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* Merge branch 'x86-mm-for-linus' of ↵Linus Torvalds2019-03-071-3/+3
|\ | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 mm cleanup from Ingo Molnar: "A single GUP cleanup" * 'x86-mm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: mm/gup: Remove the 'write' parameter from gup_fast_permitted()
| * mm/gup: Remove the 'write' parameter from gup_fast_permitted()Ira Weiny2019-02-111-3/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The 'write' parameter is unused in gup_fast_permitted() so remove it. Signed-off-by: Ira Weiny <ira.weiny@intel.com> Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: linux-mm@kvack.org Link: http://lkml.kernel.org/r/20190210223424.13934-1-ira.weiny@intel.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
* | mm: update get_user_pages_longterm to migrate pages allocated from CMA regionAneesh Kumar K.V2019-03-051-24/+176
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch updates get_user_pages_longterm to migrate pages allocated out of CMA region. This makes sure that we don't keep non-movable pages (due to page reference count) in the CMA area. This will be used by ppc64 in a later patch to avoid pinning pages in the CMA region. ppc64 uses CMA region for allocation of the hardware page table (hash page table) and not able to migrate pages out of CMA region results in page table allocation failures. One case where we hit this easy is when a guest using a VFIO passthrough device. VFIO locks all the guest's memory and if the guest memory is backed by CMA region, it becomes unmovable resulting in fragmenting the CMA and possibly preventing other guests from allocation a large enough hash page table. NOTE: We allocate the new page without using __GFP_THISNODE Link: http://lkml.kernel.org/r/20190114095438.32470-3-aneesh.kumar@linux.ibm.com Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> Cc: Alexey Kardashevskiy <aik@ozlabs.ru> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: David Gibson <david@gibson.dropbear.id.au> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Michal Hocko <mhocko@kernel.org> Cc: Mel Gorman <mgorman@techsingularity.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | mm/gup: fix gup_pmd_range() for daxYu Zhao2019-02-121-1/+2
|/ | | | | | | | | | | | | | | | | | | | | | For dax pmd, pmd_trans_huge() returns false but pmd_huge() returns true on x86. So the function works as long as hugetlb is configured. However, dax doesn't depend on hugetlb. Link: http://lkml.kernel.org/r/20190111034033.601-1-yuzhao@google.com Signed-off-by: Yu Zhao <yuzhao@google.com> Reviewed-by: Jan Kara <jack@suse.cz> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Huang Ying <ying.huang@intel.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Keith Busch <keith.busch@intel.com> Cc: "Michael S . Tsirkin" <mst@redhat.com> Cc: John Hubbard <jhubbard@nvidia.com> Cc: Wei Yang <richard.weiyang@gmail.com> Cc: Mike Rapoport <rppt@linux.ibm.com> Cc: Andrea Arcangeli <aarcange@redhat.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>
* Merge branch 'akpm' (patches from Andrew)Linus Torvalds2019-01-051-1/+1
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Merge more updates from Andrew Morton: - procfs updates - various misc bits - lib/ updates - epoll updates - autofs - fatfs - a few more MM bits * emailed patches from Andrew Morton <akpm@linux-foundation.org>: (58 commits) mm/page_io.c: fix polled swap page in checkpatch: add Co-developed-by to signature tags docs: fix Co-Developed-by docs drivers/base/platform.c: kmemleak ignore a known leak fs: don't open code lru_to_page() fs/: remove caller signal_pending branch predictions mm/: remove caller signal_pending branch predictions arch/arc/mm/fault.c: remove caller signal_pending_branch predictions kernel/sched/: remove caller signal_pending branch predictions kernel/locking/mutex.c: remove caller signal_pending branch predictions mm: select HAVE_MOVE_PMD on x86 for faster mremap mm: speed up mremap by 20x on large regions mm: treewide: remove unused address argument from pte_alloc functions initramfs: cleanup incomplete rootfs scripts/gdb: fix lx-version string output kernel/kcov.c: mark write_comp_data() as notrace kernel/sysctl: add panic_print into sysctl panic: add options to print system info when panic happens bfs: extra sanity checking and static inode bitmap exec: separate MM_ANONPAGES and RLIMIT_STACK accounting ...
