1. 21 10月, 2019 2 次提交
  2. 20 10月, 2019 15 次提交
  3. 19 10月, 2019 23 次提交
    • L
      Merge branch 'akpm' (patches from Andrew) · 998d7551
      Linus Torvalds 提交于
      Merge misc fixes from Andrew Morton:
       "Rather a lot of fixes, almost all affecting mm/"
      
      * emailed patches from Andrew Morton <akpm@linux-foundation.org>: (26 commits)
        scripts/gdb: fix debugging modules on s390
        kernel/events/uprobes.c: only do FOLL_SPLIT_PMD for uprobe register
        mm/thp: allow dropping THP from page cache
        mm/vmscan.c: support removing arbitrary sized pages from mapping
        mm/thp: fix node page state in split_huge_page_to_list()
        proc/meminfo: fix output alignment
        mm/init-mm.c: include <linux/mman.h> for vm_committed_as_batch
        mm/filemap.c: include <linux/ramfs.h> for generic_file_vm_ops definition
        mm: include <linux/huge_mm.h> for is_vma_temporary_stack
        zram: fix race between backing_dev_show and backing_dev_store
        mm/memcontrol: update lruvec counters in mem_cgroup_move_account
        ocfs2: fix panic due to ocfs2_wq is null
        hugetlbfs: don't access uninitialized memmaps in pfn_range_valid_gigantic()
        mm: memblock: do not enforce current limit for memblock_phys* family
        mm: memcg: get number of pages on the LRU list in memcgroup base on lru_zone_size
        mm/gup: fix a misnamed "write" argument, and a related bug
        mm/gup_benchmark: add a missing "w" to getopt string
        ocfs2: fix error handling in ocfs2_setattr()
        mm: memcg/slab: fix panic in __free_slab() caused by premature memcg pointer release
        mm/memunmap: don't access uninitialized memmap in memunmap_pages()
        ...
      998d7551
    • I
      scripts/gdb: fix debugging modules on s390 · 585d730d
      Ilya Leoshkevich 提交于
      Currently lx-symbols assumes that module text is always located at
      module->core_layout->base, but s390 uses the following layout:
      
        +------+  <- module->core_layout->base
        | GOT  |
        +------+  <- module->core_layout->base + module->arch->plt_offset
        | PLT  |
        +------+  <- module->core_layout->base + module->arch->plt_offset +
        | TEXT |     module->arch->plt_size
        +------+
      
      Therefore, when trying to debug modules on s390, all the symbol
      addresses are skewed by plt_offset + plt_size.
      
      Fix by adding plt_offset + plt_size to module_addr in
      load_module_symbols().
      
      Link: http://lkml.kernel.org/r/20191017085917.81791-1-iii@linux.ibm.comSigned-off-by: NIlya Leoshkevich <iii@linux.ibm.com>
      Reviewed-by: NJan Kiszka <jan.kiszka@siemens.com>
      Cc: Kieran Bingham <kbingham@kernel.org>
      Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
      Cc: Vasily Gorbik <gor@linux.ibm.com>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      585d730d
    • S
      kernel/events/uprobes.c: only do FOLL_SPLIT_PMD for uprobe register · aa5de305
      Song Liu 提交于
      Attaching uprobe to text section in THP splits the PMD mapped page table
      into PTE mapped entries.  On uprobe detach, we would like to regroup PMD
      mapped page table entry to regain performance benefit of THP.
      
      However, the regroup is broken For perf_event based trace_uprobe.  This
      is because perf_event based trace_uprobe calls uprobe_unregister twice
      on close: first in TRACE_REG_PERF_CLOSE, then in
      TRACE_REG_PERF_UNREGISTER.  The second call will split the PMD mapped
      page table entry, which is not the desired behavior.
      
      Fix this by only use FOLL_SPLIT_PMD for uprobe register case.
      
      Add a WARN() to confirm uprobe unregister never work on huge pages, and
      abort the operation when this WARN() triggers.
      
      Link: http://lkml.kernel.org/r/20191017164223.2762148-6-songliubraving@fb.com
      Fixes: 5a52c9df ("uprobe: use FOLL_SPLIT_PMD instead of FOLL_SPLIT")
      Signed-off-by: NSong Liu <songliubraving@fb.com>
      Reviewed-by: NSrikar Dronamraju <srikar@linux.vnet.ibm.com>
      Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
      Cc: Oleg Nesterov <oleg@redhat.com>
      Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
      Cc: William Kucharski <william.kucharski@oracle.com>
      Cc: Yang Shi <yang.shi@linux.alibaba.com>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      aa5de305
    • K
      mm/thp: allow dropping THP from page cache · ef18a1ca
      Kirill A. Shutemov 提交于
      Once a THP is added to the page cache, it cannot be dropped via
      /proc/sys/vm/drop_caches.  Fix this issue with proper handling in
      invalidate_mapping_pages().
      
