Commit 19e1c506 authored by Wupeng Ma's avatar Wupeng Ma
Browse files

arm64: mm: add mc support for __buffer_migrate_page 

hulk inclusion
category: feature
bugzilla: https://gitee.com/openeuler/kernel/issues/IB0OV7



--------------------------------

During our test, panic happens when kernel try to read a
user page in __buffer_migrate_page with the following trace:

  Internal error: synchronous external abort: ffffffff96000410 [#1] SMP
  pstate: 00401009 (nzcv daif +PAN -UAO -TCO BTYPE=--)
  pc : copy_page+0x40/0xbc
  lr : copy_highpage+0x3c/0x60
  sp : ffff8040de1caec0
  Call trace:
   copy_page+0x40/0xbc
   migrate_page_copy+0x44/0xd0
   __buffer_migrate_page.part.0+0x288/0x3f0
   buffer_migrate_page+0x28/0x60
   move_to_new_page+0x68/0x274
   __unmap_and_move+0x424/0x574
   unmap_and_move+0x84/0x67c
   migrate_pages+0x160/0x540
   compact_zone+0x1d8/0x5b4
   compact_zone_order+0xa4/0xfc
   try_to_compact_pages+0xb0/0x2a0
   __alloc_pages_direct_compact+0x9c/0x210
   __alloc_pages+0x844/0x1214
   alloc_pages_vma+0x388/0x3e0
   do_huge_pmd_anonymous_page+0x170/0x574
   __handle_mm_fault+0x374/0x3ac
   handle_mm_fault+0xf4/0x260
   __get_user_pages+0x218/0x42c
   __gup_longterm_locked+0x94/0x2c0
   internal_get_user_pages_fast+0x140/0x240
   pin_user_pages_fast+0x24/0x50
   __ib_umem_get.part.0+0x22c/0x4e0 [ib_uverbs]
   ib_umem_get+0x90/0xc0 [ib_uverbs]
   hns_roce_mtr_create+0x78/0x334 [hns_roce_hw_v2]
   alloc_mr_pbl+0xe4/0x18c [hns_roce_hw_v2]
   hns_roce_reg_user_mr+0xf4/0x1a0 [hns_roce_hw_v2]
   ib_uverbs_reg_mr+0x120/0x2c0 [ib_uverbs]
   ib_uverbs_handler_UVERBS_METHOD_INVOKE_WRITE+0xe4/0x180 [ib_uverbs]
   ib_uverbs_run_method+0x33c/0x3d4 [ib_uverbs]
   ib_uverbs_cmd_verbs+0x128/0x1dc [ib_uverbs]
   ib_uverbs_ioctl+0xfc/0x1d0 [ib_uverbs]
   __arm64_sys_ioctl+0xb0/0x110
   invoke_syscall+0x50/0x134
   el0_svc_common.constprop.0+0x10c/0x12c
   do_el0_svc+0x34/0xe0
   el0_svc+0x20/0x30
   el0_sync_handler+0xb8/0xc0
   el0_sync+0x160/0x180
  Code: 91020021 f2402c1f d503201f a8300c02 (a9400c22)
  ---[ end trace ccd629679fc3e8d1 ]---

To fix this, Use migrate_page_mc_extra to replace migrate_page_copy in
__buffer_migrate_page to add mc support for this function.

Signed-off-by: default avatarWupeng Ma <mawupeng1@huawei.com>
parent 8c45ad1b

mm/migrate.c

+11 −1
Original line number Diff line number Diff line
@@ -820,6 +820,7 @@ static int __buffer_migrate_page(struct address_space *mapping, 
	struct buffer_head *bh, *head;

	int rc;

	int expected_count;

	bool copy_done = false;



	if (!page_has_buffers(page))

		return migrate_page(mapping, newpage, page, mode);
@@ -860,7 +861,13 @@ static int __buffer_migrate_page(struct address_space *mapping, 
		}

	}



	if (IS_ENABLED(CONFIG_ARM64) && IS_ENABLED(CONFIG_ARCH_HAS_COPY_MC) &&

	    (mode != MIGRATE_SYNC_NO_COPY)) {

		rc = migrate_page_mc_extra(mapping, newpage, page, mode, 0);

		copy_done = true;

	} else {

		rc = migrate_page_move_mapping(mapping, newpage, page, 0);

	}

	if (rc != MIGRATEPAGE_SUCCESS)

		goto unlock_buffers;
@@ -873,6 +880,9 @@ static int __buffer_migrate_page(struct address_space *mapping, 


	} while (bh != head);



	if (copy_done)

		goto unlock_buffers;



	if (mode != MIGRATE_SYNC_NO_COPY)

		migrate_page_copy(newpage, page);

	else