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mm/memory_hotplug: don't access uninitialized memmaps in shrink_pgdat_span()
commit00d6c019b5
upstream. We might use the nid of memmaps that were never initialized. For example, if the memmap was poisoned, we will crash the kernel in pfn_to_nid() right now. Let's use the calculated boundaries of the separate zones instead. This now also avoids having to iterate over a whole bunch of subsections again, after shrinking one zone. Before commitd0dc12e86b
("mm/memory_hotplug: optimize memory hotplug"), the memmap was initialized to 0 and the node was set to the right value. After that commit, the node might be garbage. We'll have to fix shrink_zone_span() next. Link: http://lkml.kernel.org/r/20191006085646.5768-4-david@redhat.com Fixes:f1dd2cd13c
("mm, memory_hotplug: do not associate hotadded memory to zones until online") [d0dc12e86b
] Signed-off-by: David Hildenbrand <david@redhat.com> Reported-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> Cc: Oscar Salvador <osalvador@suse.de> Cc: David Hildenbrand <david@redhat.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Pavel Tatashin <pasha.tatashin@soleen.com> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Wei Yang <richardw.yang@linux.intel.com> Cc: Alexander Duyck <alexander.h.duyck@linux.intel.com> Cc: Alexander Potapenko <glider@google.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Anshuman Khandual <anshuman.khandual@arm.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Christian Borntraeger <borntraeger@de.ibm.com> Cc: Christophe Leroy <christophe.leroy@c-s.fr> Cc: Damian Tometzki <damian.tometzki@gmail.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: Gerald Schaefer <gerald.schaefer@de.ibm.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Halil Pasic <pasic@linux.ibm.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Ira Weiny <ira.weiny@intel.com> Cc: Jason Gunthorpe <jgg@ziepe.ca> Cc: Jun Yao <yaojun8558363@gmail.com> Cc: Logan Gunthorpe <logang@deltatee.com> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Masahiro Yamada <yamada.masahiro@socionext.com> Cc: "Matthew Wilcox (Oracle)" <willy@infradead.org> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Mike Rapoport <rppt@linux.ibm.com> Cc: Pankaj Gupta <pagupta@redhat.com> Cc: Paul Mackerras <paulus@samba.org> Cc: Pavel Tatashin <pavel.tatashin@microsoft.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Qian Cai <cai@lca.pw> Cc: Rich Felker <dalias@libc.org> Cc: Robin Murphy <robin.murphy@arm.com> Cc: Steve Capper <steve.capper@arm.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Tom Lendacky <thomas.lendacky@amd.com> Cc: Tony Luck <tony.luck@intel.com> Cc: Vasily Gorbik <gor@linux.ibm.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Wei Yang <richard.weiyang@gmail.com> Cc: Will Deacon <will@kernel.org> Cc: Yoshinori Sato <ysato@users.sourceforge.jp> Cc: Yu Zhao <yuzhao@google.com> Cc: <stable@vger.kernel.org> [4.13+] Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
parent
a99fc91770
commit
b55841e182
1 changed files with 16 additions and 61 deletions
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@ -459,70 +459,25 @@ static void shrink_zone_span(struct zone *zone, unsigned long start_pfn,
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zone_span_writeunlock(zone);
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zone_span_writeunlock(zone);
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}
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}
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static void shrink_pgdat_span(struct pglist_data *pgdat,
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static void update_pgdat_span(struct pglist_data *pgdat)
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unsigned long start_pfn, unsigned long end_pfn)
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{
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{
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unsigned long pgdat_start_pfn = pgdat->node_start_pfn;
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unsigned long node_start_pfn = 0, node_end_pfn = 0;
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unsigned long p = pgdat_end_pfn(pgdat); /* pgdat_end_pfn namespace clash */
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struct zone *zone;
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unsigned long pgdat_end_pfn = p;
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unsigned long pfn;
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struct mem_section *ms;
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int nid = pgdat->node_id;
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if (pgdat_start_pfn == start_pfn) {
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for (zone = pgdat->node_zones;
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/*
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zone < pgdat->node_zones + MAX_NR_ZONES; zone++) {
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* If the section is smallest section in the pgdat, it need
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unsigned long zone_end_pfn = zone->zone_start_pfn +
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* shrink pgdat->node_start_pfn and pgdat->node_spanned_pages.
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zone->spanned_pages;
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* In this case, we find second smallest valid mem_section
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* for shrinking zone.
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/* No need to lock the zones, they can't change. */
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*/
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if (zone_end_pfn > node_end_pfn)
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pfn = find_smallest_section_pfn(nid, NULL, end_pfn,
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node_end_pfn = zone_end_pfn;
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pgdat_end_pfn);
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if (zone->zone_start_pfn < node_start_pfn)
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if (pfn) {
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node_start_pfn = zone->zone_start_pfn;
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pgdat->node_start_pfn = pfn;
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pgdat->node_spanned_pages = pgdat_end_pfn - pfn;
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}
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} else if (pgdat_end_pfn == end_pfn) {
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/*
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* If the section is biggest section in the pgdat, it need
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* shrink pgdat->node_spanned_pages.
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* In this case, we find second biggest valid mem_section for
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* shrinking zone.
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*/
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pfn = find_biggest_section_pfn(nid, NULL, pgdat_start_pfn,
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start_pfn);
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if (pfn)
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pgdat->node_spanned_pages = pfn - pgdat_start_pfn + 1;
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}
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}
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/*
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pgdat->node_start_pfn = node_start_pfn;
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* If the section is not biggest or smallest mem_section in the pgdat,
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pgdat->node_spanned_pages = node_end_pfn - node_start_pfn;
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* it only creates a hole in the pgdat. So in this case, we need not
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* change the pgdat.
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* But perhaps, the pgdat has only hole data. Thus it check the pgdat
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* has only hole or not.
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*/
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pfn = pgdat_start_pfn;
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for (; pfn < pgdat_end_pfn; pfn += PAGES_PER_SECTION) {
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ms = __pfn_to_section(pfn);
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if (unlikely(!valid_section(ms)))
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continue;
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if (pfn_to_nid(pfn) != nid)
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continue;
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/* If the section is current section, it continues the loop */
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if (start_pfn == pfn)
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continue;
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/* If we find valid section, we have nothing to do */
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return;
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}
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/* The pgdat has no valid section */
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pgdat->node_start_pfn = 0;
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pgdat->node_spanned_pages = 0;
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}
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}
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static void __remove_zone(struct zone *zone, unsigned long start_pfn)
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static void __remove_zone(struct zone *zone, unsigned long start_pfn)
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@ -533,7 +488,7 @@ static void __remove_zone(struct zone *zone, unsigned long start_pfn)
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pgdat_resize_lock(zone->zone_pgdat, &flags);
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pgdat_resize_lock(zone->zone_pgdat, &flags);
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shrink_zone_span(zone, start_pfn, start_pfn + nr_pages);
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shrink_zone_span(zone, start_pfn, start_pfn + nr_pages);
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shrink_pgdat_span(pgdat, start_pfn, start_pfn + nr_pages);
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update_pgdat_span(pgdat);
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pgdat_resize_unlock(zone->zone_pgdat, &flags);
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pgdat_resize_unlock(zone->zone_pgdat, &flags);
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}
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}
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