public inbox for linux-kernel@vger.kernel.org
 help / color / mirror / Atom feed
From: Ira Weiny <ira.weiny@intel.com>
To: Ira Weiny <ira.weiny@intel.com>, Dinghao Liu <dinghao.liu@zju.edu.cn>
Cc: Dan Williams <dan.j.williams@intel.com>,
	Vishal Verma <vishal.l.verma@intel.com>,
	Dave Jiang <dave.jiang@intel.com>,
	Ira Weiny <ira.weiny@intel.com>, <nvdimm@lists.linux.dev>,
	<linux-kernel@vger.kernel.org>
Subject: Re: [PATCH] [v2] nvdimm-btt: fix several memleaks
Date: Fri, 15 Dec 2023 08:45:10 -0800	[thread overview]
Message-ID: <657c82966e358_2947c22941a@iweiny-mobl.notmuch> (raw)
In-Reply-To: <657b9cb088175_27db80294d2@iweiny-mobl.notmuch>

Ira Weiny wrote:
> Dinghao Liu wrote:

[snip]

> >  
> > -static int btt_maplocks_init(struct arena_info *arena)
> > +static int btt_maplocks_init(struct device *dev, struct arena_info *arena)
> >  {
> >  	u32 i;
> >  
> > -	arena->map_locks = kcalloc(arena->nfree, sizeof(struct aligned_lock),
> > +	arena->map_locks = devm_kcalloc(dev, arena->nfree, sizeof(struct aligned_lock),
> >  				GFP_KERNEL);
> >  	if (!arena->map_locks)
> >  		return -ENOMEM;
> > @@ -805,9 +805,6 @@ static void free_arenas(struct btt *btt)
> >  
> >  	list_for_each_entry_safe(arena, next, &btt->arena_list, list) {
> >  		list_del(&arena->list);
> > -		kfree(arena->rtt);
> > -		kfree(arena->map_locks);
> > -		kfree(arena->freelist);
> 
> This does not quite work.
> 
> free_arenas() is used in the error paths of create_arenas() and
> discover_arenas().  In those cases devm_kfree() is probably a better way
> to clean up this.
> 
> However...
> 
> >  		debugfs_remove_recursive(arena->debugfs_dir);
> >  		kfree(arena);
> 
> Why can't arena be allocated with devm_*?
> 
> We need to change this up a bit more to handle the error path vs regular
> device shutdown free (automatic devm frees).

We might want to look at using no_free_ptr() in this code.  See this
patch[1] for an example of how to inhibit the cleanup and pass the pointer
on when the function succeeds.

[1] https://lore.kernel.org/all/170261791914.1714654.6447680285357545638.stgit@dwillia2-xfh.jf.intel.com/

Ira

  reply	other threads:[~2023-12-15 16:45 UTC|newest]

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2023-12-10  8:58 [PATCH] [v2] nvdimm-btt: fix several memleaks Dinghao Liu
2023-12-15  0:24 ` Ira Weiny
2023-12-15 16:45   ` Ira Weiny [this message]
2023-12-18  9:21     ` dinghao.liu
2023-12-19 23:42       ` Ira Weiny
2023-12-20  7:52         ` dinghao.liu

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=657c82966e358_2947c22941a@iweiny-mobl.notmuch \
    --to=ira.weiny@intel.com \
    --cc=dan.j.williams@intel.com \
    --cc=dave.jiang@intel.com \
    --cc=dinghao.liu@zju.edu.cn \
    --cc=linux-kernel@vger.kernel.org \
    --cc=nvdimm@lists.linux.dev \
    --cc=vishal.l.verma@intel.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