| * mm/: remove caller signal_pending branch predictionsDavidlohr Bueso2019-01-041-1/+1
| | | | | | | | | | | | | | | | | | | | This is already done for us internally by the signal machinery. Link: http://lkml.kernel.org/r/20181116002713.8474-5-dave@stgolabs.net Signed-off-by: Davidlohr Bueso <dave@stgolabs.net> Reviewed-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | Remove 'type' argument from access_ok() functionLinus Torvalds2019-01-031-4/+2
|/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Nobody has actually used the type (VERIFY_READ vs VERIFY_WRITE) argument of the user address range verification function since we got rid of the old racy i386-only code to walk page tables by hand. It existed because the original 80386 would not honor the write protect bit when in kernel mode, so you had to do COW by hand before doing any user access. But we haven't supported that in a long time, and these days the 'type' argument is a purely historical artifact. A discussion about extending 'user_access_begin()' to do the range checking resulted this patch, because there is no way we're going to move the old VERIFY_xyz interface to that model. And it's best done at the end of the merge window when I've done most of my merges, so let's just get this done once and for all. This patch was mostly done with a sed-script, with manual fix-ups for the cases that weren't of the trivial 'access_ok(VERIFY_xyz' form. There were a couple of notable cases: - csky still had the old "verify_area()" name as an alias. - the iter_iov code had magical hardcoded knowledge of the actual values of VERIFY_{READ,WRITE} (not that they mattered, since nothing really used it) - microblaze used the type argument for a debug printout but other than those oddities this should be a total no-op patch. I tried to fix up all architectures, did fairly extensive grepping for access_ok() uses, and the changes are trivial, but I may have missed something. Any missed conversion should be trivially fixable, though. Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm/gup: finish consolidating error handlingJohn Hubbard2018-11-301-2/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Commit df06b37ffe5a ("mm/gup: cache dev_pagemap while pinning pages") attempted to operate on each page that get_user_pages had retrieved. In order to do that, it created a common exit point from the routine. However, one case was missed, which this patch fixes up. Also, there was still an unnecessary shadow declaration (with a different type) of the "ret" variable, which this patch removes. Keith's description of the situation is: This also fixes a potentially leaked dev_pagemap reference count if a failure occurs when an iteration crosses a vma boundary. I don't think it's normal to have different vma's on a users mapped zone device memory, but good to fix anyway. I actually thought that this code: /* first iteration or cross vma bound */ if (!vma || start >= vma->vm_end) { vma = find_extend_vma(mm, start); if (!vma && in_gate_area(mm, start)) { ret = get_gate_page(mm, start & PAGE_MASK, gup_flags, &vma, pages ? &pages[i] : NULL); if (ret) goto out; dealt with the "you're trying to pin the gate page, as part of this call", rather than the generic case of crossing a vma boundary. (I think there's a fine point that I must be overlooking.) But it's still a valid case, either way. Link: http://lkml.kernel.org/r/20181121081402.29641-2-jhubbard@nvidia.com Fixes: df06b37ffe5a4 ("mm/gup: cache dev_pagemap while pinning pages") Signed-off-by: John Hubbard <jhubbard@nvidia.com> Reviewed-by: Keith Busch <keith.busch@intel.com> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Dave Hansen <dave.hansen@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm/gup.c: fix follow_page_mask() kerneldoc commentMike Rapoport2018-11-181-2/+8
| | | | | | | | | | | | | | | | | Commit df06b37ffe5a ("mm/gup: cache dev_pagemap while pinning pages") modified the signature of follow_page_mask() but left the parameter description behind. Update the description to make the code and comments agree again. While at it, update formatting of the return value description to match Documentation/doc-guide/kernel-doc.rst guidelines. Link: http://lkml.kernel.org/r/1541603316-27832-1-git-send-email-rppt@linux.ibm.com Signed-off-by: Mike Rapoport <rppt@linux.ibm.com> Reviewed-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm/gup.c: fix __get_user_pages_fast() commentFengguang Wu2018-10-311-2/+2
| | | | | | | | | | | mmu_gather_tlb() no longer exists. Replace with mmu_table_batch(). Link: http://lkml.kernel.org/r/20180928053441.rpzwafzlsnp74mkl@wfg-t540p.sh.intel.com Signed-off-by: Fengguang Wu <fengguang.wu@intel.com> Reviewed-by: Andrew Morton <akpm@linux-foundation.org> Cc: Jiri Kosina <trivial@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm/gup: cache dev_pagemap while pinning pagesKeith Busch2018-10-261-45/+65
| | | | | | | | | | | | | | | | | | | | Getting pages from ZONE_DEVICE memory needs to check the backing device's live-ness, which is tracked in the device's dev_pagemap metadata. This metadata is stored in a radix tree and looking it up adds measurable software overhead. This patch avoids repeating this relatively costly operation when dev_pagemap is used by caching the last dev_pagemap while getting user pages. The gup_benchmark kernel self test reports this reduces time to get user pages to as low as 1/3 of the previous time. Link: http://lkml.kernel.org/r/20181012173040.15669-1-keith.busch@intel.com Signed-off-by: Keith Busch <keith.busch@intel.com> Reviewed-by: Dan Williams <dan.j.williams@intel.com> Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Dave Hansen <dave.hansen@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm: remove unnecessary local variable addr in __get_user_pages_fast()Wei Yang2018-10-261-3/+2
