From: mark.rutland@arm.com (Mark Rutland)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCH v3] arm64: mm: move zero page from .bss to right before swapper_pg_dir
Date: Tue, 13 Sep 2016 21:24:10 +0100 [thread overview]
Message-ID: <20160913202410.GA2947@remoulade> (raw)
In-Reply-To: <CAKv+Gu90AokunA3zOcNhwXsFpCpoY_juipnr3y68nefZk9Ff0w@mail.gmail.com>
On Tue, Sep 13, 2016 at 08:18:52PM +0100, Ard Biesheuvel wrote:
> On 13 September 2016 at 18:35, Mark Rutland <mark.rutland@arm.com> wrote:
> Thanks. But actually, I think it makes sense to make the first
> swapper_pg_dir page read-only as well, given that it is only modified
> via the fixmap, and we can trivially extend the r/o bss region to end
> at 'swapper_pg_dir + PAGE_SIZE'
>
> Thoughts?
I thought that we lazy-allocated the vmalloc region at runtime, and initialised
pgd level entries.
>From a quick dig it looks like a vmalloc() could eventually call
pgd_populate(), which seems to set a pgd entry without using a fixmap slot.
Is there some reason that won't happen at runtime?
Thanks,
Mark.
next prev parent reply other threads:[~2016-09-13 20:24 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-09-12 16:15 [PATCH v3] arm64: mm: move zero page from .bss to right before swapper_pg_dir Ard Biesheuvel
2016-09-13 17:35 ` Mark Rutland
2016-09-13 19:18 ` Ard Biesheuvel
2016-09-13 20:24 ` Mark Rutland [this message]
2016-09-13 20:29 ` Ard Biesheuvel
2016-09-14 10:19 ` Mark Rutland
2016-10-07 9:31 ` Ard Biesheuvel
2016-10-09 23:10 ` Mark Rutland
2016-10-10 9:14 ` Ard Biesheuvel
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