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2016-09-30mm: workingset: fix crash in shadow node shrinker caused by ↵Johannes Weiner
replace_page_cache_page() Antonio reports the following crash when using fuse under memory pressure: kernel BUG at /build/linux-a2WvEb/linux-4.4.0/mm/workingset.c:346! invalid opcode: 0000 [#1] SMP Modules linked in: all of them CPU: 2 PID: 63 Comm: kswapd0 Not tainted 4.4.0-36-generic #55-Ubuntu Hardware name: System manufacturer System Product Name/P8H67-M PRO, BIOS 3904 04/27/2013 task: ffff88040cae6040 ti: ffff880407488000 task.ti: ffff880407488000 RIP: shadow_lru_isolate+0x181/0x190 Call Trace: __list_lru_walk_one.isra.3+0x8f/0x130 list_lru_walk_one+0x23/0x30 scan_shadow_nodes+0x34/0x50 shrink_slab.part.40+0x1ed/0x3d0 shrink_zone+0x2ca/0x2e0 kswapd+0x51e/0x990 kthread+0xd8/0xf0 ret_from_fork+0x3f/0x70 which corresponds to the following sanity check in the shadow node tracking: BUG_ON(node->count & RADIX_TREE_COUNT_MASK); The workingset code tracks radix tree nodes that exclusively contain shadow entries of evicted pages in them, and this (somewhat obscure) line checks whether there are real pages left that would interfere with reclaim of the radix tree node under memory pressure. While discussing ways how fuse might sneak pages into the radix tree past the workingset code, Miklos pointed to replace_page_cache_page(), and indeed there is a problem there: it properly accounts for the old page being removed - __delete_from_page_cache() does that - but then does a raw raw radix_tree_insert(), not accounting for the replacement page. Eventually the page count bits in node->count underflow while leaving the node incorrectly linked to the shadow node LRU. To address this, make sure replace_page_cache_page() uses the tracked page insertion code, page_cache_tree_insert(). This fixes the page accounting and makes sure page-containing nodes are properly unlinked from the shadow node LRU again. Also, make the sanity checks a bit less obscure by using the helpers for checking the number of pages and shadows in a radix tree node. Fixes: 449dd6984d0e ("mm: keep page cache radix tree nodes in check") Link: http://lkml.kernel.org/r/20160919155822.29498-1-hannes@cmpxchg.org Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Reported-by: Antonio SJ Musumeci <trapexit@spawn.link> Debugged-by: Miklos Szeredi <miklos@szeredi.hu> Cc: <stable@vger.kernel.org> [3.15+] Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-09-28mem-hotplug: use nodes that contain memory as mask in new_node_page()Li Zhong
9bb627be47a5 ("mem-hotplug: don't clear the only node in new_node_page()") prevents allocating from an empty nodemask, but as David points out, it is still wrong. As node_online_map may include memoryless nodes, only allocating from these nodes is meaningless. This patch uses node_states[N_MEMORY] mask to prevent the above case. Fixes: 9bb627be47a5 ("mem-hotplug: don't clear the only node in new_node_page()") Fixes: 394e31d2ceb4 ("mem-hotplug: alloc new page from a nearest neighbor node when mem-offline") Link: http://lkml.kernel.org/r/1474447117.28370.6.camel@TP420 Signed-off-by: Li Zhong <zhong@linux.vnet.ibm.com> Suggested-by: David Rientjes <rientjes@google.com> Acked-by: Vlastimil Babka <vbabka@suse.cz> Cc: Michal Hocko <mhocko@suse.cz> Cc: John Allen <jallen@linux.vnet.ibm.com> Cc: Xishi Qiu <qiuxishi@huawei.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Cc: Tetsuo Handa <penguin-kernel@i-love.sakura.ne.jp> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-09-28mm,ksm: fix endless looping in allocating memory when ksm enablezhong jiang
I hit the following hung task when runing a OOM LTP test case with 4.1 kernel. Call trace: [<ffffffc000086a88>] __switch_to+0x74/0x8c [<ffffffc000a1bae0>] __schedule+0x23c/0x7bc [<ffffffc000a1c09c>] schedule+0x3c/0x94 [<ffffffc000a1eb84>] rwsem_down_write_failed+0x214/0x350 [<ffffffc000a1e32c>] down_write+0x64/0x80 [<ffffffc00021f794>] __ksm_exit+0x90/0x19c [<ffffffc0000be650>] mmput+0x118/0x11c [<ffffffc0000c3ec4>] do_exit+0x2dc/0xa74 [<ffffffc0000c46f8>] do_group_exit+0x4c/0xe4 [<ffffffc0000d0f34>] get_signal+0x444/0x5e0 [<ffffffc000089fcc>] do_signal+0x1d8/0x450 [<ffffffc00008a35c>] do_notify_resume+0x70/0x78 The oom victim cannot terminate because it needs to take mmap_sem for write while the lock is held by ksmd for read which loops in the page allocator ksm_do_scan scan_get_next_rmap_item down_read get_next_rmap_item alloc_rmap_item #ksmd will loop permanently. There is no way forward because the oom victim cannot release any memory in 4.1 based kernel. Since 4.6 we have the oom reaper which would solve this problem because it would release the memory asynchronously. Nevertheless we can relax alloc_rmap_item requirements and use __GFP_NORETRY because the allocation failure is acceptable as ksm_do_scan would just retry later after the lock got dropped. Such a patch would be also easy to backport to older stable kernels which do not have oom_reaper. While we are at it add GFP_NOWARN so the admin doesn't have to be alarmed by the allocation failure. Link: http://lkml.kernel.org/r/1474165570-44398-1-git-send-email-zhongjiang@huawei.com Signed-off-by: zhong jiang <zhongjiang@huawei.com> Suggested-by: Hugh Dickins <hughd@google.com> Suggested-by: Michal Hocko <mhocko@suse.cz> Acked-by: Michal Hocko <mhocko@suse.com> Acked-by: Hugh Dickins <hughd@google.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-09-25mm: check VMA flags to avoid invalid PROT_NONE NUMA balancingLorenzo Stoakes
The NUMA balancing logic uses an arch-specific PROT_NONE page table flag defined by pte_protnone() or pmd_protnone() to mark PTEs or huge page PMDs respectively as requiring balancing upon a subsequent page fault. User-defined PROT_NONE memory regions which also have this flag set will not normally invoke the NUMA balancing code as do_page_fault() will send a segfault to the process before handle_mm_fault() is even called. However if access_remote_vm() is invoked to access a PROT_NONE region of memory, handle_mm_fault() is called via faultin_page() and __get_user_pages() without any access checks being performed, meaning the NUMA balancing logic is incorrectly invoked on a non-NUMA memory region. A simple means of triggering this problem is to access PROT_NONE mmap'd memory using /proc/self/mem which reliably results in the NUMA handling functions being invoked when CONFIG_NUMA_BALANCING is set. This issue was reported in bugzilla (issue 99101) which includes some simple repro code. There are BUG_ON() checks in do_numa_page() and do_huge_pmd_numa_page() added at commit c0e7cad to avoid accidentally provoking strange behaviour by attempting to apply NUMA balancing to pages that are in fact PROT_NONE. The BUG_ON()'s are consistently triggered by the repro. This patch moves the PROT_NONE check into mm/memory.c rather than invoking BUG_ON() as faulting in these pages via faultin_page() is a valid reason for reaching the NUMA check with the PROT_NONE page table flag set and is therefore not always a bug. Link: https://bugzilla.kernel.org/show_bug.cgi?id=99101 Reported-by: Trevor Saunders <tbsaunde@tbsaunde.org> Signed-off-by: Lorenzo Stoakes <lstoakes@gmail.com> Acked-by: Rik van Riel <riel@redhat.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Mel Gorman <mgorman@techsingularity.net> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-09-24Merge branch 'hughd-fixes' (patches from Hugh Dickins)Linus Torvalds
