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2018-03-20Merge branch 'for-4.16-fixes' of ↵Linus Torvalds3-34/+59
git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu Pull percpu fixes from Tejun Heo: "Late percpu pull request for v4.16-rc6. - percpu allocator pool replenishing no longer triggers OOM or warning messages. Also, the alloc interface now understands __GFP_NORETRY and __GFP_NOWARN. This is to allow avoiding OOMs from userland triggered actions like bpf map creation. Also added cond_resched() in alloc loop. - perpcu allocation now can be interrupted by kill sigs to avoid deadlocking OOM killer. - Added Dennis Zhou as a co-maintainer. He has rewritten the area map allocator, understands most of the code base and has been responsive for all bug reports" * 'for-4.16-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu: percpu_ref: Update doc to dissuade users from depending on internal RCU grace periods mm: Allow to kill tasks doing pcpu_alloc() and waiting for pcpu_balance_workfn() percpu: include linux/sched.h for cond_resched() percpu: add a schedule point in pcpu_balance_workfn() percpu: allow select gfp to be passed to underlying allocators percpu: add __GFP_NORETRY semantics to the percpu balancing path percpu: match chunk allocator declarations with definitions percpu: add Dennis Zhou as a percpu co-maintainer
2018-03-19mm: Allow to kill tasks doing pcpu_alloc() and waiting for pcpu_balance_workfn()Kirill Tkhai1-2/+11
In case of memory deficit and low percpu memory pages, pcpu_balance_workfn() takes pcpu_alloc_mutex for a long time (as it makes memory allocations itself and waits for memory reclaim). If tasks doing pcpu_alloc() are choosen by OOM killer, they can't exit, because they are waiting for the mutex. The patch makes pcpu_alloc() to care about killing signal and use mutex_lock_killable(), when it's allowed by GFP flags. This guarantees, a task does not miss SIGKILL from OOM killer. Signed-off-by: Kirill Tkhai <ktkhai@virtuozzo.com> Signed-off-by: Tejun Heo <tj@kernel.org>
2018-03-19percpu: include linux/sched.h for cond_resched()Tejun Heo1-0/+1
microblaze build broke due to missing declaration of the cond_resched() invocation added recently. Let's include linux/sched.h explicitly. Signed-off-by: Tejun Heo <tj@kernel.org> Reported-by: kbuild test robot <fengguang.wu@intel.com>
2018-03-15Revert "mm/page_alloc: fix memmap_init_zone pageblock alignment"Ard Biesheuvel1-8/+5
This reverts commit 864b75f9d6b0100bb24fdd9a20d156e7cda9b5ae. Commit 864b75f9d6b0 ("mm/page_alloc: fix memmap_init_zone pageblock alignment") modified the logic in memmap_init_zone() to initialize struct pages associated with invalid PFNs, to appease a VM_BUG_ON() in move_freepages(), which is redundant by its own admission, and dereferences struct page fields to obtain the zone without checking whether the struct pages in question are valid to begin with. Commit 864b75f9d6b0 only makes it worse, since the rounding it does may cause pfn assume the same value it had in a prior iteration of the loop, resulting in an infinite loop and a hang very early in the boot. Also, since it doesn't perform the same rounding on start_pfn itself but only on intermediate values following an invalid PFN, we may still hit the same VM_BUG_ON() as before. So instead, let's fix this at the core, and ensure that the BUG check doesn't dereference struct page fields of invalid pages. Fixes: 864b75f9d6b0 ("mm/page_alloc: fix memmap_init_zone pageblock alignment") Tested-by: Jan Glauber <jglauber@cavium.com> Tested-by: Shanker Donthineni <shankerd@codeaurora.org> Cc: Daniel Vacek <neelx@redhat.com> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: Michal Hocko <mhocko@suse.com> Cc: Paul Burton <paul.burton@imgtec.com> Cc: Pavel Tatashin <pasha.tatashin@oracle.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-03-10mm/page_alloc: fix memmap_init_zone pageblock alignmentDaniel Vacek1-2/+7
Commit b92df1de5d28 ("mm: page_alloc: skip over regions of invalid pfns where possible") introduced a bug where move_freepages() triggers a VM_BUG_ON() on uninitialized page structure due to pageblock alignment. To fix this, simply align the skipped pfns in memmap_init_zone() the same way as in move_freepages_block(). Seen in one of the RHEL reports: crash> log | grep -e BUG -e RIP -e Call.Trace -e move_freepages_block -e rmqueue -e freelist -A1 kernel BUG at mm/page_alloc.c:1389! invalid opcode: 0000 [#1] SMP -- RIP: 0010:[<ffffffff8118833e>] [<ffffffff8118833e>] move_freepages+0x15e/0x160 RSP: 0018:ffff88054d727688 EFLAGS: 00010087 -- Call Trace: [<ffffffff811883b3>] move_freepages_block+0x73/0x80 [<ffffffff81189e63>] __rmqueue+0x263/0x460 [<ffffffff8118c781>] get_page_from_freelist+0x7e1/0x9e0 [<ffffffff8118caf6>] __alloc_pages_nodemask+0x176/0x420 -- RIP [<ffffffff8118833e>] move_freepages+0x15e/0x160 RSP <ffff88054d727688> crash> page_init_bug -v | grep RAM <struct resource 0xffff88067fffd2f8> 1000 - 9bfff System RAM (620.00 KiB) <struct resource 0xffff88067fffd3a0> 100000 - 430bffff System RAM ( 1.05 GiB = 1071.75 MiB = 1097472.00 KiB) <struct resource 0xffff88067fffd410> 4b0c8000 - 4bf9cfff System RAM ( 14.83 MiB = 15188.00 KiB) <struct resource 0xffff88067fffd480> 4bfac000 - 646b1fff System RAM (391.02 MiB = 400408.00 KiB) <struct resource 0xffff88067fffd560> 7b788000 - 7b7fffff System RAM (480.00 KiB) <struct resource 0xffff88067fffd640> 100000000 - 67fffffff System RAM ( 22.00 GiB) crash> page_init_bug | head -6 <struct resource 0xffff88067fffd560> 7b788000 - 7b7fffff System RAM (480.00 KiB) <struct page 0xffffea0001ede200> 1fffff00000000 0 <struct pglist_data 0xffff88047ffd9000> 1 <struct zone 0xffff88047ffd9800> DMA32 4096 1048575 <struct page 0xffffea0001ede200> 505736 505344 <struct page 0xffffea0001ed8000> 505855 <struct page 0xffffea0001edffc0> <struct page 0xffffea0001ed8000> 0 0 <struct pglist_data 0xffff88047ffd9000> 0 <struct zone 0xffff88047ffd9000> DMA 1 4095 <struct page 0xffffea0001edffc0> 1fffff00000400 0 <struct pglist_data 0xffff88047ffd9000> 1 <struct zone 0xffff88047ffd9800> DMA32 4096 1048575 BUG, zones differ! Note that this range follows two not populated sections 68000000-77ffffff in this zone. 7b788000-7b7fffff is the first one after a gap. This makes memmap_init_zone() skip all the pfns up to the beginning of this range. But this range is not pageblock (2M) aligned. In fact no range has to be. crash> kmem -p 77fff000 78000000 7b5ff000 7b600000 7b787000 7b788000 PAGE PHYSICAL MAPPING INDEX CNT FLAGS ffffea0001e00000 78000000 0 0 0 0 ffffea0001ed7fc0 7b5ff000 0 0 0 0 ffffea0001ed8000 7b600000 0 0 0 0 <<<< ffffea0001ede1c0 7b787000 0 0 0 0 ffffea0001ede200 7b788000 0 0 1 1fffff00000000 Top part of page flags should contain nodeid and zonenr, which is not the case for page ffffea0001ed8000 here (<<<<). crash> log | grep -o fffea0001ed[^\ ]* | sort -u fffea0001ed8000 fffea0001eded20 fffea0001edffc0 crash> bt -r | grep -o fffea0001ed[^\ ]* | sort -u fffea0001ed8000 fffea0001eded00 fffea0001eded20 fffea0001edffc0 Initialization of the whole beginning of the section is skipped up to the start of the range due to the commit b92df1de5d28. Now