Commit 34290e2c authored Jan 30, 2020 by Ralph Campbell Committed by Linus Torvalds Jan 31, 2020

mm/migrate: add stable check in migrate_vma_insert_page()

migrate_vma_insert_page() closely follows the code in:
  __handle_mm_fault()
    handle_pte_fault()
      do_anonymous_page()

Add a call to check_stable_address_space() after locking the page table
entry before inserting a ZONE_DEVICE private zero page mapping similar
to page faulting a new anonymous page.

Link: http://lkml.kernel.org/r/20200107211208.24595-4-rcampbell@nvidia.com


Signed-off-by: Ralph Campbell <rcampbell@nvidia.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Cc: Jerome Glisse <jglisse@redhat.com>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: Jason Gunthorpe <jgg@mellanox.com>
Cc: Bharata B Rao <bharata@linux.ibm.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Chris Down <chris@chrisdown.name>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

parent c23a0c99

mm/migrate.c

+12 −0

Original line number	Diff line number	Diff line
		@@ -48,6 +48,7 @@
		#include <linux/page_owner.h>
		#include <linux/sched/mm.h>
		#include <linux/ptrace.h>
		#include <linux/oom.h>

		#include <asm/tlbflush.h>

		@@ -2695,6 +2696,14 @@ int migrate_vma_setup(struct migrate_vma *args)
		}
		EXPORT_SYMBOL(migrate_vma_setup);

		/*
		* This code closely matches the code in:
		* __handle_mm_fault()
		* handle_pte_fault()
		* do_anonymous_page()
		* to map in an anonymous zero page but the struct page will be a ZONE_DEVICE
		* private page.
		*/
		static void migrate_vma_insert_page(struct migrate_vma *migrate,
		unsigned long addr,
		struct page *page,
		@@ -2775,6 +2784,9 @@ static void migrate_vma_insert_page(struct migrate_vma *migrate,

		ptep = pte_offset_map_lock(mm, pmdp, addr, &ptl);

		if (check_stable_address_space(mm))
		goto unlock_abort;

		if (pte_present(*ptep)) {
		unsigned long pfn = pte_pfn(*ptep);

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