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* mm/memory.c: fix modifying of page protection by insert_pfn()Jan Kara2019-05-161-5/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | [ Upstream commit cae85cb8add35f678cf487139d05e083ce2f570a ] Aneesh has reported that PPC triggers the following warning when excercising DAX code: IP set_pte_at+0x3c/0x190 LR insert_pfn+0x208/0x280 Call Trace: insert_pfn+0x68/0x280 dax_iomap_pte_fault.isra.7+0x734/0xa40 __xfs_filemap_fault+0x280/0x2d0 do_wp_page+0x48c/0xa40 __handle_mm_fault+0x8d0/0x1fd0 handle_mm_fault+0x140/0x250 __do_page_fault+0x300/0xd60 handle_page_fault+0x18 Now that is WARN_ON in set_pte_at which is VM_WARN_ON(pte_hw_valid(*ptep) && !pte_protnone(*ptep)); The problem is that on some architectures set_pte_at() cannot cope with a situation where there is already some (different) valid entry present. Use ptep_set_access_flags() instead to modify the pfn which is built to deal with modifying existing PTE. Link: http://lkml.kernel.org/r/20190311084537.16029-1-jack@suse.cz Fixes: b2770da64254 "mm: add vm_insert_mixed_mkwrite()" Signed-off-by: Jan Kara <jack@suse.cz> Reported-by: "Aneesh Kumar K.V" <aneesh.kumar@linux.ibm.com> Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> Acked-by: Dan Williams <dan.j.williams@intel.com> Cc: Chandan Rajendra <chandan@linux.ibm.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
* mm: Fix warning in insert_pfn()Jan Kara2019-05-021-2/+7
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit f2c57d91b0d96aa13ccff4e3b178038f17b00658 upstream. In DAX mode a write pagefault can race with write(2) in the following way: CPU0 CPU1 write fault for mapped zero page (hole) dax_iomap_rw() iomap_apply() xfs_file_iomap_begin() - allocates blocks dax_iomap_actor() invalidate_inode_pages2_range() - invalidates radix tree entries in given range dax_iomap_pte_fault() grab_mapping_entry() - no entry found, creates empty ... xfs_file_iomap_begin() - finds already allocated block ... vmf_insert_mixed_mkwrite() - WARNs and does nothing because there is still zero page mapped in PTE unmap_mapping_pages() This race results in WARN_ON from insert_pfn() and is occasionally triggered by fstest generic/344. Note that the race is otherwise harmless as before write(2) on CPU0 is finished, we will invalidate page tables properly and thus user of mmap will see modified data from write(2) from that point on. So just restrict the warning only to the case when the PFN in PTE is not zero page. Link: http://lkml.kernel.org/r/20180824154542.26872-1-jack@suse.cz Signed-off-by: Jan Kara <jack@suse.cz> Reviewed-by: Andrew Morton <akpm@linux-foundation.org> Cc: Ross Zwisler <ross.zwisler@linux.intel.com> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Dave Jiang <dave.jiang@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* mm/memory.c: do_fault: avoid usage of stale vm_area_structJan Stancek2019-03-231-1/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit fc8efd2ddfed3f343c11b693e87140ff358d7ff5 upstream. LTP testcase mtest06 [1] can trigger a crash on s390x running 5.0.0-rc8. This is a stress test, where one thread mmaps/writes/munmaps memory area and other thread is trying to read from it: CPU: 0 PID: 2611 Comm: mmap1 Not tainted 5.0.0-rc8+ #51 Hardware name: IBM 2964 N63 400 (z/VM 6.4.0) Krnl PSW : 0404e00180000000 00000000001ac8d8 (__lock_acquire+0x7/0x7a8) Call Trace: ([<0000000000000000>] (null)) [<00000000001adae4>] lock_acquire+0xec/0x258 [<000000000080d1ac>] _raw_spin_lock_bh+0x5c/0x98 [<000000000012a780>] page_table_free+0x48/0x1a8 [<00000000002f6e54>] do_fault+0xdc/0x670 [<00000000002fadae>] __handle_mm_fault+0x416/0x5f0 [<00000000002fb138>] handle_mm_fault+0x1b0/0x320 [<00000000001248cc>] do_dat_exception+0x19c/0x2c8 [<000000000080e5ee>] pgm_check_handler+0x19e/0x200 page_table_free() is called with NULL mm parameter, but because "0" is a valid address on s390 (see S390_lowcore), it keeps going until it eventually crashes in lockdep's lock_acquire. This crash is reproducible at least since 4.14. Problem is that "vmf->vma" used in do_fault() can become stale. Because mmap_sem may be released, other threads can come in, call munmap() and cause "vma" be returned to kmem cache, and get zeroed/re-initialized and re-used: handle_mm_fault | __handle_mm_fault | do_fault | vma = vmf->vma | do_read_fault | __do_fault | vma->vm_ops->fault(vmf); | mmap_sem is released | | | do_munmap() | remove_vma_list() | remove_vma() | vm_area_free() | # vma is released | ... | # same vma is allocated | # from kmem cache | do_mmap() | vm_area_alloc() | memset(vma, 0, ...) | pte_free(vma->vm_mm, ...); | page_table_free | spin_lock_bh(&mm->context.lock);| <crash> | Cache mm_struct to avoid using potentially stale "vma". [1] https://github.com/linux-test-project/ltp/blob/master/testcases/kernel/mem/mtest06/mmap1.c Link: http://lkml.kernel.org/r/5b3fdf19e2a5be460a384b936f5b56e13733f1b8.1551595137.git.jstancek@redhat.com Signed-off-by: Jan Stancek <jstancek@redhat.com> Reviewed-by: Andrea Arcangeli <aarcange@redhat.com> Reviewed-by: Matthew Wilcox <willy@infradead.org> Acked-by: Rafael Aquini <aquini@redhat.com> Reviewed-by: Minchan Kim <minchan@kernel.org> Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Rik van Riel <riel@surriel.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Huang Ying <ying.huang@intel.com> Cc: Souptick Joarder <jrdr.linux@gmail.com> Cc: Jerome Glisse <jglisse@redhat.com> Cc: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> Cc: David Hildenbrand <david@redhat.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: David Rientjes <rientjes@google.com> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* mm, memcg: fix reclaim deadlock with writebackMichal Hocko2019-01-161-0/+23
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit 63f3655f950186752236bb88a22f8252c11ce394 upstream. Liu Bo has experienced a deadlock between memcg (legacy) reclaim and the ext4 writeback task1: wait_on_page_bit+0x82/0xa0 shrink_page_list+0x907/0x960 shrink_inactive_list+0x2c7/0x680 shrink_node_memcg+0x404/0x830 shrink_node+0xd8/0x300 do_try_to_free_pages+0x10d/0x330 try_to_free_mem_cgroup_pages+0xd5/0x1b0 try_charge+0x14d/0x720 memcg_kmem_charge_memcg+0x3c/0xa0 memcg_kmem_charge+0x7e/0xd0 __alloc_pages_nodemask+0x178/0x260 alloc_pages_current+0x95/0x140 pte_alloc_one+0x17/0x40 __pte_alloc+0x1e/0x110 alloc_set_pte+0x5fe/0xc20 do_fault+0x103/0x970 handle_mm_fault+0x61e/0xd10 __do_page_fault+0x252/0x4d0 do_page_fault+0x30/0x80 page_fault+0x28/0x30 task2: __lock_page+0x86/0xa0 mpage_prepare_extent_to_map+0x2e7/0x310 [ext4] ext4_writepages+0x479/0xd60 do_writepages+0x1e/0x30 __writeback_single_inode+0x45/0x320 writeback_sb_inodes+0x272/0x600 __writeback_inodes_wb+0x92/0xc0 wb_writeback+0x268/0x300 wb_workfn+0xb4/0x390 process_one_work+0x189/0x420 worker_thread+0x4e/0x4b0 kthread+0xe6/0x100 ret_from_fork+0x41/0x50 He adds "task1 is waiting for the PageWriteback bit of the page that task2 has collected in mpd->io_submit->io_bio, and tasks2 is waiting for the LOCKED bit the page which tasks1 has locked" More precisely task1 is handling a page fault and it has a page locked while it charges a new page table to a memcg. That in turn hits a memory limit reclaim and the memcg reclaim for legacy controller is waiting on the writeback but that is never going to finish because the writeback itself is waiting for the page locked in the #PF path. So this is essentially ABBA deadlock: lock_page(A) SetPageWriteback(A) unlock_page(A) lock_page(B) lock_page(B) pte_alloc_pne shrink_page_list wait_on_page_writeback(A) SetPageWriteback(B) unlock_page(B) # flush A, B to clear the writeback This accumulating of more pages to flush is used by several filesystems to generate a more optimal IO patterns. Waiting for the writeback in legacy memcg controller is a workaround for pre-mature OOM killer invocations because there is no dirty IO throttling available for the controller. There is no easy way around that unfortunately. Therefore fix this specific issue by pre-allocating the page table outside of the page lock. We have that handy infrastructure for that already so simply reuse the fault-around pattern which already does this. There are probably other hidden __GFP_ACCOUNT | GFP_KERNEL allocations from under a fs page locked but they should be really rare. I am not aware of a better solution unfortunately. [akpm@linux-foundation.org: fix mm/memory.c:__do_fault()] [akpm@linux-foundation.org: coding-style fixes] [mhocko@kernel.org: enhance comment, per Johannes] Link: http://lkml.kernel.org/r/20181214084948.GA5624@dhcp22.suse.cz Link: http://lkml.kernel.org/r/20181213092221.27270-1-mhocko@kernel.org Fixes: c3b94f44fcb0 ("memcg: further prevent OOM with too many dirty pages") Signed-off-by: Michal Hocko <mhocko@suse.com> Reported-by: Liu Bo <bo.liu@linux.alibaba.com> Debugged-by: Liu Bo <bo.liu@linux.alibaba.com> Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Reviewed-by: Liu Bo <bo.liu@linux.alibaba.com> Cc: Jan Kara <jack@suse.cz> Cc: Dave Chinner <david@fromorbit.com> Cc: Theodore Ts'o <tytso@mit.edu> Cc: Vladimir Davydov <vdavydov.dev@gmail.com> Cc: Shakeel Butt <shakeelb@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> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* mm/memory.c: recheck page table entry with page table lock heldAneesh Kumar K.V2018-12-011-4/+30