| | | | | | | | | | | | | | | The local variable `addr' in __get_user_pages_fast() is just a shadow of `start'. Since `start' never changes after assignment to `addr', it is fine to replace `start' with it. Also the meaning of [start, end] is more obvious than [addr, end] when passed to gup_pgd_range(). Link: http://lkml.kernel.org/r/20180925021448.20265-1-richard.weiyang@gmail.com Signed-off-by: Wei Yang <richard.weiyang@gmail.com> Reviewed-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm: Change return type int to vm_fault_t for fault handlersSouptick Joarder2018-08-231-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | 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: do not bug_on on incorrect length in __mm_populate()Michal Hocko2018-07-141-2/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | syzbot has noticed that a specially crafted library can easily hit VM_BUG_ON in __mm_populate kernel BUG at mm/gup.c:1242! invalid opcode: 0000 [#1] SMP CPU: 2 PID: 9667 Comm: a.out Not tainted 4.18.0-rc3 #644 Hardware name: VMware, Inc. VMware Virtual Platform/440BX Desktop Reference Platform, BIOS 6.00 05/19/2017 RIP: 0010:__mm_populate+0x1e2/0x1f0 Code: 55 d0 65 48 33 14 25 28 00 00 00 89 d8 75 21 48 83 c4 20 5b 41 5c 41 5d 41 5e 41 5f 5d c3 e8 75 18 f1 ff 0f 0b e8 6e 18 f1 ff <0f> 0b 31 db eb c9 e8 93 06 e0 ff 0f 1f 00 55 48 89 e5 53 48 89 fb Call Trace: vm_brk_flags+0xc3/0x100 vm_brk+0x1f/0x30 load_elf_library+0x281/0x2e0 __ia32_sys_uselib+0x170/0x1e0 do_fast_syscall_32+0xca/0x420 entry_SYSENTER_compat+0x70/0x7f The reason is that the length of the new brk is not page aligned when we try to populate the it. There is no reason to bug on that though. do_brk_flags already aligns the length properly so the mapping is expanded as it should. All we need is to tell mm_populate about it. Besides that there is absolutely no reason to to bug_on in the first place. The worst thing that could happen is that the last page wouldn't get populated and that is far from putting system into an inconsistent state. Fix the issue by moving the length sanitization code from do_brk_flags up to vm_brk_flags. The only other caller of do_brk_flags is brk syscall entry and it makes sure to provide the proper length so t here is no need for sanitation and so we can use do_brk_flags without it. Also remove the bogus BUG_ONs. [osalvador@techadventures.net: fix up vm_brk_flags s@request@len@] Link: http://lkml.kernel.org/r/20180706090217.GI32658@dhcp22.suse.cz Signed-off-by: Michal Hocko <mhocko@suse.com> Reported-by: syzbot <syzbot+5dcb560fe12aa5091c06@syzkaller.appspotmail.com> Tested-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Reviewed-by: Oscar Salvador <osalvador@suse.de> Cc: Zi Yan <zi.yan@cs.rutgers.edu> Cc: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com> Cc: Dan Williams <dan.j.williams@intel.com> Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> Cc: Michael S. Tsirkin <mst@redhat.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: "Huang, Ying" <ying.huang@intel.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Merge tag 'libnvdimm-for-4.18' of ↵Linus Torvalds2018-06-081-10/+26
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm Pull libnvdimm updates from Dan Williams: "This adds a user for the new 'bytes-remaining' updates to memcpy_mcsafe() that you already received through Ingo via the x86-dax- for-linus pull. Not included here, but still targeting this cycle, is support for handling memory media errors (poison) consumed via userspace dax mappings. Summary: - DAX broke a fundamental assumption of truncate of file mapped pages. The truncate path assumed that it is safe to disconnect a pinned page from a file and let the filesystem reclaim the physical block. With DAX the page is equivalent to the filesystem block. Introduce dax_layout_busy_page() to enable filesystems to wait for pinned DAX pages to be released. Without this wait a filesystem could allocate blocks under active device-DMA to a new file. - DAX arranges for the block layer to be bypassed and uses dax_direct_access() + copy_to_iter() to satisfy read(2) calls. However, the memcpy_mcsafe() facility is available through the pmem block driver. In order to safely handle media errors, via the DAX block-layer bypass, introduce copy_to_iter_mcsafe(). - Fix cache management policy relative to the ACPI NFIT Platform Capabilities Structure to properly elide cache flushes when they are not necessary. The table indicates whether CPU caches are power-fail protected. Clarify that a deep flush is always performed on REQ_{FUA,PREFLUSH} requests" * tag 'libnvdimm-for-4.18' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm: (21 commits) dax: Use dax_write_cache* helpers libnvdimm, pmem: Do not flush power-fail protected CPU caches libnvdimm, pmem: Unconditionally deep flush on *sync libnvdimm, pmem: Complete REQ_FLUSH => REQ_PREFLUSH acpi, nfit: Remove ecc_unit_size dax: dax_insert_mapping_entry always succeeds libnvdimm, e820: Register all pmem resources libnvdimm: Debug probe times linvdimm, pmem: Preserve read-only setting for pmem devices x86, nfit_test: Add unit test for memcpy_mcsafe() pmem: Switch to copy_to_iter_mcsafe() dax: Report bytes remaining in dax_iomap_actor() dax: Introduce a ->copy_to_iter dax operation uio, lib: Fix CONFIG_ARCH_HAS_UACCESS_MCSAFE compilation xfs, dax: introduce xfs_break_dax_layouts() xfs: prepare xfs_break_layouts() for another layout type xfs: prepare xfs_break_layouts() to be called with XFS_MMAPLOCK_EXCL mm, fs, dax: handle layout changes to pinned dax mappings mm: fix __gup_device_huge vs unmap mm: introduce MEMORY_DEVICE_FS_DAX and CONFIG_DEV_PAGEMAP_OPS ...
