From: Nicholas Mc Guire <der.herr@hofr.at>
To: Julian Calaby <julian.calaby@gmail.com>
Cc: Nicholas Mc Guire <hofrat@osadl.org>,
Kalle Valo <kvalo@codeaurora.org>,
Eliad Peller <eliad@wizery.com>,
Johannes Berg <johannes.berg@intel.com>,
Arik Nemtsov <arik@wizery.com>, Tony Lindgren <tony@atomide.com>,
Luciano Coelho <luca@coelho.fi>,
Eyal Reizer <eyalreizer@gmail.com>,
Emmanuel Grumbach <emmanuel.grumbach@intel.com>,
linux-wireless <linux-wireless@vger.kernel.org>,
netdev <netdev@vger.kernel.org>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH] wlcore: consolidate kmalloc + memset 0 into kzalloc
Date: Tue, 22 Dec 2015 07:29:51 +0000 [thread overview]
Message-ID: <20151222072951.GA31496@osadl.at> (raw)
In-Reply-To: <CAGRGNgU+CA-jLAX=_qV27tfbyQ2cyjYo2NZOq3_7fFLc-VsCew@mail.gmail.com>
On Tue, Dec 22, 2015 at 09:56:10AM +1100, Julian Calaby wrote:
> Hi,
>
> On Tue, Dec 22, 2015 at 3:47 AM, Nicholas Mc Guire <hofrat@osadl.org> wrote:
> > This is an API consolidation only. The use of kmalloc + memset to 0
> > is equivalent to kzalloc.
> >
> > Signed-off-by: Nicholas Mc Guire <hofrat@osadl.org>
> > ---
> >
> > Found by coccinelle script (relaxed version of
> > scripts/coccinelle/api/alloc/kzalloc-simple.cocci)
> >
> > Patch was compile tested with: x86_64_defconfig +
> > CONFIG_WL12XX=m (implies CONFIG_WLCORE=m)
> >
> > Patch is against linux-next (localversion-next is -next-20151221)
> >
> > drivers/net/wireless/ti/wlcore/main.c | 3 +--
> > 1 file changed, 1 insertion(+), 2 deletions(-)
> >
> > diff --git a/drivers/net/wireless/ti/wlcore/main.c b/drivers/net/wireless/ti/wlcore/main.c
> > index ec7f6af..dfc49bf 100644
> > --- a/drivers/net/wireless/ti/wlcore/main.c
> > +++ b/drivers/net/wireless/ti/wlcore/main.c
> > @@ -838,7 +838,7 @@ static void wl12xx_read_fwlog_panic(struct wl1271 *wl)
> >
> > wl1271_info("Reading FW panic log");
> >
> > - block = kmalloc(wl->fw_mem_block_size, GFP_KERNEL);
> > + block = kzalloc(wl->fw_mem_block_size, GFP_KERNEL);
> > if (!block)
> > return;
> >
> > @@ -885,7 +885,6 @@ static void wl12xx_read_fwlog_panic(struct wl1271 *wl)
> > goto out;
> > }
> > - memset(block, 0, wl->fw_mem_block_size);
>
> I don't think you can't remove this line. It appears that the loop
> this is part of resets block to be all zero, reads a chunk of data in,
> then operates on it. I'm guessing that the code after the following
> line expects that there isn't any data left over from previous runs
> through the loop.
>
the rational for this being ok is thta the copy operation into block is:
ret = wlcore_read_hwaddr(wl, addr, block,
wl->fw_mem_block_size, false);
this will end up in the .read methods where block should be completely
overwritten (length == full block size), so within the loop if successful
this should be correct - if not successful it would "goto out" witout
using the content of block.
Am I overlooking something here ?
thx!
hofrat
next prev parent reply other threads:[~2015-12-22 7:29 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-12-21 16:47 [PATCH] wlcore: consolidate kmalloc + memset 0 into kzalloc Nicholas Mc Guire
2015-12-21 22:56 ` Julian Calaby
2015-12-22 7:29 ` Nicholas Mc Guire [this message]
2015-12-22 7:52 ` Julian Calaby
2015-12-22 7:06 ` Souptick Joarder
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