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit ff09d7ec9786be4ad7589aa987d7dc66e2dd9160 upstream. We clear the pte temporarily during read/modify/write update of the pte. If we take a page fault while the pte is cleared, the application can get SIGBUS. One such case is with remap_pfn_range without a backing vm_ops->fault callback. do_fault will return SIGBUS in that case. cpu 0 cpu1 mprotect() ptep_modify_prot_start()/pte cleared. . . page fault. . . prep_modify_prot_commit() Fix this by taking page table lock and rechecking for pte_none. [aneesh.kumar@linux.ibm.com: fix crash observed with syzkaller run] Link: http://lkml.kernel.org/r/87va6bwlfg.fsf@linux.ibm.com Link: http://lkml.kernel.org/r/20180926031858.9692-1-aneesh.kumar@linux.ibm.com Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Willem de Bruijn <willemdebruijn.kernel@gmail.com> Cc: Eric Dumazet <eric.dumazet@gmail.com> Cc: Ido Schimmel <idosch@idosch.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* mm/cow: don't bother write protecting already write-protected pagesLinus Torvalds2018-08-251-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | This is not normally noticeable, but repeated forks are unnecessarily expensive because they repeatedly dirty the parent page tables during the page table copy operation. It's trivial to just avoid write protecting the page table entry if it was already not writable. This patch was inspired by https://bugzilla.kernel.org/show_bug.cgi?id=200447 which points to an ancient "waste time re-doing fork" issue in the presence of lots of signals. That bug was fixed by Eric Biederman's signal handling series culminating in commit c3ad2c3b02e9 ("signal: Don't restart fork when signals come in"), but the unnecessary work for repeated forks is still work just fixing, particularly since the fix is trivial. Cc: Eric Biederman <ebiederm@xmission.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Merge branch 'akpm' (patches from Andrew)Linus Torvalds2018-08-231-44/+46
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Merge yet more updates from Andrew Morton: - the rest of MM - various misc fixes and tweaks * emailed patches from Andrew Morton <akpm@linux-foundation.org>: (22 commits) mm: Change return type int to vm_fault_t for fault handlers lib/fonts: convert comments to utf-8 s390: ebcdic: convert comments to UTF-8 treewide: convert ISO_8859-1 text comments to utf-8 drivers/gpu/drm/gma500/: change return type to vm_fault_t docs/core-api: mm-api: add section about GFP flags docs/mm: make GFP flags descriptions usable as kernel-doc docs/core-api: split memory management API to a separate file docs/core-api: move *{str,mem}dup* to "String Manipulation" docs/core-api: kill trailing whitespace in kernel-api.rst mm/util: add kernel-doc for kvfree mm/util: make strndup_user description a kernel-doc comment fs/proc/vmcore.c: hide vmcoredd_mmap_dumps() for nommu builds treewide: correct "differenciate" and "instanciate" typos fs/afs: use new return type vm_fault_t drivers/hwtracing/intel_th/msu.c: change return type to vm_fault_t mm: soft-offline: close the race against page allocation mm: fix race on soft-offlining free huge pages namei: allow restricted O_CREAT of FIFOs and regular files hfs: prevent crash on exit from failed search ...
| * mm: Change return type int to vm_fault_t for fault handlersSouptick Joarder2018-08-231-44/+46
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Use new return type vm_fault_t for fault handler. For now, this is just documenting that the function returns a VM_FAULT value rather than an errno. Once all instances are converted, vm_fault_t will become a distinct type. Ref-> commit 1c8f422059ae ("mm: change return type to vm_fault_t") The aim is to change the return type of finish_fault() and handle_mm_fault() to vm_fault_t type. As part of that clean up return type of all other recursively called functions have been changed to vm_fault_t type. The places from where handle_mm_fault() is getting invoked will be change to vm_fault_t type but in a separate patch. vmf_error() is the newly introduce inline function in 4.17-rc6. [akpm@linux-foundation.org: don't shadow outer local `ret' in __do_huge_pmd_anonymous_page()] Link: http://lkml.kernel.org/r/20180604171727.GA20279@jordon-HP-15-Notebook-PC Signed-off-by: Souptick Joarder <jrdr.linux@gmail.com> Reviewed-by: Matthew Wilcox <mawilcox@microsoft.com> Reviewed-by: Andrew Morton <akpm@linux-foundation.org> Cc: Matthew Wilcox <willy@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | mm: mmu_notifier fix for tlb_end_vmaNicholas Piggin2018-08-231-10/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The generic tlb_end_vma does not call invalidate_range mmu notifier, and it resets resets the mmu_gather range, which means the notifier won't be called on part of the range in case of an unmap that spans multiple vmas. ARM64 seems to be the only arch I could see that has notifiers and uses the generic tlb_end_vma. I have not actually tested it. [ Catalin and Will point out that ARM64 currently only uses the notifiers for KVM, which doesn't use the ->invalidate_range() callback right now, so it's a bug, but one that happens to not affect them. So not necessary for stable. - Linus ] Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Acked-by: Catalin Marinas <catalin.marinas@arm.com> Acked-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | mm/tlb, x86/mm: Support invalidating TLB caches for RCU_TABLE_FREEPeter Zijlstra2018-08-231-0/+18
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Jann reported that x86 was missing required TLB invalidates when he hit the !*batch slow path in tlb_remove_table(). This is indeed the case; RCU_TABLE_FREE does not provide TLB (cache) invalidates, the PowerPC-hash where this code originated and the Sparc-hash where this was subsequently used did not need that. ARM which later used this put an explicit TLB invalidate in their __p*_free_tlb() functions, and PowerPC-radix followed that example. But when we hooked up x86 we failed to consider this. Fix this by (optionally) hooking tlb_remove_table() into the TLB invalidate code. NOTE: s390 was also needing something like this and might now be able to use the generic code again. [ Modified to be on top of Nick's cleanups, which simplified this patch now that tlb_flush_mmu_tlbonly() really only flushes the TLB - Linus ] Fixes: 9e52fc2b50de ("x86/mm: Enable RCU based page table freeing (CONFIG_HAVE_RCU_TABLE_FREE=y)") Reported-by: Jann Horn <jannh@google.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Rik van Riel <riel@surriel.com> Cc: Nicholas Piggin <npiggin@gmail.com> Cc: David Miller <davem@davemloft.net> Cc: Will Deacon <will.deacon@arm.com> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: stable@kernel.org Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | mm/tlb: Remove tlb_remove_table() non-concurrent conditionPeter Zijlstra2018-08-231-9/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Will noted that only checking mm_users is incorrect; we should also check mm_count in order to cover CPUs that have a lazy reference to this mm (and could do speculative TLB operations). If removing this turns out to be a performance issue, we can re-instate a more complete check, but in tlb_table_flush() eliding the call_rcu_sched(). Fixes: 267239116987 ("mm, powerpc: move the RCU page-table freeing into generic code") Reported-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Rik van Riel <riel@surriel.com> Acked-by: Will Deacon <will.deacon@arm.com> Cc: Nicholas Piggin <npiggin@gmail.com> Cc: David Miller <davem@davemloft.net> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: stable@kernel.org Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | mm: move tlb_table_flush to tlb_flush_mmu_freeNicholas Piggin2018-08-231-3/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | There is no need to call this from tlb_flush_mmu_tlbonly, it logically belongs with tlb_flush_mmu_free. This makes future fixes simpler. [ This was originally done to allow code consolidation for the mmu_notifier fix, but it also ends up helping simplify the HAVE_RCU_TABLE_INVALIDATE fix. - Linus ] Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Acked-by: Will Deacon <will.deacon@arm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: stable@kernel.org Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | x86/mm/tlb: Revert the recent lazy TLB patchesPeter Zijlstra2018-08-221-14/+8
