruce Fields" , Jeff Layton , open list , Trond Myklebust Subject: Re: [PATCH V3] net: sunrpc: fix tracepoint Warning: unknown op '->' Message-ID: <20150827181643.GA11819@fieldses.org> References: <26296332fcef5466c2d38c5009efbc6c3e808d11.1440608659.git.panand@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <26296332fcef5466c2d38c5009efbc6c3e808d11.1440608659.git.panand@redhat.com> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3667 Lines: 103 Thanks, applying, with: Cc: stable@vger.kernel.org Fixes: 83a712e0afef "sunrpc: add some tracepoints around ..." (let me know if that's not right.) --b. On Thu, Aug 27, 2015 at 10:01:33AM +0530, Pratyush Anand wrote: > `perf stat -e sunrpc:svc_xprt_do_enqueue true` results in > > Warning: unknown op '->' > Warning: [sunrpc:svc_xprt_do_enqueue] unknown op '->' > > Similar warning for svc_handle_xprt as well. > > Actually TP_printk() should never dereference an address saved in the ring > buffer that points somewhere in the kernel. There's no guarantee that that > object still exists (with the exception of static strings). > > Therefore change all the arguments for TP_printk(), so that it references > values existing in the ring buffer only. > > While doing that, also fix another possible bug when argument xprt could be > NULL and TP_fast_assign() tries to access it's elements. > > Signed-off-by: Pratyush Anand > Reviewed-by: Jeff Layton > Acked-by: Steven Rostedt > --- > Changes since V2: > - removed storing of "rqst" now > - removed replacement of , to ; at the end of statement __entry->xprt = > xprt > Changes since V1: > - struct sockaddr memcopied to ring buffer so that its internal element can > be accessed while printing %pIS. > > include/trace/events/sunrpc.h | 21 ++++++++++++++------- > 1 file changed, 14 insertions(+), 7 deletions(-) > > diff --git a/include/trace/events/sunrpc.h b/include/trace/events/sunrpc.h > index fd1a02cb3c82..003dca933803 100644 > --- a/include/trace/events/sunrpc.h > +++ b/include/trace/events/sunrpc.h > @@ -529,18 +529,21 @@ TRACE_EVENT(svc_xprt_do_enqueue, > > TP_STRUCT__entry( > __field(struct svc_xprt *, xprt) > - __field(struct svc_rqst *, rqst) > + __field_struct(struct sockaddr_storage, ss) > + __field(int, pid) > + __field(unsigned long, flags) > ), > > TP_fast_assign( > __entry->xprt = xprt; > - __entry->rqst = rqst; > + xprt ? memcpy(&__entry->ss, &xprt->xpt_remote, sizeof(__entry->ss)) : memset(&__entry->ss, 0, sizeof(__entry->ss)); > + __entry->pid = rqst? rqst->rq_task->pid : 0; > + __entry->flags = xprt ? xprt->xpt_flags : 0; > ), > > TP_printk("xprt=0x%p addr=%pIScp pid=%d flags=%s", __entry->xprt, > - (struct sockaddr *)&__entry->xprt->xpt_remote, > - __entry->rqst ? __entry->rqst->rq_task->pid : 0, > - show_svc_xprt_flags(__entry->xprt->xpt_flags)) > + (struct sockaddr *)&__entry->ss, > + __entry->pid, show_svc_xprt_flags(__entry->flags)) > ); > > TRACE_EVENT(svc_xprt_dequeue, > @@ -589,16 +592,20 @@ TRACE_EVENT(svc_handle_xprt, > TP_STRUCT__entry( > __field(struct svc_xprt *, xprt) > __field(int, len) > + __field_struct(struct sockaddr_storage, ss) > + __field(unsigned long, flags) > ), > > TP_fast_assign( > __entry->xprt = xprt; > + xprt ? memcpy(&__entry->ss, &xprt->xpt_remote, sizeof(__entry->ss)) : memset(&__entry->ss, 0, sizeof(__entry->ss)); > __entry->len = len; > + __entry->flags = xprt ? xprt->xpt_flags : 0; > ), > > TP_printk("xprt=0x%p addr=%pIScp len=%d flags=%s", __entry->xprt, > - (struct sockaddr *)&__entry->xprt->xpt_remote, __entry->len, > - show_svc_xprt_flags(__entry->xprt->xpt_flags)) > + (struct sockaddr *)&__entry->ss, > + __entry->len, show_svc_xprt_flags(__entry->flags)) > ); > #endif /* _TRACE_SUNRPC_H */ > > -- > 2.4.3 -- 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/