any code calling move_freepages_block() (like reusing the page from a freelist as in this example) with a page from the beginning of the range will get the page rounded down to start_page ffffea0001ed8000 and passed to move_freepages() which crashes on assertion getting wrong zonenr. > VM_BUG_ON(page_zone(start_page) != page_zone(end_page)); Note, page_zone() derives the zone from page flags here. From similar machine before commit b92df1de5d28: crash> kmem -p 77fff000 78000000 7b5ff000 7b600000 7b7fe000 7b7ff000 PAGE PHYSICAL MAPPING INDEX CNT FLAGS fffff73941e00000 78000000 0 0 1 1fffff00000000 fffff73941ed7fc0 7b5ff000 0 0 1 1fffff00000000 fffff73941ed8000 7b600000 0 0 1 1fffff00000000 fffff73941edff80 7b7fe000 0 0 1 1fffff00000000 fffff73941edffc0 7b7ff000 ffff8e67e04d3ae0 ad84 1 1fffff00020068 uptodate,lru,active,mappedtodisk All the pages since the beginning of the section are initialized. move_freepages()' not gonna blow up. The same machine with this fix applied: crash> kmem -p 77fff000 78000000 7b5ff000 7b600000 7b7fe000 7b7ff000 PAGE PHYSICAL MAPPING INDEX CNT FLAGS ffffea0001e00000 78000000 0 0 0 0 ffffea0001e00000 7b5ff000 0 0 0 0 ffffea0001ed8000 7b600000 0 0 1 1fffff00000000 ffffea0001edff80 7b7fe000 0 0 1 1fffff00000000 ffffea0001edffc0 7b7ff000 ffff88017fb13720 8 2 1fffff00020068 uptodate,lru,active,mappedtodisk At least the bare minimum of pages is initialized preventing the crash as well. Customers started to report this as soon as 7.4 (where b92df1de5d28 was merged in RHEL) was released. I remember reports from September/October-ish times. It's not easily reproduced and happens on a handful of machines only. I guess that's why. But that does not make it less serious, I think. Though there actually is a report here: https://bugzilla.kernel.org/show_bug.cgi?id=196443 And there are reports for Fedora from July: https://bugzilla.redhat.com/show_bug.cgi?id=1473242 and CentOS: https://bugs.centos.org/view.php?id=13964 and we internally track several dozens reports for RHEL bug https://bugzilla.redhat.com/show_bug.cgi?id=1525121 Link: http://lkml.kernel.org/r/0485727b2e82da7efbce5f6ba42524b429d0391a.1520011945.git.neelx@redhat.com Fixes: b92df1de5d28 ("mm: page_alloc: skip over regions of invalid pfns where possible") Signed-off-by: Daniel Vacek <neelx@redhat.com> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: Michal Hocko <mhocko@suse.com> Cc: Paul Burton <paul.burton@imgtec.com> Cc: Pavel Tatashin <pasha.tatashin@oracle.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-03-10mm/memblock.c: hardcode the end_pfn being -1Daniel Vacek1-5/+5
This is just a cleanup. It aids handling the special end case in the next commit. [akpm@linux-foundation.org: make it work against current -linus, not against -mm] [akpm@linux-foundation.org: make it work against current -linus, not against -mm some more] Link: http://lkml.kernel.org/r/1ca478d4269125a99bcfb1ca04d7b88ac1aee924.1520011944.git.neelx@redhat.com Signed-off-by: Daniel Vacek <neelx@redhat.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: Pavel Tatashin <pasha.tatashin@oracle.com> Cc: Paul Burton <paul.burton@imgtec.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-03-10mm/gup.c: teach get_user_pages_unlocked to handle FOLL_NOWAITAndrea Arcangeli1-2/+5
KVM is hanging during postcopy live migration with userfaultfd because get_user_pages_unlocked is not capable to handle FOLL_NOWAIT. Earlier FOLL_NOWAIT was only ever passed to get_user_pages. Specifically faultin_page (the callee of get_user_pages_unlocked caller) doesn't know that if FAULT_FLAG_RETRY_NOWAIT was set in the page fault flags, when VM_FAULT_RETRY is returned, the mmap_sem wasn't actually released (even if nonblocking is not NULL). So it sets *nonblocking to zero and the caller won't release the mmap_sem thinking it was already released, but it wasn't because of FOLL_NOWAIT. Link: http://lkml.kernel.org/r/20180302174343.5421-2-aarcange@redhat.com Fixes: ce53053ce378c ("kvm: switch get_user_page_nowait() to get_user_pages_unlocked()") Signed-off-by: Andrea Arcangeli <aarcange@redhat.com> Reported-by: Dr. David Alan Gilbert <dgilbert@redhat.com> Tested-by: Dr. David Alan Gilbert <dgilbert@redhat.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-03-10hugetlb: fix surplus pages accountingMichal Hocko1-1/+1
Dan Rue has noticed that libhugetlbfs test suite fails counter test: # mount_point="/mnt/hugetlb/" # echo 200 > /proc/sys/vm/nr_hugepages # mkdir -p "${mount_point}" # mount -t hugetlbfs hugetlbfs "${mount_point}" # export LD_LIBRARY_PATH=/root/libhugetlbfs/libhugetlbfs-2.20/obj64 # /root/libhugetlbfs/libhugetlbfs-2.20/tests/obj64/counters Starting testcase "/root/libhugetlbfs/libhugetlbfs-2.20/tests/obj64/counters", pid 3319 Base pool size: 0 Clean... FAIL Line 326: Bad HugePages_Total: expected 0, actual 1 The bug was bisected to 0c397daea1d4 ("mm, hugetlb: further simplify hugetlb allocation API"). The reason is that alloc_surplus_huge_page() misaccounts per node surplus pages. We should increase surplus_huge_pages_node rather than nr_huge_pages_node which is already handled by alloc_fresh_huge_page. Link: http://lkml.kernel.org/r/20180221191439.GM2231@dhcp22.suse.cz Fixes: 0c397daea1d4 ("mm, hugetlb: further simplify hugetlb allocation API") Signed-off-by: Michal Hocko <mhocko@suse.com> Reported-by: Dan Rue <dan.rue@linaro.org> Tested-by: Dan Rue <dan.rue@linaro.org> Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-02-23percpu: add a schedule point in pcpu_balance_workfn()Eric Dumazet1-0/+1
When a large BPF percpu map is destroyed, I have seen pcpu_balance_workfn() holding cpu for hundreds of milliseconds. On KASAN config and 112 hyperthreads, average time to destroy a chunk is ~4 ms. [ 2489.841376] destroy chunk 1 in 4148689 ns ... [ 2490.093428] destroy chunk 32 in 4072718 ns Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: Tejun Heo <tj@kernel.org>
2018-02-22mm: don't defer struct page initialization for Xen pv guestsJuergen Gross1-0/+4
Commit f7f99100d8d9 ("mm: stop zeroing memory during allocation in vmemmap") broke Xen pv domains in some configurations, as the "Pinned" information in struct page of early page tables could get lost. This will lead to the kernel trying to write directly into the page tables instead of asking the hypervisor to do so. The result is a crash like the following: BUG: unable to handle kernel paging request at ffff8801ead19008 IP: xen_set_pud+0x4e/0xd0 PGD 1c0a067 P4D 1c0a067 PUD 23a0067 PMD 1e9de0067 PTE 80100001ead19065 Oops: 0003 [#1] PREEMPT SMP Modules linked in: CPU: 0 PID: 0 Comm: swapper/0 Not tainted 4.14.0-default+ #271 Hardware name: Dell Inc. Latitude E6440/0159N7, BIOS A07 06/26/2014 task: ffffffff81c10480 task.stack: ffffffff81c00000 RIP: e030:xen_set_pud+0x4e/0xd0 Call Trace: __pmd_alloc+0x128/0x140 ioremap_page_range+0x3f4/0x410 __ioremap_caller+0x1c3/0x2e0 acpi_os_map_iomem+0x175/0x1b0 acpi_tb_acquire_table+0x39/0x66 acpi_tb_validate_table+0x44/0x7c acpi_tb_verify_temp_table+0x45/0x304 acpi_reallocate_root_table+0x12d/0x141 acpi_early_init+0x4d/0x10a start_kernel+0x3eb/0x4a1 xen_start_kernel+0x528/0x532 Code: 48 01 e8 