From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: From: James Hogan To: Jeff Layton , "J. Bruce Fields" CC: , James Hogan , Trond Myklebust , Steven Rostedt , Ingo Molnar , Subject: [PATCH] sunrpc: Fix trace events to store data in the struct Date: Tue, 24 Feb 2015 11:47:56 +0000 Message-ID: <1424778476-28242-1-git-send-email-james.hogan@imgtec.com> MIME-Version: 1.0 Content-Type: text/plain Sender: linux-kernel-owner@vger.kernel.org List-ID: Commit 83a712e0afef ("sunrpc: add some tracepoints around enqueue and dequeue of svc_xprt") merged in v3.19-rc1 added some new trace events, however a couple of them printed data from dereferenced pointers rather than storing the data in the struct. In general this isn't safe as the print may not happen until later when the data may have changed or been freed, and nor is it portable as userland won't have access to that other data in order to interpret the trace data itself. Fix by copying the data into the struct and printing from there. Fixes: 83a712e0afef ("sunrpc: add some tracepoints around enqueue ...") Signed-off-by: James Hogan Cc: Jeff Layton Cc: J. Bruce Fields Cc: Trond Myklebust Cc: Steven Rostedt Cc: Ingo Molnar Cc: # v3.19+ --- Build tested only. Perhaps somebody familiar with the code could give it a spin to sanity check the trace output. --- include/trace/events/sunrpc.h | 22 +++++++++++++++------- 1 file changed, 15 insertions(+), 7 deletions(-) diff --git a/include/trace/events/sunrpc.h b/include/trace/events/sunrpc.h index b9c1dc6c825a..47dfcaebfaaf 100644 --- a/include/trace/events/sunrpc.h +++ b/include/trace/events/sunrpc.h @@ -503,18 +503,22 @@ 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(unsigned long, flags); + __field(int, pid) ), 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->flags = xprt ? xprt->xpt_flags : 0; + __entry->pid = rqst ? rqst->rq_task->pid : 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, @@ -562,17 +566,21 @@ TRACE_EVENT(svc_handle_xprt, TP_STRUCT__entry( __field(struct svc_xprt *, xprt) + __field_struct(struct sockaddr_storage, ss) + __field(unsigned long, flags); __field(int, len) ), TP_fast_assign( __entry->xprt = xprt; + xprt ? memcpy(&__entry->ss, &xprt->xpt_remote, sizeof(__entry->ss)) : memset(&__entry->ss, 0, sizeof(__entry->ss)); + __entry->flags = xprt ? xprt->xpt_flags : 0; __entry->len = len; ), 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 */ -- 2.0.5