|/ | | | | | | | | | | | | | | | | Revert commits: 95b0e6357d3e x86/mm/tlb: Always use lazy TLB mode 64482aafe55f x86/mm/tlb: Only send page table free TLB flush to lazy TLB CPUs ac0315896970 x86/mm/tlb: Make lazy TLB mode lazier 61d0beb5796a x86/mm/tlb: Restructure switch_mm_irqs_off() 2ff6ddf19c0e x86/mm/tlb: Leave lazy TLB mode at page table free time In order to simplify the TLB invalidate fixes for x86 and unify the parts that need backporting. We'll try again later. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Rik van Riel <riel@surriel.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Revert "mm: always flush VMA ranges affected by zap_page_range"Rik van Riel2018-08-171-13/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | There was a bug in Linux that could cause madvise (and mprotect?) system calls to return to userspace without the TLB having been flushed for all the pages involved. This could happen when multiple threads of a process made simultaneous madvise and/or mprotect calls. This was noticed in the summer of 2017, at which time two solutions were created: 56236a59556c ("mm: refactor TLB gathering API") 99baac21e458 ("mm: fix MADV_[FREE|DONTNEED] TLB flush miss problem") and 4647706ebeee ("mm: always flush VMA ranges affected by zap_page_range") We need only one of these solutions, and the former appears to be a little more efficient than the latter, so revert that one. This reverts 4647706ebeee6e50 ("mm: always flush VMA ranges affected by zap_page_range") Link: http://lkml.kernel.org/r/20180706131019.51e3a5f0@imladris.surriel.com Signed-off-by: Rik van Riel <riel@surriel.com> Acked-by: Mel Gorman <mgorman@techsingularity.net> Cc: Andy Lutomirski <luto@kernel.org> Cc: Michal Hocko <mhocko@suse.com> Cc: Minchan Kim <minchan@kernel.org> Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com> Cc: Nicholas Piggin <npiggin@gmail.com> Cc: Nadav Amit <nadav.amit@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* memcg, oom: move out_of_memory back to the charge pathMichal Hocko2018-08-171-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Commit 3812c8c8f395 ("mm: memcg: do not trap chargers with full callstack on OOM") has changed the ENOMEM semantic of memcg charges. Rather than invoking the oom killer from the charging context it delays the oom killer to the page fault path (pagefault_out_of_memory). This in turn means that many users (e.g. slab or g-u-p) will get ENOMEM when the corresponding memcg hits the hard limit and the memcg is is OOM. This is behavior is inconsistent with !memcg case where the oom killer is invoked from the allocation context and the allocator keeps retrying until it succeeds. The difference in the behavior is user visible. mmap(MAP_POPULATE) might result in not fully populated ranges while the mmap return code doesn't tell that to the userspace. Random syscalls might fail with ENOMEM etc. The primary motivation of the different memcg oom semantic was the deadlock avoidance. Things have changed since then, though. We have an async oom teardown by the oom reaper now and so we do not have to rely on the victim to tear down its memory anymore. Therefore we can return to the original semantic as long as the memcg oom killer is not handed over to the users space. There is still one thing to be careful about here though. If the oom killer is not able to make any forward progress - e.g. because there is no eligible task to kill - then we have to bail out of the charge path to prevent from same class of deadlocks. We have basically two options here. Either we fail the charge with ENOMEM or force the charge and allow overcharge. The first option has been considered more harmful than useful because rare inconsistencies in the ENOMEM behavior is hard to test for and error prone. Basically the same reason why the page allocator doesn't fail allocations under such conditions. The later might allow runaways but those should be really unlikely unless somebody misconfigures the system. E.g. allowing to migrate tasks away from the memcg to a different unlimited memcg with move_charge_at_immigrate disabled. Link: http://lkml.kernel.org/r/20180628151101.25307-1-mhocko@kernel.org Signed-off-by: Michal Hocko <mhocko@suse.com> Acked-by: Greg Thelen <gthelen@google.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Shakeel Butt <shakeelb@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm, huge page: copy target sub-page last when copy huge pageHuang Ying2018-08-171-7/+23
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Huge page helps to reduce TLB miss rate, but it has higher cache footprint, sometimes this may cause some issue. For example, when copying huge page on x86_64 platform, the cache footprint is 4M. But on a Xeon E5 v3 2699 CPU, there are 18 cores, 36 threads, and only 45M LLC (last level cache). That is, in average, there are 2.5M LLC for each core and 1.25M LLC for each thread. If the cache contention is heavy when copying the huge page, and we copy the huge page from the begin to the end, it is possible that the begin of huge page is evicted from the cache after we finishing copying the end of the huge page. And it is possible for the application to access the begin of the huge page after copying the huge page. In c79b57e462b5d ("mm: hugetlb: clear target sub-page last when clearing huge page"), to keep the cache lines of the target subpage hot, the order to clear the subpages in the huge page in clear_huge_page() is changed to clearing the subpage which is furthest from the target subpage firstly, and the target subpage last. The similar order changing helps huge page copying too. That is implemented in this patch. Because we have put the order algorithm into a separate function, the implementation is quite simple. The patch is a generic optimization which should benefit quite some workloads, not for a specific use case. To demonstrate the performance benefit of the patch, we tested it with vm-scalability run on transparent huge page. With this patch, the throughput increases ~16.6% in vm-scalability anon-cow-seq test case with 36 processes on a 2 socket Xeon E5 v3 2699 system (36 cores, 72 threads). The test case set /sys/kernel/mm/transparent_hugepage/enabled to be always, mmap() a big anonymous memory area and populate it, then forked 36 child processes, each writes to the anonymous memory area from the begin to the end, so cause copy on write. For each child process, other child processes could be seen as other workloads which generate heavy cache pressure. At the same time, the IPC (instruction per cycle) increased from 0.63 to 0.78, and the time spent in user space is reduced ~7.2%. Link: http://lkml.kernel.org/r/20180524005851.4079-3-ying.huang@intel.com Signed-off-by: "Huang, Ying" <ying.huang@intel.com> Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com> Cc: Andi Kleen <andi.kleen@intel.com> Cc: Jan Kara <jack@suse.cz> Cc: Michal Hocko <mhocko@suse.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Hugh Dickins <hughd@google.com> Cc: Minchan Kim <minchan@kernel.org> Cc: Shaohua Li <shli@fb.com> Cc: Christopher Lameter <cl@linux.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm, clear_huge_page: move order algorithm into a separate functionHuang Ying2018-08-171-34/+56