| * Merge branch 'for-4.18/dax' into libnvdimm-for-nextDan Williams2018-06-081-10/+26
| |\
| | * mm: fix __gup_device_huge vs unmapDan Williams2018-05-221-10/+26
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | get_user_pages_fast() for device pages is missing the typical validation that all page references have been taken while the mapping was valid. Without this validation truncate operations can not reliably coordinate against new page reference events like O_DIRECT. Cc: <stable@vger.kernel.org> Fixes: 3565fce3a659 ("mm, x86: get_user_pages() for dax mappings") Reported-by: Jan Kara <jack@suse.cz> Reviewed-by: Jan Kara <jack@suse.cz> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
* | | mm, gup: prevent pmd checking race in follow_pmd_mask()Huang Ying2018-06-071-11/+27
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | mmap_sem will be read locked when calling follow_pmd_mask(). But this cannot prevent PMD from being changed for all cases when PTL is unlocked, for example, from pmd_trans_huge() to pmd_none() via MADV_DONTNEED. So it is possible for the pmd_present() check in follow_pmd_mask() to encounter an invalid PMD. This may cause an incorrect VM_BUG_ON() or an infinite loop. Fix this by reading the PMD entry into a local variable with READ_ONCE() and checking the local variable and pmd_none() in the retry loop. As Kirill pointed out, with PTL unlocked, the *pmd may be changed under us, so reading it directly again and again may incur weird bugs. So although using *pmd directly other than for pmd_present() checking may be safe, it is still better to replace them to read *pmd once and check the local variable multiple times. When PTL unlocked, replace all *pmd with local variable was suggested by Kirill. Link: http://lkml.kernel.org/r/20180419083514.1365-1-ying.huang@intel.com Signed-off-by: "Huang, Ying" <ying.huang@intel.com> Reviewed-by: Zi Yan <zi.yan@cs.rutgers.edu> Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com> Cc: Dan Williams <dan.j.williams@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | | mm: introduce ARCH_HAS_PTE_SPECIALLaurent Dufour2018-06-071-2/+2
|/ / | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* / proc: do not access cmdline nor environ from file-backed areasWilly Tarreau2018-05-171-0/+3
|/ | | | | | | | | | | | | | | | | | | | | | | | | | | | proc_pid_cmdline_read() and environ_read() directly access the target process' VM to retrieve the command line and environment. If this process remaps these areas onto a file via mmap(), the requesting process may experience various issues such as extra delays if the underlying device is slow to respond. Let's simply refuse to access file-backed areas in these functions. For this we add a new FOLL_ANON gup flag that is passed to all calls to access_remote_vm(). The code already takes care of such failures (including unmapped areas). Accesses via /proc/pid/mem were not changed though. This was assigned CVE-2018-1120. Note for stable backports: the patch may apply to kernels prior to 4.11 but silently miss one location; it must be checked that no call to access_remote_vm() keeps zero as the last argument. Reported-by: Qualys Security Advisory <qsa@qualys.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Oleg Nesterov <oleg@redhat.com> Cc: stable@vger.kernel.org Signed-off-by: Willy Tarreau <w@1wt.eu> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm/gup.c: document return valueMichael S. Tsirkin2018-04-131-1/+3
| | | | | | | | | | | | | | | | | | __get_user_pages_fast handles errors differently from get_user_pages_fast: the former always returns the number of pages pinned, the later might return a negative error code. Link: http://lkml.kernel.org/r/1522962072-182137-6-git-send-email-mst@redhat.com Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Reviewed-by: Andrew Morton <akpm@linux-foundation.org> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Huang Ying <ying.huang@intel.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Thorsten Leemhuis <regressions@leemhuis.info> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* get_user_pages_fast(): return -EFAULT on access_ok failureMichael S. Tsirkin2018-04-131-1/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | get_user_pages_fast is supposed to be a faster drop-in equivalent of get_user_pages. As such, callers expect it to return a negative return code when passed an invalid address, and never expect it to return 0 when passed a positive number of pages, since its documentation says: * Returns number of pages pinned. This may be fewer than the number * requested. If nr_pages is 0 or negative, returns 0. If no pages * were pinned, returns -errno. When get_user_pages_fast fall back on get_user_pages this is exactly what happens. Unfortunately the implementation is inconsistent: it returns 0 if passed a kernel address, confusing callers: for example, the following is pretty common but does not appear to do the right thing with a kernel address: ret = get_user_pages_fast(addr, 1, writeable, &page); if (ret < 0) return ret; Change get_user_pages_fast to return -EFAULT when supplied a kernel address to make it match expectations. All callers have been audited for consistency with the documented semantics. Link: http://lkml.kernel.org/r/1522962072-182137-4-git-send-email-mst@redhat.com Fixes: 5b65c4677a57 ("mm, x86/mm: Fix performance regression in get_user_pages_fast()") Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Reported-by: syzbot+6304bf97ef436580fede@syzkaller.appspotmail.com Reviewed-by: Andrew Morton <akpm@linux-foundation.org> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Huang Ying <ying.huang@intel.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Thorsten Leemhuis <regressions@leemhuis.info> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm/gup.c: fix coding style issues.Mario Leinweber2018-04-051-2/+2
