From mboxrd@z Thu Jan 1 00:00:00 1970 From: David Ahern Subject: Re: [PATCH] net: Change the layout of structure trace_event_raw_fib_table_lookup Date: Mon, 13 Aug 2018 08:40:32 -0600 Message-ID: References: <1534127212-13186-1-git-send-email-zong@andestech.com> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit Cc: zongbox@gmail.com, greentime@andestech.com To: Zong Li , rostedt@goodmis.org, mingo@redhat.com, netdev@vger.kernel.org, linux-kernel@vger.kernel.org Return-path: In-Reply-To: <1534127212-13186-1-git-send-email-zong@andestech.com> Content-Language: en-US Sender: linux-kernel-owner@vger.kernel.org List-Id: netdev.vger.kernel.org On 8/12/18 8:26 PM, Zong Li wrote: > There is an unalignment access about the structure > 'trace_event_raw_fib_table_lookup'. > > In include/trace/events/fib.h, there is a memory operation which casting > the 'src' data member to a pointer, and then store a value to this > pointer point to. > > p32 = (__be32 *) __entry->src; > *p32 = flp->saddr; > > The offset of 'src' in structure trace_event_raw_fib_table_lookup is not > four bytes alignment. On some architectures, they don't permit the > unalignment access, it need to pay the price to handle this situation in > exception handler. > > Adjust the layout of structure to avoid this case. > > Signed-off-by: Zong Li > --- > include/trace/events/fib.h | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > Fixes: 9f323973c915 ("net/ipv4: Udate fib_table_lookup tracepoint") Acked-by: David Ahern Do you also need a similar change to fib6_table_lookup in include/trace/events/fib6.h?