      Link: http://lkml.kernel.org/r/20191017164223.2762148-5-songliubraving@fb.com
      Fixes: 99cb0dbd ("mm,thp: add read-only THP support for (non-shmem) FS")
      Signed-off-by: NKirill A. Shutemov <kirill.shutemov@linux.intel.com>
      Signed-off-by: NSong Liu <songliubraving@fb.com>
      Tested-by: NSong Liu <songliubraving@fb.com>
      Acked-by: NYang Shi <yang.shi@linux.alibaba.com>
      Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
      Cc: Oleg Nesterov <oleg@redhat.com>
      Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
      Cc: William Kucharski <william.kucharski@oracle.com>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      ef18a1ca
    • W
      mm/vmscan.c: support removing arbitrary sized pages from mapping · 906d278d
      William Kucharski 提交于
      __remove_mapping() assumes that pages can only be either base pages or
      HPAGE_PMD_SIZE.  Ask the page what size it is.
      
      Link: http://lkml.kernel.org/r/20191017164223.2762148-4-songliubraving@fb.com
      Fixes: 99cb0dbd ("mm,thp: add read-only THP support for (non-shmem) FS")
      Signed-off-by: NWilliam Kucharski <william.kucharski@oracle.com>
      Signed-off-by: NMatthew Wilcox (Oracle) <willy@infradead.org>
      Signed-off-by: NSong Liu <songliubraving@fb.com>
      Acked-by: NYang Shi <yang.shi@linux.alibaba.com>
      Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
      Cc: Oleg Nesterov <oleg@redhat.com>
      Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      906d278d
    • K
      mm/thp: fix node page state in split_huge_page_to_list() · 06d3eff6
      Kirill A. Shutemov 提交于
      Make sure split_huge_page_to_list() handles the state of shmem THP and
      file THP properly.
      
      Link: http://lkml.kernel.org/r/20191017164223.2762148-3-songliubraving@fb.com
      Fixes: 60fbf0ab ("mm,thp: stats for file backed THP")
      Signed-off-by: NKirill A. Shutemov <kirill.shutemov@linux.intel.com>
      Signed-off-by: NSong Liu <songliubraving@fb.com>
      Tested-by: NSong Liu <songliubraving@fb.com>
      Acked-by: NYang Shi <yang.shi@linux.alibaba.com>
      Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
      Cc: Oleg Nesterov <oleg@redhat.com>
      Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
      Cc: William Kucharski <william.kucharski@oracle.com>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      06d3eff6
    • K
      proc/meminfo: fix output alignment · 2be5fbf9
      Kirill A. Shutemov 提交于
      Patch series "Fixes for THP in page cache", v2.
      
      This patch (of 5):
      
      Add extra space for FileHugePages and FilePmdMapped, so the output is
      aligned with other rows.
      
      Link: http://lkml.kernel.org/r/20191017164223.2762148-2-songliubraving@fb.com
      Fixes: 60fbf0ab ("mm,thp: stats for file backed THP")
      Signed-off-by: NKirill A. Shutemov <kirill.shutemov@linux.intel.com>
      Signed-off-by: NSong Liu <songliubraving@fb.com>
      Tested-by: NSong Liu <songliubraving@fb.com>
      Acked-by: NYang Shi <yang.shi@linux.alibaba.com>
      Cc: Matthew Wilcox <willy@infradead.org>
      Cc: Oleg Nesterov <oleg@redhat.com>
      Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
      Cc: William Kucharski <william.kucharski@oracle.com>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      2be5fbf9
    • B
      mm/init-mm.c: include <linux/mman.h> for vm_committed_as_batch · a2ae8c05
      Ben Dooks (Codethink) 提交于
      mm_init.c needs to include <linux/mman.h> for the definition of
      vm_committed_as_batch.  Fixes the following sparse warning:
      
        mm/mm_init.c:141:5: warning: symbol 'vm_committed_as_batch' was not declared. Should it be static?
      
      Link: http://lkml.kernel.org/r/20191016091509.26708-1-ben.dooks@codethink.co.ukSigned-off-by: NBen Dooks <ben.dooks@codethink.co.uk>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      a2ae8c05
    • B
      mm/filemap.c: include <linux/ramfs.h> for generic_file_vm_ops definition · d0e6a582
      Ben Dooks 提交于
      The generic_file_vm_ops is defined in <linux/ramfs.h> so include it to
      fix the following warning:
      
        mm/filemap.c:2717:35: warning: symbol 'generic_file_vm_ops' was not declared. Should it be static?
      
      Link: http://lkml.kernel.org/r/20191008102311.25432-1-ben.dooks@codethink.co.ukSigned-off-by: NBen Dooks <ben.dooks@codethink.co.uk>
      Reviewed-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      d0e6a582
    • B
      mm: include <linux/huge_mm.h> for is_vma_temporary_stack · 444f84fd
      Ben Dooks 提交于
      Include <linux/huge_mm.h> for the definition of is_vma_temporary_stack
      to fix the following sparse warning:
      
        mm/rmap.c:1673:6: warning: symbol 'is_vma_temporary_stack' was not declared. Should it be static?
      