48 0f 42 15 a2 fd be 00 48 01 d0 48 ba 00 00 00 00 00 ea ff ff 48 c1 e8 0c 48 c1 e0 06 48 01 d0 48 8b 00 f6 c4 02 75 5d <4c> 89 65 00 5b 5d 41 5c c3 65 8b 05 52 9f fe 7e 89 c0 48 0f a3 RIP: xen_set_pud+0x4e/0xd0 RSP: ffffffff81c03cd8 CR2: ffff8801ead19008 ---[ end trace 38eca2e56f1b642e ]--- Avoid this problem by not deferring struct page initialization when running as Xen pv guest. Pavel said: : This is unique for Xen, so this particular issue won't effect other : configurations. I am going to investigate if there is a way to : re-enable deferred page initialization on xen guests. [akpm@linux-foundation.org: explicitly include xen.h] Link: http://lkml.kernel.org/r/20180216154101.22865-1-jgross@suse.com Fixes: f7f99100d8d95d ("mm: stop zeroing memory during allocation in vmemmap") Signed-off-by: Juergen Gross <jgross@suse.com> Reviewed-by: Pavel Tatashin <pasha.tatashin@oracle.com> Cc: Steven Sistare <steven.sistare@oracle.com> Cc: Daniel Jordan <daniel.m.jordan@oracle.com> Cc: Bob Picco <bob.picco@oracle.com> Cc: <stable@vger.kernel.org> [4.15.x] Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-02-22vmalloc: fix __GFP_HIGHMEM usage for vmalloc_32 on 32b systemsMichal Hocko1-3/+7
Kai Heng Feng has noticed that BUG_ON(PageHighMem(pg)) triggers in drivers/media/common/saa7146/saa7146_core.c since 19809c2da28a ("mm, vmalloc: use __GFP_HIGHMEM implicitly"). saa7146_vmalloc_build_pgtable uses vmalloc_32 and it is reasonable to expect that the resulting page is not in highmem. The above commit aimed to add __GFP_HIGHMEM only for those requests which do not specify any zone modifier gfp flag. vmalloc_32 relies on GFP_VMALLOC32 which should do the right thing. Except it has been missed that GFP_VMALLOC32 is an alias for GFP_KERNEL on 32b architectures. Thanks to Matthew to notice this. Fix the problem by unconditionally setting GFP_DMA32 in GFP_VMALLOC32 for !64b arches (as a bailout). This should do the right thing and use ZONE_NORMAL which should be always below 4G on 32b systems. Debugged by Matthew Wilcox. [akpm@linux-foundation.org: coding-style fixes] Link: http://lkml.kernel.org/r/20180212095019.GX21609@dhcp22.suse.cz Fixes: 19809c2da28a ("mm, vmalloc: use __GFP_HIGHMEM implicitly”) Signed-off-by: Michal Hocko <mhocko@suse.com> Reported-by: Kai Heng Feng <kai.heng.feng@canonical.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Laura Abbott <labbott@redhat.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-02-22mm/swap.c: make functions and their kernel-doc agree (again)Mike Rapoport1-1/+1
There was a conflict between the commit e02a9f048ef7 ("mm/swap.c: make functions and their kernel-doc agree") and the commit f144c390f905 ("mm: docs: fix parameter names mismatch") that both tried to fix mismatch betweeen pagevec_lookup_entries() parameter names and their description. Since nr_entries is a better name for the parameter, fix the description again. Link: http://lkml.kernel.org/r/1518116946-20947-1-git-send-email-rppt@linux.vnet.ibm.com Signed-off-by: Mike Rapoport <rppt@linux.vnet.ibm.com> Acked-by: Randy Dunlap <rdunlap@infradead.org> 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>
2018-02-22mm/zpool.c: zpool_evictable: fix mismatch in parameter name and kernel-docMike Rapoport1-1/+1
[akpm@linux-foundation.org: add colon, per Randy] Link: http://lkml.kernel.org/r/1518116984-21141-1-git-send-email-rppt@linux.vnet.ibm.com Signed-off-by: Mike Rapoport <rppt@linux.vnet.ibm.com> Reviewed-by: Andrew Morton <akpm@linux-foundation.org> Cc: Randy Dunlap <rdunlap@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-02-22mm, swap, frontswap: fix THP swap if frontswap enabledHuang Ying1-0/+6
It was reported by Sergey Senozhatsky that if THP (Transparent Huge Page) and frontswap (via zswap) are both enabled, when memory goes low so that swap is triggered, segfault and memory corruption will occur in random user space applications as follow, kernel: urxvt[338]: segfault at 20 ip 00007fc08889ae0d sp 00007ffc73a7fc40 error 6 in libc-2.26.so[7fc08881a000+1ae000] #0 0x00007fc08889ae0d _int_malloc (libc.so.6) #1 0x00007fc08889c2f3 malloc (libc.so.6) #2 0x0000560e6004bff7 _Z14rxvt_wcstoutf8PKwi (urxvt) #3 0x0000560e6005e75c n/a (urxvt) #4 0x0000560e6007d9f1 _ZN16rxvt_perl_interp6invokeEP9rxvt_term9hook_typez (urxvt) #5 0x0000560e6003d988 _ZN9rxvt_term9cmd_parseEv (urxvt) #6 0x0000560e60042804 _ZN9rxvt_term6pty_cbERN2ev2ioEi (urxvt) #7 0x0000560e6005c10f _Z17ev_invoke_pendingv (urxvt) #8 0x0000560e6005cb55 ev_run (urxvt) #9 0x0000560e6003b9b9 main (urxvt) #10 0x00007fc08883af4a __libc_start_main (libc.so.6) #11 0x0000560e6003f9da _start (urxvt) After bisection, it was found the first bad commit is bd4c82c22c36 ("mm, THP, swap: delay splitting THP after swapped out"). The root cause is as follows: When the pages are written to swap device during swapping out in swap_writepage(), zswap (fontswap) is tried to compress the pages to improve performance. But zswap (frontswap) will treat THP as a normal page, so only the head page is saved. After swapping in, tail pages will not be restored to their original contents, causing memory corruption in the applications. This is fixed by refusing to save page in the frontswap store functions if the page is a THP. So that the THP will be swapped out to swap device. Another choice is to split THP if frontswap is enabled. But it is found that the frontswap enabling isn't flexible. For example, if CONFIG_ZSWAP=y (cannot be module), frontswap will be enabled even if zswap itself isn't enabled. Frontswap has multiple backends, to make it easy for one backend to enable THP support, the THP checking is put in backend frontswap store functions instead of the general interfaces. Link: http://lkml.kernel.org/r/20180209084947.22749-1-ying.huang@intel.com Fixes: bd4c82c22c367e068 ("mm, THP, swap: delay splitting THP after swapped out") Signed-off-by: "Huang, Ying" <ying.huang@intel.com> Reported-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Tested-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Suggested-by: Minchan Kim <minchan@kernel.org> [put THP checking in backend] Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Cc: Dan Streetman <ddstreet@ieee.org> Cc: Seth Jennings <sjenning@redhat.com> Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Cc: Shaohua Li <shli@kernel.org> Cc: Michal Hocko <mhocko@suse.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: Shakeel Butt <shakeelb@google.com> Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com> Cc: Juergen Gross <jgross@suse.com> Cc: <stable@vger.kernel.org> [4.14] Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-02-22mm, mlock, vmscan: no more skipping pagevecsShakeel Butt3-93/+54
