From: Borislav Petkov <bp@alien8.de>
To: James Morse <james.morse@arm.com>
Cc: linux-edac@vger.kernel.org,
Mauro Carvalho Chehab <mchehab@kernel.org>,
Tony Luck <tony.luck@intel.com>,
Robert Richter <rrichter@marvell.com>,
John Garry <john.garry@huawei.com>
Subject: Re: [PATCH 0/2] EDAC, ghes: Fix use after free and add reference
Date: Mon, 14 Oct 2019 19:53:19 +0200 [thread overview]
Message-ID: <20191014175319.GH4715@zn.tnic> (raw)
In-Reply-To: <86ba3fcf-d29c-1d6a-d8c3-2a03cb11263e@arm.com>
On Mon, Oct 14, 2019 at 06:40:33PM +0100, James Morse wrote:
> Keeping both avoids the !pvt check in ghes_edac_report_mem_error() going wrong, but I'm
> not entirely sure what that is trying to stop...
It must've been some sanity-check in
f04c62a7036a ("ghes_edac: add support for reporting errors via EDAC")
> The possibility of races between notifications and unregister only occurred to me after
> testing the first patch, so they ended up as different things in my head: I thought it
> deserved its own commit log as its unrelated to the KASAN splat.
To me they fix two different aspects of the missing counting on unreg.
> I think you need some kind of reference count to know how many more GHES.x there are out
> there that may call unregister, otherwise you race with notifications.
Provided unregister cannot be called concurrently, the
if (!ghes_pvt)
return;
in ghes_edac_unregister() should suffice.
But just to be on the safe side, it could get an "instance_mutex" or so
under which ghes_pvt is set and cleared and then that silly counter can
simply go away.
Thoughts?
--
Regards/Gruss,
Boris.
https://people.kernel.org/tglx/notes-about-netiquette
next prev parent reply other threads:[~2019-10-14 17:53 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-10-14 17:19 [PATCH 0/2] EDAC, ghes: Fix use after free and add reference James Morse
2019-10-14 17:19 ` [PATCH 1/2] EDAC, ghes: Fix Use after free in ghes_edac remove path James Morse
2019-10-14 17:19 ` [PATCH 2/2] EDAC, ghes: Reference count GHES users of ghes_edac James Morse
2019-10-14 17:30 ` [PATCH 0/2] EDAC, ghes: Fix use after free and add reference Borislav Petkov
2019-10-14 17:40 ` James Morse
2019-10-14 17:53 ` Borislav Petkov [this message]
2019-10-16 15:17 ` Borislav Petkov
2019-10-16 15:30 ` James Morse
2019-10-16 18:50 ` Borislav Petkov
2019-10-21 7:37 ` Borislav Petkov
2019-10-21 10:52 ` Robert Richter
2019-10-22 13:25 ` Robert Richter
2019-10-15 13:25 ` Borislav Petkov
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