From: Dan Williams <dan.j.williams@intel.com> To: linux-mm@kvack.org Cc: 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: [PATCH v2 2/5] mm: Teach pfn_to_online_page() to consider subsection validity Date: Tue, 12 Jan 2021 01:34:47 -0800 [thread overview] Message-ID: <161044408728.1482714.9086710868634042303.stgit@dwillia2-desk3.amr.corp.intel.com> (raw) In-Reply-To: <161044407603.1482714.16630477578392768273.stgit@dwillia2-desk3.amr.corp.intel.com> pfn_section_valid() determines pfn validity on subsection granularity. pfn_valid_within() internally uses pfn_section_valid(), but gates it with early_section() to preserve the traditional behavior of pfn_valid() before subsection support was added. pfn_to_online_page() wants the explicit precision that pfn_valid() does not offer, so use pfn_section_valid() directly. Since pfn_to_online_page() already open codes the validity of the section number vs NR_MEM_SECTIONS, there's not much value to using pfn_valid_within(), just use pfn_section_valid(). This loses the valid_section() check that pfn_valid_within() was performing, but that was already redundant with the online check. Fixes: b13bc35193d9 ("mm/hotplug: invalid PFNs from pfn_to_online_page()") Cc: Qian Cai <cai@lca.pw> Cc: Michal Hocko <mhocko@suse.com> Reported-by: David Hildenbrand <david@redhat.com> --- mm/memory_hotplug.c | 16 ++++++++++++---- 1 file changed, 12 insertions(+), 4 deletions(-) diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c index 55a69d4396e7..a845b3979bc0 100644 --- a/mm/memory_hotplug.c +++ b/mm/memory_hotplug.c @@ -308,11 +308,19 @@ 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; + + 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); _______________________________________________ Linux-nvdimm mailing list -- linux-nvdimm@lists.01.org To unsubscribe send an email to linux-nvdimm-leave@lists.01.org
WARNING: multiple messages have this Message-ID (diff)
From: Dan Williams <dan.j.williams@intel.com> To: linux-mm@kvack.org Cc: 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: [PATCH v2 2/5] mm: Teach pfn_to_online_page() to consider subsection validity Date: Tue, 12 Jan 2021 01:34:47 -0800 [thread overview] Message-ID: <161044408728.1482714.9086710868634042303.stgit@dwillia2-desk3.amr.corp.intel.com> (raw) In-Reply-To: <161044407603.1482714.16630477578392768273.stgit@dwillia2-desk3.amr.corp.intel.com> pfn_section_valid() determines pfn validity on subsection granularity. pfn_valid_within() internally uses pfn_section_valid(), but gates it with early_section() to preserve the traditional behavior of pfn_valid() before subsection support was added. pfn_to_online_page() wants the explicit precision that pfn_valid() does not offer, so use pfn_section_valid() directly. Since pfn_to_online_page() already open codes the validity of the section number vs NR_MEM_SECTIONS, there's not much value to using pfn_valid_within(), just use pfn_section_valid(). This loses the valid_section() check that pfn_valid_within() was performing, but that was already redundant with the online check. Fixes: b13bc35193d9 ("mm/hotplug: invalid PFNs from pfn_to_online_page()") Cc: Qian Cai <cai@lca.pw> Cc: Michal Hocko <mhocko@suse.com> Reported-by: David Hildenbrand <david@redhat.com> --- mm/memory_hotplug.c | 16 ++++++++++++---- 1 file changed, 12 insertions(+), 4 deletions(-) diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c index 55a69d4396e7..a845b3979bc0 100644 --- a/mm/memory_hotplug.c +++ b/mm/memory_hotplug.c @@ -308,11 +308,19 @@ 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; + + 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);
next prev parent reply other threads:[~2021-01-12 9:34 UTC|newest] Thread overview: 34+ messages / expand[flat|nested] mbox.gz Atom feed top 2021-01-12 9:34 [PATCH v2 0/5] mm: Fix pfn_to_online_page() with respect to ZONE_DEVICE Dan Williams 2021-01-12 9:34 ` Dan Williams 2021-01-12 9:34 ` [PATCH v2 1/5] mm: Move pfn_to_online_page() out of line Dan Williams 2021-01-12 9:34 ` Dan Williams 2021-01-12 9:46 ` David Hildenbrand 2021-01-12 9:46 ` David Hildenbrand 2021-01-12 10:19 ` Oscar Salvador 2021-01-12 10:19 ` Oscar Salvador 2021-01-12 9:34 ` Dan Williams [this message] 2021-01-12 9:34 ` [PATCH v2 2/5] mm: Teach pfn_to_online_page() to consider subsection validity Dan Williams 2021-01-12 9:53 ` David Hildenbrand 2021-01-12 9:53 ` David Hildenbrand 2021-01-12 10:48 ` Oscar Salvador 2021-01-12 10:48 ` Oscar Salvador 2021-01-12 22:20 ` Dan Williams 2021-01-12 22:20 ` Dan Williams 2021-01-12 22:20 ` Dan Williams 2021-01-12 9:34 ` [PATCH v2 3/5] mm: Teach pfn_to_online_page() about ZONE_DEVICE section collisions Dan Williams 2021-01-12 9:34 ` Dan Williams 2021-01-12 10:01 ` David Hildenbrand 2021-01-12 10:01 ` David Hildenbrand 2021-01-12 11:00 ` Oscar Salvador 2021-01-12 11:00 ` Oscar Salvador 2021-01-12 9:34 ` [PATCH v2 4/5] mm: Fix page reference leak in soft_offline_page() Dan Williams 2021-01-12 9:34 ` Dan Williams 2021-01-12 9:53 ` Oscar Salvador 2021-01-12 9:53 ` Oscar Salvador 2021-01-12 20:03 ` Dan Williams 2021-01-12 20:03 ` Dan Williams 2021-01-12 20:03 ` Dan Williams 2021-01-12 10:16 ` David Hildenbrand 2021-01-12 10:16 ` David Hildenbrand 2021-01-12 9:35 ` [PATCH v2 5/5] libnvdimm/namespace: Fix visibility of namespace resource attribute Dan Williams 2021-01-12 9:35 ` Dan Williams
Reply instructions: You may reply publicly to this message via plain-text email using any one of the following methods: * Save the following mbox file, import it into your mail client, and reply-to-all from there: mbox Avoid top-posting and favor interleaved quoting: https://en.wikipedia.org/wiki/Posting_style#Interleaved_style * Reply using the --to, --cc, and --in-reply-to switches of git-send-email(1): git send-email \ --in-reply-to=161044408728.1482714.9086710868634042303.stgit@dwillia2-desk3.amr.corp.intel.com \ --to=dan.j.williams@intel.com \ --cc=cai@lca.pw \ --cc=david@redhat.com \ --cc=linux-kernel@vger.kernel.org \ --cc=linux-mm@kvack.org \ --cc=linux-nvdimm@lists.01.org \ --cc=mhocko@suse.com \ /path/to/YOUR_REPLY https://kernel.org/pub/software/scm/git/docs/git-send-email.html * If your mail client supports setting the In-Reply-To header via mailto: links, try the mailto: linkBe sure your reply has a Subject: header at the top and a blank line before the message body.
This is an external index of several public inboxes, see mirroring instructions on how to clone and mirror all data and code used by this external index.