      Link: http://lkml.kernel.org/r/20191009151155.27763-1-ben.dooks@codethink.co.ukSigned-off-by: NBen Dooks <ben.dooks@codethink.co.uk>
      Reviewed-by: NQian Cai <cai@lca.pw>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      444f84fd
    • C
      zram: fix race between backing_dev_show and backing_dev_store · f7daefe4
      Chenwandun 提交于
      CPU0:				       CPU1:
      backing_dev_show		       backing_dev_store
          ......				   ......
          file = zram->backing_dev;
          down_read(&zram->init_lock);	   down_read(&zram->init_init_lock)
          file_path(file, ...);		   zram->backing_dev = backing_dev;
          up_read(&zram->init_lock);		   up_read(&zram->init_lock);
      
      gets the value of zram->backing_dev too early in backing_dev_show, which
      resultin the value being NULL at the beginning, and not NULL later.
      
      backtrace:
        d_path+0xcc/0x174
        file_path+0x10/0x18
        backing_dev_show+0x40/0xb4
        dev_attr_show+0x20/0x54
        sysfs_kf_seq_show+0x9c/0x10c
        kernfs_seq_show+0x28/0x30
        seq_read+0x184/0x488
        kernfs_fop_read+0x5c/0x1a4
        __vfs_read+0x44/0x128
        vfs_read+0xa0/0x138
        SyS_read+0x54/0xb4
      
      Link: http://lkml.kernel.org/r/1571046839-16814-1-git-send-email-chenwandun@huawei.comSigned-off-by: NChenwandun <chenwandun@huawei.com>
      Acked-by: NMinchan Kim <minchan@kernel.org>
      Cc: Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com>
      Cc: Jens Axboe <axboe@kernel.dk>
      Cc: <stable@vger.kernel.org>	[4.14+]
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      f7daefe4
    • K
      mm/memcontrol: update lruvec counters in mem_cgroup_move_account · ae8af438
      Konstantin Khlebnikov 提交于
      Mapped, dirty and writeback pages are also counted in per-lruvec stats.
      These counters needs update when page is moved between cgroups.
      
      Currently is nobody *consuming* the lruvec versions of these counters and
      that there is no user-visible effect.
      
      Link: http://lkml.kernel.org/r/157112699975.7360.1062614888388489788.stgit@buzz
      Fixes: 00f3ca2c ("mm: memcontrol: per-lruvec stats infrastructure")
      Signed-off-by: NKonstantin Khlebnikov <khlebnikov@yandex-team.ru>
      Acked-by: NJohannes Weiner <hannes@cmpxchg.org>
      Acked-by: NMichal Hocko <mhocko@suse.com>
      Cc: Vladimir Davydov <vdavydov.dev@gmail.com
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      ae8af438
    • Y
      ocfs2: fix panic due to ocfs2_wq is null · b918c430
      Yi Li 提交于
      mount.ocfs2 failed when reading ocfs2 filesystem superblock encounters
      an error.  ocfs2_initialize_super() returns before allocating ocfs2_wq.
      ocfs2_dismount_volume() triggers the following panic.
      
        Oct 15 16:09:27 cnwarekv-205120 kernel: On-disk corruption discovered.Please run fsck.ocfs2 once the filesystem is unmounted.
        Oct 15 16:09:27 cnwarekv-205120 kernel: (mount.ocfs2,22804,44): ocfs2_read_locked_inode:537 ERROR: status = -30
        Oct 15 16:09:27 cnwarekv-205120 kernel: (mount.ocfs2,22804,44): ocfs2_init_global_system_inodes:458 ERROR: status = -30
        Oct 15 16:09:27 cnwarekv-205120 kernel: (mount.ocfs2,22804,44): ocfs2_init_global_system_inodes:491 ERROR: status = -30
        Oct 15 16:09:27 cnwarekv-205120 kernel: (mount.ocfs2,22804,44): ocfs2_initialize_super:2313 ERROR: status = -30
        Oct 15 16:09:27 cnwarekv-205120 kernel: (mount.ocfs2,22804,44): ocfs2_fill_super:1033 ERROR: status = -30
        ------------[ cut here ]------------
        Oops: 0002 [#1] SMP NOPTI
        CPU: 1 PID: 11753 Comm: mount.ocfs2 Tainted: G  E
              4.14.148-200.ckv.x86_64 #1
        Hardware name: Sugon H320-G30/35N16-US, BIOS 0SSDX017 12/21/2018
        task: ffff967af0520000 task.stack: ffffa5f05484000
        RIP: 0010:mutex_lock+0x19/0x20
        Call Trace:
          flush_workqueue+0x81/0x460
          ocfs2_shutdown_local_alloc+0x47/0x440 [ocfs2]
          ocfs2_dismount_volume+0x84/0x400 [ocfs2]
          ocfs2_fill_super+0xa4/0x1270 [ocfs2]
          ? ocfs2_initialize_super.isa.211+0xf20/0xf20 [ocfs2]
          mount_bdev+0x17f/0x1c0
          mount_fs+0x3a/0x160
      
      Link: http://lkml.kernel.org/r/1571139611-24107-1-git-send-email-yili@winhong.comSigned-off-by: NYi Li <yilikernel@gmail.com>
      Reviewed-by: NJoseph Qi <joseph.qi@linux.alibaba.com>
      Cc: Mark Fasheh <mark@fasheh.com>
      Cc: Joel Becker <jlbec@evilplan.org>
      Cc: Junxiao Bi <junxiao.bi@oracle.com>
      Cc: Changwei Ge <gechangwei@live.cn>
      Cc: Gang He <ghe@suse.com>
      Cc: Jun Piao <piaojun@huawei.com>
      Cc: <stable@vger.kernel.org>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      b918c430
    • D
      hugetlbfs: don't access uninitialized memmaps in pfn_range_valid_gigantic() · f231fe42
      David Hildenbrand 提交于
      Uninitialized memmaps contain garbage and in the worst case trigger
      kernel BUGs, especially with CONFIG_PAGE_POISONING.  They should not get
      touched.
      
