From: "Richardson, Bruce" <bruce.richardson@intel.com>
To: "Yang, Ziye" <ziye.yang@intel.com>
Cc: "dev@dpdk.org" <dev@dpdk.org>
Subject: Re: [dpdk-dev] [PATCH] librte_eal: fix wrong args operation in eal_parse_args
Date: Wed, 11 May 2016 12:21:16 +0000 [thread overview]
Message-ID: <59AF69C657FD0841A61C55336867B5B035A51A28@IRSMSX103.ger.corp.intel.com> (raw)
In-Reply-To: <FA6C2217B01E9D48A581BB486602101401756545@shsmsx102.ccr.corp.intel.com>
> -----Original Message-----
> From: Yang, Ziye
> Sent: Wednesday, May 11, 2016 12:51 PM
> To: Richardson, Bruce <bruce.richardson@intel.com>
> Cc: dev@dpdk.org
> Subject: RE: [dpdk-dev] [PATCH] librte_eal: fix wrong args operation in
> eal_parse_args
>
> Hi Bruce,
>
> Could it be fixed later? If not, it should be documented. I faced this
> issued today, and found that dpdk changed my last arg. In my mind, dpdk
> should not change the argv[last], which will confuse the users.
>
We can certainly consider changing it, but I am concerned about stability of existing apps. I think it needs some discussion and consensus on-list before a change like this is made.
For right now, definitely the behavior should be documented. Would you consider submitting a documentation update patch for this issue instead of this code change?
Thanks,
/Bruce
> Best Regards,
> Ziye Yang
>
> -----Original Message-----
> From: Richardson, Bruce
> Sent: Wednesday, May 11, 2016 7:25 PM
> To: Yang, Ziye <ziye.yang@intel.com>
> Cc: dev@dpdk.org
> Subject: Re: [dpdk-dev] [PATCH] librte_eal: fix wrong args operation in
> eal_parse_args
>
> On Wed, May 11, 2016 at 01:28:21PM +0800, Ziye Yang wrote:
> > This patch is used to fix wrong operation on user input args.
> > eal_parse_args function should not operate the args passed by the
> > user. If the element in argv is generated by malloc function, changing
> > it will cause memory issues when free the args.
> >
> > Signed-off-by: Ziye Yang <ziye.yang@intel.com>
> > ---
> > lib/librte_eal/bsdapp/eal/eal.c | 2 --
> > lib/librte_eal/linuxapp/eal/eal.c | 2 --
> > 2 files changed, 4 deletions(-)
> >
> > diff --git a/lib/librte_eal/bsdapp/eal/eal.c
> > b/lib/librte_eal/bsdapp/eal/eal.c index 06bfd4e..0eef92d 100644
> > --- a/lib/librte_eal/bsdapp/eal/eal.c
> > +++ b/lib/librte_eal/bsdapp/eal/eal.c
> > @@ -420,8 +420,6 @@ eal_parse_args(int argc, char **argv)
> > goto out;
> > }
> >
> > - if (optind >= 0)
> > - argv[optind-1] = prgname;
> > ret = optind-1;
> >
> > out:
> > diff --git a/lib/librte_eal/linuxapp/eal/eal.c
> > b/lib/librte_eal/linuxapp/eal/eal.c
> > index 8aafd51..ba9d1ac 100644
> > --- a/lib/librte_eal/linuxapp/eal/eal.c
> > +++ b/lib/librte_eal/linuxapp/eal/eal.c
> > @@ -658,8 +658,6 @@ eal_parse_args(int argc, char **argv)
> > goto out;
> > }
> >
> > - if (optind >= 0)
> > - argv[optind-1] = prgname;
> > ret = optind-1;
> >
> > out:
> This is a behaviour change in DPDK. The behaviour has always been that
> after calling eal init, you can update your argv/argc values by the number
> of args parsed and then parse your app args as normal, since argv[0] will
> still point to your program name. While I agree that having the current
> behaviour may cause some problems, changing this behaviour may break
> applications that have been written to use the existing behaviour.
>
> Since it is only the last EAL parameter arg that is modified, I think it
> would be acceptable to have the behaviour well documented and then expect
> any app to store a second copy of the pointer to be modified if it is
> needed for a subsequent free call, for example.
>
> /Bruce
next prev parent reply other threads:[~2016-05-11 12:21 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-05-11 5:28 Ziye Yang
2016-05-11 11:24 ` Bruce Richardson
2016-05-11 11:51 ` Yang, Ziye
2016-05-11 12:21 ` Richardson, Bruce [this message]
2016-05-11 13:39 ` Yang, Ziye
2016-05-11 14:07 ` Richardson, Bruce
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