From: Oscar Salvador <osalvador@suse.de>
To: Dan Williams <dan.j.williams@intel.com>
Cc: linux-mm@kvack.org, Qian Cai <cai@lca.pw>,
Michal Hocko <mhocko@suse.com>,
David Hildenbrand <david@redhat.com>,
linux-nvdimm@lists.01.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH v3 2/6] mm: Teach pfn_to_online_page() to consider subsection validity
Date: Wed, 13 Jan 2021 09:30:52 +0100 [thread overview]
Message-ID: <20210113083048.GA23676@linux> (raw)
In-Reply-To: <161052332755.1805594.9846390935351758277.stgit@dwillia2-desk3.amr.corp.intel.com>
On Tue, Jan 12, 2021 at 11:35:27PM -0800, Dan Williams wrote:
> pfn_section_valid() determines pfn validity on subsection granularity
> where pfn_valid() may be limited to coarse section granularity.
> Explicitly validate subsections after pfn_valid() succeeds.
>
> Fixes: b13bc35193d9 ("mm/hotplug: invalid PFNs from pfn_to_online_page()")
> Cc: Qian Cai <cai@lca.pw>
> Cc: Michal Hocko <mhocko@suse.com>
> Cc: Oscar Salvador <osalvador@suse.de>
> Reported-by: David Hildenbrand <david@redhat.com>
> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Reviewed-by: Oscar Salvador <osalvador@suse.de>
> ---
> mm/memory_hotplug.c | 24 ++++++++++++++++++++----
> 1 file changed, 20 insertions(+), 4 deletions(-)
>
> diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c
> index 55a69d4396e7..9f37f8a68da4 100644
> --- a/mm/memory_hotplug.c
> +++ b/mm/memory_hotplug.c
> @@ -308,11 +308,27 @@ static int check_hotplug_memory_addressable(unsigned long pfn,
> struct page *pfn_to_online_page(unsigned long pfn)
> {
> unsigned long nr = pfn_to_section_nr(pfn);
> + struct mem_section *ms;
> +
> + if (nr >= NR_MEM_SECTIONS)
> + return NULL;
> +
> + ms = __nr_to_section(nr);
> + if (!online_section(ms))
> + return NULL;
> +
> + /*
> + * Save some code text when online_section() +
> + * pfn_section_valid() are sufficient.
> + */
> + if (IS_ENABLED(CONFIG_HAVE_ARCH_PFN_VALID))
> + if (!pfn_valid(pfn))
> + return NULL;
> +
> + if (!pfn_section_valid(ms, pfn))
> + return NULL;
>
> - if (nr < NR_MEM_SECTIONS && online_section_nr(nr) &&
> - pfn_valid_within(pfn))
> - return pfn_to_page(pfn);
> - return NULL;
> + return pfn_to_page(pfn);
> }
> EXPORT_SYMBOL_GPL(pfn_to_online_page);
>
>
--
Oscar Salvador
SUSE L3
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WARNING: multiple messages have this Message-ID (diff)
From: Oscar Salvador <osalvador@suse.de>
To: Dan Williams <dan.j.williams@intel.com>
Cc: linux-mm@kvack.org, Qian Cai <cai@lca.pw>,
Michal Hocko <mhocko@suse.com>,
David Hildenbrand <david@redhat.com>,
vishal.l.verma@intel.com, linux-nvdimm@lists.01.org,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH v3 2/6] mm: Teach pfn_to_online_page() to consider subsection validity
Date: Wed, 13 Jan 2021 09:30:52 +0100 [thread overview]
Message-ID: <20210113083048.GA23676@linux> (raw)
In-Reply-To: <161052332755.1805594.9846390935351758277.stgit@dwillia2-desk3.amr.corp.intel.com>
On Tue, Jan 12, 2021 at 11:35:27PM -0800, Dan Williams wrote:
> pfn_section_valid() determines pfn validity on subsection granularity
> where pfn_valid() may be limited to coarse section granularity.
> Explicitly validate subsections after pfn_valid() succeeds.