      Let's make sure that we only consider online memory (managed by the
      buddy) that has initialized memmaps.  ZONE_DEVICE is not applicable.
      
      page_zone() will call page_to_nid(), which will trigger
      VM_BUG_ON_PGFLAGS(PagePoisoned(page), page) with CONFIG_PAGE_POISONING
      and CONFIG_DEBUG_VM_PGFLAGS when called on uninitialized memmaps.  This
      can be the case when an offline memory block (e.g., never onlined) is
      spanned by a zone.
      
      Note: As explained by Michal in [1], alloc_contig_range() will verify
      the range.  So it boils down to the wrong access in this function.
      
      [1] http://lkml.kernel.org/r/20180423000943.GO17484@dhcp22.suse.cz
      
      Link: http://lkml.kernel.org/r/20191015120717.4858-1-david@redhat.com
      Fixes: f1dd2cd1 ("mm, memory_hotplug: do not associate hotadded memory to zones until online")	[visible after d0dc12e8]
      Signed-off-by: NDavid Hildenbrand <david@redhat.com>
      Reported-by: NMichal Hocko <mhocko@kernel.org>
      Acked-by: NMichal Hocko <mhocko@suse.com>
      Reviewed-by: NMike Kravetz <mike.kravetz@oracle.com>
      Cc: Anshuman Khandual <anshuman.khandual@arm.com>
      Cc: <stable@vger.kernel.org>	[4.13+]
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      f231fe42
    • M
      mm: memblock: do not enforce current limit for memblock_phys* family · f3057ad7
      Mike Rapoport 提交于
      Until commit 92d12f95 ("memblock: refactor internal allocation
      functions") the maximal address for memblock allocations was forced to
      memblock.current_limit only for the allocation functions returning
      virtual address.  The changes introduced by that commit moved the limit
      enforcement into the allocation core and as a result the allocation
      functions returning physical address also started to limit allocations
      to memblock.current_limit.
      
      This caused breakage of etnaviv GPU driver:
      
        etnaviv etnaviv: bound 130000.gpu (ops gpu_ops)
        etnaviv etnaviv: bound 134000.gpu (ops gpu_ops)
        etnaviv etnaviv: bound 2204000.gpu (ops gpu_ops)
        etnaviv-gpu 130000.gpu: model: GC2000, revision: 5108
        etnaviv-gpu 130000.gpu: command buffer outside valid memory window
        etnaviv-gpu 134000.gpu: model: GC320, revision: 5007
        etnaviv-gpu 134000.gpu: command buffer outside valid memory window
        etnaviv-gpu 2204000.gpu: model: GC355, revision: 1215
        etnaviv-gpu 2204000.gpu: Ignoring GPU with VG and FE2.0
      
      Restore the behaviour of memblock_phys* family so that these functions
      will not enforce memblock.current_limit.
      
      Link: http://lkml.kernel.org/r/1570915861-17633-1-git-send-email-rppt@kernel.org
      Fixes: 92d12f95 ("memblock: refactor internal allocation functions")
      Signed-off-by: NMike Rapoport <rppt@linux.ibm.com>
      Reported-by: NAdam Ford <aford173@gmail.com>
      Tested-by: Adam Ford <aford173@gmail.com>	[imx6q-logicpd]
      Cc: Catalin Marinas <catalin.marinas@arm.com>
      Cc: Christoph Hellwig <hch@lst.de>
      Cc: Fabio Estevam <festevam@gmail.com>
      Cc: Lucas Stach <l.stach@pengutronix.de>
      Cc: <stable@vger.kernel.org>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      f3057ad7
    • H
      mm: memcg: get number of pages on the LRU list in memcgroup base on lru_zone_size · b11edebb
      Honglei Wang 提交于
      Commit 1a61ab80 ("mm: memcontrol: replace zone summing with
      lruvec_page_state()") has made lruvec_page_state to use per-cpu counters
      instead of calculating it directly from lru_zone_size with an idea that
      this would be more effective.
      
      Tim has reported that this is not really the case for their database
      benchmark which is showing an opposite results where lruvec_page_state
      is taking up a huge chunk of CPU cycles (about 25% of the system time
      which is roughly 7% of total cpu cycles) on 5.3 kernels.  The workload
      is running on a larger machine (96cpus), it has many cgroups (500) and
      it is heavily direct reclaim bound.
      
      Tim Chen said:
      