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Patch series "mm, huge page: Copy target sub-page last when copy huge page", v2. Huge page helps to reduce TLB miss rate, but it has higher cache footprint, sometimes this may cause some issue. For example, when copying huge page on x86_64 platform, the cache footprint is 4M. But on a Xeon E5 v3 2699 CPU, there are 18 cores, 36 threads, and only 45M LLC (last level cache). That is, in average, there are 2.5M LLC for each core and 1.25M LLC for each thread. If the cache contention is heavy when copying the huge page, and we copy the huge page from the begin to the end, it is possible that the begin of huge page is evicted from the cache after we finishing copying the end of the huge page. And it is possible for the application to access the begin of the huge page after copying the huge page. In c79b57e462b5d ("mm: hugetlb: clear target sub-page last when clearing huge page"), to keep the cache lines of the target subpage hot, the order to clear the subpages in the huge page in clear_huge_page() is changed to clearing the subpage which is furthest from the target subpage firstly, and the target subpage last. The similar order changing helps huge page copying too. That is implemented in this patchset. The patchset is a generic optimization which should benefit quite some workloads, not for a specific use case. To demonstrate the performance benefit of the patchset, we have tested it with vm-scalability run on transparent huge page. With this patchset, the throughput increases ~16.6% in vm-scalability anon-cow-seq test case with 36 processes on a 2 socket Xeon E5 v3 2699 system (36 cores, 72 threads). The test case set /sys/kernel/mm/transparent_hugepage/enabled to be always, mmap() a big anonymous memory area and populate it, then forked 36 child processes, each writes to the anonymous memory area from the begin to the end, so cause copy on write. For each child process, other child processes could be seen as other workloads which generate heavy cache pressure. At the same time, the IPC (instruction per cycle) increased from 0.63 to 0.78, and the time spent in user space is reduced ~7.2%. This patch (of 4): In c79b57e462b5d ("mm: hugetlb: clear target sub-page last when clearing huge page"), to keep the cache lines of the target subpage hot, the order to clear the subpages in the huge page in clear_huge_page() is changed to clearing the subpage which is furthest from the target subpage firstly, and the target subpage last. This optimization could be applied to copying huge page too with the same order algorithm. To avoid code duplication and reduce maintenance overhead, in this patch, the order algorithm is moved out of clear_huge_page() into a separate function: process_huge_page(). So that we can use it for copying huge page too. This will change the direct calls to clear_user_highpage() into the indirect calls. But with the proper inline support of the compilers, the indirect call will be optimized to be the direct call. Our tests show no performance change with the patch. This patch is a code cleanup without functionality change. Link: http://lkml.kernel.org/r/20180524005851.4079-2-ying.huang@intel.com Signed-off-by: "Huang, Ying" <ying.huang@intel.com> Suggested-by: Mike Kravetz <mike.kravetz@oracle.com> Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com> Cc: Andi Kleen <andi.kleen@intel.com> Cc: Jan Kara <jack@suse.cz> Cc: Michal Hocko <mhocko@suse.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Hugh Dickins <hughd@google.com> Cc: Minchan Kim <minchan@kernel.org> Cc: Shaohua Li <shli@fb.com> Cc: Christopher Lameter <cl@linux.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* thp: use mm_file_counter to determine update which rss counterYang Shi2018-08-171-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | Since commit eca56ff906bd ("mm, shmem: add internal shmem resident memory accounting"), MM_SHMEMPAGES is added to separate the shmem accounting from regular files. So, all shmem pages should be accounted to MM_SHMEMPAGES instead of MM_FILEPAGES. And, normal 4K shmem pages have been accounted to MM_SHMEMPAGES, so shmem thp pages should be not treated differently. Account them to MM_SHMEMPAGES via mm_counter_file() since shmem pages are swap backed to keep consistent with normal 4K shmem pages. This will not change the rss counter of processes since shmem pages are still a part of it. The /proc/pid/status and /proc/pid/statm counters will however be more accurate wrt shmem usage, as originally intended. And as eca56ff906bd ("mm, shmem: add internal shmem resident memory accounting") mentioned, oom also could report more accurate "shmem-rss". Link: http://lkml.kernel.org/r/1529442518-17398-1-git-send-email-yang.shi@linux.alibaba.com Signed-off-by: Yang Shi <yang.shi@linux.alibaba.com> Acked-by: Vlastimil Babka <vbabka@suse.cz> Cc: Hugh Dickins <hughd@google.com> Cc: 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>
* dax: remove VM_MIXEDMAP for fsdax and device daxDave Jiang2018-08-171-0/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch is reworked from an earlier patch that Dan has posted: https://patchwork.kernel.org/patch/10131727/ VM_MIXEDMAP is used by dax to direct mm paths like vm_normal_page() that the memory page it is dealing with is not typical memory from the linear map. The get_user_pages_fast() path, since it does not resolve the vma, is already using {pte,pmd}_devmap() as a stand-in for VM_MIXEDMAP, so we use that as a VM_MIXEDMAP replacement in some locations. In the cases where there is no pte to consult we fallback to using vma_is_dax() to detect the VM_MIXEDMAP special case. Now that we have explicit driver pfn_t-flag opt-in/opt-out for get_user_pages() support for DAX we can stop setting VM_MIXEDMAP. This also means we no longer need to worry about safely manipulating vm_flags in a future where we support dynamically changing the dax mode of a file. DAX should also now be supported with madvise_behavior(), vma_merge(), and copy_page_range(). This patch has been tested against ndctl unit test. It has also been tested against xfstests commit: 625515d using fake pmem created by memmap and no additional issues have been observed. Link: http://lkml.kernel.org/r/152847720311.55924.16999195879201817653.stgit@djiang5-desk3.ch.intel.com Signed-off-by: Dave Jiang <dave.jiang@intel.com> Acked-by: Dan Williams <dan.j.williams@intel.com> Cc: Jan Kara <jack@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Merge tag 'for-4.19/block-20180812' of git://git.kernel.dk/linux-blockLinus Torvalds2018-08-141-5/+6
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Pull block updates from Jens Axboe: "First pull request for this merge window, there will also be a followup request with some stragglers. This pull request contains: - Fix for a thundering heard issue in the wbt block code (Anchal Agarwal) - A few NVMe pull requests: * Improved tracepoints (Keith) * Larger inline data support for RDMA (Steve Wise) * RDMA setup/teardown fixes (Sagi) * Effects log suppor for NVMe target (Chaitanya Kulkarni) * Buffered IO suppor for NVMe target (Chaitanya Kulkarni) * TP4004 (ANA) support (Christoph) * Various NVMe fixes - Block io-latency controller support. Much needed support for properly containing block devices. (Josef) - Series improving how we handle sense information on the stack (Kees) - Lightnvm fixes and updates/improvements (Mathias/Javier et al) - Zoned device support for null_blk (Matias) - AIX partition fixes (Mauricio Faria de Oliveira) - DIF checksum code made generic (Max Gurtovoy) - Add support for discard in iostats (Michael Callahan / Tejun) - Set of updates for BFQ (Paolo) - Removal of async write support for bsg (Christoph) - Bio page dirtying and clone fixups (Christoph) - Set of bcache fix/changes (via Coly) - Series improving blk-mq queue setup/teardown speed (Ming) - Series improving merging performance on blk-mq (Ming) - Lots of other fixes and cleanups from a slew of folks" * tag 'for-4.19/block-20180812' of git://git.kernel.dk/linux-block: (190 commits) blkcg: Make blkg_root_lookup() work for queues in bypass mode bcache: fix error setting writeback_rate through sysfs interface null_blk: add lock drop/acquire annotation Blk-throttle: reduce tail io latency when iops limit is enforced block: paride: pd: mark expected switch fall-throughs block: Ensure that a request queue is dissociated from the cgroup controller block: Introduce blk_exit_queue() blkcg: Introduce blkg_root_lookup() block: Remove two superfluous #include directives blk-mq: count the hctx as active before allocating tag block: bvec_nr_vecs() returns value for wrong slab bcache: trivial - remove tailing backslash in macro BTREE_FLAG bcache: make the pr_err statement used for ENOENT only in sysfs_attatch section bcache: set max writeback rate when I/O request is idle bcache: add code comments for bset.c bcache: fix mistaken comments in request.c bcache: fix mistaken code comments in bcache.h bcache: add a comment in super.c bcache: avoid unncessary cache prefetch bch_btree_node_get() bcache: display rate debug parameters to 0 when writeback is not running ...