When a thread mlocks an address space backed either by file pages which are currently not present in memory or swapped out anon pages (not in swapcache), a new page is allocated and added to the local pagevec (lru_add_pvec), I/O is triggered and the thread then sleeps on the page. On I/O completion, the thread can wake on a different CPU, the mlock syscall will then sets the PageMlocked() bit of the page but will not be able to put that page in unevictable LRU as the page is on the pagevec of a different CPU. Even on drain, that page will go to evictable LRU because the PageMlocked() bit is not checked on pagevec drain. The page will eventually go to right LRU on reclaim but the LRU stats will remain skewed for a long time. This patch puts all the pages, even unevictable, to the pagevecs and on the drain, the pages will be added on their LRUs correctly by checking their evictability. This resolves the mlocked pages on pagevec of other CPUs issue because when those pagevecs will be drained, the mlocked file pages will go to unevictable LRU. Also this makes the race with munlock easier to resolve because the pagevec drains happen in LRU lock. However there is still one place which makes a page evictable and does PageLRU check on that page without LRU lock and needs special attention. TestClearPageMlocked() and isolate_lru_page() in clear_page_mlock(). #0: __pagevec_lru_add_fn #1: clear_page_mlock SetPageLRU() if (!TestClearPageMlocked()) return smp_mb() // <--required // inside does PageLRU if (!PageMlocked()) if (isolate_lru_page()) move to evictable LRU putback_lru_page() else move to unevictable LRU In '#1', TestClearPageMlocked() provides full memory barrier semantics and thus the PageLRU check (inside isolate_lru_page) can not be reordered before it. In '#0', without explicit memory barrier, the PageMlocked() check can be reordered before SetPageLRU(). If that happens, '#0' can put a page in unevictable LRU and '#1' might have just cleared the Mlocked bit of that page but fails to isolate as PageLRU fails as '#0' still hasn't set PageLRU bit of that page. That page will be stranded on the unevictable LRU. There is one (good) side effect though. Without this patch, the pages allocated for System V shared memory segment are added to evictable LRUs even after shmctl(SHM_LOCK) on that segment. This patch will correctly put such pages to unevictable LRU. Link: http://lkml.kernel.org/r/20171121211241.18877-1-shakeelb@google.com Signed-off-by: Shakeel Butt <shakeelb@google.com> Acked-by: Vlastimil Babka <vbabka@suse.cz> Cc: Jérôme Glisse <jglisse@redhat.com> Cc: Huang Ying <ying.huang@intel.com> Cc: Tim Chen <tim.c.chen@linux.intel.com> Cc: Michal Hocko <mhocko@kernel.org> Cc: Greg Thelen <gthelen@google.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Balbir Singh <bsingharora@gmail.com> Cc: Minchan Kim <minchan@kernel.org> Cc: Shaohua Li <shli@fb.com> Cc: Jan Kara <jack@suse.cz> Cc: Nicholas Piggin <npiggin@gmail.com> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Mel Gorman <mgorman@suse.de> Cc: Hugh Dickins <hughd@google.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>
2018-02-18percpu: allow select gfp to be passed to underlying allocatorsDennis Zhou3-12/+10
The prior patch added support for passing gfp flags through to the underlying allocators. This patch allows users to pass along gfp flags (currently only __GFP_NORETRY and __GFP_NOWARN) to the underlying allocators. This should allow users to decide if they are ok with failing allocations recovering in a more graceful way. Additionally, gfp passing was done as additional flags in the previous patch. Instead, change this to caller passed semantics. GFP_KERNEL is also removed as the default flag. It continues to be used for internally caused underlying percpu allocations. V2: Removed gfp_percpu_mask in favor of doing it inline. Removed GFP_KERNEL as a default flag for __alloc_percpu_gfp. Signed-off-by: Dennis Zhou <dennisszhou@gmail.com> Suggested-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Christoph Lameter <cl@linux.com> Signed-off-by: Tejun Heo <tj@kernel.org>
2018-02-18percpu: add __GFP_NORETRY semantics to the percpu balancing pathDennis Zhou3-28/+42
Percpu memory using the vmalloc area based chunk allocator lazily populates chunks by first requesting the full virtual address space required for the chunk and subsequently adding pages as allocations come through. To ensure atomic allocations can succeed, a workqueue item is used to maintain a minimum number of empty pages. In certain scenarios, such as reported in [1], it is possible that physical memory becomes quite scarce which can result in either a rather long time spent trying to find free pages or worse, a kernel panic. This patch adds support for __GFP_NORETRY and __GFP_NOWARN passing them through to the underlying allocators. This should prevent any unnecessary panics potentially caused by the workqueue item. The passing of gfp around is as additional flags rather than a full set of flags. The next patch will change these to caller passed semantics. V2: Added const modifier to gfp flags in the balance path. Removed an extra whitespace. [1] https://lkml.org/lkml/2018/2/12/551 Signed-off-by: Dennis Zhou <dennisszhou@gmail.com> Suggested-by: Daniel Borkmann <daniel@iogearbox.net> Reported-by: syzbot+adb03f3f0bb57ce3acda@syzkaller.appspotmail.com Acked-by: Christoph Lameter <cl@linux.com> Signed-off-by: Tejun Heo <tj@kernel.org>
2018-02-18percpu: match chunk allocator declarations with definitionsDennis Zhou1-2/+4
At some point the function declaration parameters got out of sync with the function definitions in percpu-vm.c and percpu-km.c. This patch makes them match again. Signed-off-by: Dennis Zhou <dennisszhou@gmail.com> Acked-by: Christoph Lameter <cl@linux.com> Signed-off-by: Tejun Heo <tj@kernel.org>
2018-02-16mm: hide a #warning for COMPILE_TESTArnd Bergmann1-1/+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>
2018-02-15Merge branch 'x86-urgent-for-linus' of ↵Linus Torvalds1-2/+0
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 fixes from Ingo Molnar: "Misc fixes all across the map: - /proc/kcore vsyscall related fixes - LTO fix - build warning fix - CPU hotplug fix - Kconfig NR_CPUS cleanups - cpu_has() cleanups/robustification - .gitignore fix - memory-failure unmapping fix - UV platform fix" * 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/mm, mm/hwpoison: Don't unconditionally unmap kernel 1:1 pages x86/error_inject: Make just_return_func() globally visible x86/platform/UV: Fix GAM Range Table entries less than 1GB x86/build: Add arch/x86/tools/insn_decoder_test to .gitignore x86/smpboot: Fix uncore_pci_remove() indexing bug when hot-removing a physical CPU x86/mm/kcore: Add vsyscall page to /proc/kcore conditionally vfs/proc/kcore, x86/mm/kcore: Fix SMAP fault when dumping vsyscall user page x86/Kconfig: Further simplify the NR_CPUS config x86/Kconfig: Simplify NR_CPUS config x86/MCE: Fix build warning introduced by "x86: do not use print_symbol()" x86/cpufeature: Update _static_cpu_has() to use all named variables x86/cpufeature: Reindent _static_cpu_has()
2018-02-13x86/mm, mm/hwpoison: Don't unconditionally unmap kernel 1:1 pagesTony Luck1-2/+0