Merge VM fixes from High Dickins: "I get the impression that Andrew is away or busy at the moment, so I'm going to send you three independent uncontroversial little mm fixes directly - though none is strictly a 4.8 regression fix. - shmem: fix tmpfs to handle the huge= option properly from Toshi Kani is a one-liner to fix a major embarrassment in 4.8's hugepages on tmpfs feature: although Hillf pointed it out in June, somehow both Kirill and I repeatedly dropped the ball on this one. You might wonder if the feature got tested at all with that bug in: yes, it did, but for wider testing coverage, Kirill and I had each relied too much on an override which bypasses that condition. - huge tmpfs: fix Committed_AS leak just a run-of-the-mill accounting fix in the same feature. - mm: delete unnecessary and unsafe init_tlb_ubc() is an unrelated fix to 4.3's TLB flush batching in reclaim: the bug would be rare, and none of us will be shamed if this one misses 4.8; but it got such a quick ack from Mel today that I'm inclined to offer it along with the first two" * emailed patches from Hugh Dickins <hughd@google.com>: mm: delete unnecessary and unsafe init_tlb_ubc() huge tmpfs: fix Committed_AS leak shmem: fix tmpfs to handle the huge= option properly
2016-09-24mm: delete unnecessary and unsafe init_tlb_ubc()Hugh Dickins
init_tlb_ubc() looked unnecessary to me: tlb_ubc is statically initialized with zeroes in the init_task, and copied from parent to child while it is quiescent in arch_dup_task_struct(); so I went to delete it. But inserted temporary debug WARN_ONs in place of init_tlb_ubc() to check that it was always empty at that point, and found them firing: because memcg reclaim can recurse into global reclaim (when allocating biosets for swapout in my case), and arrive back at the init_tlb_ubc() in shrink_node_memcg(). Resetting tlb_ubc.flush_required at that point is wrong: if the upper level needs a deferred TLB flush, but the lower level turns out not to, we miss a TLB flush. But fortunately, that's the only part of the protocol that does not nest: with the initialization removed, cpumask collects bits from upper and lower levels, and flushes TLB when needed. Fixes: 72b252aed506 ("mm: send one IPI per CPU to TLB flush all entries after unmapping pages") Signed-off-by: Hugh Dickins <hughd@google.com> Acked-by: Mel Gorman <mgorman@techsingularity.net> Cc: stable@vger.kernel.org # 4.3+ Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-09-24huge tmpfs: fix Committed_AS leakHugh Dickins
Under swapping load on huge tmpfs, /proc/meminfo's Committed_AS grows bigger and bigger: just a cosmetic issue for most users, but disabling for those who run without overcommit (/proc/sys/vm/overcommit_memory 2). shmem_uncharge() was forgetting to unaccount __vm_enough_memory's charge, and shmem_charge() was forgetting it on the filesystem-full error path. Fixes: 800d8c63b2e9 ("shmem: add huge pages support") Signed-off-by: Hugh Dickins <hughd@google.com> Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-09-24shmem: fix tmpfs to handle the huge= option properlyToshi Kani
shmem_get_unmapped_area() checks SHMEM_SB(sb)->huge incorrectly, which leads to a reversed effect of "huge=" mount option. Fix the check in shmem_get_unmapped_area(). Note, the default value of SHMEM_SB(sb)->huge remains as SHMEM_HUGE_NEVER. User will need to specify "huge=" option to enable huge page mappings. Reported-by: Hillf Danton <hillf.zj@alibaba-inc.com> Signed-off-by: Toshi Kani <toshi.kani@hpe.com> Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Signed-off-by: Hugh Dickins <hughd@google.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-09-20mm: usercopy: Check for module addressesLaura Abbott
While running a compile on arm64, I hit a memory exposure usercopy: kernel memory exposure attempt detected from fffffc0000f3b1a8 (buffer_head) (1 bytes) ------------[ cut here ]------------ kernel BUG at mm/usercopy.c:75! Internal error: Oops - BUG: 0 [#1] SMP Modules linked in: ip6t_rpfilter ip6t_REJECT nf_reject_ipv6 xt_conntrack ip_set nfnetlink ebtable_broute bridge stp llc ebtable_nat ip6table_security ip6table_raw ip6table_nat nf_conntrack_ipv6 nf_defrag_ipv6 nf_nat_ipv6 ip6table_mangle iptable_security iptable_raw iptable_nat nf_conntrack_ipv4 nf_defrag_ipv4 nf_nat_ipv4 nf_nat nf_conntrack iptable_mangle ebtable_filter ebtables ip6table_filter ip6_tables vfat fat xgene_edac xgene_enet edac_core i2c_xgene_slimpro i2c_core at803x realtek xgene_dma mdio_xgene gpio_dwapb gpio_xgene_sb xgene_rng mailbox_xgene_slimpro nfsd auth_rpcgss nfs_acl lockd grace sunrpc xfs libcrc32c sdhci_of_arasan sdhci_pltfm sdhci mmc_core xhci_plat_hcd gpio_keys CPU: 0 PID: 19744 Comm: updatedb Tainted: G W 4.8.0-rc3-threadinfo+ #1 Hardware name: AppliedMicro X-Gene Mustang Board/X-Gene Mustang Board, BIOS 3.06.12 Aug 12 2016 task: fffffe03df944c00 task.stack: fffffe00d128c000 PC is at __check_object_size+0x70/0x3f0 LR is at __check_object_size+0x70/0x3f0 ... [<fffffc00082b4280>] __check_object_size+0x70/0x3f0 [<fffffc00082cdc30>] filldir64+0x158/0x1a0 [<fffffc0000f327e8>] __fat_readdir+0x4a0/0x558 [fat] [<fffffc0000f328d4>] fat_readdir+0x34/0x40 [fat] [<fffffc00082cd8f8>] iterate_dir+0x190/0x1e0 [<fffffc00082cde58>] SyS_getdents64+0x88/0x120 [<fffffc0008082c70>] el0_svc_naked+0x24/0x28 fffffc0000f3b1a8 is a module address. Modules may have compiled in strings which could get copied to userspace. In this instance, it looks like "." which matches with a size of 1 byte. Extend the is_vmalloc_addr check to be is_vmalloc_or_module_addr to cover all possible cases. Signed-off-by: Laura Abbott <labbott@redhat.com> Signed-off-by: Kees Cook <keescook@chromium.org>
2016-09-19mm: memcontrol: make per-cpu charge cache IRQ-safe for socket accountingJohannes Weiner
During cgroup2 rollout into production, we started encountering css refcount underflows and css access crashes in the memory controller. Splitting the heavily shared css reference counter into logical users narrowed the imbalance down to the cgroup2 socket memory accounting. The problem turns out to be the per-cpu charge cache. Cgroup1 had a separate socket counter, but the new cgroup2 socket accounting goes through the common charge path that uses a shared per-cpu cache for all memory that is being tracked. Those caches are safe against scheduling preemption, but not against interrupts - such as the newly added packet receive path. When cache draining is interrupted by network RX taking pages out of the cache, the resuming drain operation will put references of in-use pages, thus causing the imbalance. Disable IRQs during all per-cpu charge cache operations. Fixes: f7e1cb6ec51b ("mm: memcontrol: account socket memory in unified hierarchy memory controller") Link: http://lkml.kernel.org/r/20160914194846.11153-1-hannes@cmpxchg.org Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: Tejun Heo <tj@kernel.org> Cc: "David S. Miller" <davem@davemloft.net> Cc: Michal Hocko <mhocko@suse.cz> Cc: Vladimir Davydov <vdavydov@virtuozzo.com> Cc: <stable@vger.kernel.org> [4.5+] Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-09-19mm: fix the page_swap_info() BUG_ON checkSantosh Shilimkar
Commit 62c230bc1790 ("mm: add support for a filesystem to activate swap files and use direct_IO for writing swap pages") replaced the swap_aops dirty hook from __set_page_dirty_no_writeback() with swap_set_page_dirty(). For normal cases without these special SWP flags code path falls back to __set_page_dirty_no_writeback() so the behaviour is expected to be the same as before. But swap_set_page_dirty() makes use of the page_swap_info() helper to get the swap_info_struct to check for the flags like SWP_FILE, SWP_BLKDEV etc as desired for those features. This helper has BUG_ON(!PageSwapCache(page)) which is racy and safe only for the set_page_dirty_lock() path. For the set_page_dirty() path which is often needed for cases to be called from irq context, kswapd() can toggle the flag behind the back while the call is getting executed when system is low on memory and heavy swapping is ongoing. This ends up with undesired kernel panic. This patch just moves the check outside the helper to its users appropriately to fix kernel panic for the described path. Couple of users of helpers already take care of SwapCache condition so I skipped them. Link: http://lkml.kernel.org/r/1473460718-31013-1-git-send-email-santosh.shilimkar@oracle.com Signed-off-by: Santosh Shilimkar <santosh.shilimkar@oracle.com> Cc: Mel Gorman <mgorman@suse.de> Cc: Joe Perches <joe@perches.com> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Rik van Riel <riel@redhat.com> Cc: David S. Miller <davem@davemloft.net> Cc: Jens Axboe <axboe@fb.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Hugh Dickins <hughd@google.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: <stable@vger.kernel.org> [4.7.x] Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-09-19mm: avoid endless recursion in dump_page()Kirill A. Shutemov