| * memcontrol: schedule throttling if we are congestedTejun Heo2018-07-091-5/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Memory allocations can induce swapping via kswapd or direct reclaim. If we are having IO done for us by kswapd and don't actually go into direct reclaim we may never get scheduled for throttling. So instead check to see if our cgroup is congested, and if so schedule the throttling. Before we return to user space the throttling stuff will only throttle if we actually required it. Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Josef Bacik <jbacik@fb.com> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
* | Merge branch 'l1tf-final' of ↵Linus Torvalds2018-08-141-10/+27
|\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Merge L1 Terminal Fault fixes from Thomas Gleixner: "L1TF, aka L1 Terminal Fault, is yet another speculative hardware engineering trainwreck. It's a hardware vulnerability which allows unprivileged speculative access to data which is available in the Level 1 Data Cache when the page table entry controlling the virtual address, which is used for the access, has the Present bit cleared or other reserved bits set. If an instruction accesses a virtual address for which the relevant page table entry (PTE) has the Present bit cleared or other reserved bits set, then speculative execution ignores the invalid PTE and loads the referenced data if it is present in the Level 1 Data Cache, as if the page referenced by the address bits in the PTE was still present and accessible. While this is a purely speculative mechanism and the instruction will raise a page fault when it is retired eventually, the pure act of loading the data and making it available to other speculative instructions opens up the opportunity for side channel attacks to unprivileged malicious code, similar to the Meltdown attack. While Meltdown breaks the user space to kernel space protection, L1TF allows to attack any physical memory address in the system and the attack works across all protection domains. It allows an attack of SGX and also works from inside virtual machines because the speculation bypasses the extended page table (EPT) protection mechanism. The assoicated CVEs are: CVE-2018-3615, CVE-2018-3620, CVE-2018-3646 The mitigations provided by this pull request include: - Host side protection by inverting the upper address bits of a non present page table entry so the entry points to uncacheable memory. - Hypervisor protection by flushing L1 Data Cache on VMENTER. - SMT (HyperThreading) control knobs, which allow to 'turn off' SMT by offlining the sibling CPU threads. The knobs are available on the kernel command line and at runtime via sysfs - Control knobs for the hypervisor mitigation, related to L1D flush and SMT control. The knobs are available on the kernel command line and at runtime via sysfs - Extensive documentation about L1TF including various degrees of mitigations. Thanks to all people who have contributed to this in various ways - patches, review, testing, backporting - and the fruitful, sometimes heated, but at the end constructive discussions. There is work in progress to provide other forms of mitigations, which might be less horrible performance wise for a particular kind of workloads, but this is not yet ready for consumption due to their complexity and limitations" * 'l1tf-final' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (75 commits) x86/microcode: Allow late microcode loading with SMT disabled tools headers: Synchronise x86 cpufeatures.h for L1TF additions x86/mm/kmmio: Make the tracer robust against L1TF x86/mm/pat: Make set_memory_np() L1TF safe x86/speculation/l1tf: Make pmd/pud_mknotpresent() invert x86/speculation/l1tf: Invert all not present mappings cpu/hotplug: Fix SMT supported evaluation KVM: VMX: Tell the nested hypervisor to skip L1D flush on vmentry x86/speculation: Use ARCH_CAPABILITIES to skip L1D flush on vmentry x86/speculation: Simplify sysfs report of VMX L1TF vulnerability Documentation/l1tf: Remove Yonah processors from not vulnerable list x86/KVM/VMX: Don't set l1tf_flush_l1d from vmx_handle_external_intr() x86/irq: Let interrupt handlers set kvm_cpu_l1tf_flush_l1d x86: Don't include linux/irq.h from asm/hardirq.h x86/KVM/VMX: Introduce per-host-cpu analogue of l1tf_flush_l1d x86/irq: Demote irq_cpustat_t::__softirq_pending to u16 x86/KVM/VMX: Move the l1tf_flush_l1d test to vmx_l1d_flush() x86/KVM/VMX: Replace 'vmx_l1d_flush_always' with 'vmx_l1d_flush_cond' x86/KVM/VMX: Don't set l1tf_flush_l1d to true from vmx_l1d_flush() cpu/hotplug: detect SMT disabled by BIOS ...
| * | x86/speculation/l1tf: Disallow non privileged high MMIO PROT_NONE mappingsAndi Kleen2018-06-201-10/+27
| |/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | For L1TF PROT_NONE mappings are protected by inverting the PFN in the page table entry. This sets the high bits in the CPU's address space, thus making sure to point to not point an unmapped entry to valid cached memory. Some server system BIOSes put the MMIO mappings high up in the physical address space. If such an high mapping was mapped to unprivileged users they could attack low memory by setting such a mapping to PROT_NONE. This could happen through a special device driver which is not access protected. Normal /dev/mem is of course access protected. To avoid this forbid PROT_NONE mappings or mprotect for high MMIO mappings. Valid page mappings are allowed because the system is then unsafe anyways. It's not expected that users commonly use PROT_NONE on MMIO. But to minimize any impact this is only enforced if the mapping actually refers to a high MMIO address (defined as the MAX_PA-1 bit being set), and also skip the check for root. For mmaps this is straight forward and can be handled in vm_insert_pfn and in remap_pfn_range(). For mprotect it's a bit trickier. At the point where the actual PTEs are accessed a lot of state has been changed and it would be difficult to undo on an error. Since this is a uncommon case use a separate early page talk walk pass for MMIO PROT_NONE mappings that checks for this condition early. For non MMIO and non PROT_NONE there are no changes. Signed-off-by: Andi Kleen <ak@linux.intel.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Josh Poimboeuf <jpoimboe@redhat.com> Acked-by: Dave Hansen <dave.hansen@intel.com>
* | Merge branch 'x86-mm-for-linus' of ↵Linus Torvalds2018-08-131-8/+14
|\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 mm updates from Thomas Gleixner: - Make lazy TLB mode even lazier to avoid pointless switch_mm() operations, which reduces CPU load by 1-2% for memcache workloads - Small cleanups and improvements all over the place * 'x86-mm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/mm: Remove redundant check for kmem_cache_create() arm/asm/tlb.h: Fix build error implicit func declaration x86/mm/tlb: Make clear_asid_other() static x86/mm/tlb: Skip atomic operations for 'init_mm' in switch_mm_irqs_off() x86/mm/tlb: Always use lazy TLB mode x86/mm/tlb: Only send page table free TLB flush to lazy TLB CPUs x86/mm/tlb: Make lazy TLB mode lazier x86/mm/tlb: Restructure switch_mm_irqs_off() x86/mm/tlb: Leave lazy TLB mode at page table free time mm: Allocate the mm_cpumask (mm->cpu_bitmap[]) dynamically based on nr_cpu_ids x86/mm: Add TLB purge to free pmd/pte page interfaces ioremap: Update pgtable free interfaces with addr x86/mm: Disable ioremap free page handling on x86-PAE
| * | x86/mm/tlb: Leave lazy TLB mode at page table free timeRik van Riel2018-07-171-8/+14
| |/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Andy discovered that speculative memory accesses while in lazy TLB mode can crash a system, when a CPU tries to dereference a speculative access using memory contents that used to be valid page table memory, but have since been reused for something else and point into la-la land. The latter problem can be prevented in two ways. The first is to always send a TLB shootdown IPI to CPUs in lazy TLB mode, while the second one is to only send the TLB shootdown at page table freeing time. The second should result in fewer IPIs, since operationgs like mprotect and madvise are very common with some workloads, but do not involve page table freeing. Also, on munmap, batching of page table freeing covers much larger ranges of virtual memory than the batching of unmapped user pages. Tested-by: Song Liu <songliubraving@fb.com> Signed-off-by: Rik van Riel <riel@surriel.com> Acked-by: Dave Hansen <dave.hansen@intel.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: efault@gmx.de Cc: kernel-team@fb.com Cc: luto@kernel.org Link: http://lkml.kernel.org/r/20180716190337.26133-3-riel@surriel.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
* | mm/memory.c: check return value of ioremap_protjie@chenjie6@huwei.com2018-08-101-0/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | ioremap_prot() can return NULL which could lead to an oops. Link: http://lkml.kernel.org/r/1533195441-58594-1-git-send-email-chenjie6@huawei.com Signed-off-by: chen jie <chenjie6@huawei.com> Reviewed-by: Andrew Morton <akpm@linux-foundation.org> Cc: Li Zefan <lizefan@huawei.com> Cc: chenjie <chenjie6@huawei.com> Cc: Yang Shi <shy828301@gmail.com> Cc: Alexey Dobriyan <adobriyan@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | mm: delete historical BUG from zap_pmd_range()Hugh Dickins2018-08-011-4/+2
|/ | | | | | | | | | | | | | | | | | | | | | | | | | | Delete the old VM_BUG_ON_VMA() from zap_pmd_range(), which asserted that mmap_sem must be held when splitting an "anonymous" vma there. Whether that's still strictly true nowadays is not entirely clear, but the danger of sometimes crashing on the BUG is now fairly clear. Even with the new stricter rules for anonymous vma marking, the condition it checks for can possible trigger. Commit 44960f2a7b63 ("staging: ashmem: Fix SIGBUS crash when traversing mmaped ashmem pages") is good, and originally I thought it was safe from that VM_BUG_ON_VMA(), because the /dev/ashmem fd exposed to the user is disconnected from the vm_file in the vma, and madvise(,,MADV_REMOVE) insists on VM_SHARED. But after I read John's earlier mail, drawing attention to the vfs_fallocate() in there: I may be wrong, and I don't know if Android has THP in the config anyway, but it looks to me like an unmap_mapping_range() from ashmem's vfs_fallocate() could hit precisely the VM_BUG_ON_VMA(), once it's vma_is_anonymous(). Signed-off-by: Hugh Dickins <hughd@google.com> Cc: John Stultz <john.stultz@linaro.org> Cc: Kirill Shutemov <kirill.shutemov@linux.intel.com> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Merge branch 'akpm' (patches from Andrew)Linus Torvalds2018-06-071-13/+23
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Merge updates from Andrew Morton: - a few misc things - ocfs2 updates - v9fs updates - MM - procfs updates - lib/ updates - autofs updates * emailed patches from Andrew Morton <akpm@linux-foundation.org>: (118 commits) autofs: small cleanup in autofs_getpath() autofs: clean up includes autofs: comment on selinux changes needed for module autoload autofs: update MAINTAINERS entry for autofs autofs: use autofs instead of autofs4 in documentation autofs: rename autofs documentation files autofs: create autofs Kconfig and Makefile autofs: delete fs/autofs4 source files autofs: update fs/autofs4/Makefile autofs: update fs/autofs4/Kconfig autofs: copy autofs4 to autofs autofs4: use autofs instead of autofs4 everywhere autofs4: merge auto_fs.h and auto_fs4.h fs/binfmt_misc.c: do not allow offset overflow checkpatch: improve patch recognition lib/ucs2_string.c: add MODULE_LICENSE() lib/mpi: headers cleanup lib/percpu_ida.c: use _irqsave() instead of local_irq_save() + spin_lock lib/idr.c: remove simple_ida_lock lib/bitmap.c: micro-optimization for __bitmap_complement() ...