      : The problem can also be reproduced by running simple multi-threaded
      : pmbench benchmark with a fast Optane SSD swap (see profile below).
      :
      :
      : 6.15%     3.08%  pmbench          [kernel.vmlinux]            [k] lruvec_lru_size
      :             |
      :             |--3.07%--lruvec_lru_size
      :             |          |
      :             |          |--2.11%--cpumask_next
      :             |          |          |
      :             |          |           --1.66%--find_next_bit
      :             |          |
      :             |           --0.57%--call_function_interrupt
      :             |                     |
      :             |                      --0.55%--smp_call_function_interrupt
      :             |
      :             |--1.59%--0x441f0fc3d009
      :             |          _ops_rdtsc_init_base_freq
      :             |          access_histogram
      :             |          page_fault
      :             |          __do_page_fault
      :             |          handle_mm_fault
      :             |          __handle_mm_fault
      :             |          |
      :             |           --1.54%--do_swap_page
      :             |                     swapin_readahead
      :             |                     swap_cluster_readahead
      :             |                     |
      :             |                      --1.53%--read_swap_cache_async
      :             |                                __read_swap_cache_async
      :             |                                alloc_pages_vma
      :             |                                __alloc_pages_nodemask
      :             |                                __alloc_pages_slowpath
      :             |                                try_to_free_pages
      :             |                                do_try_to_free_pages
      :             |                                shrink_node
      :             |                                shrink_node_memcg
      :             |                                |
      :             |                                |--0.77%--lruvec_lru_size
      :             |                                |
      :             |                                 --0.76%--inactive_list_is_low
      :             |                                           |
      :             |                                            --0.76%--lruvec_lru_size
      :             |
      :              --1.50%--measure_read
      :                        page_fault
      :                        __do_page_fault
      :                        handle_mm_fault
      :                        __handle_mm_fault
      :                        do_swap_page
      :                        swapin_readahead
      :                        swap_cluster_readahead
      :                        |
      :                         --1.48%--read_swap_cache_async
      :                                   __read_swap_cache_async
      :                                   alloc_pages_vma
      :                                   __alloc_pages_nodemask
      :                                   __alloc_pages_slowpath
      :                                   try_to_free_pages
      :                                   do_try_to_free_pages
      :                                   shrink_node
      :                                   shrink_node_memcg
      :                                   |
      :                                   |--0.75%--inactive_list_is_low
      :                                   |          |
      :                                   |           --0.75%--lruvec_lru_size
      :                                   |
      :                                    --0.73%--lruvec_lru_size
      
      The likely culprit is the cache traffic the lruvec_page_state_local
      generates.  Dave Hansen says:
      
      : I was thinking purely of the cache footprint.  If it's reading
      : pn->lruvec_stat_local->count[idx] is three separate cachelines, so 192
      : bytes of cache *96 CPUs = 18k of data, mostly read-only.  1 cgroup would
      : be 18k of data for the whole system and the caching would be pretty
      : efficient and all 18k would probably survive a tight page fault loop in
      : the L1.  500 cgroups would be ~90k of data per CPU thread which doesn't
      : fit in the L1 and probably wouldn't survive a tight page fault loop if
      : both logical threads were banging on different cgroups.
      :
      : It's just a theory, but it's why I noted the number of cgroups when I
      : initially saw this show up in profiles
      
      Fix the regression by partially reverting the said commit and calculate
      the lru size explicitly.
      
      Link: http://lkml.kernel.org/r/20190905071034.16822-1-honglei.wang@oracle.com
      Fixes: 1a61ab80 ("mm: memcontrol: replace zone summing with lruvec_page_state()")
      Signed-off-by: NHonglei Wang <honglei.wang@oracle.com>
      Reported-by: NTim Chen <tim.c.chen@linux.intel.com>
      Acked-by: NTim Chen <tim.c.chen@linux.intel.com>
      Tested-by: NTim Chen <tim.c.chen@linux.intel.com>
      Acked-by: NMichal Hocko <mhocko@suse.com>
      Cc: Vladimir Davydov <vdavydov.dev@gmail.com>
      Cc: Johannes Weiner <hannes@cmpxchg.org>
      Cc: Roman Gushchin <guro@fb.com>
      Cc: Tejun Heo <tj@kernel.org>
      Cc: Dave Hansen <dave.hansen@intel.com>
      Cc: <stable@vger.kernel.org>	[5.2+]
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      b11edebb
    • J
      mm/gup: fix a misnamed "write" argument, and a related bug · 0cd22afd
      John Hubbard 提交于
      In several routines, the "flags" argument is incorrectly named "write".
      Change it to "flags".
      
      Also, in one place, the misnaming led to an actual bug:
      "flags & FOLL_WRITE" is required, rather than just "flags".
      (That problem was flagged by krobot, in v1 of this patch.)
      
      Also, change the flags argument from int, to unsigned int.
      
      You can see that this was a simple oversight, because the
      calling code passes "flags" to the fifth argument:
      
      gup_pgd_range():
          ...
          if (!gup_huge_pd(__hugepd(pgd_val(pgd)), addr,
      		    PGDIR_SHIFT, next, flags, pages, nr))
      
      ...which, until this patch, the callees referred to as "write".
      
      Also, change two lines to avoid checkpatch line length
      complaints, and another line to fix another oversight
      that checkpatch called out: missing "int" on pdshift.
      
      Link: http://lkml.kernel.org/r/20191014184639.1512873-3-jhubbard@nvidia.com
      Fixes: b798bec4 ("mm/gup: change write parameter to flags in fast walk")
      Signed-off-by: NJohn Hubbard <jhubbard@nvidia.com>
      Reported-by: Nkbuild test robot <lkp@intel.com>
      Suggested-by: NKirill A. Shutemov <kirill@shutemov.name>
      Suggested-by: NIra Weiny <ira.weiny@intel.com>
      Acked-by: NKirill A. Shutemov <kirill.shutemov@linux.intel.com>
      Reviewed-by: NIra Weiny <ira.weiny@intel.com>
      Cc: Christoph Hellwig <hch@lst.de>
      Cc: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
      Cc: Keith Busch <keith.busch@intel.com>
      Cc: Shuah Khan <shuah@kernel.org>
      Cc: Christoph Hellwig <hch@infradead.org>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      0cd22afd
    • J
      mm/gup_benchmark: add a missing "w" to getopt string · 6f24c8d3
      John Hubbard 提交于
      Even though gup_benchmark.c has code to handle the -w command-line option,
      the "w" is not part of the getopt string.  It looks as if it has been
      missing the whole time.
      
