From: "haiyangtan(谭海洋)" <haiyangtan@tencent.com>
To: "Dumitrescu, Cristian" <cristian.dumitrescu@intel.com>,
Stephen Hemminger <stephen@networkplumber.org>
Cc: "dev@dpdk.org" <dev@dpdk.org>
Subject: [dpdk-dev] reply: [PATCH] hash: fix possible uninitialized variable
Date: Mon, 24 Dec 2018 11:49:18 +0000 [thread overview]
Message-ID: <3329f1ccb3704be3be5631fa627723c5@tencent.com> (raw)
> -----Original Message-----
> From: Dumitrescu, Cristian <cristian.dumitrescu@intel.com>
> 发送时间: 2018年12月24日 18:30
> 收件人: Stephen Hemminger <stephen@networkplumber.org>;
> haiyangtan <haiyangtan@tencent.com>
> Cc: dev@dpdk.org
> Subject: RE: [dpdk-dev] [PATCH] hash: fix possible uninitialized variable(Internet
> mail)
>
>
>
> > -----Original Message-----
> > From: Stephen Hemminger [mailto:stephen@networkplumber.org]
> > Sent: Sunday, December 23, 2018 7:44 AM
> > To: Haiyang Tan <haiyangtan@tencent.com>
> > Cc: Dumitrescu, Cristian <cristian.dumitrescu@intel.com>; dev@dpdk.org
> > Subject: Re: [dpdk-dev] [PATCH] hash: fix possible uninitialized variable
> >
> > On Sat, 22 Dec 2018 04:10:59 -0800
> > Haiyang Tan <haiyangtan@tencent.com> wrote:
> >
> > > The uninitialized field 'extra_flag' of hash_cuckoo_params may enable
> > > certain feature silently. Typically, if bit0 of 'extra_flag' set, the
> > > hardware transactional memory support will be enabled unexpectedly.
> > >
> > > Signed-off-by: Haiyang Tan <haiyangtan@tencent.com>
> >
> > This is not necessary. Structure initializations will fill in the other
> > elements with zero.
> >
> > https://gcc.gnu.org/onlinedocs/gcc-4.9.0/gcc/Designated-Inits.html
> > Omitted field members are implicitly initialized the same as objects that
> > have static storage duration.
>
> Agree with Stephen, this is part of the C language.
>
> Haiyang, are you experiencing a real issue in your app or is your proposal
> triggered purely by code review?
>
> Haiyang, it seems that the extra_flags was recently added in librte_hash, but
> left behind in librte_table. For better readability, I suggest you send a quick
> patch that explicitly initializes the extra_flag with 0, what do you think?
>
> struct rte_hash_parameters hash_cuckoo_params = {
> ...
> .extra_flag = 0,
> };
>
> Regards,
> Cristian
>
Hi Stephen and Cristian, I have checked C99 standard and get the same conclusion which mentioned in stephen's email,
So this patch is unnecessary and please ignore it.
BR!
Haiyang
reply other threads:[~2018-12-24 11:49 UTC|newest]
Thread overview: [no followups] expand[flat|nested] mbox.gz Atom feed
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=3329f1ccb3704be3be5631fa627723c5@tencent.com \
--to=haiyangtan@tencent.com \
--cc=cristian.dumitrescu@intel.com \
--cc=dev@dpdk.org \
--cc=stephen@networkplumber.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).