From: Johannes Berg <johannes@sipsolutions.net>
To: Nicolai Stange <nicstange@gmail.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
"Paul E.McKenney" <paulmck@linux.vnet.ibm.com>,
linux-kernel@vger.kernel.org
Subject: Re: [RFC PATCH 8/9] debugfs: defer debugfs_fsdata allocation to first usage
Date: Wed, 03 May 2017 07:43:58 +0200 [thread overview]
Message-ID: <1493790238.2602.3.camel@sipsolutions.net> (raw)
In-Reply-To: <87y3ufvxaz.fsf@gmail.com> (sfid-20170502_220600_227096_F45CC85C)
On Tue, 2017-05-02 at 22:05 +0200, Nicolai Stange wrote:
> > So either you could return some valid ops (perhaps
> > debugfs_noop_file_operations although those don't have .name or
> > .poll, so it doesn't cover everything), or you can just BUG_ON()
> > here directly, saving the incomprehensible crash later.
>
> The purpose of that WARN_ON() there was to turn a potentially
> incomprehensible crash into a comprehensible one ;)
>
> In order to avoid a new BUG_ON(), what about keeping the WARN_ON() as
> is and returning NULL instead of the garbage? That would crash
> current on first access and the earlier warning would hopefully give
> some clue?
Yeah, I guess that might work. Probably less harmful to the system than
a BUG_ON(), but I still operate under the assumption that there might
actually be something mapped at NULL - not sure if that's still true.
johannes
next prev parent reply other threads:[~2017-05-03 5:44 UTC|newest]
Thread overview: 43+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-03-23 14:54 deadlock in synchronize_srcu() in debugfs? Johannes Berg
2017-03-23 15:29 ` Johannes Berg
2017-03-24 8:56 ` Johannes Berg
2017-03-24 9:24 ` Johannes Berg
2017-03-24 17:45 ` Paul E. McKenney
2017-03-24 18:51 ` Johannes Berg
2017-03-24 19:33 ` Paul E. McKenney
2017-03-24 20:20 ` Paul E. McKenney
2017-03-27 11:18 ` Johannes Berg
2017-03-23 15:36 ` Nicolai Stange
2017-03-23 15:47 ` Johannes Berg
2017-03-27 11:36 ` Johannes Berg
2017-03-30 7:32 ` Nicolai Stange
2017-03-30 7:55 ` Johannes Berg
2017-03-30 10:27 ` Nicolai Stange
2017-03-30 11:11 ` Johannes Berg
2017-03-31 9:03 ` Nicolai Stange
2017-03-31 9:44 ` Johannes Berg
2017-04-16 9:51 ` [RFC PATCH 0/9] debugfs: per-file removal protection Nicolai Stange
2017-04-16 9:51 ` [RFC PATCH 1/9] debugfs: add support for more elaborate ->d_fsdata Nicolai Stange
2017-04-16 9:51 ` [RFC PATCH 2/9] debugfs: implement per-file removal protection Nicolai Stange
2017-04-18 2:23 ` [lkp-robot] [debugfs] f3e7155d08: BUG:unable_to_handle_kernel kernel test robot
2017-04-23 18:37 ` Nicolai Stange
2017-04-24 6:36 ` Ye Xiaolong
2017-04-16 9:51 ` [RFC PATCH 3/9] debugfs: debugfs_real_fops(): drop __must_hold sparse annotation Nicolai Stange
2017-04-16 9:51 ` [RFC PATCH 4/9] debugfs: convert to debugfs_file_get() and -put() Nicolai Stange
2017-04-16 9:51 ` [RFC PATCH 5/9] IB/hfi1: " Nicolai Stange
2017-04-16 9:51 ` [RFC PATCH 6/9] debugfs: purge obsolete SRCU based removal protection Nicolai Stange
2017-04-16 9:51 ` [RFC PATCH 7/9] debugfs: call debugfs_real_fops() only after debugfs_file_get() Nicolai Stange
2017-04-16 9:51 ` [RFC PATCH 8/9] debugfs: defer debugfs_fsdata allocation to first usage Nicolai Stange
2017-04-18 9:36 ` Johannes Berg
2017-05-02 20:05 ` Nicolai Stange
2017-05-03 5:43 ` Johannes Berg [this message]
2017-04-16 9:51 ` [RFC PATCH 9/9] debugfs: free debugfs_fsdata instances Nicolai Stange
2017-04-17 16:01 ` Paul E. McKenney
2017-04-18 9:39 ` Johannes Berg
2017-04-18 13:31 ` Paul E. McKenney
2017-04-18 13:40 ` Johannes Berg
2017-04-18 15:17 ` Paul E. McKenney
2017-04-18 15:20 ` Johannes Berg
2017-04-18 17:19 ` Paul E. McKenney
2017-03-23 15:37 ` deadlock in synchronize_srcu() in debugfs? Paul E. McKenney
2017-03-23 15:46 ` Johannes Berg
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=1493790238.2602.3.camel@sipsolutions.net \
--to=johannes@sipsolutions.net \
--cc=gregkh@linuxfoundation.org \
--cc=linux-kernel@vger.kernel.org \
--cc=nicstange@gmail.com \
--cc=paulmck@linux.vnet.ibm.com \
/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).