Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932963AbbHZNNI (ORCPT ); Wed, 26 Aug 2015 09:13:08 -0400 Received: from mail-qk0-f177.google.com ([209.85.220.177]:36767 "EHLO mail-qk0-f177.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752748AbbHZNNG (ORCPT ); Wed, 26 Aug 2015 09:13:06 -0400 Date: Wed, 26 Aug 2015 09:13:02 -0400 From: Jeff Layton To: Pratyush Anand Cc: bfields@fieldses.org, Steven Rostedt , Ingo Molnar , "J. Bruce Fields" , Jeff Layton , linux-kernel@vger.kernel.org (open list), Masami Hiramatsu , Trond Myklebust Subject: Re: [PATCH V2] net: sunrpc: fix tracepoint Warning: unknown op '->' Message-ID: <20150826091302.61c53f77@tlielax.poochiereds.net> In-Reply-To: <9a330bdb057e1a0db14c6e475b94cab2a1e1e134.1440592574.git.panand@redhat.com> References: <9a330bdb057e1a0db14c6e475b94cab2a1e1e134.1440592574.git.panand@redhat.com> X-Mailer: Claws Mail 3.11.1 (GTK+ 2.24.28; x86_64-redhat-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3572 Lines: 101 On Wed, 26 Aug 2015 18:10:44 +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 > Acked-by: Steven Rostedt > --- > 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 | 23 ++++++++++++++++------- > 1 file changed, 16 insertions(+), 7 deletions(-) > > diff --git a/include/trace/events/sunrpc.h b/include/trace/events/sunrpc.h > index fd1a02cb3c82..75a16fcc0795 100644 > --- a/include/trace/events/sunrpc.h > +++ b/include/trace/events/sunrpc.h > @@ -529,18 +529,23 @@ TRACE_EVENT(svc_xprt_do_enqueue, > > TP_STRUCT__entry( > __field(struct svc_xprt *, xprt) > + __field_struct(struct sockaddr_storage, ss) > __field(struct svc_rqst *, rqst) nit: I think you should be able to avoid storing "rqst" now. > + __field(int, pid) > + __field(unsigned long, flags) > ), > > TP_fast_assign( > - __entry->xprt = xprt; > + __entry->xprt = xprt, Shouldn't that line end with ';'? > + xprt ? memcpy(&__entry->ss, &xprt->xpt_remote, sizeof(__entry->ss)) : memset(&__entry->ss, 0, sizeof(__entry->ss)); > __entry->rqst = rqst; > + __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 +594,20 @@ 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; > + __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 */ > Looks good otherwise. Thanks for fixing this! Reviewed-by: Jeff Layton -- 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/