| * mm: remove odd HAVE_PTE_SPECIALLaurent Dufour2018-06-071-9/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Remove the additional define HAVE_PTE_SPECIAL and rely directly on CONFIG_ARCH_HAS_PTE_SPECIAL. There is no functional change introduced by this patch Link: http://lkml.kernel.org/r/1523533733-25437-1-git-send-email-ldufour@linux.vnet.ibm.com Signed-off-by: Laurent Dufour <ldufour@linux.vnet.ibm.com> Acked-by: David Rientjes <rientjes@google.com> Reviewed-by: Andrew Morton <akpm@linux-foundation.org> Cc: Jerome Glisse <jglisse@redhat.com> Cc: Michal Hocko <mhocko@kernel.org> Cc: Christophe LEROY <christophe.leroy@c-s.fr> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * mm: introduce ARCH_HAS_PTE_SPECIALLaurent Dufour2018-06-071-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Currently the PTE special supports is turned on in per architecture header files. Most of the time, it is defined in arch/*/include/asm/pgtable.h depending or not on some other per architecture static definition. This patch introduce a new configuration variable to manage this directly in the Kconfig files. It would later replace __HAVE_ARCH_PTE_SPECIAL. Here notes for some architecture where the definition of __HAVE_ARCH_PTE_SPECIAL is not obvious: arm __HAVE_ARCH_PTE_SPECIAL which is currently defined in arch/arm/include/asm/pgtable-3level.h which is included by arch/arm/include/asm/pgtable.h when CONFIG_ARM_LPAE is set. So select ARCH_HAS_PTE_SPECIAL if ARM_LPAE. powerpc __HAVE_ARCH_PTE_SPECIAL is defined in 2 files: - arch/powerpc/include/asm/book3s/64/pgtable.h - arch/powerpc/include/asm/pte-common.h The first one is included if (PPC_BOOK3S & PPC64) while the second is included in all the other cases. So select ARCH_HAS_PTE_SPECIAL all the time. sparc: __HAVE_ARCH_PTE_SPECIAL is defined if defined(__sparc__) && defined(__arch64__) which are defined through the compiler in sparc/Makefile if !SPARC32 which I assume to be if SPARC64. So select ARCH_HAS_PTE_SPECIAL if SPARC64 There is no functional change introduced by this patch. Link: http://lkml.kernel.org/r/1523433816-14460-2-git-send-email-ldufour@linux.vnet.ibm.com Signed-off-by: Laurent Dufour <ldufour@linux.vnet.ibm.com> Suggested-by: Jerome Glisse <jglisse@redhat.com> Reviewed-by: Jerome Glisse <jglisse@redhat.com> Acked-by: David Rientjes <rientjes@google.com> Cc: Michal Hocko <mhocko@kernel.org> Cc: "Aneesh Kumar K . V" <aneesh.kumar@linux.vnet.ibm.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Will Deacon <will.deacon@arm.com> Cc: Yoshinori Sato <ysato@users.sourceforge.jp> Cc: Rich Felker <dalias@libc.org> Cc: David S. Miller <davem@davemloft.net> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: Vineet Gupta <vgupta@synopsys.com> Cc: Palmer Dabbelt <palmer@sifive.com> Cc: Albert Ou <albert@sifive.com> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: David Rientjes <rientjes@google.com> Cc: Robin Murphy <robin.murphy@arm.com> Cc: Christophe LEROY <christophe.leroy@c-s.fr> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * fs/dax.c: use new return type vm_fault_tSouptick Joarder2018-06-071-4/+17
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Use new return type vm_fault_t for fault handler. For now, this is just documenting that the function returns a VM_FAULT value rather than an errno. Once all instances are converted, vm_fault_t will become a distinct type. commit 1c8f422059ae ("mm: change return type to vm_fault_t") There was an existing bug inside dax_load_hole() if vm_insert_mixed had failed to allocate a page table, we'd return VM_FAULT_NOPAGE instead of VM_FAULT_OOM. With new vmf_insert_mixed() this issue is addressed. vm_insert_mixed_mkwrite has inefficiency when it returns an error value, driver has to convert it to vm_fault_t type. With new vmf_insert_mixed_mkwrite() this limitation will be addressed. Link: http://lkml.kernel.org/r/20180510181121.GA15239@jordon-HP-15-Notebook-PC Signed-off-by: Souptick Joarder <jrdr.linux@gmail.com> Reviewed-by: Jan Kara <jack@suse.cz> Reviewed-by: Matthew Wilcox <mawilcox@microsoft.com> Reviewed-by: Ross Zwisler <ross.zwisler@linux.intel.com> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Michal Hocko <mhocko@suse.com> Cc: "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>
* | mm: Remove return value of zap_vma_ptes()Leon Romanovsky2018-06-011-4/+3
|/ | | | | | | | | All callers of zap_vma_ptes() are not interested in the return value of that function, so let's simplify its interface and drop the return value. Signed-off-by: Leon Romanovsky <leonro@mellanox.com> Signed-off-by: Doug Ledford <dledford@redhat.com>
* mm: swap: unify cluster-based and vma-based swap readaheadMinchan Kim2018-04-051-7/+4
| | | | | | | | | | | | | | | This patch makes do_swap_page() not need to be aware of two different swap readahead algorithms. Just unify cluster-based and vma-based readahead function call. Link: http://lkml.kernel.org/r/1509520520-32367-3-git-send-email-minchan@kernel.org Link: http://lkml.kernel.org/r/20180220085249.151400-3-minchan@kernel.org Signed-off-by: Minchan Kim <minchan@kernel.org> Reviewed-by: Andrew Morton <akpm@linux-foundation.org> Cc: Hugh Dickins <hughd@google.com> Cc: Huang Ying <ying.huang@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm: swap: clean up swap readaheadMinchan Kim2018-04-051-20/+6
| | | | | | | | | | | | | | | | | | | | | | | | When I see recent change of swap readahead, I am very unhappy about current code structure which diverges two swap readahead algorithm in do_swap_page. This patch is to clean it up. Main motivation is that fault handler doesn't need to be aware of readahead algorithms but just should call swapin_readahead. As first step, this patch cleans up a little bit but not perfect (I just separate for review easier) so next patch will make the goal complete. [minchan@kernel.org: do not check readahead flag with THP anon] Link: http://lkml.kernel.org/r/874lm83zho.fsf@yhuang-dev.intel.com Link: http://lkml.kernel.org/r/20180227232611.169883-1-minchan@kernel.org Link: http://lkml.kernel.org/r/1509520520-32367-2-git-send-email-minchan@kernel.org Link: http://lkml.kernel.org/r/20180220085249.151400-2-minchan@kernel.org Signed-off-by: Minchan Kim <minchan@kernel.org> Reviewed-by: Andrew Morton <akpm@linux-foundation.org> Cc: Hugh Dickins <hughd@google.com> Cc: Huang Ying <ying.huang@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm, swap: Add infrastructure for saving page metadata on swapKhalid Aziz2018-03-181-0/+1
