From: Andrea Righi <andrea@betterlinux.com>
To: Julia Lawall <julia@diku.dk>
Cc: Andrew Morton <akpm@linux-foundation.org>,
trivial@kernel.org, kernel-janitors@vger.kernel.org,
Stefani Seibold <stefani@seibold.net>,
"Ira W. Snyder" <iws@ovro.caltech.edu>,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH 1/11] kernel/kfifo.c: trivial: use BUG_ON
Date: Tue, 02 Aug 2011 12:03:29 +0000 [thread overview]
Message-ID: <20110802120329.GA9088@thinkpad> (raw)
In-Reply-To: <Pine.LNX.4.64.1108021349330.24349@ask.diku.dk>
On Tue, Aug 02, 2011 at 01:52:49PM +0200, Julia Lawall wrote:
> On Tue, 2 Aug 2011, Andrea Righi wrote:
>
> > On Tue, Aug 02, 2011 at 12:34:54PM +0200, Julia Lawall wrote:
> > > From: Julia Lawall <julia@diku.dk>
> > >
> > > Use BUG_ON(x) rather than if(x) BUG();
> > >
> > > The semantic patch that fixes this problem is as follows:
> > > (http://coccinelle.lip6.fr/)
> > >
> > > // <smpl>
> > > @@ identifier x; @@
> > > -if (x) BUG();
> > > +BUG_ON(x);
> > >
> > > @@ identifier x; @@
> > > -if (!x) BUG();
> > > +BUG_ON(!x);
> > > // </smpl>
> > >
> > > Signed-off-by: Julia Lawall <julia@diku.dk>
> > >
> >
> > The patch looks good. However, I think we should just get rid of the
> > BUG_ON() there. If nents is 0, setup_sgl_buf() would just returns 0 and
> > nothing critical will happen.
>
> I don't know the code at all. Indeed, I'm not sure to see any uses of eg
> __kfifo_dma_in_prepare_r, except in demo code. But that would imply
> returning 0 for two different reasons: asking for nothing and being out of
> space.
>
> julia
Right. But I'd prefer to return nothing also when asking nothing rather
than crashing the kernel.
-Andrea
WARNING: multiple messages have this Message-ID (diff)
From: Andrea Righi <andrea@betterlinux.com>
To: Julia Lawall <julia@diku.dk>
Cc: Andrew Morton <akpm@linux-foundation.org>,
trivial@kernel.org, kernel-janitors@vger.kernel.org,
Stefani Seibold <stefani@seibold.net>,
"Ira W. Snyder" <iws@ovro.caltech.edu>,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH 1/11] kernel/kfifo.c: trivial: use BUG_ON
Date: Tue, 2 Aug 2011 14:03:29 +0200 [thread overview]
Message-ID: <20110802120329.GA9088@thinkpad> (raw)
In-Reply-To: <Pine.LNX.4.64.1108021349330.24349@ask.diku.dk>
On Tue, Aug 02, 2011 at 01:52:49PM +0200, Julia Lawall wrote:
> On Tue, 2 Aug 2011, Andrea Righi wrote:
>
> > On Tue, Aug 02, 2011 at 12:34:54PM +0200, Julia Lawall wrote:
> > > From: Julia Lawall <julia@diku.dk>
> > >
> > > Use BUG_ON(x) rather than if(x) BUG();
> > >
> > > The semantic patch that fixes this problem is as follows:
> > > (http://coccinelle.lip6.fr/)
> > >
> > > // <smpl>
> > > @@ identifier x; @@
> > > -if (x) BUG();
> > > +BUG_ON(x);
> > >
> > > @@ identifier x; @@
> > > -if (!x) BUG();
> > > +BUG_ON(!x);
> > > // </smpl>
> > >
> > > Signed-off-by: Julia Lawall <julia@diku.dk>
> > >
> >
> > The patch looks good. However, I think we should just get rid of the
> > BUG_ON() there. If nents is 0, setup_sgl_buf() would just returns 0 and
> > nothing critical will happen.
>
> I don't know the code at all. Indeed, I'm not sure to see any uses of eg
> __kfifo_dma_in_prepare_r, except in demo code. But that would imply
> returning 0 for two different reasons: asking for nothing and being out of
> space.
