From: Richard Weinberger <richard@nod.at>
To: Boris Brezillon <boris.brezillon@free-electrons.com>
Cc: linux-mtd@lists.infradead.org, linux-kernel@vger.kernel.org,
        marek.vasut@gmail.com, cyrille.pitchen@wedev4u.fr,
        computersforpeace@gmail.com, dwmw2@infradead.org
Subject: Re: [PATCH] mtd: spi-nor: Check for spi_nor_hwcaps_read2cmd() return value
Date: Mon, 18 Sep 2017 15:39:25 +0200
Message-ID: <2454131.y020cBOLnt@blindfold>
In-Reply-To: <20170918113945.1549571f@bbrezillon>
References: <20170917095750.14059-1-richard@nod.at> <20170918113945.1549571f@bbrezillon>
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Am Montag, 18. September 2017, 11:39:45 CEST schrieb Boris Brezillon:
> On Sun, 17 Sep 2017 11:57:50 +0200
> 
> Richard Weinberger <richard@nod.at> wrote:
> > The function can return a negativ value in case of errors,
> > don't use it blindly as array index.
> > 
> > Detected by CoverityScan CID#1418067 ("Memory - illegal accesses")
> > Fixes: f384b352cbf0 ("mtd: spi-nor: parse Serial Flash Discoverable
> > Parameters (SFDP) tables")
> 
> Hm, not sure but I think "Fixes:" should not be wrapped.

Hmm, vi tried to be smart. ;-\ 

> 
> > Signed-off-by: Richard Weinberger <richard@nod.at>
> > ---
> > 
> >  drivers/mtd/spi-nor/spi-nor.c | 3 +++
> >  1 file changed, 3 insertions(+)
> > 
> > diff --git a/drivers/mtd/spi-nor/spi-nor.c b/drivers/mtd/spi-nor/spi-nor.c
> > index cf1d4a15e10a..d71765739a93 100644
> > --- a/drivers/mtd/spi-nor/spi-nor.c
> > +++ b/drivers/mtd/spi-nor/spi-nor.c
> > @@ -2145,6 +2145,9 @@ static int spi_nor_parse_bfpt(struct spi_nor *nor,
> > 
> >  		params->hwcaps.mask |= rd->hwcaps;
> >  		cmd = spi_nor_hwcaps_read2cmd(rd->hwcaps);
> > 
> > +		if (cmd < 0)
> > +			return -EINVAL;
> 
> Why not returning cmd directly?

I thought about that too but the only other user of that function also returns
-EINVAL upon error.
Maybe Cyrille can give more input whether we should propagate 
spi_nor_hwcaps_read2cmd()'s return values or not.

Thanks,
//richard