In the following commit: ce0fa3e56ad2 ("x86/mm, mm/hwpoison: Clear PRESENT bit for kernel 1:1 mappings of poison pages") ... we added code to memory_failure() to unmap the page from the kernel 1:1 virtual address space to avoid speculative access to the page logging additional errors. But memory_failure() may not always succeed in taking the page offline, especially if the page belongs to the kernel. This can happen if there are too many corrected errors on a page and either mcelog(8) or drivers/ras/cec.c asks to take a page offline. Since we remove the 1:1 mapping early in memory_failure(), we can end up with the page unmapped, but still in use. On the next access the kernel crashes :-( There are also various debug paths that call memory_failure() to simulate occurrence of an error. Since there is no actual error in memory, we don't need to map out the page for those cases. Revert most of the previous attempt and keep the solution local to arch/x86/kernel/cpu/mcheck/mce.c. Unmap the page only when: 1) there is a real error 2) memory_failure() succeeds. All of this only applies to 64-bit systems. 32-bit kernel doesn't map all of memory into kernel space. It isn't worth adding the code to unmap the piece that is mapped because nobody would run a 32-bit kernel on a machine that has recoverable machine checks. Signed-off-by: Tony Luck <tony.luck@intel.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@suse.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Dave <dave.hansen@intel.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Robert (Persistent Memory) <elliott@hpe.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-mm@kvack.org Cc: stable@vger.kernel.org #v4.14 Fixes: ce0fa3e56ad2 ("x86/mm, mm/hwpoison: Clear PRESENT bit for kernel 1:1 mappings of poison pages") Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-02-12vfs: do bulk POLL* -> EPOLL* replacementLinus Torvalds2-4/+4
This is the mindless scripted replacement of kernel use of POLL* variables as described by Al, done by this script: for V in IN OUT PRI ERR RDNORM RDBAND WRNORM WRBAND HUP RDHUP NVAL MSG; do L=`git grep -l -w POLL$V | grep -v '^t' | grep -v /um/ | grep -v '^sa' | grep -v '/poll.h$'|grep -v '^D'` for f in $L; do sed -i "-es/^\([^\"]*\)\(\<POLL$V\>\)/\\1E\\2/" $f; done done with de-mangling cleanups yet to come. NOTE! On almost all architectures, the EPOLL* constants have the same values as the POLL* constants do. But they keyword here is "almost". For various bad reasons they aren't the same, and epoll() doesn't actually work quite correctly in some cases due to this on Sparc et al. The next patch from Al will sort out the final differences, and we should be all done. Scripted-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-02-07Merge branch 'akpm' (patches from Andrew)Linus Torvalds22-95/+198
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 ...
2018-02-07mm: docs: add blank lines to silence sphinx "Unexpected indentation" errorsMike Rapoport3-0/+4
Link: http://lkml.kernel.org/r/1516700871-22279-4-git-send-email-rppt@linux.vnet.ibm.com Signed-off-by: Mike Rapoport <rppt@linux.vnet.ibm.com> Cc: Jonathan Corbet <corbet@lwn.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-02-07mm: docs: fix parameter names mismatchMike Rapoport8-20/+20
There are several places where parameter descriptions do no match the actual code. Fix it. Link: http://lkml.kernel.org/r/1516700871-22279-3-git-send-email-rppt@linux.vnet.ibm.com Signed-off-by: Mike Rapoport <rppt@linux.vnet.ibm.com> Cc: Jonathan Corbet <corbet@lwn.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-02-07mm: docs: fixup punctuationMike Rapoport5-27/+27
so that kernel-doc will properly recognize the parameter and function descriptions. Link: http://lkml.kernel.org/r/1516700871-22279-2-git-send-email-rppt@linux.vnet.ibm.com Signed-off-by: Mike Rapoport <rppt@linux.vnet.ibm.com> Cc: Jonathan Corbet <corbet@lwn.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-02-07mm/memblock: memblock_is_map/region_memory can be booleanYaowei Bai1-3/+3
Make memblock_is_map/region_memory return bool due to these two functions only using either true or false as its return value. No functional change. Link: http://lkml.kernel.org/r/1513266622-15860-2-git-send-email-baiyaowei@cmss.chinamobile.com Signed-off-by: Yaowei Bai <baiyaowei@cmss.chinamobile.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-02-07mm: remove unneeded kallsyms includeSergey Senozhatsky1-4/+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>
2018-02-07mm/userfaultfd.c: remove duplicate includePravin Shedge1-1/+0
These duplicate includes have been found with scripts/checkincludes.pl but they have been removed manually to avoid removing false positives. Link: http://lkml.kernel.org/r/1512580957-6071-1-git-send-email-pravin.shedge4linux@gmail.com Signed-off-by: Pravin Shedge <pravin.shedge4linux@gmail.com> Cc: Michal Hocko <mhocko@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-02-07pids: introduce find_get_task_by_vpid() helperMike Rapoport1-5/+1
There are several functions that do find_task_by_vpid() followed by get_task_struct(). We can use a helper function instead. Link: http://lkml.kernel.org/r/1509602027-11337-1-git-send-email-rppt@linux.vnet.ibm.com Signed-off-by: Mike Rapoport <rppt@linux.vnet.ibm.com> Acked-by: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-02-07kasan: fix prototype author email addressAndrey Konovalov2-2/+2
Use the new one. Link: http://lkml.kernel.org/r/de3b7ffc30a55178913a7d3865216aa7accf6c40.1515775666.git.andreyknvl@google.com Signed-off-by: Andrey Konovalov <andreyknvl@google.com> Cc: Andrey Ryabinin <aryabinin@virtuozzo.com> Cc: Dmitry Vyukov <dvyukov@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-02-07kasan: detect invalid freesDmitry Vyukov1-0/+6
Detect frees of pointers into middle of heap objects. Link: http://lkml.kernel.org/r/cb569193190356beb018a03bb8d6fbae67e7adbc.1514378558.git.dvyukov@google.com Signed-off-by: Dmitry Vyukov <dvyukov@google.com> Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>a Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-02-07kasan: unify code between kasan_slab_free() and kasan_poison_kfree()Dmitry Vyukov1-16/+12
Both of these functions deal with freeing of slab objects. However, kasan_poison_kfree() mishandles SLAB_TYPESAFE_BY_RCU (must also not poison such objects) and does not detect double-frees. Unify code between these functions. This solves both of the problems and allows to add more common code (e.g. detection of invalid frees). Link: http://lkml.kernel.org/r/385493d863acf60408be219a021c3c8e27daa96f.1514378558.git.dvyukov@google.com Signed-off-by: Dmitry Vyukov <dvyukov@google.com> Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>a Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-02-07kasan: detect invalid frees for large mempool objectsDmitry Vyukov2-6/+11
Detect frees of pointers into middle of mempool objects. I did a one-off test, but it turned out to be very tricky, so I reverted it. First, mempool does not call kasan_poison_kfree() unless allocation function fails. I stubbed an allocation function to fail on second and subsequent allocations. But then mempool stopped to call kasan_poison_kfree() at all, because it does it only when allocation function is mempool_kmalloc(). We could support this special failing test allocation function in mempool, but it also can't live with kasan tests, because these are in a module. Link: http://lkml.kernel.org/r/bf7a7d035d7a5ed62d2dd0e3d2e8a4fcdf456aa7.1514378558.git.dvyukov@google.com Signed-off-by: Dmitry Vyukov <dvyukov@google.com> Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>a Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-02-07kasan: don't use __builtin_return_address(1)Dmitry Vyukov5-14/+14