>
> Fixes: b13bc35193d9 ("mm/hotplug: invalid PFNs from pfn_to_online_page()")
> Cc: Qian Cai <cai@lca.pw>
> Cc: Michal Hocko <mhocko@suse.com>
> Cc: Oscar Salvador <osalvador@suse.de>
> Reported-by: David Hildenbrand <david@redhat.com>
> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Reviewed-by: Oscar Salvador <osalvador@suse.de>
> ---
> mm/memory_hotplug.c | 24 ++++++++++++++++++++----
> 1 file changed, 20 insertions(+), 4 deletions(-)
>
> diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c
> index 55a69d4396e7..9f37f8a68da4 100644
> --- a/mm/memory_hotplug.c
> +++ b/mm/memory_hotplug.c
> @@ -308,11 +308,27 @@ static int check_hotplug_memory_addressable(unsigned long pfn,
> struct page *pfn_to_online_page(unsigned long pfn)
> {
> unsigned long nr = pfn_to_section_nr(pfn);
> + struct mem_section *ms;
> +
> + if (nr >= NR_MEM_SECTIONS)
> + return NULL;
> +
> + ms = __nr_to_section(nr);
> + if (!online_section(ms))
> + return NULL;
> +
> + /*
> + * Save some code text when online_section() +
> + * pfn_section_valid() are sufficient.
> + */
> + if (IS_ENABLED(CONFIG_HAVE_ARCH_PFN_VALID))
> + if (!pfn_valid(pfn))
> + return NULL;
> +
> + if (!pfn_section_valid(ms, pfn))
> + return NULL;
>
> - if (nr < NR_MEM_SECTIONS && online_section_nr(nr) &&
> - pfn_valid_within(pfn))
> - return pfn_to_page(pfn);
> - return NULL;
> + return pfn_to_page(pfn);
> }
> EXPORT_SYMBOL_GPL(pfn_to_online_page);
>
>
--
Oscar Salvador
SUSE L3
next prev parent reply other threads:[~2021-01-13 8:31 UTC|newest]
Thread overview: 25+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-01-13 7:35 [PATCH v3 0/6] mm: Fix pfn_to_online_page() with respect to ZONE_DEVICE Dan Williams
2021-01-13 7:35 ` Dan Williams
2021-01-13 7:35 ` [PATCH v3 1/6] mm: Move pfn_to_online_page() out of line Dan Williams
2021-01-13 7:35 ` Dan Williams
2021-01-13 7:35 ` [PATCH v3 2/6] mm: Teach pfn_to_online_page() to consider subsection validity Dan Williams
2021-01-13 7:35 ` Dan Williams
2021-01-13 8:29 ` David Hildenbrand
2021-01-13 8:29 ` David Hildenbrand
2021-01-13 21:52 ` Dan Williams
2021-01-13 21:52 ` Dan Williams
2021-01-13 21:52 ` Dan Williams
2021-01-13 8:30 ` Oscar Salvador [this message]
2021-01-13 8:30 ` Oscar Salvador
2021-01-13 7:35 ` [PATCH v3 3/6] mm: Teach pfn_to_online_page() about ZONE_DEVICE section collisions Dan Williams
2021-01-13 7:35 ` Dan Williams
2021-01-13 7:35 ` [PATCH v3 4/6] mm: Fix page reference leak in soft_offline_page() Dan Williams
2021-01-13 7:35 ` Dan Williams
2021-01-13 7:35 ` [PATCH v3 5/6] mm: Fix memory_failure() handling of dax-namespace metadata Dan Williams
2021-01-13 7:35 ` Dan Williams
2021-01-13 8:31 ` David Hildenbrand
2021-01-13 8:31 ` David Hildenbrand
2021-01-13 7:35 ` [PATCH v3 6/6] libnvdimm/namespace: Fix visibility of namespace resource attribute Dan Williams
2021-01-13 7:35 ` Dan Williams
2021-01-13 8:35 ` Greg KH
2021-01-13 8:35 ` Greg KH
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