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Date:   Tue, 9 Feb 2021 20:10:00 +0100
From:   Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To:     Thiago Jung Bauermann <bauerman@linux.ibm.com>
Cc:     linux-kernel@vger.kernel.org, stable@vger.kernel.org,
        Roman Gushchin <guro@fb.com>,
        Mike Rapoport <rppt@linux.ibm.com>,
        Joonsoo Kim <iamjoonsoo.kim@lge.com>,
        Michal Hocko <mhocko@kernel.org>,
        Rik van Riel <riel@surriel.com>,
        Wonhyuk Yang <vvghjk1234@gmail.com>,
        Andrew Morton <akpm@linux-foundation.org>,
        Linus Torvalds <torvalds@linux-foundation.org>,
        Sasha Levin <sashal@kernel.org>
Subject: Re: [PATCH 5.10 051/120] memblock: do not start bottom-up
 allocations with kernel_end
Message-ID: <YCLeCPWy6samik/W@kroah.com>
References: <20210208145818.395353822@linuxfoundation.org>
 <20210208145820.464727041@linuxfoundation.org>
 <875z31th2q.fsf@manicouagan.localdomain>
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On Tue, Feb 09, 2021 at 12:07:57PM -0300, Thiago Jung Bauermann wrote:
> 
> Greg Kroah-Hartman <gregkh@linuxfoundation.org> writes:
> 
> > From: Roman Gushchin <guro@fb.com>
> >
> > [ Upstream commit 2dcb3964544177c51853a210b6ad400de78ef17d ]
> >
> > With kaslr the kernel image is placed at a random place, so starting the
> > bottom-up allocation with the kernel_end can result in an allocation
> > failure and a warning like this one:
> 
> Not sure if this is ready for stable yet (including stable branches 4.19
> and 5.4), since it seems to uncover latent bugs in x86 early memory
> reservation. I asked about this issue here:
> 
> https://lore.kernel.org/lkml/87ft26yuwg.fsf@manicouagan.localdomain/

If there are fixes for this that get merged, please make sure they get
tagged properly to go to the stable trees as well.

thanks,

greg k-h