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From: Bruce Korb <bruce.korb@gmail.com>
To: James Simmons <jsimmons@infradead.org>
Cc: Kees Cook <keescook@chromium.org>,
	Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
	Oleg Drokin <oleg.drokin@intel.com>,
	Andreas Dilger <andreas.dilger@intel.com>,
	Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	"John L. Hammond" <john.hammond@intel.com>,
	Emoly Liu <emoly.liu@intel.com>,
	Vitaly Fertman <vitaly_fertman@xyratex.com>,
	Bruno Faccini <bruno.faccini@intel.com>,
	Lustre Development List <lustre-devel@lists.lustre.org>,
	devel@driverdev.osuosl.org
Subject: Re: [PATCH] staging: lustre: ldlm: use designated initializers
Date: Mon, 19 Dec 2016 08:47:50 -0800	[thread overview]
Message-ID: <CAKRnqNLFM_96NK3QbeoF-zC4KTe8oc7Q-eejzPgkE==XUHrwkQ@mail.gmail.com> (raw)
In-Reply-To: <alpine.LFD.2.20.1612191614320.25173@casper.infradead.org>

On Mon, Dec 19, 2016 at 8:22 AM, James Simmons
>> --- a/drivers/staging/lustre/lustre/ldlm/ldlm_flock.c
>> +++ b/drivers/staging/lustre/lustre/ldlm/ldlm_flock.c
>> @@ -143,7 +143,7 @@ static int ldlm_process_flock_lock(struct ldlm_lock *req, __u64 *flags,
>>       int added = (mode == LCK_NL);
>>       int overlaps = 0;
>>       int splitted = 0;
>> -     const struct ldlm_callback_suite null_cbs = { NULL };
>> +     const struct ldlm_callback_suite null_cbs = { };
>>
>>       CDEBUG(D_DLMTRACE,
>>              "flags %#llx owner %llu pid %u mode %u start %llu end %llu\n",
>
> Nak. Filling null_cbs with random data is a bad idea. If you look at
> ldlm_lock_create() where this is used you have
>
> if (cbs) {
>         lock->l_blocking_ast = cbs->lcs_blocking;
>         lock->l_completion_ast = cbs->lcs_completion;
>         lock->l_glimpse_ast = cbs->lcs_glimpse;
> }
>
> Having lock->l_* point to random addresses is a bad idea.
> What really needs to be done is proper initialization of that
> structure. A bunch of patches will be coming to address this.

I'm not understanding the effect of the original difference.  If you
specify any initializer, then all fields not specified are filled with
zero bits. Any pointers are, perforce, NULL.  That should make both "{
NULL }" and "{}" equivalent.  Maybe a worthwhile change would be to:

    static const struct ldlm_callback_suite null_cbs;

then it is not even necessary to specify an initializer.

WARNING: multiple messages have this Message-ID (diff)
From: Bruce Korb <bruce.korb@gmail.com>
To: James Simmons <jsimmons@infradead.org>
Cc: Kees Cook <keescook@chromium.org>,
	Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
	Oleg Drokin <oleg.drokin@intel.com>,
	Andreas Dilger <andreas.dilger@intel.com>,
	Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	"John L. Hammond" <john.hammond@intel.com>,
	Emoly Liu <emoly.liu@intel.com>,
	Vitaly Fertman <vitaly_fertman@xyratex.com>,
	Bruno Faccini <bruno.faccini@intel.com>,
	Lustre Development List <lustre-devel@lists.lustre.org>,
	devel@driverdev.osuosl.org
Subject: [lustre-devel] [PATCH] staging: lustre: ldlm: use designated initializers
Date: Mon, 19 Dec 2016 16:48:31 -0000	[thread overview]
Message-ID: <CAKRnqNLFM_96NK3QbeoF-zC4KTe8oc7Q-eejzPgkE==XUHrwkQ@mail.gmail.com> (raw)
In-Reply-To: <alpine.LFD.2.20.1612191614320.25173@casper.infradead.org>

