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From: Geert Uytterhoeven <geert@linux-m68k.org>
To: Biju Das <biju.das@bp.renesas.com>
Cc: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>,
	Simon Horman <horms@verge.net.au>,
	Geert Uytterhoeven <geert+renesas@glider.be>,
	Chris Paterson <Chris.Paterson2@renesas.com>,
	Alexandre Belloni <alexandre.belloni@bootlin.com>,
	Alessandro Zummo <a.zummo@towertech.it>,
	Fabrizio Castro <fabrizio.castro@bp.renesas.com>,
	linux-rtc@vger.kernel.org,
	Linux-Renesas <linux-renesas-soc@vger.kernel.org>
Subject: Re: [PATCH v3] nvmem: check invalid number of bytes in nvmem_{read,write}()
Date: Tue, 11 Dec 2018 12:06:17 +0100	[thread overview]
Message-ID: <CAMuHMdXraSz4dtBi0hzZ-w_goKiy_fObE0S-Vi6xQhSxHNnhqQ@mail.gmail.com> (raw)
In-Reply-To: <OSBPR01MB210338DE328981500C6992F8B8A60@OSBPR01MB2103.jpnprd01.prod.outlook.com>

Hi Biju,

On Tue, Dec 11, 2018 at 11:55 AM Biju Das <biju.das@bp.renesas.com> wrote:
> > Subject: Re: [PATCH v3] nvmem: check invalid number of bytes in
> > nvmem_{read,write}()
> >
> > After applying this patch I get below errors with W=1 C=1
> >
> > On 11/12/18 09:24, Biju Das wrote:
> > > +if (unlikely(check_add_overflow(bytes, offset, &new_bytes)))
> > > +return -EOVERFLOW;
> > >   drivers/nvmem/core.c:82:13: error: incompatible types in comparison
> > expression (different type sizes)
> > drivers/nvmem/core.c:82:13: error: incompatible types in comparison
> > expression (different type sizes)
> > drivers/nvmem/core.c:113:13: error: incompatible types in comparison
> > expression (different type sizes)
> > drivers/nvmem/core.c:113:13: error: incompatible types in comparison
> > expression (different type sizes)
>
> I was trying with arm32 toolchain and compiler happy. Now tried with Arm64 toolchain, it provides a warning and the below typecast fixed the issue.
> if (unlikely(check_add_overflow(bytes, (size_t)offset, &new_bytes)))
>
> Does typecasting to (size_t)  fixed the issue in your environment? Please let  me know.

That's a side-effect of offset not being loff_t...
I think that should be fixed first, else you will forget about
removing the cast later
("casts are evil").

Gr{oetje,eeting}s,

                        Geert

-- 
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
                                -- Linus Torvalds

  reply	other threads:[~2018-12-11 11:06 UTC|newest]

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-12-11  9:24 [PATCH v3] nvmem: check invalid number of bytes in nvmem_{read,write}() Biju Das
2018-12-11  9:55 ` Srinivas Kandagatla
2018-12-11 10:54   ` Biju Das
2018-12-11 11:06     ` Geert Uytterhoeven [this message]
2018-12-11 11:10       ` Srinivas Kandagatla
2018-12-11 11:27         ` Geert Uytterhoeven

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