__builtin_return_address(1) is unreliable without frame pointers. With defconfig on kmalloc_pagealloc_invalid_free test I am getting: BUG: KASAN: double-free or invalid-free in (null) Pass caller PC from callers explicitly. Link: http://lkml.kernel.org/r/9b01bc2d237a4df74ff8472a3bf6b7635908de01.1514378558.git.dvyukov@google.com Signed-off-by: Dmitry Vyukov <dvyukov@google.com> Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>a Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-02-07kasan: detect invalid frees for large objectsDmitry Vyukov4-13/+9
Patch series "kasan: detect invalid frees". KASAN detects double-frees, but does not detect invalid-frees (when a pointer into a middle of heap object is passed to free). We recently had a very unpleasant case in crypto code which freed an inner object inside of a heap allocation. This left unnoticed during free, but totally corrupted heap and later lead to a bunch of random crashes all over kernel code. Detect invalid frees. This patch (of 5): Detect frees of pointers into middle of large heap objects. I dropped const from kasan_kfree_large() because it starts propagating through a bunch of functions in kasan_report.c, slab/slub nearest_obj(), all of their local variables, fixup_red_left(), etc. Link: http://lkml.kernel.org/r/1b45b4fe1d20fc0de1329aab674c1dd973fee723.1514378558.git.dvyukov@google.com Signed-off-by: Dmitry Vyukov <dvyukov@google.com> Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>a Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-02-07kasan: add functions for unpoisoning stack variablesAlexander Potapenko2-0/+59
As a code-size optimization, LLVM builds since r279383 may bulk-manipulate the shadow region when (un)poisoning large memory blocks. This requires new callbacks that simply do an uninstrumented memset(). This fixes linking the Clang-built kernel when using KASAN. [arnd@arndb.de: add declarations for internal functions] Link: http://lkml.kernel.org/r/20180105094112.2690475-1-arnd@arndb.de [fengguang.wu@intel.com: __asan_set_shadow_00 can be static] Link: http://lkml.kernel.org/r/20171223125943.GA74341@lkp-ib03 [ghackmann@google.com: fix memset() parameters, and tweak commit message to describe new callbacks] Link: http://lkml.kernel.org/r/20171204191735.132544-6-paullawrence@google.com Signed-off-by: Alexander Potapenko <glider@google.com> Signed-off-by: Greg Hackmann <ghackmann@google.com> Signed-off-by: Paul Lawrence <paullawrence@google.com> Signed-off-by: Fengguang Wu <fengguang.wu@intel.com> Signed-off-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Andrey Ryabinin <aryabinin@virtuozzo.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Masahiro Yamada <yamada.masahiro@socionext.com> Cc: Matthias Kaehlcke <mka@chromium.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-02-07kasan: support alloca() poisoningPaul Lawrence3-0/+46
clang's AddressSanitizer implementation adds redzones on either side of alloca()ed buffers. These redzones are 32-byte aligned and at least 32 bytes long. __asan_alloca_poison() is passed the size and address of the allocated buffer, *excluding* the redzones on either side. The left redzone will always be to the immediate left of this buffer; but AddressSanitizer may need to add padding between the end of the buffer and the right redzone. If there are any 8-byte chunks inside this padding, we should poison those too. __asan_allocas_unpoison() is just passed the top and bottom of the dynamic stack area, so unpoisoning is simpler. Link: http://lkml.kernel.org/r/20171204191735.132544-4-paullawrence@google.com Signed-off-by: Greg Hackmann <ghackmann@google.com> Signed-off-by: Paul Lawrence <paullawrence@google.com> Acked-by: Andrey Ryabinin <aryabinin@virtuozzo.com> Cc: Alexander Potapenko <glider@google.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Masahiro Yamada <yamada.masahiro@socionext.com> Cc: Matthias Kaehlcke <mka@chromium.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-02-06Merge tag 'libnvdimm-for-4.16' of ↵Linus Torvalds7-95/+96
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 ...
2018-02-04Merge tag 'usercopy-v4.16-rc1' of ↵Linus Torvalds5-93/+195
git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux Pull hardened usercopy whitelisting from Kees Cook: "Currently, hardened usercopy performs dynamic bounds checking on slab cache objects. This is good, but still leaves a lot of kernel memory available to be copied to/from userspace in the face of bugs. To further restrict what memory is available for copying, this creates a way to whitelist specific areas of a given slab cache object for copying to/from userspace, allowing much finer granularity of access control. Slab caches that are never exposed to userspace can declare no whitelist for their objects, thereby keeping them unavailable to userspace via dynamic copy operations. (Note, an implicit form of whitelisting is the use of constant sizes in usercopy operations and get_user()/put_user(); these bypass all hardened usercopy checks since these sizes cannot change at runtime.) This new check is WARN-by-default, so any mistakes can be found over the next several releases without breaking anyone's system. The series has roughly the following sections: - remove %p and improve reporting with offset - prepare infrastructure and whitelist kmalloc - update VFS subsystem with whitelists - update SCSI subsystem with whitelists - update network subsystem with whitelists - update process memory with whitelists - update per-architecture thread_struct with whitelists - update KVM with whitelists and fix ioctl bug - mark all other allocations as not whitelisted - update lkdtm for more sensible test overage" * tag 'usercopy-v4.16-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux: (38 commits) lkdtm: Update usercopy tests for whitelisting usercopy: Restrict non-usercopy caches to size 0 kvm: x86: fix KVM_XEN_HVM_CONFIG ioctl kvm: whitelist struct kvm_vcpu_arch arm: Implement thread_struct whitelist for hardened usercopy arm64: Implement thread_struct whitelist for hardened usercopy x86: Implement thread_struct whitelist for hardened usercopy fork: Provide usercopy whitelisting for task_struct fork: Define usercopy region in thread_stack slab caches fork: Define usercopy region in mm_struct slab caches net: Restrict unwhitelisted proto caches to size 0 sctp: Copy struct sctp_sock.autoclose to userspace using put_user() sctp: Define usercopy region in SCTP proto slab cache caif: Define usercopy region in caif proto slab cache ip: Define usercopy region in IP proto slab cache net: Define usercopy region in struct proto slab cache scsi: Define usercopy region in scsi_sense_cache slab cache cifs: Define usercopy region in cifs_request slab cache vxfs: Define usercopy region in vxfs_inode slab cache ufs: Define usercopy region in ufs_inode_cache slab cache ...
