From: "Luck, Tony" <tony.luck@intel.com>
To: Jane Chu <jane.chu@oracle.com>
Cc: "Williams, Dan J" <dan.j.williams@intel.com>,
"bp@alien8.de" <bp@alien8.de>,
"tglx@linutronix.de" <tglx@linutronix.de>,
"mingo@redhat.com" <mingo@redhat.com>,
"dave.hansen@linux.intel.com" <dave.hansen@linux.intel.com>,
"x86@kernel.org" <x86@kernel.org>,
"linux-edac@vger.kernel.org" <linux-edac@vger.kernel.org>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
"hch@lst.de" <hch@lst.de>,
"nvdimm@lists.linux.dev" <nvdimm@lists.linux.dev>
Subject: Re: [PATCH v3] x86/mce: retrieve poison range from hardware
Date: Mon, 18 Jul 2022 14:37:53 -0700 [thread overview]
Message-ID: <YtXSsUmh5XcVXGa3@agluck-desk3.sc.intel.com> (raw)
In-Reply-To: <5a92e418-9f50-8212-92a0-4ac39cefa9ef@oracle.com>
On Mon, Jul 18, 2022 at 09:11:33PM +0000, Jane Chu wrote:
> On 7/18/2022 12:22 PM, Luck, Tony wrote:
> >> It appears the kernel is trusting that ->physical_addr_mask is non-zero
> >> in other paths. So this is at least equally broken in the presence of a
> >> broken BIOS. The impact is potentially larger though with this change,
> >> so it might be a good follow-on patch to make sure that
> >> ->physical_addr_mask gets fixed up to a minimum mask value.
> >
> > Agreed. Separate patch to sanitize early, so other kernel code can just use it.
> >
>
> Is it possible that with
> if (mem->validation_bits & CPER_MEM_VALID_PA_MASK)
> the ->physical_addr_mask is still untrustworthy?
The validation_bits just show which fields the BIOS *says* it filled in.
If a validation bit isn't set, then Linux should certainly ignore that
field. But if it is set, then Linux needs to decide whether to use the
value, or do a sanity check first.
-Tony
prev parent reply other threads:[~2022-07-18 21:38 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-07-17 23:48 [PATCH v3] x86/mce: retrieve poison range from hardware Jane Chu
2022-07-18 16:19 ` Luck, Tony
2022-07-18 19:15 ` Dan Williams
2022-07-18 19:22 ` Luck, Tony
2022-07-18 21:11 ` Jane Chu
2022-07-18 21:37 ` Luck, Tony [this message]
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