From: Julia Lawall <julia.lawall@lip6.fr>
To: Sasha Levin <sashal@kernel.org>
Cc: michal.lkml@markovi.net, nicolas.palix@imag.fr,
linux-kernel@vger.kernel.org, cocci@systeme.lip6.fr,
Markus.Elfring@web.de, Pavel Machek <pavel@ucw.cz>,
wen.yang99@zte.com.cn
Subject: Re: [Cocci] Coccinelle: semantic patch for missing of_node_put
Date: Mon, 20 May 2019 21:53:40 +0200 (CEST) [thread overview]
Message-ID: <alpine.DEB.2.21.1905202151140.2561@hadrien> (raw)
In-Reply-To: <20190520172041.GH11972@sasha-vm>
On Mon, 20 May 2019, Sasha Levin wrote:
> On Mon, May 20, 2019 at 11:52:37AM +0200, Julia Lawall wrote:
> >
> >
> > On Mon, 20 May 2019, Pavel Machek wrote:
> >
> > > Hi!
> > >
> > > > A semantic patch has no access to comments. The only thing I can see to
> > > > do is to use python to interact with some external tools. For example,
> > > > you could write some code to collect the comments in a file and the
> > > lines
> > > > on which they occur, and then get the comment that most closely precedes
> > > > the start of the function.
> > >
> > > How dangerous is missing of_node_put? AFAICT it will only result into
> > > very small, one-time memory leak, right?
> > >
> > > Could we make sure these patches are _not_ going to stable? Leaking
> > > few bytes once per boot is not really a serious bug.
> >
> > Sasha,
> >
> > Probably patches that add only of_node_put should not be auto selected for
> > stable.
>
> I can filter them out, but those are fixes, right? Why are we concerned
> about them making it into -stable?
One of them may have introduced a crash. If there is a bad reference
count manipulation elsewhere, then fixing one could cause a later
incorrect one to make a double free.
On the other hand, I don't know if the one that seemed to cause a crash
really caused a crash. It was detected by syzkaller, and it is also
possible that git bisect ended up at the wrong place.
In any case, forgetting an of_node_put will normally just waste a little
memory, so probably stable kernels don't care.
julia
_______________________________________________
Cocci mailing list
Cocci@systeme.lip6.fr
https://systeme.lip6.fr/mailman/listinfo/cocci
WARNING: multiple messages have this Message-ID (diff)
From: Julia Lawall <julia.lawall@lip6.fr>
To: Sasha Levin <sashal@kernel.org>
Cc: Pavel Machek <pavel@ucw.cz>,
wen.yang99@zte.com.cn, Markus.Elfring@web.de,
cocci@systeme.lip6.fr, linux-kernel@vger.kernel.org,
Gilles Muller <Gilles.Muller@lip6.fr>,
yamada.masahiro@socionext.com, michal.lkml@markovi.net,
nicolas.palix@imag.fr
Subject: Re: Coccinelle: semantic patch for missing of_node_put
Date: Mon, 20 May 2019 21:53:40 +0200 (CEST) [thread overview]
Message-ID: <alpine.DEB.2.21.1905202151140.2561@hadrien> (raw)
In-Reply-To: <20190520172041.GH11972@sasha-vm>
On Mon, 20 May 2019, Sasha Levin wrote:
> On Mon, May 20, 2019 at 11:52:37AM +0200, Julia Lawall wrote:
> >
> >
> > On Mon, 20 May 2019, Pavel Machek wrote:
> >
> > > Hi!
> > >
> > > > A semantic patch has no access to comments. The only thing I can see to
> > > > do is to use python to interact with some external tools. For example,
> > > > you could write some code to collect the comments in a file and the
> > > lines
> > > > on which they occur, and then get the comment that most closely precedes
> > > > the start of the function.
> > >
> > > How dangerous is missing of_node_put? AFAICT it will only result into
> > > very small, one-time memory leak, right?
> > >
> > > Could we make sure these patches are _not_ going to stable? Leaking
> > > few bytes once per boot is not really a serious bug.
> >
> > Sasha,
> >
> > Probably patches that add only of_node_put should not be auto selected for
> > stable.
>
> I can filter them out, but those are fixes, right? Why are we concerned
> about them making it into -stable?
One of them may have introduced a crash. If there is a bad reference
count manipulation elsewhere, then fixing one could cause a later
incorrect one to make a double free.
On the other hand, I don't know if the one that seemed to cause a crash
really caused a crash. It was detected by syzkaller, and it is also
possible that git bisect ended up at the wrong place.
In any case, forgetting an of_node_put will normally just waste a little
memory, so probably stable kernels don't care.
julia
next prev parent reply other threads:[~2019-05-20 19:54 UTC|newest]
Thread overview: 30+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <201905171432571474636@zte.com.cn>
2019-05-17 7:14 ` Coccinelle: semantic patch for missing of_node_put Julia Lawall
2019-05-17 8:22 ` [Cocci] " Markus Elfring
2019-05-17 8:22 ` Markus Elfring
2019-05-20 9:33 ` Pavel Machek
2019-05-20 9:51 ` Julia Lawall
2019-05-20 9:52 ` [Cocci] " Julia Lawall
2019-05-20 9:52 ` Julia Lawall
2019-05-20 17:20 ` [Cocci] " Sasha Levin
2019-05-20 17:20 ` Sasha Levin
2019-05-20 19:53 ` Julia Lawall [this message]
2019-05-20 19:53 ` Julia Lawall
2019-05-20 20:11 ` [Cocci] " Markus Elfring
2019-05-20 20:11 ` Markus Elfring
2019-05-17 8:10 ` [Cocci] " Markus Elfring
2019-05-17 8:10 ` Markus Elfring
2019-05-18 14:43 ` [Cocci] " Markus Elfring
2019-05-18 14:43 ` Markus Elfring
2019-06-04 5:08 ` [Cocci] " Markus Elfring
2019-06-04 5:08 ` Markus Elfring
2019-06-04 5:50 ` [Cocci] " wen.yang99
2019-06-04 6:36 ` Markus Elfring
2019-06-04 6:36 ` Markus Elfring
2019-06-04 8:55 ` [Cocci] " wen.yang99
2019-06-04 9:08 ` Markus Elfring
2019-06-04 9:08 ` Markus Elfring
2019-06-04 11:28 ` [Cocci] " Markus Elfring
2019-06-04 11:28 ` Markus Elfring
2019-06-05 18:23 ` [Cocci] Coccinelle: Searching for “when done” in function comments Markus Elfring
2019-06-05 18:23 ` Markus Elfring
2019-05-09 1:47 [Cocci] [PATCH] coccinelle: semantic patch for missing of_node_put wen.yang99
2019-05-09 8:10 ` [Cocci] Coccinelle: " Markus Elfring
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=alpine.DEB.2.21.1905202151140.2561@hadrien \
--to=julia.lawall@lip6.fr \
--cc=Markus.Elfring@web.de \
--cc=cocci@systeme.lip6.fr \
--cc=linux-kernel@vger.kernel.org \
--cc=michal.lkml@markovi.net \
--cc=nicolas.palix@imag.fr \
--cc=pavel@ucw.cz \
--cc=sashal@kernel.org \
--cc=wen.yang99@zte.com.cn \
/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 an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.