dump_page() uses page_mapcount() to get mapcount of the page. page_mapcount() has VM_BUG_ON_PAGE(PageSlab(page)) as mapcount doesn't make sense for slab pages and the field in struct page used for other information. It leads to recursion if dump_page() called for slub page and DEBUG_VM is enabled: dump_page() -> page_mapcount() -> VM_BUG_ON_PAGE() -> dump_page -> ... Let's avoid calling page_mapcount() for slab pages in dump_page(). Link: http://lkml.kernel.org/r/20160908082137.131076-1-kirill.shutemov@linux.intel.com Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-09-19mm, thp: fix leaking mapped pte in __collapse_huge_page_swapin()Ebru Akagunduz
Currently, khugepaged does not permit swapin if there are enough young pages in a THP. The problem is when a THP does not have enough young pages, khugepaged leaks mapped ptes. This patch prohibits leaking mapped ptes. Link: http://lkml.kernel.org/r/1472820276-7831-1-git-send-email-ebru.akagunduz@gmail.com Signed-off-by: Ebru Akagunduz <ebru.akagunduz@gmail.com> Suggested-by: Andrea Arcangeli <aarcange@redhat.com> Reviewed-by: Andrea Arcangeli <aarcange@redhat.com> Reviewed-by: Rik van Riel <riel@redhat.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-09-19khugepaged: fix use-after-free in collapse_huge_page()Kirill A. Shutemov
hugepage_vma_revalidate() tries to re-check if we still should try to collapse small pages into huge one after the re-acquiring mmap_sem. The problem Dmitry Vyukov reported[1] is that the vma found by hugepage_vma_revalidate() can be suitable for huge pages, but not the same vma we had before dropping mmap_sem. And dereferencing original vma can lead to fun results.. Let's use vma hugepage_vma_revalidate() found instead of assuming it's the same as what we had before the lock was dropped. [1] http://lkml.kernel.org/r/CACT4Y+Z3gigBvhca9kRJFcjX0G70V_nRhbwKBU+yGoESBDKi9Q@mail.gmail.com Link: http://lkml.kernel.org/r/20160907122559.GA6542@black.fi.intel.com Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Reported-by: Dmitry Vyukov <dvyukov@google.com> Reviewed-by: Andrea Arcangeli <aarcange@redhat.com> Cc: Ebru Akagunduz <ebru.akagunduz@gmail.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Vegard Nossum <vegard.nossum@oracle.com> Cc: Sasha Levin <levinsasha928@gmail.com> Cc: Konstantin Khlebnikov <koct9i@gmail.com> Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com> Cc: Greg Thelen <gthelen@google.com> Cc: Suleiman Souhlal <suleiman@google.com> Cc: Hugh Dickins <hughd@google.com> Cc: David Rientjes <rientjes@google.com> Cc: syzkaller <syzkaller@googlegroups.com> Cc: Kostya Serebryany <kcc@google.com> Cc: Alexander Potapenko <glider@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-09-19mem-hotplug: don't clear the only node in new_node_page()Li Zhong
Commit 394e31d2ceb4 ("mem-hotplug: alloc new page from a nearest neighbor node when mem-offline") introduced new_node_page() for memory hotplug. In new_node_page(), the nid is cleared before calling __alloc_pages_nodemask(). But if it is the only node of the system, and the first round allocation fails, it will not be able to get memory from an empty nodemask, and will trigger oom. The patch checks whether it is the last node on the system, and if it is, then don't clear the nid in the nodemask. Fixes: 394e31d2ceb4 ("mem-hotplug: alloc new page from a nearest neighbor node when mem-offline") Link: http://lkml.kernel.org/r/1473044391.4250.19.camel@TP420 Signed-off-by: Li Zhong <zhong@linux.vnet.ibm.com> Reported-by: John Allen <jallen@linux.vnet.ibm.com> Acked-by: Vlastimil Babka <vbabka@suse.cz> Cc: Xishi Qiu <qiuxishi@huawei.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-09-10Merge branch 'libnvdimm-fixes' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm Pull libnvdimm fixes from Dan Williams: "nvdimm fixes for v4.8, two of them are tagged for -stable: - Fix devm_memremap_pages() to use track_pfn_insert(). Otherwise, DAX pmd mappings end up with an uncached pgprot, and unusable performance for the device-dax interface. The device-dax interface appeared in 4.7 so this is tagged for -stable. - Fix a couple VM_BUG_ON() checks in the show_smaps() path to understand DAX pmd entries. This fix is tagged for -stable. - Fix a mis-merge of the nfit machine-check handler to flip the polarity of an if() to match the final version of the patch that Vishal sent for 4.8-rc1. Without this the nfit machine check handler never detects / inserts new 'badblocks' entries which applications use to identify lost portions of files. - For test purposes, fix the nvdimm_clear_poison() path to operate on legacy / simulated nvdimm memory ranges. Without this fix a test can set badblocks, but never clear them on these ranges. - Fix the range checking done by dax_dev_pmd_fault(). This is not tagged for -stable since this problem is mitigated by specifying aligned resources at device-dax setup time. These patches have appeared in a next release over the past week. The recent rebase you can see in the timestamps was to drop an invalid fix as identified by the updated device-dax unit tests [1]. The -mm touches have an ack from Andrew" [1]: "[ndctl PATCH 0/3] device-dax test for recent kernel bugs" https://lists.01.org/pipermail/linux-nvdimm/2016-September/006855.html * 'libnvdimm-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm: libnvdimm: allow legacy (e820) pmem region to clear bad blocks nfit, mce: Fix SPA matching logic in MCE handler mm: fix cache mode of dax pmd mappings mm: fix show_smap() for zone_device-pmd ranges dax: fix mapping size check
2016-09-09mm: fix show_smap() for zone_device-pmd rangesDan Williams
Attempting to dump /proc/<pid>/smaps for a process with pmd dax mappings currently results in the following VM_BUG_ONs: kernel BUG at mm/huge_memory.c:1105! task: ffff88045f16b140 task.stack: ffff88045be14000 RIP: 0010:[<ffffffff81268f9b>] [<ffffffff81268f9b>] follow_trans_huge_pmd+0x2cb/0x340 [..] Call Trace: [<ffffffff81306030>] smaps_pte_range+0xa0/0x4b0 [<ffffffff814c2755>] ? vsnprintf+0x255/0x4c0 [<ffffffff8123c46e>] __walk_page_range+0x1fe/0x4d0 [<ffffffff8123c8a2>] walk_page_vma+0x62/0x80 [<ffffffff81307656>] show_smap+0xa6/0x2b0 kernel BUG at fs/proc/task_mmu.c:585! RIP: 0010:[<ffffffff81306469>] [<ffffffff81306469>] smaps_pte_range+0x499/0x4b0 Call Trace: [<ffffffff814c2795>] ? vsnprintf+0x255/0x4c0 [<ffffffff8123c46e>] __walk_page_range+0x1fe/0x4d0 [<ffffffff8123c8a2>] walk_page_vma+0x62/0x80 [<ffffffff81307696>] show_smap+0xa6/0x2b0 These locations are sanity checking page flags that must be set for an anonymous transparent huge page, but are not set for the zone_device pages associated with dax mappings. Cc: Ross Zwisler <ross.zwisler@linux.intel.com> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Acked-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2016-09-07usercopy: remove page-spanning test for nowKees Cook