| | | | | | | | | | | | | | | | | | If a processor supports special metadata for a page, for example ADI version tags on SPARC M7, this metadata must be saved when the page is swapped out. The same metadata must be restored when the page is swapped back in. This patch adds two new architecture specific functions - arch_do_swap_page() to be called when a page is swapped in, and arch_unmap_one() to be called when a page is being unmapped for swap out. These architecture hooks allow page metadata to be saved if the architecture supports it. Signed-off-by: Khalid Aziz <khalid.aziz@oracle.com> Cc: Khalid Aziz <khalid@gonehiking.org> Acked-by: Jerome Marchand <jmarchan@redhat.com> Reviewed-by: Anthony Yznaga <anthony.yznaga@oracle.com> Acked-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: David S. Miller <davem@davemloft.net>
* mm: hide a #warning for COMPILE_TESTArnd Bergmann2018-02-161-1/+1
| | | | | | | | | | | | | | | | We get a warning about some slow configurations in randconfig kernels: mm/memory.c:83:2: error: #warning Unfortunate NUMA and NUMA Balancing config, growing page-frame for last_cpupid. [-Werror=cpp] The warning is reasonable by itself, but gets in the way of randconfig build testing, so I'm hiding it whenever CONFIG_COMPILE_TEST is set. The warning was added in 2013 in commit 75980e97dacc ("mm: fold page->_last_nid into page->flags where possible"). Cc: stable@vger.kernel.org Signed-off-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Merge branch 'akpm' (patches from Andrew)Linus Torvalds2018-02-061-4/+0
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Merge misc updates from Andrew Morton: - kasan updates - procfs - lib/bitmap updates - other lib/ updates - checkpatch tweaks - rapidio - ubsan - pipe fixes and cleanups - lots of other misc bits * emailed patches from Andrew Morton <akpm@linux-foundation.org>: (114 commits) Documentation/sysctl/user.txt: fix typo MAINTAINERS: update ARM/QUALCOMM SUPPORT patterns MAINTAINERS: update various PALM patterns MAINTAINERS: update "ARM/OXNAS platform support" patterns MAINTAINERS: update Cortina/Gemini patterns MAINTAINERS: remove ARM/CLKDEV SUPPORT file pattern MAINTAINERS: remove ANDROID ION pattern mm: docs: add blank lines to silence sphinx "Unexpected indentation" errors mm: docs: fix parameter names mismatch mm: docs: fixup punctuation pipe: read buffer limits atomically pipe: simplify round_pipe_size() pipe: reject F_SETPIPE_SZ with size over UINT_MAX pipe: fix off-by-one error when checking buffer limits pipe: actually allow root to exceed the pipe buffer limits pipe, sysctl: remove pipe_proc_fn() pipe, sysctl: drop 'min' parameter from pipe-max-size converter kasan: rework Kconfig settings crash_dump: is_kdump_kernel can be boolean kernel/mutex: mutex_is_locked can be boolean ...
| * mm: remove unneeded kallsyms includeSergey Senozhatsky2018-02-061-4/+0
| | | | | | | | | | | | | | | | | | | | | | | | The file was converted from print_symbol() to %pSR a while ago in commit 071361d3473e ("mm: Convert print_symbol to %pSR"). kallsyms does not seem to be needed anymore. Link: http://lkml.kernel.org/r/20171208025616.16267-3-sergey.senozhatsky@gmail.com Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Cc: Michal Hocko <mhocko@suse.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | Merge tag 'libnvdimm-for-4.16' of ↵Linus Torvalds2018-02-061-1/+15
|\ \ | |/ |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm Pull libnvdimm updates from Ross Zwisler: - Require struct page by default for filesystem DAX to remove a number of surprising failure cases. This includes failures with direct I/O, gdb and fork(2). - Add support for the new Platform Capabilities Structure added to the NFIT in ACPI 6.2a. This new table tells us whether the platform supports flushing of CPU and memory controller caches on unexpected power loss events. - Revamp vmem_altmap and dev_pagemap handling to clean up code and better support future future PCI P2P uses. - Deprecate the ND_IOCTL_SMART_THRESHOLD command whose payload has become out-of-sync with recent versions of the NVDIMM_FAMILY_INTEL spec, and instead rely on the generic ND_CMD_CALL approach used by the two other IOCTL families, NVDIMM_FAMILY_{HPE,MSFT}. - Enhance nfit_test so we can test some of the new things added in version 1.6 of the DSM specification. This includes testing firmware download and simulating the Last Shutdown State (LSS) status. * tag 'libnvdimm-for-4.16' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm: (37 commits) libnvdimm, namespace: remove redundant initialization of 'nd_mapping' acpi, nfit: fix register dimm error handling libnvdimm, namespace: make min namespace size 4K tools/testing/nvdimm: force nfit_test to depend on instrumented modules libnvdimm/nfit_test: adding support for unit testing enable LSS status libnvdimm/nfit_test: add firmware download emulation nfit-test: Add platform cap support from ACPI 6.2a to test libnvdimm: expose platform persistence attribute for nd_region acpi: nfit: add persistent memory control flag for nd_region acpi: nfit: Add support for detect platform CPU cache flush on power loss device-dax: Fix trailing semicolon libnvdimm, btt: fix uninitialized err_lock dax: require 'struct page' by default for filesystem dax ext2: auto disable dax instead of failing mount ext4: auto disable dax instead of failing mount mm, dax: introduce pfn_t_special() mm: Fix devm_memremap_pages() collision handling mm: Fix memory size alignment in devm_memremap_pages_release() memremap: merge find_dev_pagemap into get_dev_pagemap memremap: change devm_memremap_pages interface to use struct dev_pagemap ...
