From: "Rafael J. Wysocki" <rafael@kernel.org>
To: "Rafael J. Wysocki" <rafael@kernel.org>
Cc: Mike Rapoport <rppt@linux.ibm.com>,
David Hildenbrand <david@redhat.com>,
George Kennedy <george.kennedy@oracle.com>,
Robert Moore <robert.moore@intel.com>,
Erik Kaneda <erik.kaneda@intel.com>,
Rafael Wysocki <rafael.j.wysocki@intel.com>,
Len Brown <lenb@kernel.org>,
ACPI Devel Maling List <linux-acpi@vger.kernel.org>,
"open list:ACPI COMPONENT ARCHITECTURE (ACPICA)"
<devel@acpica.org>,
Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>,
Dan Carpenter <dan.carpenter@oracle.com>,
Dhaval Giani <dhaval.giani@oracle.com>,
Andrew Morton <akpm@linux-foundation.org>,
Vlastimil Babka <vbabka@suse.cz>,
Oscar Salvador <osalvador@suse.de>,
Wei Yang <richard.weiyang@linux.alibaba.com>,
Pankaj Gupta <pankaj.gupta.linux@gmail.com>,
Michal Hocko <mhocko@suse.com>
Subject: Re: [PATCH 1/1] ACPI: fix acpi table use after free
Date: Mon, 15 Mar 2021 19:05:24 +0100 [thread overview]
Message-ID: <CAJZ5v0jf-DppG2PWwH+rQPy5untyp2inaoFg46GkxniPzRKnyA@mail.gmail.com> (raw)
In-Reply-To: <CAJZ5v0g1H6hCVbAAFajhn0AYRMU4GkZOqggOB6LVdgFx_vfwOA@mail.gmail.com>
On Mon, Mar 15, 2021 at 5:19 PM Rafael J. Wysocki <rafael@kernel.org> wrote:
>
> On Sun, Mar 14, 2021 at 8:00 PM Mike Rapoport <rppt@linux.ibm.com> wrote:
> >
> > On Thu, Mar 11, 2021 at 04:36:31PM +0100, Rafael J. Wysocki wrote:
> > > On Wed, Mar 10, 2021 at 8:47 PM David Hildenbrand <david@redhat.com> wrote:
> > > > >
> > > > > There is some care that should be taken to make sure we get the order
> > > > > right, but I don't see a fundamental issue here.
> > >
> > > Me neither.
> > >
> > > > > If I understand correctly, Rafael's concern is about changing the parts of
> > > > > ACPICA that should be OS agnostic, so I think we just need another place to
> > > > > call memblock_reserve() rather than acpi_tb_install_table_with_override().
> > >
> > > Something like this.
> > >
> > > There is also the problem that memblock_reserve() needs to be called
> > > for all of the tables early enough, which will require some reordering
> > > of the early init code.
> > >
> > > > > Since the reservation should be done early in x86::setup_arch() (and
> > > > > probably in arm64::setup_arch()) we might just have a function that parses
> > > > > table headers and reserves them, similarly to how we parse the tables
> > > > > during KASLR setup.
> > >
> > > Right.
> >
> > I've looked at it a bit more and we do something like the patch below that
> > nearly duplicates acpi_tb_parse_root_table() which is not very nice.
>
> It looks to me that the code need not be duplicated (see below).
>
> > Besides, reserving ACPI tables early and then calling acpi_table_init()
> > (and acpi_tb_parse_root_table() again would mean doing the dance with
> > early_memremap() twice for no good reason.
>
> That'd be simply inefficient which is kind of acceptable to me to start with.
>
> And I changing the ACPICA code can be avoided at least initially, it
> by itself would be a good enough reason.
>
> > I believe the most effective way to deal with this would be to have a
> > function that does parsing, reservation and installs the tables supplied by
> > the firmware which can be called really early and then another function
> > that overrides tables if needed a some later point.
>
> I agree that this should be the direction to go into.
>
> However, it looks to me that something like the following could be
> done to start with:
>
> (a) Make __acpi_map_table() call memblock_reserve() in addition to
> early_memremap().
>
> My assumption here is that the memblock_reserve() will simply be
> ignored if it is called too late.
>
> (b) Introduce acpi_reserve_tables() as something like
>
> void __init acpi_table_reserve(void)
> {
> acpi_initialize_tables(initial_tables, ACPI_MAX_TABLES, 0);
> }
>
> Because initial_tables is passed to acpi_initialize_tables() above and
> allow_resize is 0, the array used by it will simply get overwritten
> when acpi_table_init() gets called.
>
> (c) Make setup_arch() call acpi_table_reserve() like in the original
> patch from George.
>
> Would that work?
Well, that doesn't work, so more digging ...
next prev parent reply other threads:[~2021-03-15 18:06 UTC|newest]
Thread overview: 33+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-03-03 20:09 [PATCH 1/1] ACPI: fix acpi table use after free George Kennedy
2021-03-04 12:14 ` Rafael J. Wysocki
2021-03-04 23:14 ` George Kennedy
2021-03-05 13:30 ` Rafael J. Wysocki
2021-03-05 13:40 ` David Hildenbrand
2021-03-05 15:24 ` George Kennedy
2021-03-10 18:39 ` Rafael J. Wysocki
2021-03-10 18:54 ` Rafael J. Wysocki
2021-03-10 19:10 ` David Hildenbrand
2021-03-10 19:38 ` Mike Rapoport
2021-03-10 19:47 ` David Hildenbrand
2021-03-11 15:36 ` Rafael J. Wysocki
2021-03-14 18:59 ` Mike Rapoport
2021-03-15 16:19 ` Rafael J. Wysocki
2021-03-15 18:05 ` Rafael J. Wysocki [this message]
2021-03-17 20:14 ` Rafael J. Wysocki
2021-03-17 22:28 ` George Kennedy
2021-03-18 15:42 ` Rafael J. Wysocki
2021-03-18 7:25 ` Mike Rapoport
2021-03-18 10:50 ` Rafael J. Wysocki
2021-03-18 15:22 ` Rafael J. Wysocki
2021-03-20 8:25 ` Mike Rapoport
2021-03-22 16:57 ` Rafael J. Wysocki
2021-03-23 19:26 ` [PATCH] ACPI: tables: x86: Reserve memory occupied by ACPI tables Rafael J. Wysocki
2021-03-24 8:24 ` Mike Rapoport
2021-03-24 13:27 ` Rafael J. Wysocki
2021-03-24 13:49 ` George Kennedy
2021-03-24 15:42 ` George Kennedy
2021-03-24 15:44 ` Rafael J. Wysocki
2021-03-07 7:46 ` [PATCH 1/1] ACPI: fix acpi table use after free Mike Rapoport
2021-03-09 17:54 ` Mike Rapoport
2021-03-09 18:29 ` Rafael J. Wysocki
2021-03-09 20:16 ` Mike Rapoport
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