A custom allocator without __GFP_COMP that copies to userspace has been found in vmw_execbuf_process[1], so this disables the page-span checker by placing it behind a CONFIG for future work where such things can be tracked down later. [1] https://bugzilla.redhat.com/show_bug.cgi?id=1373326 Reported-by: Vinson Lee <vlee@freedesktop.org> Fixes: f5509cc18daa ("mm: Hardened usercopy") Signed-off-by: Kees Cook <keescook@chromium.org>
2016-09-01mm, mempolicy: task->mempolicy must be NULL before dropping final referenceDavid Rientjes
KASAN allocates memory from the page allocator as part of kmem_cache_free(), and that can reference current->mempolicy through any number of allocation functions. It needs to be NULL'd out before the final reference is dropped to prevent a use-after-free bug: BUG: KASAN: use-after-free in alloc_pages_current+0x363/0x370 at addr ffff88010b48102c CPU: 0 PID: 15425 Comm: trinity-c2 Not tainted 4.8.0-rc2+ #140 ... Call Trace: dump_stack kasan_object_err kasan_report_error __asan_report_load2_noabort alloc_pages_current <-- use after free depot_save_stack save_stack kasan_slab_free kmem_cache_free __mpol_put <-- free do_exit This patch sets current->mempolicy to NULL before dropping the final reference. Link: http://lkml.kernel.org/r/alpine.DEB.2.10.1608301442180.63329@chino.kir.corp.google.com Fixes: cd11016e5f52 ("mm, kasan: stackdepot implementation. Enable stackdepot for SLAB") Signed-off-by: David Rientjes <rientjes@google.com> Reported-by: Vegard Nossum <vegard.nossum@oracle.com> Acked-by: Andrey Ryabinin <aryabinin@virtuozzo.com> Cc: Alexander Potapenko <glider@google.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: <stable@vger.kernel.org> [4.6+] Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-09-01mm, vmscan: only allocate and reclaim from zones with pages managed by the ↵Mel Gorman
buddy allocator Firmware Assisted Dump (FA_DUMP) on ppc64 reserves substantial amounts of memory when booting a secondary kernel. Srikar Dronamraju reported that multiple nodes may have no memory managed by the buddy allocator but still return true for populated_zone(). Commit 1d82de618ddd ("mm, vmscan: make kswapd reclaim in terms of nodes") was reported to cause kswapd to spin at 100% CPU usage when fadump was enabled. The old code happened to deal with the situation of a populated node with zero free pages by co-incidence but the current code tries to reclaim populated zones without realising that is impossible. We cannot just convert populated_zone() as many existing users really need to check for present_pages. This patch introduces a managed_zone() helper and uses it in the few cases where it is critical that the check is made for managed pages -- zonelist construction and page reclaim. Link: http://lkml.kernel.org/r/20160831195104.GB8119@techsingularity.net Signed-off-by: Mel Gorman <mgorman@techsingularity.net> Reported-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Tested-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Acked-by: Michal Hocko <mhocko@suse.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-09-01mm, oom: prevent premature OOM killer invocation for high order requestMichal Hocko
There have been several reports about pre-mature OOM killer invocation in 4.7 kernel when order-2 allocation request (for the kernel stack) invoked OOM killer even during basic workloads (light IO or even kernel compile on some filesystems). In all reported cases the memory is fragmented and there are no order-2+ pages available. There is usually a large amount of slab memory (usually dentries/inodes) and further debugging has shown that there are way too many unmovable blocks which are skipped during the compaction. Multiple reporters have confirmed that the current linux-next which includes [1] and [2] helped and OOMs are not reproducible anymore. A simpler fix for the late rc and stable is to simply ignore the compaction feedback and retry as long as there is a reclaim progress and we are not getting OOM for order-0 pages. We already do that for CONFING_COMPACTION=n so let's reuse the same code when compaction is enabled as well. [1] http://lkml.kernel.org/r/20160810091226.6709-1-vbabka@suse.cz [2] http://lkml.kernel.org/r/f7a9ea9d-bb88-bfd6-e340-3a933559305a@suse.cz Fixes: 0a0337e0d1d1 ("mm, oom: rework oom detection") Link: http://lkml.kernel.org/r/20160823074339.GB23577@dhcp22.suse.cz Signed-off-by: Michal Hocko <mhocko@suse.com> Tested-by: Olaf Hering <olaf@aepfle.de> Tested-by: Ralf-Peter Rohbeck <Ralf-Peter.Rohbeck@quantum.com> Cc: Markus Trippelsdorf <markus@trippelsdorf.de> Cc: Arkadiusz Miskiewicz <a.miskiewicz@gmail.com> Cc: Ralf-Peter Rohbeck <Ralf-Peter.Rohbeck@quantum.com> Cc: Jiri Slaby <jslaby@suse.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Joonsoo Kim <js1304@gmail.com> Cc: Tetsuo Handa <penguin-kernel@i-love.sakura.ne.jp> Cc: David Rientjes <rientjes@google.com> Cc: <stable@vger.kernel.org> [4.7.x] Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-08-26mm: silently skip readahead for DAX inodesRoss Zwisler
For DAX inodes we need to be careful to never have page cache pages in the mapping->page_tree. This radix tree should be composed only of DAX exceptional entries and zero pages. ltp's readahead02 test was triggering a warning because we were trying to insert a DAX exceptional entry but found that a page cache page had already been inserted into the tree. This page was being inserted into the radix tree in response to a readahead(2) call. Readahead doesn't make sense for DAX inodes, but we don't want it to report a failure either. Instead, we just return success and don't do any work. Link: http://lkml.kernel.org/r/20160824221429.21158-1-ross.zwisler@linux.intel.com Signed-off-by: Ross Zwisler <ross.zwisler@linux.intel.com> Reported-by: Jeff Moyer <jmoyer@redhat.com> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Dave Chinner <david@fromorbit.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Jan Kara <jack@suse.com> Cc: <stable@vger.kernel.org> [4.5+] Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-08-26mm: memcontrol: avoid unused function warningArnd Bergmann
A bugfix in v4.8-rc2 introduced a harmless warning when CONFIG_MEMCG_SWAP is disabled but CONFIG_MEMCG is enabled: mm/memcontrol.c:4085:27: error: 'mem_cgroup_id_get_online' defined but not used [-Werror=unused-function] static struct mem_cgroup *mem_cgroup_id_get_online(struct mem_cgroup *memcg) This moves the function inside of the #ifdef block that hides the calling function, to avoid the warning. Fixes: 1f47b61fb407 ("mm: memcontrol: fix swap counter leak on swapout from offline cgroup") Link: http://lkml.kernel.org/r/20160824113733.2776701-1-arnd@arndb.de Signed-off-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Michal Hocko <mhocko@suse.com> Acked-by: Vladimir Davydov <vdavydov@virtuozzo.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-08-26mm: clarify COMPACTION Kconfig textMichal Hocko
The current wording of the COMPACTION Kconfig help text doesn't emphasise that disabling COMPACTION might cripple the page allocator which relies on the compaction quite heavily for high order requests and an unexpected OOM can happen with the lack of compaction. Make sure we are vocal about that. Link: http://lkml.kernel.org/r/20160823091726.GK23577@dhcp22.suse.cz Signed-off-by: Michal Hocko <mhocko@suse.com> Cc: Markus Trippelsdorf <markus@trippelsdorf.de> Cc: Mel Gorman <mgorman@suse.de> Cc: Joonsoo Kim <js1304@gmail.com> Cc: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-08-26soft_dirty: fix soft_dirty during THP splitAndrea Arcangeli