      On my machine, this leads naturally to the following predictable result:
      
        $ sudo ./gup_benchmark -w
        ./gup_benchmark: invalid option -- 'w'
      
      ...which is fixed with this commit.
      
      Link: http://lkml.kernel.org/r/20191014184639.1512873-2-jhubbard@nvidia.comSigned-off-by: NJohn Hubbard <jhubbard@nvidia.com>
      Acked-by: NKirill A. Shutemov <kirill.shutemov@linux.intel.com>
      Cc: Keith Busch <keith.busch@intel.com>
      Cc: Shuah Khan <shuah@kernel.org>
      Cc: Christoph Hellwig <hch@infradead.org>
      Cc: "Aneesh Kumar K . V" <aneesh.kumar@linux.ibm.com>
      Cc: Ira Weiny <ira.weiny@intel.com>
      Cc: Christoph Hellwig <hch@lst.de>
      Cc: kbuild test robot <lkp@intel.com>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      6f24c8d3
    • C
      ocfs2: fix error handling in ocfs2_setattr() · ce750f43
      Chengguang Xu 提交于
      Should set transfer_to[USRQUOTA/GRPQUOTA] to NULL on error case before
      jumping to do dqput().
      
      Link: http://lkml.kernel.org/r/20191010082349.1134-1-cgxu519@mykernel.netSigned-off-by: NChengguang Xu <cgxu519@mykernel.net>
      Reviewed-by: NJoseph Qi <joseph.qi@linux.alibaba.com>
      Cc: Mark Fasheh <mark@fasheh.com>
      Cc: Joel Becker <jlbec@evilplan.org>
      Cc: Junxiao Bi <junxiao.bi@oracle.com>
      Cc: Changwei Ge <gechangwei@live.cn>
      Cc: Gang He <ghe@suse.com>
      Cc: Jun Piao <piaojun@huawei.com>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      ce750f43
    • R
      mm: memcg/slab: fix panic in __free_slab() caused by premature memcg pointer release · b749ecfa
      Roman Gushchin 提交于
      Karsten reported the following panic in __free_slab() happening on a s390x
      machine:
      
        Unable to handle kernel pointer dereference in virtual kernel address space
        Failing address: 0000000000000000 TEID: 0000000000000483
        Fault in home space mode while using kernel ASCE.
        AS:00000000017d4007 R3:000000007fbd0007 S:000000007fbff000 P:000000000000003d
        Oops: 0004 ilc:3 Ý#1¨ PREEMPT SMP
        Modules linked in: tcp_diag inet_diag xt_tcpudp ip6t_rpfilter ip6t_REJECT nf_reject_ipv6 ipt_REJECT nf_reject_ipv4 xt_conntrack ip6table_nat ip6table_mangle ip6table_raw ip6table_security iptable_at nf_nat
        CPU: 0 PID: 0 Comm: swapper/0 Not tainted 5.3.0-05872-g6133e3e4bada-dirty #14
        Hardware name: IBM 2964 NC9 702 (z/VM 6.4.0)
        Krnl PSW : 0704d00180000000 00000000003cadb6 (__free_slab+0x686/0x6b0)
                   R:0 T:1 IO:1 EX:1 Key:0 M:1 W:0 P:0 AS:3 CC:1 PM:0 RI:0 EA:3
        Krnl GPRS: 00000000f3a32928 0000000000000000 000000007fbf5d00 000000000117c4b8
                   0000000000000000 000000009e3291c1 0000000000000000 0000000000000000
                   0000000000000003 0000000000000008 000000002b478b00 000003d080a97600
                   0000000000000003 0000000000000008 000000002b478b00 000003d080a97600
                   000000000117ba00 000003e000057db0 00000000003cabcc 000003e000057c78
        Krnl Code: 00000000003cada6: e310a1400004        lg      %r1,320(%r10)
                   00000000003cadac: c0e50046c286        brasl   %r14,ca32b8
                  #00000000003cadb2: a7f4fe36            brc     15,3caa1e
                  >00000000003cadb6: e32060800024        stg     %r2,128(%r6)
                   00000000003cadbc: a7f4fd9e            brc     15,3ca8f8
                   00000000003cadc0: c0e50046790c        brasl   %r14,c99fd8
                   00000000003cadc6: a7f4fe2c            brc     15,3caa
                   00000000003cadc6: a7f4fe2c            brc     15,3caa1e
                   00000000003cadca: ecb1ffff00d9        aghik   %r11,%r1,-1
        Call Trace:
        (<00000000003cabcc> __free_slab+0x49c/0x6b0)
         <00000000001f5886> rcu_core+0x5a6/0x7e0
         <0000000000ca2dea> __do_softirq+0xf2/0x5c0
         <0000000000152644> irq_exit+0x104/0x130
         <000000000010d222> do_IRQ+0x9a/0xf0
         <0000000000ca2344> ext_int_handler+0x130/0x134
         <0000000000103648> enabled_wait+0x58/0x128
        (<0000000000103634> enabled_wait+0x44/0x128)
         <0000000000103b00> arch_cpu_idle+0x40/0x58
         <0000000000ca0544> default_idle_call+0x3c/0x68
         <000000000018eaa4> do_idle+0xec/0x1c0
         <000000000018ee0e> cpu_startup_entry+0x36/0x40
         <000000000122df34> arch_call_rest_init+0x5c/0x88
         <0000000000000000> 0x0
        INFO: lockdep is turned off.
        Last Breaking-Event-Address:
         <00000000003ca8f4> __free_slab+0x1c4/0x6b0
        Kernel panic - not syncing: Fatal exception in interrupt
      
