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Date:      Wed, 18 Sep 2019 09:37:17 +0100
From:      Warner Losh <imp@bsdimp.com>
To:        "Conrad E. Meyer" <cem@freebsd.org>
Cc:        Toomas Soome <tsoome@freebsd.org>, src-committers <src-committers@freebsd.org>,  svn-src-all <svn-src-all@freebsd.org>, svn-src-head <svn-src-head@freebsd.org>
Subject:   Re: svn commit: r352451 - head/stand/libsa
Message-ID:  <CANCZdfpa6d2aeGm5cC8DUMCjEVXUwSFST8x70D0tSL5JiTJ6VQ@mail.gmail.com>
In-Reply-To: <CAG6CVpW5V7%2BkZZyMBuF_8A3Ns3ETTfaBwqzBqhSq7Ve%2BPJoDJw@mail.gmail.com>
References:  <201909171616.x8HGGlkb066218@repo.freebsd.org> <CAG6CVpW5V7%2BkZZyMBuF_8A3Ns3ETTfaBwqzBqhSq7Ve%2BPJoDJw@mail.gmail.com>

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On Wed, Sep 18, 2019, 12:18 AM Conrad Meyer <cem@freebsd.org> wrote:

> Well, hang on; it's also perfectly legal for a malloc implementation
> to return NULL for requests of zero bytes.  You can access exactly the
> number of bytes requested in the allocation; and free(NULL) works as
> expected.  NULL (0) is also aligned to any size you could want.
>

Legal, yes.  But it is different than all the other FreeBSD environments,
so the loader becomes the odd man out. This restores the consistency.

Warner

Best,
> Conrad
>
> On Tue, Sep 17, 2019 at 9:16 AM Toomas Soome <tsoome@freebsd.org> wrote:
> >
> > Author: tsoome
> > Date: Tue Sep 17 16:16:46 2019
> > New Revision: 352451
> > URL: https://svnweb.freebsd.org/changeset/base/352451
> >
> > Log:
> >   loader: revert r352421
> >
> >   As insisted by kib, malloc(0) is quite legal.
> >
> > Modified:
> >   head/stand/libsa/zalloc_malloc.c
> >
> > Modified: head/stand/libsa/zalloc_malloc.c
> >
> ==============================================================================
> > --- head/stand/libsa/zalloc_malloc.c    Tue Sep 17 15:53:40 2019
> (r352450)
> > +++ head/stand/libsa/zalloc_malloc.c    Tue Sep 17 16:16:46 2019
> (r352451)
> > @@ -73,9 +73,6 @@ Malloc_align(size_t bytes, size_t alignment)
> >  {
> >         Guard *res;
> >
> > -       if (bytes == 0)
> > -               return (NULL);
> > -
> >  #ifdef USEENDGUARD
> >         bytes += MALLOCALIGN + 1;
> >  #else
>



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