While adding proper userfaultfd_wp support with bits in pagetable and swap entry to avoid false positives WP userfaults through swap/fork/ KSM/etc, I've been adding a framework that mostly mirrors soft dirty. So I noticed in one place I had to add uffd_wp support to the pagetables that wasn't covered by soft_dirty and I think it should have. Example: in the THP migration code migrate_misplaced_transhuge_page() pmd_mkdirty is called unconditionally after mk_huge_pmd. entry = mk_huge_pmd(new_page, vma->vm_page_prot); entry = maybe_pmd_mkwrite(pmd_mkdirty(entry), vma); That sets soft dirty too (it's a false positive for soft dirty, the soft dirty bit could be more finegrained and transfer the bit like uffd_wp will do.. pmd/pte_uffd_wp() enforces the invariant that when it's set pmd/pte_write is not set). However in the THP split there's no unconditional pmd_mkdirty after mk_huge_pmd and pte_swp_mksoft_dirty isn't called after the migration entry is created. The code sets the dirty bit in the struct page instead of setting it in the pagetable (which is fully equivalent as far as the real dirty bit is concerned, as the whole point of pagetable bits is to be eventually flushed out of to the page, but that is not equivalent for the soft-dirty bit that gets lost in translation). This was found by code review only and totally untested as I'm working to actually replace soft dirty and I don't have time to test potential soft dirty bugfixes as well :). Transfer the soft_dirty from pmd to pte during THP splits. This fix avoids losing the soft_dirty bit and avoids userland memory corruption in the checkpoint. Fixes: eef1b3ba053aa6 ("thp: implement split_huge_pmd()") Link: http://lkml.kernel.org/r/1471610515-30229-2-git-send-email-aarcange@redhat.com Signed-off-by: Andrea Arcangeli <aarcange@redhat.com> Acked-by: Pavel Emelyanov <xemul@virtuozzo.com> Cc: "Kirill A. Shutemov" <kirill@shutemov.name> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-08-22usercopy: fix overlap check for kernel textJosh Poimboeuf
When running with a local patch which moves the '_stext' symbol to the very beginning of the kernel text area, I got the following panic with CONFIG_HARDENED_USERCOPY: usercopy: kernel memory exposure attempt detected from ffff88103dfff000 (<linear kernel text>) (4096 bytes) ------------[ cut here ]------------ kernel BUG at mm/usercopy.c:79! invalid opcode: 0000 [#1] SMP ... CPU: 0 PID: 4800 Comm: cp Not tainted 4.8.0-rc3.after+ #1 Hardware name: Dell Inc. PowerEdge R720/0X3D66, BIOS 2.5.4 01/22/2016 task: ffff880817444140 task.stack: ffff880816274000 RIP: 0010:[<ffffffff8121c796>] __check_object_size+0x76/0x413 RSP: 0018:ffff880816277c40 EFLAGS: 00010246 RAX: 000000000000006b RBX: ffff88103dfff000 RCX: 0000000000000000 RDX: 0000000000000000 RSI: ffff88081f80dfa8 RDI: ffff88081f80dfa8 RBP: ffff880816277c90 R08: 000000000000054c R09: 0000000000000000 R10: 0000000000000005 R11: 0000000000000006 R12: 0000000000001000 R13: ffff88103e000000 R14: ffff88103dffffff R15: 0000000000000001 FS: 00007fb9d1750800(0000) GS:ffff88081f800000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00000000021d2000 CR3: 000000081a08f000 CR4: 00000000001406f0 Stack: ffff880816277cc8 0000000000010000 000000043de07000 0000000000000000 0000000000001000 ffff880816277e60 0000000000001000 ffff880816277e28 000000000000c000 0000000000001000 ffff880816277ce8 ffffffff8136c3a6 Call Trace: [<ffffffff8136c3a6>] copy_page_to_iter_iovec+0xa6/0x1c0 [<ffffffff8136e766>] copy_page_to_iter+0x16/0x90 [<ffffffff811970e3>] generic_file_read_iter+0x3e3/0x7c0 [<ffffffffa06a738d>] ? xfs_file_buffered_aio_write+0xad/0x260 [xfs] [<ffffffff816e6262>] ? down_read+0x12/0x40 [<ffffffffa06a61b1>] xfs_file_buffered_aio_read+0x51/0xc0 [xfs] [<ffffffffa06a6692>] xfs_file_read_iter+0x62/0xb0 [xfs] [<ffffffff812224cf>] __vfs_read+0xdf/0x130 [<ffffffff81222c9e>] vfs_read+0x8e/0x140 [<ffffffff81224195>] SyS_read+0x55/0xc0 [<ffffffff81003a47>] do_syscall_64+0x67/0x160 [<ffffffff816e8421>] entry_SYSCALL64_slow_path+0x25/0x25 RIP: 0033:[<00007fb9d0c33c00>] 0x7fb9d0c33c00 RSP: 002b:00007ffc9c262f28 EFLAGS: 00000246 ORIG_RAX: 0000000000000000 RAX: ffffffffffffffda RBX: fffffffffff8ffff RCX: 00007fb9d0c33c00 RDX: 0000000000010000 RSI: 00000000021c3000 RDI: 0000000000000004 RBP: 00000000021c3000 R08: 0000000000000000 R09: 00007ffc9c264d6c R10: 00007ffc9c262c50 R11: 0000000000000246 R12: 0000000000010000 R13: 00007ffc9c2630b0 R14: 0000000000000004 R15: 0000000000010000 Code: 81 48 0f 44 d0 48 c7 c6 90 4d a3 81 48 c7 c0 bb b3 a2 81 48 0f 44 f0 4d 89 e1 48 89 d9 48 c7 c7 68 16 a3 81 31 c0 e8 f4 57 f7 ff <0f> 0b 48 8d 90 00 40 00 00 48 39 d3 0f 83 22 01 00 00 48 39 c3 RIP [<ffffffff8121c796>] __check_object_size+0x76/0x413 RSP <ffff880816277c40> The checked object's range [ffff88103dfff000, ffff88103e000000) is valid, so there shouldn't have been a BUG. The hardened usercopy code got confused because the range's ending address is the same as the kernel's text starting address at 0xffff88103e000000. The overlap check is slightly off. Fixes: f5509cc18daa ("mm: Hardened usercopy") Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com> Signed-off-by: Kees Cook <keescook@chromium.org>
2016-08-22usercopy: avoid potentially undefined behavior in pointer mathEric Biggers
check_bogus_address() checked for pointer overflow using this expression, where 'ptr' has type 'const void *': ptr + n < ptr Since pointer wraparound is undefined behavior, gcc at -O2 by default treats it like the following, which would not behave as intended: (long)n < 0 Fortunately, this doesn't currently happen for kernel code because kernel code is compiled with -fno-strict-overflow. But the expression should be fixed anyway to use well-defined integer arithmetic, since it could be treated differently by different compilers in the future or could be reported by tools checking for undefined behavior. Signed-off-by: Eric Biggers <ebiggers@google.com> Signed-off-by: Kees Cook <keescook@chromium.org>
2016-08-11mm/memory_hotplug.c: initialize per_cpu_nodestats for hotadded pgdatsReza Arbab
The following oops occurs after a pgdat is hotadded: Unable to handle kernel paging request for data at address 0x00c30001 Faulting instruction address: 0xc00000000022f8f4 Oops: Kernel access of bad area, sig: 11 [#1] SMP NR_CPUS=2048 NUMA pSeries Modules linked in: ip6t_rpfilter ip6t_REJECT nf_reject_ipv6 ipt_REJECT nf_reject_ipv4 xt_conntrack ebtable_nat ebtable_broute bridge stp llc ebtable_filter ebtables ip6table_nat nf_conntrack_ipv6 nf_defrag_ipv6 nf_nat_ipv6 ip6table_mangle ip6table_security ip6table_raw ip6table_filter ip6_tables iptable_nat nf_conntrack_ipv4 nf_defrag_ipv4 nf_nat_ipv4 nf_nat nf_conntrack iptable_mangle iptable_security iptable_raw iptable_filter nls_utf8 isofs sg virtio_balloon uio_pdrv_genirq uio ip_tables xfs libcrc32c sr_mod cdrom sd_mod virtio_net ibmvscsi scsi_transport_srp virtio_pci virtio_ring virtio dm_mirror dm_region_hash dm_log dm_mod CPU: 0 PID: 0 Comm: swapper/0 Tainted: G W 4.8.0-rc1-device #110 task: c000000000ef3080 task.stack: c000000000f6c000 NIP: c00000000022f8f4 LR: c00000000022f948 CTR: 0000000000000000 REGS: c000000000f6fa50 TRAP: 0300 Tainted: G W (4.8.0-rc1-device) MSR: 800000010280b033 <SF,VEC,VSX,EE,FP,ME,IR,DR,RI,LE,TM[E]> CR: 84002028 XER: 20000000 CFAR: d000000001d2013c DAR: 0000000000c30001 DSISR: 40000000 SOFTE: 0 NIP refresh_cpu_vm_stats+0x1a4/0x2f0 LR refresh_cpu_vm_stats+0x1f8/0x2f0 Call Trace: refresh_cpu_vm_stats+0x1f8/0x2f0 (unreliable) Add per_cpu_nodestats initialization to the hotplug codepath. Link: http://lkml.kernel.org/r/1470931473-7090-1-git-send-email-arbab@linux.vnet.ibm.com Signed-off-by: Reza Arbab <arbab@linux.vnet.ibm.com> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: Paul Mackerras <paulus@ozlabs.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-08-11mm, oom: fix uninitialized ret in task_will_free_mem()Geert Uytterhoeven