>
> julia
Right. But I'd prefer to return nothing also when asking nothing rather
than crashing the kernel.
-Andrea
next prev parent reply other threads:[~2011-08-02 12:03 UTC|newest]
Thread overview: 52+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-08-02 10:34 [PATCH 0/11] trivial: use BUG_ON Julia Lawall
2011-08-02 10:34 ` Julia Lawall
2011-08-02 10:34 ` [PATCH 1/11] kernel/kfifo.c: " Julia Lawall
2011-08-02 10:34 ` Julia Lawall
2011-08-02 11:33 ` Andrea Righi
2011-08-02 11:33 ` Andrea Righi
2011-08-02 11:52 ` Julia Lawall
2011-08-02 11:52 ` Julia Lawall
2011-08-02 12:03 ` Andrea Righi [this message]
2011-08-02 12:03 ` Andrea Righi
2011-08-02 15:20 ` Julia Lawall
2011-08-02 15:20 ` Julia Lawall
2011-08-02 19:27 ` Julia Lawall
2011-08-02 19:27 ` Julia Lawall
2011-08-02 20:09 ` Andrea Righi
2011-08-02 20:09 ` Andrea Righi
2011-08-03 6:30 ` Stefani Seibold
2011-08-03 6:30 ` Stefani Seibold
2011-08-02 10:34 ` [PATCH 2/11] drivers/message/fusion/mptsas.c: " Julia Lawall
2011-08-02 10:34 ` Julia Lawall
2011-08-04 6:54 ` [PATCH 2/11] drivers/message/fusion/mptsas.c: trivial: use Nandigama, Nagalakshmi
2011-08-04 6:54 ` [PATCH 2/11] drivers/message/fusion/mptsas.c: trivial: use BUG_ON Nandigama, Nagalakshmi
2011-08-04 7:13 ` walter harms
2011-08-02 10:34 ` [PATCH 3/11] arch/arm/mach-s3c64xx/dma.c: " Julia Lawall
2011-08-02 10:34 ` Julia Lawall
2011-08-02 10:34 ` Julia Lawall
2011-08-02 10:34 ` [PATCH 4/11] arch/x86/kvm/vmx.c: " Julia Lawall
2011-08-02 10:34 ` Julia Lawall
2011-08-02 16:44 ` Marcelo Tosatti
2011-08-02 16:44 ` Marcelo Tosatti
2011-08-02 10:34 ` [PATCH 5/11] kernel/sysctl.c: " Julia Lawall
2011-08-02 10:34 ` Julia Lawall
2011-08-02 10:34 ` [PATCH 6/11] drivers/iommu/iommu.c: " Julia Lawall
2011-08-02 10:34 ` Julia Lawall
2011-08-02 10:35 ` [PATCH 7/11] arch/m32r/kernel/smp.c: " Julia Lawall
2011-08-02 10:35 ` Julia Lawall
2011-08-02 10:55 ` KOSAKI Motohiro
2011-08-02 10:55 ` KOSAKI Motohiro
2011-08-02 10:35 ` [PATCH 8/11] fs/btrfs/volumes.c: " Julia Lawall
2011-08-02 10:35 ` Julia Lawall
2011-08-02 10:35 ` [PATCH 9/11] drivers/target/target_core_rd.c: " Julia Lawall
2011-08-02 10:35 ` Julia Lawall
2011-08-04 18:05 ` [PATCH 9/11] drivers/target/target_core_rd.c: trivial: use Nicholas A. Bellinger
2011-08-04 18:05 ` [PATCH 9/11] drivers/target/target_core_rd.c: trivial: use BUG_ON Nicholas A. Bellinger
2011-08-02 10:35 ` [PATCH 10/11] arch/openrisc/mm/init.c: " Julia Lawall
2011-08-02 10:35 ` Julia Lawall
2011-08-02 13:55 ` Jonas Bonn
2011-08-02 13:55 ` Jonas Bonn
2011-08-02 10:35 ` [PATCH 11/11] arch/tile/mm/init.c: " Julia Lawall
2011-08-02 10:35 ` Julia Lawall
2011-08-02 20:28 ` Chris Metcalf
2011-08-02 20:28 ` Chris Metcalf
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