| | | | | | | | | | | - Fixed style error: 8 spaces -> 1 tab. - Fixed style warning: Corrected misleading indentation. Link: http://lkml.kernel.org/r/20180302210254.31888-1-marioleinweber@web.de Signed-off-by: Mario Leinweber <marioleinweber@web.de> Reviewed-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm/gup.c: teach get_user_pages_unlocked to handle FOLL_NOWAITAndrea Arcangeli2018-03-091-2/+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>
* Merge tag 'libnvdimm-for-4.16' of ↵Linus Torvalds2018-02-061-2/+5
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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: optimize dev_pagemap reference counting around get_dev_pagemapChristoph Hellwig2018-01-081-2/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | Change the calling convention so that get_dev_pagemap always consumes the previous reference instead of doing this using an explicit earlier call to put_dev_pagemap in the callers. The callers will still need to put the final reference after finishing the loop over the pages. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Logan Gunthorpe <logang@deltatee.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
* | Merge branch 'work.get_user_pages_fast' of ↵Linus Torvalds2018-01-311-31/+15
|\ \ | |/ |/| | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs Pull get_user_pages_fast updates from Al Viro: "A bit more get_user_pages work" * 'work.get_user_pages_fast' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: kvm: switch get_user_page_nowait() to get_user_pages_unlocked() __get_user_pages_locked(): get rid of notify_drop argument get_user_pages_unlocked(): pass true to __get_user_pages_locked() notify_drop cris: switch to get_user_pages_fast() fold __get_user_pages_unlocked() into its sole remaining caller
| * __get_user_pages_locked(): get rid of notify_drop argumentAl Viro2017-12-021-6/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | The only caller that doesn't pass true in it is get_user_pages() and it passes NULL in locked. The only place where we check it is if (notify_locked && lock_dropped && *locked) and lock_dropped can become true only if we have locked != NULL. In other words, the second part of condition will be false when called by get_user_pages(). Just get rid of the argument and turn the condition into if (lock_dropped && *locked) Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
| * get_user_pages_unlocked(): pass true to __get_user_pages_locked() notify_dropAl Viro2017-12-021-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Equivalent transformation - the only place in __get_user_pages_locked() where we look at notify_drop argument is if (notify_drop && lock_dropped && *locked) { up_read(&mm->mmap_sem); *locked = 0; } in the very end. Changing notify_drop from false to true won't change behaviour unless *locked is non-zero. The caller is ret = __get_user_pages_locked(current, mm, start, nr_pages, pages, NULL, &locked, false, gup_flags | FOLL_TOUCH); if (locked) up_read(&mm->mmap_sem); so in that case the original kernel would have done up_read() right after return from __get_user_pages_locked(), while the modified one would've done it right before the return. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
| * fold __get_user_pages_unlocked() into its sole remaining callerAl Viro2017-12-021-26/+10
| | | | | | | | Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* | Revert "mm: replace p??_write with pte_access_permitted in fault + gup paths"Linus Torvalds2017-12-151-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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: introduce get_user_pages_longtermDan Williams2017-11-291-0/+64
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Patch series "introduce get_user_pages_longterm()", v2. Here is a new get_user_pages api for cases where a driver intends to keep an elevated page count indefinitely. This is distinct from usages like iov_iter_get_pages where the elevated page counts are transient. The iov_iter_get_pages cases immediately turn around and submit the pages to a device driver which will put_page when the i/o operation completes (under kernel control). In the longterm case userspace is responsible for dropping the page reference at some undefined point in the future. This is untenable for filesystem-dax case where the filesystem is in control of the lifetime of the block / page and needs reasonable limits on how long it can wait for pages in a mapping to become idle. Fixing filesystems to actually wait for dax pages to be idle before blocks from a truncate/hole-punch operation are repurposed is saved for a later patch series. Also, allowing longterm registration of dax mappings is a future patch series that introduces a "map with lease" semantic where the kernel can revoke a lease and force userspace to drop its page references. I have also tagged these for -stable to purposely break cases that might assume that longterm memory registrations for filesystem-dax mappings were supported by the kernel. The behavior regression this policy change implies is one of the reasons we maintain the "dax enabled. Warning: EXPERIMENTAL, use at your own risk" notification when mounting a filesystem in dax mode. It is worth noting the device-dax interface does not suffer the same constraints since it does not support file space management operations like hole-punch. This patch (of 4): Until there is a