mm/oom_kill.c: In function `task_will_free_mem': mm/oom_kill.c:767: warning: `ret' may be used uninitialized in this function If __task_will_free_mem() is never called inside the for_each_process() loop, ret will not be initialized. Fixes: 1af8bb43269563e4 ("mm, oom: fortify task_will_free_mem()") Link: http://lkml.kernel.org/r/1470255599-24841-1-git-send-email-geert@linux-m68k.org Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org> Acked-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Acked-by: Michal Hocko <mhocko@suse.com> Cc: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-08-11kasan: remove the unnecessary WARN_ONCE from quarantine.cAlexander Potapenko
It's quite unlikely that the user will so little memory that the per-CPU quarantines won't fit into the given fraction of the available memory. Even in that case he won't be able to do anything with the information given in the warning. Link: http://lkml.kernel.org/r/1470929182-101413-1-git-send-email-glider@google.com Signed-off-by: Alexander Potapenko <glider@google.com> Acked-by: Andrey Ryabinin <aryabinin@virtuozzo.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Andrey Konovalov <adech.fo@gmail.com> Cc: Christoph Lameter <cl@linux.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Kuthonuzo Luruo <kuthonuzo.luruo@hpe.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-08-11mm: memcontrol: fix memcg id ref counter on swap charge moveVladimir Davydov
Since commit 73f576c04b94 ("mm: memcontrol: fix cgroup creation failure after many small jobs") swap entries do not pin memcg->css.refcnt directly. Instead, they pin memcg->id.ref. So we should adjust the reference counters accordingly when moving swap charges between cgroups. Fixes: 73f576c04b941 ("mm: memcontrol: fix cgroup creation failure after many small jobs") Link: http://lkml.kernel.org/r/9ce297c64954a42dc90b543bc76106c4a94f07e8.1470219853.git.vdavydov@virtuozzo.com Signed-off-by: Vladimir Davydov <vdavydov@virtuozzo.com> Acked-by: Michal Hocko <mhocko@suse.com> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Cc: <stable@vger.kernel.org> [3.19+] Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-08-11mm: memcontrol: fix swap counter leak on swapout from offline cgroupVladimir Davydov
An offline memory cgroup might have anonymous memory or shmem left charged to it and no swap. Since only swap entries pin the id of an offline cgroup, such a cgroup will have no id and so an attempt to swapout its anon/shmem will not store memory cgroup info in the swap cgroup map. As a result, memcg->swap or memcg->memsw will never get uncharged from it and any of its ascendants. Fix this by always charging swapout to the first ancestor cgroup that hasn't released its id yet. [hannes@cmpxchg.org: add comment to mem_cgroup_swapout] [vdavydov@virtuozzo.com: use WARN_ON_ONCE() in mem_cgroup_id_get_online()] Link: http://lkml.kernel.org/r/20160803123445.GJ13263@esperanza Fixes: 73f576c04b941 ("mm: memcontrol: fix cgroup creation failure after many small jobs") Link: http://lkml.kernel.org/r/5336daa5c9a32e776067773d9da655d2dc126491.1470219853.git.vdavydov@virtuozzo.com Signed-off-by: Vladimir Davydov <vdavydov@virtuozzo.com> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: Michal Hocko <mhocko@suse.com> Cc: <stable@vger.kernel.org> [3.19+] Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-08-11proc, meminfo: use correct helpers for calculating LRU sizes in meminfoMel Gorman
meminfo_proc_show() and si_mem_available() are using the wrong helpers for calculating the size of the LRUs. The user-visible impact is that there appears to be an abnormally high number of unevictable pages. Link: http://lkml.kernel.org/r/20160805105805.GR2799@techsingularity.net Signed-off-by: Mel Gorman <mgorman@techsingularity.net> Cc: Dave Chinner <david@fromorbit.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-08-11mm/hugetlb: fix incorrect hugepages count during mem hotplugzhong jiang
When memory hotplug operates, free hugepages will be freed if the movable node is offline. Therefore, /proc/sys/vm/nr_hugepages will be incorrect. Fix it by reducing max_huge_pages when the node is offlined. n-horiguchi@ah.jp.nec.com said: : dissolve_free_huge_page intends to break a hugepage into buddy, and the : destination hugepage is supposed to be allocated from the pool of the : destination node, so the system-wide pool size is reduced. So adding : h->max_huge_pages-- makes sense to me. Link: http://lkml.kernel.org/r/1470624546-902-1-git-send-email-zhongjiang@huawei.com Signed-off-by: zhong jiang <zhongjiang@huawei.com> Cc: Mike Kravetz <mike.kravetz@oracle.com> Acked-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-08-10mm/slub.c: run free_partial() outside of the kmem_cache_node->list_lockChris Wilson
With debugobjects enabled and using SLAB_DESTROY_BY_RCU, when a kmem_cache_node is destroyed the call_rcu() may trigger a slab allocation to fill the debug object pool (__debug_object_init:fill_pool). Everywhere but during kmem_cache_destroy(), discard_slab() is performed outside of the kmem_cache_node->list_lock and avoids a lockdep warning about potential recursion: ============================================= [ INFO: possible recursive locking detected ] 4.8.0-rc1-gfxbench+ #1 Tainted: G U --------------------------------------------- rmmod/8895 is trying to acquire lock: (&(&n->list_lock)->rlock){-.-...}, at: [<ffffffff811c80d7>] get_partial_node.isra.63+0x47/0x430 but task is already holding lock: (&(&n->list_lock)->rlock){-.-...}, at: [<ffffffff811cbda4>] __kmem_cache_shutdown+0x54/0x320 other info that might help us debug this: Possible unsafe locking scenario: CPU0 ---- lock(&(&n->list_lock)->rlock); lock(&(&n->list_lock)->rlock); *** DEADLOCK *** May be due to missing lock nesting notation 5 locks held by rmmod/8895: #0: (&dev->mutex){......}, at: driver_detach+0x42/0xc0 #1: (&dev->mutex){......}, at: driver_detach+0x50/0xc0 #2: (cpu_hotplug.dep_map){++++++}, at: get_online_cpus+0x2d/0x80 #3: (slab_mutex){+.+.+.}, at: kmem_cache_destroy+0x3c/0x220 #4: (&(&n->list_lock)->rlock){-.-...}, at: __kmem_cache_shutdown+0x54/0x320 stack backtrace: CPU: 6 PID: 8895 Comm: rmmod Tainted: G U 4.8.0-rc1-gfxbench+ #1 Hardware name: Gigabyte Technology Co., Ltd. H87M-D3H/H87M-D3H, BIOS F11 08/18/2015 Call Trace: __lock_acquire+0x1646/0x1ad0 lock_acquire+0xb2/0x200 _raw_spin_lock+0x36/0x50 get_partial_node.isra.63+0x47/0x430 ___slab_alloc.constprop.67+0x1a7/0x3b0 __slab_alloc.isra.64.constprop.66+0x43/0x80 kmem_cache_alloc+0x236/0x2d0 __debug_object_init+0x2de/0x400 debug_object_activate+0x109/0x1e0 __call_rcu.constprop.63+0x32/0x2f0 call_rcu+0x12/0x20 discard_slab+0x3d/0x40 __kmem_cache_shutdown+0xdb/0x320 shutdown_cache+0x19/0x60 kmem_cache_destroy+0x1ae/0x220 i915_gem_load_cleanup+0x14/0x40 [i915] i915_driver_unload+0x151/0x180 [i915] i915_pci_remove+0x14/0x20 [i915] pci_device_remove+0x34/0xb0 __device_release_driver+0x95/0x140 driver_detach+0xb6/0xc0 bus_remove_driver+0x53/0xd0 driver_unregister+0x27/0x50 pci_unregister_driver+0x25/0x70 i915_exit+0x1a/0x1e2 [i915] SyS_delete_module+0x193/0x1f0 entry_SYSCALL_64_fastpath+0x1c/0xac Fixes: 52b4b950b507 ("mm: slab: free kmem_cache_node after destroy sysfs file") Link: http://lkml.kernel.org/r/1470759070-18743-1-git-send-email-chris@chris-wilson.co.uk Reported-by: Dave Gordon <david.s.gordon@intel.com> Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk> Reviewed-by: Vladimir Davydov <vdavydov@virtuozzo.com> Acked-by: Christoph Lameter <cl@linux.com> Cc: Pekka Enberg <penberg@kernel.org> Cc: David Rientjes <rientjes@google.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Dmitry Safonov <dsafonov@virtuozzo.com> Cc: Daniel Vetter <daniel.vetter@ffwll.ch> Cc: Dave Gordon <david.s.gordon@intel.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-08-10rmap: fix compound check logic in page_remove_file_rmapSteve Capper
