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Date:      Tue, 17 Sep 2019 12:05:26 +0300
From:      Toomas Soome <tsoome@me.com>
To:        Konstantin Belousov <kostikbel@gmail.com>
Cc:        Toomas Soome <tsoome@FreeBSD.org>, src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org
Subject:   Re: svn commit: r352421 - head/stand/libsa
Message-ID:  <6762A429-F17F-46D1-A55B-BD9C627D6903@me.com>
In-Reply-To: <20190917085641.GY2559@kib.kiev.ua>
References:  <201909162028.x8GKS9jK064079@repo.freebsd.org> <20190917085641.GY2559@kib.kiev.ua>

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> On 17 Sep 2019, at 11:56, Konstantin Belousov <kostikbel@gmail.com> =
wrote:
>=20
> On Mon, Sep 16, 2019 at 08:28:09PM +0000, Toomas Soome wrote:
>> Author: tsoome
>> Date: Mon Sep 16 20:28:08 2019
>> New Revision: 352421
>> URL: https://svnweb.freebsd.org/changeset/base/352421
>>=20
>> Log:
>>  loader: Malloc(0) should return NULL.
>>=20
>>  We really should not allocate anything with size 0.
> Why ?  This is quite unexpected from other environments, where
> malloc(0) returns unique object.
>=20

Hiding bugs. And, we are not getting unique object, we are getting chunk =
of memory with payload length of 0 and the memory content depends on if =
head and tail guards are used - the chunk is with size at least =
MALLOCALIGN (16 or 64 bytes) and the chunk is from random location of =
heap.

rgds,
toomas=



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