solution to the dma-to-dax vs truncate problem it is not safe to allow long standing memory registrations against filesytem-dax vmas. Device-dax vmas do not have this problem and are explicitly allowed. This is temporary until a "memory registration with layout-lease" mechanism can be implemented for the affected sub-systems (RDMA and V4L2). [akpm@linux-foundation.org: use kcalloc()] Link: http://lkml.kernel.org/r/151068939435.7446.13560129395419350737.stgit@dwillia2-desk3.amr.corp.intel.com Fixes: 3565fce3a659 ("mm, x86: get_user_pages() for dax mappings") Signed-off-by: Dan Williams <dan.j.williams@intel.com> Suggested-by: Christoph Hellwig <hch@lst.de> Cc: Doug Ledford <dledford@redhat.com> Cc: Hal Rosenstock <hal.rosenstock@gmail.com> Cc: Inki Dae <inki.dae@samsung.com> Cc: Jan Kara <jack@suse.cz> Cc: Jason Gunthorpe <jgg@mellanox.com> Cc: Jeff Moyer <jmoyer@redhat.com> Cc: Joonyoung Shim <jy0922.shim@samsung.com> Cc: Kyungmin Park <kyungmin.park@samsung.com> Cc: Mauro Carvalho Chehab <mchehab@kernel.org> Cc: Mel Gorman <mgorman@suse.de> Cc: Ross Zwisler <ross.zwisler@linux.intel.com> Cc: Sean Hefty <sean.hefty@intel.com> Cc: Seung-Woo Kim <sw0312.kim@samsung.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>
* | mm: replace pte_write with pte_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 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>
* Merge branch 'x86/urgent' into x86/mm, to pick up fixesIngo Molnar2017-10-201-3/+28
|\ | | | | | | Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * mm/device-public-memory: device memory cache coherent with CPUJérôme Glisse2017-09-081-0/+7
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Platform with advance system bus (like CAPI or CCIX) allow device memory to be accessible from CPU in a cache coherent fashion. Add a new type of ZONE_DEVICE to represent such memory. The use case are the same as for the un-addressable device memory but without all the corners cases. Link: http://lkml.kernel.org/r/20170817000548.32038-19-jglisse@redhat.com Signed-off-by: Jérôme Glisse <jglisse@redhat.com> Cc: Aneesh Kumar <aneesh.kumar@linux.vnet.ibm.com> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Ross Zwisler <ross.zwisler@linux.intel.com> Cc: Balbir Singh <bsingharora@gmail.com> Cc: David Nellans <dnellans@nvidia.com> Cc: Evgeny Baskakov <ebaskakov@nvidia.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: John Hubbard <jhubbard@nvidia.com> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Mark Hairgrove <mhairgrove@nvidia.com> Cc: Michal Hocko <mhocko@kernel.org> Cc: Sherry Cheung <SCheung@nvidia.com> Cc: Subhash Gutti <sgutti@nvidia.com> Cc: Vladimir Davydov <vdavydov.dev@gmail.com> Cc: Bob Liu <liubo95@huawei.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * mm: thp: check pmd migration entry in common pathZi Yan2017-09-081-2/+20
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When THP migration is being used, memory management code needs to handle pmd migration entries properly. This patch uses !pmd_present() or is_swap_pmd() (depending on whether pmd_none() needs separate code or not) to check pmd migration entries at the places where a pmd entry is present. Since pmd-related code uses split_huge_page(), split_huge_pmd(), pmd_trans_huge(), pmd_trans_unstable(), or pmd_none_or_trans_huge_or_clear_bad(), this patch: 1. adds pmd migration entry split code in split_huge_pmd(), 2. takes care of pmd migration entries whenever pmd_trans_huge() is present, 3. makes pmd_none_or_trans_huge_or_clear_bad() pmd migration entry aware. Since split_huge_page() uses split_huge_pmd() and pmd_trans_unstable() is equivalent to pmd_none_or_trans_huge_or_clear_bad(), we do not change them. Until this commit, a pmd entry should be: 1. pointing to a pte page, 2. is_swap_pmd(), 3. pmd_trans_huge(), 4. pmd_devmap(), or 5. pmd_none(). Signed-off-by: Zi Yan <zi.yan@cs.rutgers.edu> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Anshuman Khandual <khandual@linux.vnet.ibm.com> Cc: Dave Hansen <dave.hansen@intel.com> Cc: David Nellans <dnellans@nvidia.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: Minchan Kim <minchan@kernel.org> Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Andrea Arcangeli <aarcange@redhat.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>
| * mm/gup: make __gup_device_* require THPOliver O'Halloran2017-09-061-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | These functions are the only bits of generic code that use {pud,pmd}_pfn() without checking for CONFIG_TRANSPARENT_HUGEPAGE. This works fine on x86, the only arch with devmap support, since the *_pfn() functions are always defined there, but this isn't true for every architecture. Link: http://lkml.kernel.org/r/20170626063833.11094-1-oohall@gmail.com Signed-off-by: Oliver O'Halloran <oohall@gmail.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, x86/mm: Fix performance regression in get_user_pages_fast()Kirill A. Shutemov2017-09-131-39/+58
|/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The 0-day test bot found a performance regression that was tracked down to switching x86 to the generic get_user_pages_fast() implementation: http://lkml.kernel.org/r/20170710024020.GA26389@yexl-desktop The regression was caused by the fact that we now use local_irq_save() + local_irq_restore() in get_user_pages_fast() to disable interrupts. In x86 implementation local_irq_disable() + local_irq_enable() was used. The fix is to make get_user_pages_fast() use local_irq_disable(), leaving local_irq_save() for __get_user_pages_fast() that can be called with interrupts disabled. Numbers for pinning a gigabyte of memory, one page a time, 20 repeats: Before: Average: 14.91 ms, stddev: 0.45 ms After: Average: 10.76 ms, stddev: 0.18 ms Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Huang Ying <ying.huang@intel.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Thorsten Leemhuis <regressions@leemhuis.info> Cc: linux-mm@kvack.org Fixes: e585513b76f7 ("x86/mm/gup: Switch GUP to the generic get_user_page_fast() implementation") Link: http://lkml.kernel.org/r/20170908215603.9189-3-kirill.shutemov@linux.intel.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