On Mon, Dec 19, 2016 at 8:22 AM, James Simmons
>> --- a/drivers/staging/lustre/lustre/ldlm/ldlm_flock.c
>> +++ b/drivers/staging/lustre/lustre/ldlm/ldlm_flock.c
>> @@ -143,7 +143,7 @@ static int ldlm_process_flock_lock(struct ldlm_lock *req, __u64 *flags,
>>       int added = (mode == LCK_NL);
>>       int overlaps = 0;
>>       int splitted = 0;
>> -     const struct ldlm_callback_suite null_cbs = { NULL };
>> +     const struct ldlm_callback_suite null_cbs = { };
>>
>>       CDEBUG(D_DLMTRACE,
>>              "flags %#llx owner %llu pid %u mode %u start %llu end %llu\n",
>
> Nak. Filling null_cbs with random data is a bad idea. If you look at
> ldlm_lock_create() where this is used you have
>
> if (cbs) {
>         lock->l_blocking_ast = cbs->lcs_blocking;
>         lock->l_completion_ast = cbs->lcs_completion;
>         lock->l_glimpse_ast = cbs->lcs_glimpse;
> }
>
> Having lock->l_* point to random addresses is a bad idea.
> What really needs to be done is proper initialization of that
> structure. A bunch of patches will be coming to address this.

I'm not understanding the effect of the original difference.  If you
specify any initializer, then all fields not specified are filled with
zero bits. Any pointers are, perforce, NULL.  That should make both "{
NULL }" and "{}" equivalent.  Maybe a worthwhile change would be to:

    static const struct ldlm_callback_suite null_cbs;

then it is not even necessary to specify an initializer.

  reply	other threads:[~2016-12-19 16:48 UTC|newest]

Thread overview: 35+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-12-17  1:00 [PATCH] staging: lustre: ldlm: use designated initializers Kees Cook
2016-12-17  1:00 ` [lustre-devel] " Kees Cook
2016-12-19 16:22 ` James Simmons
2016-12-19 16:22   ` [lustre-devel] " James Simmons
2016-12-19 16:47   ` Bruce Korb [this message]
2016-12-19 16:48     ` Bruce Korb
2016-12-19 17:12     ` James Simmons
2016-12-19 17:12       ` [lustre-devel] " James Simmons
2016-12-20  7:10     ` Dan Carpenter
2016-12-20  7:10       ` [lustre-devel] " Dan Carpenter
2016-12-20 14:57       ` Hammond, John
2016-12-20 14:57         ` [lustre-devel] " Hammond, John
2016-12-20 16:47         ` Bruce Korb
2016-12-20 16:48           ` [lustre-devel] " Bruce Korb
2016-12-20 18:52           ` Dan Carpenter
2016-12-20 18:52             ` [lustre-devel] " Dan Carpenter
2016-12-20 19:07         ` Dan Carpenter
2016-12-20 19:07           ` [lustre-devel] " Dan Carpenter
2016-12-20 19:46           ` Kees Cook
2016-12-20 19:46             ` [lustre-devel] " Kees Cook
2016-12-19 16:50   ` Patrick Farrell
2016-12-19 17:11     ` James Simmons
2016-12-19 17:11       ` James Simmons
2016-12-20 10:40   ` Dan Carpenter
2016-12-20 10:40     ` [lustre-devel] " Dan Carpenter
2016-12-20 17:29 ` Designated initializers, struct randomization and addressing? Joe Perches
2016-12-20 17:29   ` [lustre-devel] " Joe Perches
2017-01-03 23:47   ` Kees Cook
2017-01-03 23:55     ` Bruce Korb
2017-01-04  0:13       ` Kees Cook
2017-01-04  6:27     ` Julia Lawall
2017-01-04  6:35       ` Kees Cook
2017-01-04 16:55         ` Stephen Hemminger
2017-01-04 17:37           ` Julia Lawall
2017-01-04 22:30           ` Kees Cook

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