From: David Miller <davem@davemloft.net>
To: gbastien@versatic.net
Cc: netdev@vger.kernel.org, mathieu.desnoyers@efficios.com,
rostedt@goodmis.org, mingo@redhat.com
Subject: Re: [PATCH v3] net: Add trace events for all receive exit points
Date: Fri, 16 Nov 2018 19:50:36 -0800 (PST) [thread overview]
Message-ID: <20181116.195036.1120979831963497428.davem@davemloft.net> (raw)
In-Reply-To: <20181113201326.5627-1-gbastien@versatic.net>
From: Geneviève Bastien <gbastien@versatic.net>
Date: Tue, 13 Nov 2018 15:13:26 -0500
> @@ -5222,9 +5228,14 @@ static void netif_receive_skb_list_internal(struct list_head *head)
> */
> int netif_receive_skb(struct sk_buff *skb)
> {
> + int ret;
> +
> trace_netif_receive_skb_entry(skb);
>
> - return netif_receive_skb_internal(skb);
> + ret = netif_receive_skb_internal(skb);
> + trace_netif_receive_skb_exit(skb, ret);
Every time I read this code from now on I'm going to say to myself
"oh crap, we reference 'skb' after it's potentially freed up"
I really don't like this.
I know only the pointer is used, but that pointer can be reallocated
to another SLAB object, even another SKB, by the time these exit
tracepoints execute.
Sorry, I can't really convince myself to apply this now.
next prev parent reply other threads:[~2018-11-17 14:05 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-11-13 20:13 [PATCH v3] net: Add trace events for all receive exit points Geneviève Bastien
2018-11-17 3:50 ` David Miller [this message]
2018-11-17 18:27 ` Mathieu Desnoyers
2018-11-18 6:19 ` David Miller
2018-11-19 15:27 ` Geneviève Bastien
2018-11-19 17:47 ` Geneviève Bastien
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20181116.195036.1120979831963497428.davem@davemloft.net \
--to=davem@davemloft.net \
--cc=gbastien@versatic.net \
--cc=mathieu.desnoyers@efficios.com \
--cc=mingo@redhat.com \
--cc=netdev@vger.kernel.org \
--cc=rostedt@goodmis.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).