2018-02-03Merge branch 'for-4.16/nfit' into libnvdimm-for-nextRoss Zwisler7-18/+26
2018-02-03Revert "defer call to mem_cgroup_sk_alloc()"Roman Gushchin1-0/+14
This patch effectively reverts commit 9f1c2674b328 ("net: memcontrol: defer call to mem_cgroup_sk_alloc()"). Moving mem_cgroup_sk_alloc() to the inet_csk_accept() completely breaks memcg socket memory accounting, as packets received before memcg pointer initialization are not accounted and are causing refcounting underflow on socket release. Actually the free-after-use problem was fixed by commit c0576e397508 ("net: call cgroup_sk_alloc() earlier in sk_clone_lock()") for the cgroup pointer. So, let's revert it and call mem_cgroup_sk_alloc() just before cgroup_sk_alloc(). This is safe, as we hold a reference to the socket we're cloning, and it holds a reference to the memcg. Also, let's drop BUG_ON(mem_cgroup_is_root()) check from mem_cgroup_sk_alloc(). I see no reasons why bumping the root memcg counter is a good reason to panic, and there are no realistic ways to hit it. Signed-off-by: Roman Gushchin <guro@fb.com> Cc: Eric Dumazet <edumazet@google.com> Cc: David S. Miller <davem@davemloft.net> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Tejun Heo <tj@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-02-01mm/swap.c: make functions and their kernel-doc agreeRandy Dunlap1-6/+5
Fix some basic kernel-doc notation in mm/swap.c: - for function lru_cache_add_anon(), make its kernel-doc function name match its function name and change colon to hyphen following the function name - for function pagevec_lookup_entries(), change the function parameter name from nr_pages to nr_entries since that is more descriptive of what the parameter actually is and then it matches the kernel-doc comments also Fix function kernel-doc to match the change in commit 67fd707f4681: - drop the kernel-doc notation for @nr_pages from pagevec_lookup_range() and correct the function description for that change Link: http://lkml.kernel.org/r/3b42ee3e-04a9-a6ca-6be4-f00752a114fe@infradead.org Fixes: 67fd707f4681 ("mm: remove nr_pages argument from pagevec_lookup_{,range}_tag()") Signed-off-by: Randy Dunlap <rdunlap@infradead.org> Reviewed-by: Andrew Morton <akpm@linux-foundation.org> Cc: Jan Kara <jack@suse.cz> Cc: Matthew Wilcox <willy@infradead.org> Cc: Hugh Dickins <hughd@google.com> Cc: Michal Hocko <mhocko@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-02-01mm, memory_hotplug: fix memmap initializationMichal Hocko1-8/+14
Bharata has noticed that onlining a newly added memory doesn't increase the total memory, pointing to commit f7f99100d8d9 ("mm: stop zeroing memory during allocation in vmemmap") as a culprit. This commit has changed the way how the memory for memmaps is initialized and moves it from the allocation time to the initialization time. This works properly for the early memmap init path. It doesn't work for the memory hotplug though because we need to mark page as reserved when the sparsemem section is created and later initialize it completely during onlining. memmap_init_zone is called in the early stage of onlining. With the current code it calls __init_single_page and as such it clears up the whole stage and therefore online_pages_range skips those pages. Fix this by skipping mm_zero_struct_page in __init_single_page for memory hotplug path. This is quite uggly but unifying both early init and memory hotplug init paths is a large project. Make sure we plug the regression at least. Link: http://lkml.kernel.org/r/20180130101141.GW21609@dhcp22.suse.cz Fixes: f7f99100d8d9 ("mm: stop zeroing memory during allocation in vmemmap") Signed-off-by: Michal Hocko <mhocko@suse.com> Reported-by: Bharata B Rao <bharata@linux.vnet.ibm.com> Tested-by: Bharata B Rao <bharata@linux.vnet.ibm.com> Reviewed-by: Pavel Tatashin <pasha.tatashin@oracle.com> Cc: Steven Sistare <steven.sistare@oracle.com> Cc: Daniel Jordan <daniel.m.jordan@oracle.com> Cc: Bob Picco <bob.picco@oracle.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-02-01mm: correct comments regarding do_fault_around()William Kucharski1-11/+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>
2018-02-01mm: numa: do not trap faults on shared data section pages.Henry Willard1-0/+5
Workloads consisting of a large number of processes running the same program with a very large shared data segment may experience performance problems when numa balancing attempts to migrate the shared cow pages. This manifests itself with many processes or tasks in TASK_UNINTERRUPTIBLE state waiting for the shared pages to be migrated. The program listed below simulates the conditions with these results when run with 288 processes on a 144 core/8 socket machine. Average throughput Average throughput Average throughput with numa_balancing=0 with numa_balancing=1 with numa_balancing=1 without the patch with the patch --------------------- --------------------- --------------------- 2118782 2021534 2107979 Complex production environments show less variability and fewer poorly performing outliers accompanied with a smaller number of processes waiting on NUMA page migration with this patch applied. In some cases, %iowait drops from 16%-26% to 0. // SPDX-License-Identifier: GPL-2.0 /* * Copyright (c) 2017 Oracle and/or its affiliates. All rights reserved. */ #include <sys/time.h> #include <stdio.h> #include <wait.h> #include <sys/mman.h> int a[1000000] = {13}; int main(int argc, const char **argv) { int n = 0; int i; pid_t pid; int stat; int *count_array; int cpu_count = 288; long total = 0; struct timeval t1, t2 = {(argc > 1 ? atoi(argv[1]) : 10), 0}; if (argc > 2) cpu_count = atoi(argv[2]); count_array = mmap(NULL, cpu_count * sizeof(int), (PROT_READ|PROT_WRITE), (MAP_SHARED|MAP_ANONYMOUS), 0, 0); if (count_array == MAP_FAILED) { perror("mmap:"); return 0; } for (i = 0; i < cpu_count; ++i) { pid = fork(); if (pid <= 0) break; if ((i & 0xf) == 0) usleep(2); } if (pid != 0) { if (i == 0) { perror("fork:"); return 0; } for (;;) { pid = wait(&stat); if (pid < 0) break; } for (i = 0; i < cpu_count; ++i) total += count_array[i]; printf("Total %ld\n", total); munmap(count_array, cpu_count * sizeof(int)); return 0; } gettimeofday(&t1, 0); timeradd(&t1, &t2, &t1); while (timercmp(&t2, &t1, <)) { int b = 0; int j; for (j = 0; j < 1000000; j++) b += a[j]; gettimeofday(&t2, 0); n++; } count_array[i] = n; return 0; } This patch changes change_pte_range() to skip shared copy-on-write pages when called from change_prot_numa(). NOTE: change_prot_numa() is nominally called from task_numa_work() and queue_pages_test_walk(). task_numa_work() is the auto NUMA balancing path, and queue_pages_test_walk() is part of explicit NUMA policy management. However, queue_pages_test_walk() only calls change_prot_numa() when MPOL_MF_LAZY is specified and currently that is not allowed, so change_prot_numa() is only called from auto NUMA balancing. In the case of explicit NUMA policy management, shared pages are not migrated unless MPOL_MF_MOVE_ALL is specified, and MPOL_MF_MOVE_ALL depends on CAP_SYS_NICE. Currently, there is no way to pass information about MPOL_MF_MOVE_ALL to change_pte_range. This will have to be fixed if MPOL_MF_LAZY is enabled and MPOL_MF_MOVE_ALL is to be honored in lazy migration mode. task_numa_work() skips the read-only VMAs of programs and shared libraries. Link: http://lkml.kernel.org/r/1516751617-7369-1-git-send-email-henry.willard@oracle.com Signed-off-by: Henry Willard <henry.willard@oracle.com> Reviewed-by: Håkon Bugge <haakon.bugge@oracle.com> Reviewed-by: Steve Sistare <steven.sistare@oracle.com> Acked-by: Mel Gorman <mgorman@suse.de> Cc: Kate Stewart <kstewart@linuxfoundation.org> Cc: Zi Yan <zi.yan@cs.rutgers.edu> Cc: Philippe Ombredanne <pombredanne@nexb.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.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>