      The kernel panics on an attempt to dereference the NULL memcg pointer.
      When shutdown_cache() is called from the kmem_cache_destroy() context, a
      memcg kmem_cache might have empty slab pages in a partial list, which are
      still charged to the memory cgroup.
      
      These pages are released by free_partial() at the beginning of
      shutdown_cache(): either directly or by scheduling a RCU-delayed work
      (if the kmem_cache has the SLAB_TYPESAFE_BY_RCU flag).  The latter case
      is when the reported panic can happen: memcg_unlink_cache() is called
      immediately after shrinking partial lists, without waiting for scheduled
      RCU works.  It sets the kmem_cache->memcg_params.memcg pointer to NULL,
      and the following attempt to dereference it by __free_slab() from the
      RCU work context causes the panic.
      
      To fix the issue, let's postpone the release of the memcg pointer to
      destroy_memcg_params().  It's called from a separate work context by
      slab_caches_to_rcu_destroy_workfn(), which contains a full RCU barrier.
      This guarantees that all scheduled page release RCU works will complete
      before the memcg pointer will be zeroed.
      
      Big thanks for Karsten for the perfect report containing all necessary
      information, his help with the analysis of the problem and testing of the
      fix.
      
      Link: http://lkml.kernel.org/r/20191010160549.1584316-1-guro@fb.com
      Fixes: fb2f2b0a ("mm: memcg/slab: reparent memcg kmem_caches on cgroup removal")
      Signed-off-by: NRoman Gushchin <guro@fb.com>
      Reported-by: NKarsten Graul <kgraul@linux.ibm.com>
      Tested-by: NKarsten Graul <kgraul@linux.ibm.com>
      Acked-by: NVlastimil Babka <vbabka@suse.cz>
      Reviewed-by: NShakeel Butt <shakeelb@google.com>
      Cc: Karsten Graul <kgraul@linux.ibm.com>
      Cc: Vladimir Davydov <vdavydov.dev@gmail.com>
      Cc: David Rientjes <rientjes@google.com>
      Cc: <stable@vger.kernel.org>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      b749ecfa
    • A
      mm/memunmap: don't access uninitialized memmap in memunmap_pages() · 77e080e7
      Aneesh Kumar K.V 提交于
      Patch series "mm/memory_hotplug: Shrink zones before removing memory",
      v6.
      
      This series fixes the access of uninitialized memmaps when shrinking
      zones/nodes and when removing memory.  Also, it contains all fixes for
      crashes that can be triggered when removing certain namespace using
      memunmap_pages() - ZONE_DEVICE, reported by Aneesh.
      
      We stop trying to shrink ZONE_DEVICE, as it's buggy, fixing it would be
      more involved (we don't have SECTION_IS_ONLINE as an indicator), and
      shrinking is only of limited use (set_zone_contiguous() cannot detect
      the ZONE_DEVICE as contiguous).
      
      We continue shrinking !ZONE_DEVICE zones, however, I reduced the amount
      of code to a minimum.  Shrinking is especially necessary to keep
      zone->contiguous set where possible, especially, on memory unplug of
      DIMMs at zone boundaries.
      
      --------------------------------------------------------------------------
      
      Zones are now properly shrunk when offlining memory blocks or when
      onlining failed.  This allows to properly shrink zones on memory unplug
      even if the separate memory blocks of a DIMM were onlined to different
      zones or re-onlined to a different zone after offlining.
      
      Example:
      
        :/# cat /proc/zoneinfo
        Node 1, zone  Movable
                spanned  0
                present  0
                managed  0
        :/# echo "online_movable" > /sys/devices/system/memory/memory41/state
        :/# echo "online_movable" > /sys/devices/system/memory/memory43/state
        :/# cat /proc/zoneinfo
        Node 1, zone  Movable
                spanned  98304
                present  65536
                managed  65536
        :/# echo 0 > /sys/devices/system/memory/memory43/online
        :/# cat /proc/zoneinfo
        Node 1, zone  Movable
                spanned  32768
                present  32768
                managed  32768
        :/# echo 0 > /sys/devices/system/memory/memory41/online
        :/# cat /proc/zoneinfo
        Node 1, zone  Movable
                spanned  0
                present  0
                managed  0
      
      This patch (of 10):
      
      With an altmap, the memmap falling into the reserved altmap space are not
      initialized and, therefore, contain a garbage NID and a garbage zone.
      Make sure to read the NID/zone from a memmap that was initialized.
      
