From: "Edgecombe, Rick P" <rick.p.edgecombe@intel.com>
To: "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
"linux-mm@kvack.org" <linux-mm@kvack.org>,
"corbet@lwn.net" <corbet@lwn.net>,
"pasha.tatashin@soleen.com" <pasha.tatashin@soleen.com>,
"akpm@linux-foundation.org" <akpm@linux-foundation.org>,
"linux-doc@vger.kernel.org" <linux-doc@vger.kernel.org>
Subject: Re: [PATCH 1/3] mm/page_table_check: Check writable zero page in page table check
Date: Mon, 12 Sep 2022 15:58:14 +0000 [thread overview]
Message-ID: <8e83a99a22b19f0189ea68c99d20eb4b0a18dd59.camel@intel.com> (raw)
In-Reply-To: <20220911095923.3614387-2-pasha.tatashin@soleen.com>
On Sun, 2022-09-11 at 09:59 +0000, Pasha Tatashin wrote:
> From: Rick Edgecombe <rick.p.edgecombe@intel.com>
>
> The zero page should remain all zero, so that it can be mapped as
> read-only for read faults of memory that should be zeroed. If it is
> ever
> mapped writable to userspace, it could become non-zero and so other
> apps
> would unexpectedly get non-zero data. So the zero page should never
> be
> mapped writable to userspace. Check for this condition in
> page_table_check_set().
>
> Signed-off-by: Rick Edgecombe <rick.p.edgecombe@intel.com>
> Signed-off-by: Pasha Tatashin <pasha.tatashin@soleen.com>
> ---
> mm/page_table_check.c | 2 ++
> 1 file changed, 2 insertions(+)
>
Thanks. Should we put this at the end, in order to not add any more
BUG_ON()'s to the kernel? Or I can just send a follow up and add the
docs you asked for.
next prev parent reply other threads:[~2022-09-12 15:58 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-09-11 9:59 [PATCH 0/3] page table check default to warn instead of panic Pasha Tatashin
2022-09-11 9:59 ` [PATCH 1/3] mm/page_table_check: Check writable zero page in page table check Pasha Tatashin
2022-09-12 15:58 ` Edgecombe, Rick P [this message]
2022-09-26 8:26 ` David Hildenbrand
2022-09-11 9:59 ` [PATCH 2/3] mm/page_table_check: Do WARN_ON instead of BUG_ON by default Pasha Tatashin
2022-09-11 16:08 ` Matthew Wilcox
2022-09-11 20:42 ` Pasha Tatashin
2022-09-26 8:28 ` David Hildenbrand
2022-09-26 1:16 ` [mm/page_table_check] 6e807506f4: WARNING:at_mm/page_table_check.c:#page_table_check_set kernel test robot
2022-09-11 9:59 ` [PATCH 3/3] doc/vm: add information about page_table_check=panic Pasha Tatashin
2022-09-12 20:23 ` [PATCH 0/3] page table check default to warn instead of panic Andrew Morton
2022-09-20 18:11 ` Pasha Tatashin
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