2018-02-01hugetlb, mbind: fall back to default policy if vma is NULLMichal Hocko2-4/+4
Dan Carpenter has noticed that mbind migration callback (new_page) can get a NULL vma pointer and choke on it inside alloc_huge_page_vma which relies on the VMA to get the hstate. We used to BUG_ON this case but the BUG_+ON has been removed recently by "hugetlb, mempolicy: fix the mbind hugetlb migration". The proper way to handle this is to get the hstate from the migrated page and rely on huge_node (resp. get_vma_policy) do the right thing with null VMA. We are currently falling back to the default mempolicy in that case which is in line what THP path is doing here. Link: http://lkml.kernel.org/r/20180110104712.GR1732@dhcp22.suse.cz Signed-off-by: Michal Hocko <mhocko@suse.com> Reported-by: Dan Carpenter <dan.carpenter@oracle.com> Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Cc: Mike Kravetz <mike.kravetz@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-02-01hugetlb, mempolicy: fix the mbind hugetlb migrationMichal Hocko2-16/+20
do_mbind migration code relies on alloc_huge_page_noerr for hugetlb pages. alloc_huge_page_noerr uses alloc_huge_page which is a highlevel allocation function which has to take care of reserves, overcommit or hugetlb cgroup accounting. None of that is really required for the page migration because the new page is only temporal and either will replace the original page or it will be dropped. This is essentially as for other migration call paths and there shouldn't be any reason to handle mbind in a special way. The current implementation is even suboptimal because the migration might fail just because the hugetlb cgroup limit is reached, or the overcommit is saturated. Fix this by making mbind like other hugetlb migration paths. Add a new migration helper alloc_huge_page_vma as a wrapper around alloc_huge_page_nodemask with additional mempolicy handling. alloc_huge_page_noerr has no more users and it can go. Link: http://lkml.kernel.org/r/20180103093213.26329-7-mhocko@kernel.org Signed-off-by: Michal Hocko <mhocko@suse.com> Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com> Reviewed-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Cc: Andrea Reale <ar@linux.vnet.ibm.com> Cc: Anshuman Khandual <khandual@linux.vnet.ibm.com> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Zi Yan <zi.yan@cs.rutgers.edu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-02-01mm, hugetlb: further simplify hugetlb allocation APIMichal Hocko1-37/+43
Hugetlb allocator has several layer of allocation functions depending and the purpose of the allocation. There are two allocators depending on whether the page can be allocated from the page allocator or we need a contiguous allocator. This is currently opencoded in alloc_fresh_huge_page which is the only path that might allocate giga pages which require the later allocator. Create alloc_fresh_huge_page which hides this implementation detail and use it in all callers which hardcoded the buddy allocator path (__hugetlb_alloc_buddy_huge_page). This shouldn't introduce any funtional change because both migration and surplus allocators exlude giga pages explicitly. While we are at it let's do some renaming. The current scheme is not consistent and overly painfull to read and understand. Get rid of prefix underscores from most functions. There is no real reason to make names longer. * alloc_fresh_huge_page is the new layer to abstract underlying allocator * __hugetlb_alloc_buddy_huge_page becomes shorter and neater alloc_buddy_huge_page. * Former alloc_fresh_huge_page becomes alloc_pool_huge_page because we put the new page directly to the pool * alloc_surplus_huge_page can drop the opencoded prep_new_huge_page code as it uses alloc_fresh_huge_page now * others lose their excessive prefix underscores to make names shorter [dan.carpenter@oracle.com: fix double unlock bug in alloc_surplus_huge_page()] Link: http://lkml.kernel.org/r/20180109200559.g3iz5kvbdrz7yydp@mwanda Link: http://lkml.kernel.org/r/20180103093213.26329-6-mhocko@kernel.org Signed-off-by: Michal Hocko <mhocko@suse.com> Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com> Reviewed-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Cc: Andrea Reale <ar@linux.vnet.ibm.com> Cc: Anshuman Khandual <khandual@linux.vnet.ibm.com> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Zi Yan <zi.yan@cs.rutgers.edu> Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-02-01mm, hugetlb: get rid of surplus page accounting tricksMichal Hocko1-39/+23
alloc_surplus_huge_page increases the pool size and the number of surplus pages opportunistically to prevent from races with the pool size change. See commit d1c3fb1f8f29 ("hugetlb: introduce nr_overcommit_hugepages sysctl") for more details. The resulting code is unnecessarily hairy, cause code duplication and doesn't allow to share the allocation paths. Moreover pool size changes tend to be very seldom so optimizing for them is not really reasonable. Simplify the code and allow to allocate a fresh surplus page as long as we are under the overcommit limit and then recheck the condition after the allocation and drop the new page if the situation has changed. This should provide a reasonable guarantee that an abrupt allocation requests will not go way off the limit. If we consider races with the pool shrinking and enlarging then we should be reasonably safe as well. In the first case we are off by one in the worst case and the second case should work OK because the page is not yet visible. We can waste CPU cycles for the allocation but that should be acceptable for a relatively rare condition. Link: http://lkml.kernel.org/r/20180103093213.26329-5-mhocko@kernel.org Signed-off-by: Michal Hocko <mhocko@suse.com> Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com> Reviewed-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Cc: Andrea Reale <ar@linux.vnet.ibm.com> Cc: Anshuman Khandual <khandual@linux.vnet.ibm.com> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Zi Yan <zi.yan@cs.rutgers.edu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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