      This fixes a kernel crash that is observed when destroying a namespace:
      
        kernel BUG at include/linux/mm.h:1107!
        cpu 0x1: Vector: 700 (Program Check) at [c000000274087890]
            pc: c0000000004b9728: memunmap_pages+0x238/0x340
            lr: c0000000004b9724: memunmap_pages+0x234/0x340
        ...
            pid   = 3669, comm = ndctl
        kernel BUG at include/linux/mm.h:1107!
          devm_action_release+0x30/0x50
          release_nodes+0x268/0x2d0
          device_release_driver_internal+0x174/0x240
          unbind_store+0x13c/0x190
          drv_attr_store+0x44/0x60
          sysfs_kf_write+0x70/0xa0
          kernfs_fop_write+0x1ac/0x290
          __vfs_write+0x3c/0x70
          vfs_write+0xe4/0x200
          ksys_write+0x7c/0x140
          system_call+0x5c/0x68
      
      The "page_zone(pfn_to_page(pfn)" was introduced by 69324b8f ("mm,
      devm_memremap_pages: add MEMORY_DEVICE_PRIVATE support"), however, I
      think we will never have driver reserved memory with
      MEMORY_DEVICE_PRIVATE (no altmap AFAIKS).
      
      [david@redhat.com: minimze code changes, rephrase description]
      Link: http://lkml.kernel.org/r/20191006085646.5768-2-david@redhat.com
      Fixes: 2c2a5af6 ("mm, memory_hotplug: add nid parameter to arch_remove_memory")
      Signed-off-by: NAneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
      Signed-off-by: NDavid Hildenbrand <david@redhat.com>
      Cc: Dan Williams <dan.j.williams@intel.com>
      Cc: Jason Gunthorpe <jgg@ziepe.ca>
      Cc: Logan Gunthorpe <logang@deltatee.com>
      Cc: Ira Weiny <ira.weiny@intel.com>
      Cc: Damian Tometzki <damian.tometzki@gmail.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: 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: Jun Yao <yaojun8558363@gmail.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: Michal Hocko <mhocko@suse.com>
      Cc: Mike Rapoport <rppt@linux.ibm.com>
      Cc: Oscar Salvador <osalvador@suse.de>
      Cc: Pankaj Gupta <pagupta@redhat.com>
      Cc: Paul Mackerras <paulus@samba.org>
      Cc: Pavel Tatashin <pasha.tatashin@soleen.com>
      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: Wei Yang <richardw.yang@linux.intel.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>	[5.0+]
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      77e080e7
    • D
      mm/memory_hotplug: don't access uninitialized memmaps in shrink_pgdat_span() · 00d6c019
      David Hildenbrand 提交于
      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 commit d0dc12e8 ("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: f1dd2cd1 ("mm, memory_hotplug: do not associate hotadded memory to zones until online")	[d0dc12e8]
      Signed-off-by: NDavid Hildenbrand <david@redhat.com>
      Reported-by: NAneesh 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: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      00d6c019
    • Q
      mm/page_owner: don't access uninitialized memmaps when reading /proc/pagetypeinfo · a26ee565
      Qian Cai 提交于
      Uninitialized memmaps contain garbage and in the worst case trigger
      kernel BUGs, especially with CONFIG_PAGE_POISONING.  They should not get
      touched.
      
      For example, when not onlining a memory block that is spanned by a zone
      and reading /proc/pagetypeinfo with CONFIG_DEBUG_VM_PGFLAGS and
      CONFIG_PAGE_POISONING, we can trigger a kernel BUG:
      
        :/# echo 1 > /sys/devices/system/memory/memory40/online
        :/# echo 1 > /sys/devices/system/memory/memory42/online
        :/# cat /proc/pagetypeinfo > test.file
         page:fffff2c585200000 is uninitialized and poisoned
         raw: ffffffffffffffff ffffffffffffffff ffffffffffffffff ffffffffffffffff
         raw: ffffffffffffffff ffffffffffffffff ffffffffffffffff ffffffffffffffff
         page dumped because: VM_BUG_ON_PAGE(PagePoisoned(p))
         There is not page extension available.
         ------------[ cut here ]------------
         kernel BUG at include/linux/mm.h:1107!
         invalid opcode: 0000 [#1] SMP NOPTI
      
      Please note that this change does not affect ZONE_DEVICE, because
      pagetypeinfo_showmixedcount_print() is called from
      mm/vmstat.c:pagetypeinfo_showmixedcount() only for populated zones, and
      ZONE_DEVICE is never populated (zone->present_pages always 0).
      
      [david@redhat.com: move check to outer loop, add comment, rephrase description]
      Link: http://lkml.kernel.org/r/20191011140638.8160-1-david@redhat.com
      Fixes: f1dd2cd1 ("mm, memory_hotplug: do not associate hotadded memory to zones until online") # visible after d0dc12e8Signed-off-by: NQian Cai <cai@lca.pw>
      Signed-off-by: NDavid Hildenbrand <david@redhat.com>
      Acked-by: NMichal Hocko <mhocko@suse.com>
      Acked-by: NVlastimil Babka <vbabka@suse.cz>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Cc: "Peter Zijlstra (Intel)" <peterz@infradead.org>
      Cc: Miles Chen <miles.chen@mediatek.com>
      Cc: Mike Rapoport <rppt@linux.vnet.ibm.com>
      Cc: Qian Cai <cai@lca.pw>
      Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
      Cc: <stable@vger.kernel.org>	[4.13+]
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      a26ee565