| * mm, dax: introduce pfn_t_special()Dan Williams2018-01-191-1/+15
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In support of removing the VM_MIXEDMAP indication from DAX VMAs, introduce pfn_t_special() for drivers to indicate that _PAGE_SPECIAL should be used for DAX ptes. This also helps identify drivers like dccssblk that only want to use DAX in a read-only fashion without get_user_pages() support. Ideally we could delete axonram and dcssblk DAX support, but if we need to keep it better make it explicit that axonram and dcssblk only support a sub-set of DAX due to missing _PAGE_DEVMAP support. Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
* | mm: correct comments regarding do_fault_around()William Kucharski2018-01-311-11/+11
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | There are multiple comments surrounding do_fault_around that memtion fault_around_pages() and fault_around_mask(), two routines that do not exist. These comments should be reworded to reference fault_around_bytes, the value which is used to determine how much do_fault_around() will attempt to read when processing a fault. These comments should have been updated when fault_around_pages() and fault_around_mask() were removed in commit aecd6f44266c ("mm: close race between do_fault_around() and fault_around_bytes_set()"). Fixes: aecd6f44266c1 ("mm: close race between do_fault_around() and fault_around_bytes_set()") Link: http://lkml.kernel.org/r/302D0B14-C7E9-44C6-8BED-033F9ACBD030@oracle.com Signed-off-by: William Kucharski <william.kucharski@oracle.com> Reviewed-by: Larry Bassel <larry.bassel@oracle.com> Cc: Michal Hocko <mhocko@suse.com> Cc: "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>
* | mm: add unmap_mapping_pages()Matthew Wilcox2018-01-311-12/+31
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Several users of unmap_mapping_range() would prefer to express their range in pages rather than bytes. Unfortuately, on a 32-bit kernel, you have to remember to cast your page number to a 64-bit type before shifting it, and four places in the current tree didn't remember to do that. That's a sign of a bad interface. Conveniently, unmap_mapping_range() actually converts from bytes into pages, so hoist the guts of unmap_mapping_range() into a new function unmap_mapping_pages() and convert the callers which want to use pages. Link: http://lkml.kernel.org/r/20171206142627.GD32044@bombadil.infradead.org Signed-off-by: Matthew Wilcox <mawilcox@microsoft.com> Reported-by: "zhangyi (F)" <yi.zhang@huawei.com> Reviewed-by: Ross Zwisler <ross.zwisler@linux.intel.com> 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>
* | mm: update comment describing tlb_gather_mmuMike Rapoport2018-01-311-4/+11
| | | | | | | | | | | | | | | | | | | | | | | | | | The comment describes @fullmm argument, but the function has no such parameter. Update the comment to match the code and convert it to kernel-doc markup. Link: http://lkml.kernel.org/r/1512394531-2264-1-git-send-email-rppt@linux.vnet.ibm.com Signed-off-by: Mike Rapoport <rppt@linux.vnet.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | mm/memory.c: release locked page in do_swap_page()Minchan Kim2018-01-191-2/+8
|/ | | | | | | | | | | | | | | | | | | | | | | | | James reported a bug in swap paging-in from his testing. It is that do_swap_page doesn't release locked page so system hang-up happens due to a deadlock on PG_locked. It was introduced by 0bcac06f27d7 ("mm, swap: skip swapcache for swapin of synchronous device") because I missed swap cache hit places to update swapcache variable to work well with other logics against swapcache in do_swap_page. This patch fixes it. Debugged by James Bottomley. Link: http://lkml.kernel.org/r/<1514407817.4169.4.camel@HansenPartnership.com> Link: http://lkml.kernel.org/r/20180102235606.GA19438@bbox Signed-off-by: Minchan Kim <minchan@kernel.org> Reported-by: James Bottomley <James.Bottomley@hansenpartnership.com> Acked-by: Hugh Dickins <hughd@google.com> Cc: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Cc: Huang Ying <ying.huang@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Revert "mm: replace p??_write with pte_access_permitted in fault + gup paths"Linus Torvalds2017-12-151-4/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This reverts commits 5c9d2d5c269c, c7da82b894e9, and e7fe7b5cae90. We'll probably need to revisit this, but basically we should not complicate the get_user_pages_fast() case, and checking the actual page table protection key bits will require more care anyway, since the protection keys depend on the exact state of the VM in question. Particularly when doing a "remote" page lookup (ie in somebody elses VM, not your own), you need to be much more careful than this was. Dave Hansen says: "So, the underlying bug here is that we now a get_user_pages_remote() and then go ahead and do the p*_access_permitted() checks against the current PKRU. This was introduced recently with the addition of the new p??_access_permitted() calls. We have checks in the VMA path for the "remote" gups and we avoid consulting PKRU for them. This got missed in the pkeys selftests because I did a ptrace read, but not a *write*. I also didn't explicitly test it against something where a COW needed to be done" It's also not entirely clear that it makes sense to check the protection key bits at this level at all. But one possible eventual solution is to make the get_user_pages_fast() case just abort if it sees protection key bits set, which makes us fall back to the regular get_user_pages() case, which then has a vma and can do the check there if we want to. We'll see. Somewhat related to this all: what we _do_ want to do some day is to check the PAGE_USER bit - it should obviously always be set for user pages, but it would be a good check to have back. Because we have no generic way to test for it, we lost it as part of moving over from the architecture-specific x86 GUP implementation to the generic one in commit e585513b76f7 ("x86/mm/gup: Switch GUP to the generic get_user_page_fast() implementation"). Cc: Peter Zijlstra <peterz@infradead.org> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: "Jérôme Glisse" <jglisse@redhat.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm/memory.c: mark wp_huge_pmd() inline to prevent build failureGeert Uytterhoeven2017-12-141-1/+2
| | | | | | | | | | | | | | | | | | | | | | | | | With gcc 4.1.2: mm/memory.o: In function `wp_huge_pmd': memory.c:(.text+0x9b4): undefined reference to `do_huge_pmd_wp_page' Interestingly, wp_huge_pmd() is emitted in the assembler output, but never called. Apparently replacing the call to pmd_write() in __handle_mm_fault() by a call to the more complex pmd_access_permitted() reduced the ability of the compiler to remove unused code. Fix this by marking wp_huge_pmd() inline, like was done in commit 91a90140f998 ("mm/memory.c: mark create_huge_pmd() inline to prevent build failure") for a similar problem. [akpm@linux-foundation.org: add comment] Link: http://lkml.kernel.org/r/1512335500-10889-1-git-send-email-geert@linux-m68k.org Fixes: c7da82b894e9eef6 ("mm: replace pmd_write with pmd_access_permitted in fault + gup paths") Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Merge branch 'akpm' (patches from Andrew)Linus Torvalds2017-11-291-4/+4
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Mergr misc fixes from Andrew Morton: "28 fixes" * emailed patches from Andrew Morton <akpm@linux-foundation.org>: (28 commits) fs/hugetlbfs/inode.c: change put_page/unlock_page order in hugetlbfs_fallocate() mm/hugetlb: fix NULL-pointer dereference on 5-level paging machine autofs: revert "autofs: fix AT_NO_AUTOMOUNT not being honored" autofs: revert "autofs: take more care to not update last_used on path walk" fs/fat/inode.c: fix sb_rdonly() change mm, memcg: fix mem_cgroup_swapout() for THPs mm: migrate: fix an incorrect call of prep_transhuge_page() kmemleak: add scheduling point to kmemleak_scan() scripts/bloat-o-meter: don't fail with division by 0 fs/mbcache.c: make count_objects() more robust Revert "mm/page-writeback.c: print a warning if the vm dirtiness settings are illogical" mm/madvise.c: fix madvise() infinite loop under special circumstances exec: avoid RLIMIT_STACK races with prlimit() IB/core: disable memory registration of filesystem-dax vmas v4l2: disable filesystem-dax mapping support mm: fail get_vaddr_frames() for filesystem-dax mappings mm: introduce get_user_pages_longterm device-dax: implement ->split() to catch invalid munmap attempts mm, hugetlbfs: introduce ->split() to vm_operations_struct scripts/faddr2line: extend usage on generic arch ...
| * mm: replace pte_write with pte_access_permitted in fault + gup pathsDan Williams2017-11-291-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The 'access_permitted' helper is used in the gup-fast path and goes beyond the simple _PAGE_RW check to also: - validate that the mapping is writable from a protection keys standpoint - validate that the pte has _PAGE_USER set since all fault paths where pte_write is must be referencing user-memory. Link: http://lkml.kernel.org/r/151043111604.2842.8051684481794973100.stgit@dwillia2-desk3.amr.corp.intel.com Signed-off-by: Dan Williams <dan.j.williams@intel.com> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: "Jérôme Glisse" <jglisse@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * mm: replace pmd_write with pmd_access_permitted in fault + gup pathsDan Williams2017-11-291-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The 'access_permitted' helper is used in the gup-fast path and goes beyond the simple _PAGE_RW check to also: - validate that the mapping is writable from a protection keys standpoint - validate that the pte has _PAGE_USER set since all fault paths where pmd_write is must be referencing user-memory. Link: http://lkml.kernel.org/r/151043111049.2842.15241454964150083466.stgit@dwillia2-desk3.amr.corp.intel.com Signed-off-by: Dan Williams <dan.j.williams@intel.com> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: "Jérôme Glisse" <jglisse@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * mm: replace pud_write with pud_access_permitted in fault + gup pathsDan Williams2017-11-291-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The 'access_permitted' helper is used in the gup-fast path and goes beyond the simple _PAGE_RW check to also: - validate that the mapping is writable from a protection keys standpoint - validate that the pte has _PAGE_USER set since all fault paths where pud_write is must be referencing user-memory. [dan.j.williams@intel.com: fix powerpc compile error] Link: http://lkml.kernel.org/r/151129127237.37405.16073414520854722485.stgit@dwillia2-desk3.amr.corp.intel.com Link: http://lkml.kernel.org/r/151043110453.2842.2166049702068628177.stgit@dwillia2-desk3.amr.corp.intel.com Signed-off-by: Dan Williams <dan.j.williams@intel.com> Cc: Dave Hansen <dave.hansen@intel.com> Cc: "David S. Miller" <davem@davemloft.net> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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