* mm, gup: ensure real head page is ref-counted when using hugepagesPunit Agrawal2017-07-061-6/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When speculatively taking references to a hugepage using page_cache_add_speculative() in gup_huge_pmd(), it is assumed that the page returned by pmd_page() is the head page. Although normally true, this assumption doesn't hold when the hugepage comprises of successive page table entries such as when using contiguous bit on arm64 at PTE or PMD levels. This can be addressed by ensuring that the page passed to page_cache_add_speculative() is the real head or by de-referencing the head page within the function. We take the first approach to keep the usage pattern aligned with page_cache_get_speculative() where users already pass the appropriate page, i.e., the de-referenced head. Apply the same logic to fix gup_huge_[pud|pgd]() as well. [punit.agrawal@arm.com: fix arm64 ltp failure] Link: http://lkml.kernel.org/r/20170619170145.25577-5-punit.agrawal@arm.com Link: http://lkml.kernel.org/r/20170522133604.11392-3-punit.agrawal@arm.com Signed-off-by: Punit Agrawal <punit.agrawal@arm.com> Acked-by: Steve Capper <steve.capper@arm.com> Cc: Michal Hocko <mhocko@suse.com> Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> Cc: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Will Deacon <will.deacon@arm.com> Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Hillf Danton <hillf.zj@alibaba-inc.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>
* mm, gup: remove broken VM_BUG_ON_PAGE compound check for hugepagesWill Deacon2017-07-061-3/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When operating on hugepages with DEBUG_VM enabled, the GUP code checks the compound head for each tail page prior to calling page_cache_add_speculative. This is broken, because on the fast-GUP path (where we don't hold any page table locks) we can be racing with a concurrent invocation of split_huge_page_to_list. split_huge_page_to_list deals with this race by using page_ref_freeze to freeze the page and force concurrent GUPs to fail whilst the component pages are modified. This modification includes clearing the compound_head field for the tail pages, so checking this prior to a successful call to page_cache_add_speculative can lead to false positives: In fact, page_cache_add_speculative *already* has this check once the page refcount has been successfully updated, so we can simply remove the broken calls to VM_BUG_ON_PAGE. Link: http://lkml.kernel.org/r/20170522133604.11392-2-punit.agrawal@arm.com Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Punit Agrawal <punit.agrawal@arm.com> Acked-by: Steve Capper <steve.capper@arm.com> Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Hillf Danton <hillf.zj@alibaba-inc.com> Cc: Michal Hocko <mhocko@suse.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>
* mm/follow_page_mask: add support for hugepage directory entryAneesh Kumar K.V2017-07-061-0/+33
| | | | | | | | | | | | | | | | | | | | | | Architectures like ppc64 supports hugepage size that is not mapped to any of of the page table levels. Instead they add an alternate page table entry format called hugepage directory (hugepd). hugepd indicates that the page table entry maps to a set of hugetlb pages. Add support for this in generic follow_page_mask code. We already support this format in the generic gup code. The default implementation prints warning and returns NULL. We will add ppc64 support in later patches Link: http://lkml.kernel.org/r/1494926612-23928-7-git-send-email-aneesh.kumar@linux.vnet.ibm.com Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Cc: Anshuman Khandual <khandual@linux.vnet.ibm.com> Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Mike Kravetz <kravetz@us.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm/follow_page_mask: add support for hugetlb pgd entriesAnshuman Khandual2017-07-061-0/+7
| | | | | | | | | | | | | | | | ppc64 supports pgd hugetlb entries. Add code to handle hugetlb pgd entries to follow_page_mask so that ppc64 can switch to it to handle hugetlbe entries. Link: http://lkml.kernel.org/r/1494926612-23928-5-git-send-email-aneesh.kumar@linux.vnet.ibm.com Signed-off-by: Anshuman Khandual <khandual@linux.vnet.ibm.com> Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Mike Kravetz <kravetz@us.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm/follow_page_mask: split follow_page_mask to smaller functions.Aneesh Kumar K.V2017-07-061-57/+91
| | | | | | | | | | | | | | | | | Makes code reading easy. No functional changes in this patch. In a followup patch, we will be updating the follow_page_mask to handle hugetlb hugepd format so that archs like ppc64 can switch to the generic version. This split helps in doing that nicely. Link: http://lkml.kernel.org/r/1494926612-23928-3-git-send-email-aneesh.kumar@linux.vnet.ibm.com Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Reviewed-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Cc: Anshuman Khandual <khandual@linux.vnet.ibm.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Mike Kravetz <kravetz@us.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Merge branch 'linus' into x86/mm, to pick up fixesIngo Molnar2017-06-221-5/+0
