From: Dave Hansen <dave.hansen@intel.com>
To: Dan Williams <dan.j.williams@intel.com>,
tglx@linutronix.de, mingo@redhat.com, bp@alien8.de
Cc: stable@vger.kernel.org, Dave Hansen <dave.hansen@linux.intel.com>,
Andy Lutomirski <luto@kernel.org>,
Peter Zijlstra <peterz@infradead.org>,
x86@kernel.org, "H. Peter Anvin" <hpa@zytor.com>,
Yi Zhang <yi.zhang@redhat.com>,
linux-kernel@vger.kernel.org, linux-nvdimm@lists.01.org,
willy@infradead.org
Subject: Re: [PATCH] x86/mm: Fix leak of pmd ptlock
Date: Tue, 5 Jan 2021 07:40:16 -0800 [thread overview]
Message-ID: <df5209ad-e527-92ce-52a2-33e1aa9deaff@intel.com> (raw)
In-Reply-To: <160697689204.605323.17629854984697045602.stgit@dwillia2-desk3.amr.corp.intel.com>
On 12/2/20 10:28 PM, Dan Williams wrote:
> Commit 28ee90fe6048 ("x86/mm: implement free pmd/pte page interfaces")
> introduced a new location where a pmd was released, but neglected to run
> the pmd page destructor. In fact, this happened previously for a
> different pmd release path and was fixed by commit:
>
> c283610e44ec ("x86, mm: do not leak page->ptl for pmd page tables").
>
> This issue was hidden until recently because the failure mode is silent,
> but commit:
Looks sane. Thanks as always for the thorough changelog and the
investigation into why we're suddenly seeing this now.
I agree that ridding ourselves of open-coded free_page()'s is a good
idea, but this patch itself needs to be around for stable anyway. So,
Acked-by: Dave Hansen <dave.hansen@linux.intel.com>
prev parent reply other threads:[~2021-01-05 15:41 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-12-03 6:28 [PATCH] x86/mm: Fix leak of pmd ptlock Dan Williams
2020-12-03 10:54 ` Peter Zijlstra
2020-12-16 3:25 ` Dan Williams
2021-01-05 4:18 ` Dan Williams
2021-01-05 15:40 ` Dave Hansen [this message]
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