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From: Eric Blake <eblake@redhat.com>
To: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>,
	qemu-devel@nongnu.org
Cc: Jason Wang <jasowang@redhat.com>, armbru@redhat.com
Subject: Re: [PATCH v4 1/5] net: Clarify early exit condition
Date: Tue, 19 Jan 2021 10:08:03 -0600	[thread overview]
Message-ID: <689a713c-b190-aa77-106d-24ad8e3fc49e@redhat.com> (raw)
In-Reply-To: <7e1edd6a-dbdf-3c4c-4dfa-c181418d09bd@virtuozzo.com>

On 1/13/21 10:54 PM, Vladimir Sementsov-Ogievskiy wrote:
> 14.01.2021 01:10, Eric Blake wrote:
>> On first glance, the loop in qmp_query_rx_filter() has early return
>> paths that could leak any allocation of filter_list from a previous
>> iteration.  But on closer inspection, it is obvious that all of the
>> early exits are guarded by has_name, and that the bulk of the loop
>> body can be executed at most once if the user is filtering by name,
>> thus, any early exit coincides with an empty list.  Add asserts to
>> make this obvious.
> 
> A bit simpler (for me :) observation:
> 
> But on closer inspection, it is obvious that all of the early exits are
> guarded by has_name, and in case when has_name is true we leave the loop

s/in case//

> (by break) immediately after allocation and assigning filter_list for
> the first time.

Replacing my wording with this touched-up sentence is fine with me, if
Markus would like to tweak the queued commit to incorporate it.

-- 
Eric Blake, Principal Software Engineer
Red Hat, Inc.           +1-919-301-3226
Virtualization:  qemu.org | libvirt.org



  reply	other threads:[~2021-01-19 16:09 UTC|newest]

Thread overview: 16+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-01-13 22:10 [PATCH v4 0/5] Common macros for QAPI list growth Eric Blake
2021-01-13 22:10 ` [PATCH v4 1/5] net: Clarify early exit condition Eric Blake
2021-01-14  4:54   ` Vladimir Sementsov-Ogievskiy
2021-01-19 16:08     ` Eric Blake [this message]
2021-01-13 22:10 ` [PATCH v4 2/5] qapi: A couple more QAPI_LIST_PREPEND() stragglers Eric Blake
2021-01-14  5:18   ` Vladimir Sementsov-Ogievskiy
2021-01-13 22:10 ` [PATCH v4 3/5] qapi: Introduce QAPI_LIST_APPEND Eric Blake
2021-01-14 12:59   ` Markus Armbruster
2021-01-13 22:10 ` [PATCH v4 4/5] qapi: Use QAPI_LIST_APPEND in trivial cases Eric Blake
2021-01-13 22:10 ` [PATCH v4 5/5] qapi: More complex uses of QAPI_LIST_APPEND Eric Blake
2021-01-14 13:08   ` Markus Armbruster
2021-01-26  9:31   ` Markus Armbruster
2021-01-27 18:12     ` Eric Blake
2021-01-28  7:45       ` Markus Armbruster
2021-02-05 17:13     ` Eric Blake
2021-01-14 13:15 ` [PATCH v4 0/5] Common macros for QAPI list growth Markus Armbruster

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