In page_remove_file_rmap(.) we have the following check: VM_BUG_ON_PAGE(compound && !PageTransHuge(page), page); This is meant to check for either HugeTLB pages or THP when a compound page is passed in. Unfortunately, if one disables CONFIG_TRANSPARENT_HUGEPAGE, then PageTransHuge(.) will always return false, provoking BUGs when one runs the libhugetlbfs test suite. This patch replaces PageTransHuge(), with PageHead() which will work for both HugeTLB and THP. Fixes: dd78fedde4b9 ("rmap: support file thp") Link: http://lkml.kernel.org/r/1470838217-5889-1-git-send-email-steve.capper@arm.com Signed-off-by: Steve Capper <steve.capper@arm.com> Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Huang Shijie <shijie.huang@arm.com> Cc: Will Deacon <will.deacon@arm.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-08-10mm, rmap: fix false positive VM_BUG() in page_add_file_rmap()Kirill A. Shutemov
PageTransCompound() doesn't distinguish THP from from any other type of compound pages. This can lead to false-positive VM_BUG_ON() in page_add_file_rmap() if called on compound page from a driver[1]. I think we can exclude such cases by checking if the page belong to a mapping. The VM_BUG_ON_PAGE() is downgraded to VM_WARN_ON_ONCE(). This path should not cause any harm to non-THP page, but good to know if we step on anything else. [1] http://lkml.kernel.org/r/c711e067-0bff-a6cb-3c37-04dfe77d2db1@redhat.com Link: http://lkml.kernel.org/r/20160810161345.GA67522@black.fi.intel.com Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Reported-by: Laura Abbott <labbott@redhat.com> Tested-by: Laura Abbott <labbott@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-08-10mm/page_alloc.c: recalculate some of node threshold when on/offline memoryJoonsoo Kim
Some of node threshold depends on number of managed pages in the node. When memory is going on/offline, it can be changed and we need to adjust them. Add recalculation to appropriate places and clean-up related functions for better maintenance. Link: http://lkml.kernel.org/r/1470724248-26780-2-git-send-email-iamjoonsoo.kim@lge.com Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com> Acked-by: Mel Gorman <mgorman@techsingularity.net> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Minchan Kim <minchan@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-08-10mm/page_alloc.c: fix wrong initialization when sysctl_min_unmapped_ratio changesJoonsoo Kim
Before resetting min_unmapped_pages, we need to initialize min_unmapped_pages rather than min_slab_pages. Fixes: a5f5f91da6 (mm: convert zone_reclaim to node_reclaim) Link: http://lkml.kernel.org/r/1470724248-26780-1-git-send-email-iamjoonsoo.kim@lge.com Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com> Acked-by: Mel Gorman <mgorman@techsingularity.net> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Minchan Kim <minchan@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-08-10thp: move shmem_huge_enabled() outside of SYSFS ifdefArnd Bergmann
The newly introduced shmem_huge_enabled() function has two definitions, but neither of them is visible if CONFIG_SYSFS is disabled, leading to a build error: mm/khugepaged.o: In function `khugepaged': khugepaged.c:(.text.khugepaged+0x3ca): undefined reference to `shmem_huge_enabled' This changes the #ifdef guards around the definition to match those that are used in the header file. Fixes: e496cf3d7821 ("thp: introduce CONFIG_TRANSPARENT_HUGE_PAGECACHE") Link: http://lkml.kernel.org/r/20160809123638.1357593-1-arnd@arndb.de Signed-off-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-08-09mm: memcontrol: only mark charged pages with PageKmemcgVladimir Davydov
To distinguish non-slab pages charged to kmemcg we mark them PageKmemcg, which sets page->_mapcount to -512. Currently, we set/clear PageKmemcg in __alloc_pages_nodemask()/free_pages_prepare() for any page allocated with __GFP_ACCOUNT, including those that aren't actually charged to any cgroup, i.e. allocated from the root cgroup context. To avoid overhead in case cgroups are not used, we only do that if memcg_kmem_enabled() is true. The latter is set iff there are kmem-enabled memory cgroups (online or offline). The root cgroup is not considered kmem-enabled. As a result, if a page is allocated with __GFP_ACCOUNT for the root cgroup when there are kmem-enabled memory cgroups and is freed after all kmem-enabled memory cgroups were removed, e.g. # no memory cgroups has been created yet, create one mkdir /sys/fs/cgroup/memory/test # run something allocating pages with __GFP_ACCOUNT, e.g. # a program using pipe dmesg | tail # remove the memory cgroup rmdir /sys/fs/cgroup/memory/test we'll get bad page state bug complaining about page->_mapcount != -1: BUG: Bad page state in process swapper/0 pfn:1fd945c page:ffffea007f651700 count:0 mapcount:-511 mapping: (null) index:0x0 flags: 0x1000000000000000() To avoid that, let's mark with PageKmemcg only those pages that are actually charged to and hence pin a non-root memory cgroup. Fixes: 4949148ad433 ("mm: charge/uncharge kmemcg from generic page allocator paths") Reported-and-tested-by: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: Vladimir Davydov <vdavydov@virtuozzo.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-08-08Merge tag 'usercopy-v4.8' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux Pull usercopy protection from Kees Cook: "Tbhis implements HARDENED_USERCOPY verification of copy_to_user and copy_from_user bounds checking for most architectures on SLAB and SLUB" * tag 'usercopy-v4.8' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux: mm: SLUB hardened usercopy support mm: SLAB hardened usercopy support s390/uaccess: Enable hardened usercopy sparc/uaccess: Enable hardened usercopy powerpc/uaccess: Enable hardened usercopy ia64/uaccess: Enable hardened usercopy arm64/uaccess: Enable hardened usercopy ARM: uaccess: Enable hardened usercopy x86/uaccess: Enable hardened usercopy mm: Hardened usercopy mm: Implement stack frame object validation mm: Add is_migrate_cma_page
2016-08-07mm: make __swap_writepage() use bio_set_op_attrs()Jens Axboe
Cleaner than manipulating bio->bi_rw flags directly. Signed-off-by: Jens Axboe <axboe@fb.com>
2016-08-07block/mm: make bdev_ops->rw_page() take a bool for read/writeJens Axboe
Commit abf545484d31 changed it from an 'rw' flags type to the newer ops based interface, but now we're effectively leaking some bdev internals to the rest of the kernel. Since we only care about whether it's a read or a write at that level, just pass in a bool 'is_write' parameter instead. Then we can also move op_is_write() and friends back under CONFIG_BLOCK protection. Reviewed-by: Mike Christie <mchristi@redhat.com> Signed-off-by: Jens Axboe <axboe@fb.com>
2016-08-05Merge branch 'for-linus' of git://git.kernel.dk/linux-blockLinus Torvalds
Pull block fixes from Jens Axboe: "Here's the second round of block updates for this merge window. It's a mix of fixes for changes that went in previously in this round, and fixes in general. This pull request contains: - Fixes for loop from Christoph - A bdi vs gendisk lifetime fix from Dan, worth two cookies. - A blk-mq timeout fix, when on frozen queues. From Gabriel. - Writeback fix from Jan, ensuring that __writeback_single_inode() does the right thing. - Fix for bio->bi_rw usage in f2fs from me. - Error path deadlock fix in blk-mq sysfs registration from me. - Floppy O_ACCMODE fix from Jiri. - Fix to the new bio op methods from Mike. One more followup will be coming here, ensuring that we don't propagate the block types outside of block. That, and a rename of bio->bi_rw is coming right after -rc1 is cut. - Various little fixes" * 'for-linus' of git://git.kernel.dk/linux-block: mm/block: convert rw_page users to bio op use loop: make do_req_filebacked more robust loop: don't try to use AIO for discards blk-mq: fix deadlock in blk_mq_register_disk() error path Include: blkdev: Removed duplicate 'struct request;' declaration. Fixup direct bi_rw modifiers block: fix bdi vs gendisk lifetime mismatch blk-mq: Allow timeouts to run while queue is freezing nbd: fix race in ioctl block: fix use-after-free in seq file f2fs: drop bio->bi_rw manual assignment block: add missing group association in bio-cloning functions blkcg: kill unused field nr_undestroyed_grps writeback: Write dirty times for WB_SYNC_ALL writeback floppy: fix open(O_ACCMODE) for ioctl-only open
