Re: [PATCH v3 3/4] hugetlb: Fix return value of __setup handlers

From: Muchun Song
Date: Wed Apr 13 2022 - 04:21:52 EST


On Wed, Apr 13, 2022 at 04:16:11PM +0800, liupeng (DM) wrote:
>
> On 2022/4/13 15:55, Muchun Song wrote:
> > On Wed, Apr 13, 2022 at 03:29:14AM +0000, Peng Liu wrote:
> > > When __setup() return '0', using invalid option values causes the
> > > entire kernel boot option string to be reported as Unknown. Hugetlb
> > > calls __setup() and will return '0' when set invalid parameter
> > > string.
> > >
> > > The following phenomenon is observed:
> > > cmdline:
> > > hugepagesz=1Y hugepages=1
> > > dmesg:
> > > HugeTLB: unsupported hugepagesz=1Y
> > > HugeTLB: hugepages=1 does not follow a valid hugepagesz, ignoring
> > > Unknown kernel command line parameters "hugepagesz=1Y hugepages=1"
> > >
> > > Since hugetlb will print warning/error information before return for
> > > invalid parameter string, just use return '1' to avoid print again.
> > >
> > Can't return -EINVAL? It is weird to return 1 on failure.
> >
> > Thanks.
> >
> > .
>
> Not against "return -EINVAL", but consistent with:
> 1d02b444b8d1 ("tracing: Fix return value of __setup handlers")

I think it is better not return 1. I don't think it's a good habit we
should follow.

Thanks.

Thanks.