2016-08-05Merge tag 'powerpc-4.8-2' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux Pull more powerpc updates from Michael Ellerman: "These were delayed for various reasons, so I let them sit in next a bit longer, rather than including them in my first pull request. Fixes: - Fix early access to cpu_spec relocation from Benjamin Herrenschmidt - Fix incorrect event codes in power9-event-list from Madhavan Srinivasan - Move register_process_table() out of ppc_md from Michael Ellerman Use jump_label use for [cpu|mmu]_has_feature(): - Add mmu_early_init_devtree() from Michael Ellerman - Move disable_radix handling into mmu_early_init_devtree() from Michael Ellerman - Do hash device tree scanning earlier from Michael Ellerman - Do radix device tree scanning earlier from Michael Ellerman - Do feature patching before MMU init from Michael Ellerman - Check features don't change after patching from Michael Ellerman - Make MMU_FTR_RADIX a MMU family feature from Aneesh Kumar K.V - Convert mmu_has_feature() to returning bool from Michael Ellerman - Convert cpu_has_feature() to returning bool from Michael Ellerman - Define radix_enabled() in one place & use static inline from Michael Ellerman - Add early_[cpu|mmu]_has_feature() from Michael Ellerman - Convert early cpu/mmu feature check to use the new helpers from Aneesh Kumar K.V - jump_label: Make it possible for arches to invoke jump_label_init() earlier from Kevin Hao - Call jump_label_init() in apply_feature_fixups() from Aneesh Kumar K.V - Remove mfvtb() from Kevin Hao - Move cpu_has_feature() to a separate file from Kevin Hao - Add kconfig option to use jump labels for cpu/mmu_has_feature() from Michael Ellerman - Add option to use jump label for cpu_has_feature() from Kevin Hao - Add option to use jump label for mmu_has_feature() from Kevin Hao - Catch usage of cpu/mmu_has_feature() before jump label init from Aneesh Kumar K.V - Annotate jump label assembly from Michael Ellerman TLB flush enhancements from Aneesh Kumar K.V: - radix: Implement tlb mmu gather flush efficiently - Add helper for finding SLBE LLP encoding - Use hugetlb flush functions - Drop multiple definition of mm_is_core_local - radix: Add tlb flush of THP ptes - radix: Rename function and drop unused arg - radix/hugetlb: Add helper for finding page size - hugetlb: Add flush_hugetlb_tlb_range - remove flush_tlb_page_nohash Add new ptrace regsets from Anshuman Khandual and Simon Guo: - elf: Add powerpc specific core note sections - Add the function flush_tmregs_to_thread - Enable in transaction NT_PRFPREG ptrace requests - Enable in transaction NT_PPC_VMX ptrace requests - Enable in transaction NT_PPC_VSX ptrace requests - Adapt gpr32_get, gpr32_set functions for transaction - Enable support for NT_PPC_CGPR - Enable support for NT_PPC_CFPR - Enable support for NT_PPC_CVMX - Enable support for NT_PPC_CVSX - Enable support for TM SPR state - Enable NT_PPC_TM_CTAR, NT_PPC_TM_CPPR, NT_PPC_TM_CDSCR - Enable support for NT_PPPC_TAR, NT_PPC_PPR, NT_PPC_DSCR - Enable support for EBB registers - Enable support for Performance Monitor registers" * tag 'powerpc-4.8-2' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux: (48 commits) powerpc/mm: Move register_process_table() out of ppc_md powerpc/perf: Fix incorrect event codes in power9-event-list powerpc/32: Fix early access to cpu_spec relocation powerpc/ptrace: Enable support for Performance Monitor registers powerpc/ptrace: Enable support for EBB registers powerpc/ptrace: Enable support for NT_PPPC_TAR, NT_PPC_PPR, NT_PPC_DSCR powerpc/ptrace: Enable NT_PPC_TM_CTAR, NT_PPC_TM_CPPR, NT_PPC_TM_CDSCR powerpc/ptrace: Enable support for TM SPR state powerpc/ptrace: Enable support for NT_PPC_CVSX powerpc/ptrace: Enable support for NT_PPC_CVMX powerpc/ptrace: Enable support for NT_PPC_CFPR powerpc/ptrace: Enable support for NT_PPC_CGPR powerpc/ptrace: Adapt gpr32_get, gpr32_set functions for transaction powerpc/ptrace: Enable in transaction NT_PPC_VSX ptrace requests powerpc/ptrace: Enable in transaction NT_PPC_VMX ptrace requests powerpc/ptrace: Enable in transaction NT_PRFPREG ptrace requests powerpc/process: Add the function flush_tmregs_to_thread elf: Add powerpc specific core note sections powerpc/mm: remove flush_tlb_page_nohash powerpc/mm/hugetlb: Add flush_hugetlb_tlb_range ...
2016-08-04mm/memblock.c: fix NULL dereference errorzijun_hu
It causes NULL dereference error and failure to get type_a->regions[0] info if parameter type_b of __next_mem_range_rev() == NULL Fix this by checking before dereferring and initializing idx_b to 0 The approach is tested by dumping all types of region via __memblock_dump_all() and __next_mem_range_rev() fixed to UART separately the result is okay after checking the logs. Link: http://lkml.kernel.org/r/57A0320D.6070102@zoho.com Signed-off-by: zijun_hu <zijun_hu@htc.com> Tested-by: zijun_hu <zijun_hu@htc.com> Acked-by: Tejun Heo <tj@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-08-04slub: drop bogus inline for fixup_red_left()Geert Uytterhoeven
With m68k-linux-gnu-gcc-4.1: include/linux/slub_def.h:126: warning: `fixup_red_left' declared inline after being called include/linux/slub_def.h:126: warning: previous declaration of `fixup_red_left' was here Commit c146a2b98eb5 ("mm, kasan: account for object redzone in SLUB's nearest_obj()") made fixup_red_left() global, but forgot to remove the inline keyword. Fixes: c146a2b98eb5898e ("mm, kasan: account for object redzone in SLUB's nearest_obj()") Link: http://lkml.kernel.org/r/1470256262-1586-1-git-send-email-geert@linux-m68k.org Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Alexander Potapenko <glider@google.com> Acked-by: David Rientjes <rientjes@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-08-04mm: initialise per_cpu_nodestats for all online pgdats at bootMel Gorman
Paul Mackerras and Reza Arbab reported that machines with memoryless nodes fail when vmstats are refreshed. Paul reported an oops as follows Unable to handle kernel paging request for data at address 0xff7a10000 Faulting instruction address: 0xc000000000270cd0 Oops: Kernel access of bad area, sig: 11 [#1] SMP NR_CPUS=2048 NUMA PowerNV Modules linked in: CPU: 0 PID: 1 Comm: swapper/0 Not tainted 4.7.0-kvm+ #118 task: c000000ff0680010 task.stack: c000000ff0704000 NIP: c000000000270cd0 LR: c000000000270ce8 CTR: 0000000000000000 REGS: c000000ff0707900 TRAP: 0300 Not tainted (4.7.0-kvm+) MSR: 9000000102009033 <SF,HV,VEC,EE,ME,IR,DR,RI,LE,TM[E]> CR: 846b6824 XER: 20000000 CFAR: c000000000008768 DAR: 0000000ff7a10000 DSISR: 42000000 SOFTE: 1 NIP refresh_zone_stat_thresholds+0x80/0x240 LR refresh_zone_stat_thresholds+0x98/0x240 Call Trace: refresh_zone_stat_thresholds+0xb8/0x240 (unreliable) Both supplied potential fixes but one potentially misses checks and another had redundant initialisations. This version initialises per_cpu_nodestats on a per-pgdat basis instead of on a per-zone basis. Link: http://lkml.kernel.org/r/20160804092404.GI2799@techsingularity.net Signed-off-by: Mel Gorman <mgorman@techsingularity.net> Reported-by: Paul Mackerras <paulus@ozlabs.org> Reported-by: Reza Arbab <arbab@linux.vnet.ibm.com> Tested-by: Reza Arbab <arbab@linux.vnet.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-08-04mm/memblock: fix a typo in a commentAlexander Kuleshov
s/accomodate/accommodate/ Link: http://lkml.kernel.org/r/20160804121824.18100-1-kuleshovmail@gmail.com Signed-off-by: Alexander Kuleshov <kuleshovmail@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>