|\ | | | | | | Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * mm: larger stack guard gap, between vmasHugh Dickins2017-06-191-5/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Stack guard page is a useful feature to reduce a risk of stack smashing into a different mapping. We have been using a single page gap which is sufficient to prevent having stack adjacent to a different mapping. But this seems to be insufficient in the light of the stack usage in userspace. E.g. glibc uses as large as 64kB alloca() in many commonly used functions. Others use constructs liks gid_t buffer[NGROUPS_MAX] which is 256kB or stack strings with MAX_ARG_STRLEN. This will become especially dangerous for suid binaries and the default no limit for the stack size limit because those applications can be tricked to consume a large portion of the stack and a single glibc call could jump over the guard page. These attacks are not theoretical, unfortunatelly. Make those attacks less probable by increasing the stack guard gap to 1MB (on systems with 4k pages; but make it depend on the page size because systems with larger base pages might cap stack allocations in the PAGE_SIZE units) which should cover larger alloca() and VLA stack allocations. It is obviously not a full fix because the problem is somehow inherent, but it should reduce attack space a lot. One could argue that the gap size should be configurable from userspace, but that can be done later when somebody finds that the new 1MB is wrong for some special case applications. For now, add a kernel command line option (stack_guard_gap) to specify the stack gap size (in page units). Implementation wise, first delete all the old code for stack guard page: because although we could get away with accounting one extra page in a stack vma, accounting a larger gap can break userspace - case in point, a program run with "ulimit -S -v 20000" failed when the 1MB gap was counted for RLIMIT_AS; similar problems could come with RLIMIT_MLOCK and strict non-overcommit mode. Instead of keeping gap inside the stack vma, maintain the stack guard gap as a gap between vmas: using vm_start_gap() in place of vm_start (or vm_end_gap() in place of vm_end if VM_GROWSUP) in just those few places which need to respect the gap - mainly arch_get_unmapped_area(), and and the vma tree's subtree_gap support for that. Original-patch-by: Oleg Nesterov <oleg@redhat.com> Original-patch-by: Michal Hocko <mhocko@suse.com> Signed-off-by: Hugh Dickins <hughd@google.com> Acked-by: Michal Hocko <mhocko@suse.com> Tested-by: Helge Deller <deller@gmx.de> # parisc Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | x86/mm/gup: Switch GUP to the generic get_user_page_fast() implementationKirill A. Shutemov2017-06-131-5/+5
|/ | | | | | | | | | | | | | | | | | | | | | | | This patch provides all required callbacks required by the generic get_user_pages_fast() code and switches x86 over - and removes the platform specific implementation. Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-arch@vger.kernel.org Cc: linux-mm@kvack.org Link: http://lkml.kernel.org/r/20170606113133.22974-2-kirill.shutemov@linux.intel.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
* mm/hugetlb: report -EHWPOISON not -EFAULT when FOLL_HWPOISON is specifiedJames Morse2017-06-021-12/+8
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | KVM uses get_user_pages() to resolve its stage2 faults. KVM sets the FOLL_HWPOISON flag causing faultin_page() to return -EHWPOISON when it finds a VM_FAULT_HWPOISON. KVM handles these hwpoison pages as a special case. (check_user_page_hwpoison()) When huge pages are involved, this doesn't work so well. get_user_pages() calls follow_hugetlb_page(), which stops early if it receives VM_FAULT_HWPOISON from hugetlb_fault(), eventually returning -EFAULT to the caller. The step to map this to -EHWPOISON based on the FOLL_ flags is missing. The hwpoison special case is skipped, and -EFAULT is returned to user-space, causing Qemu or kvmtool to exit. Instead, move this VM_FAULT_ to errno mapping code into a header file and use it from faultin_page() and follow_hugetlb_page(). With this, KVM works as expected. This isn't a problem for arm64 today as we haven't enabled MEMORY_FAILURE, but I can't see any reason this doesn't happen on x86 too, so I think this should be a fix. This doesn't apply earlier than stable's v4.11.1 due to all sorts of cleanup. [james.morse@arm.com: add vm_fault_to_errno() call to faultin_page()] suggested. Link: http://lkml.kernel.org/r/20170525171035.16359-1-james.morse@arm.com [akpm@linux-foundation.org: coding-style fixes] Link: http://lkml.kernel.org/r/20170524160900.28786-1-james.morse@arm.com Signed-off-by: James Morse <james.morse@arm.com> Acked-by: Punit Agrawal <punit.agrawal@arm.com> Acked-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Cc: "Kirill A . Shutemov" <kirill.shutemov@linux.intel.com> Cc: <stable@vger.kernel.org> [4.11.1+] Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm/gup.c: fix access_ok() argument typeArnd Bergmann2017-05-031-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | MIPS just got changed to only accept a pointer argument for access_ok(), causing one warning in drivers/scsi/pmcraid.c. I tried changing x86 the same way and found the same warning in __get_user_pages_fast() and nowhere else in the kernel during randconfig testing: mm/gup.c: In function '__get_user_pages_fast': mm/gup.c:1578:6: error: passing argument 1 of '__chk_range_not_ok' makes pointer from integer without a cast [-Werror=int-conversion] It would probably be a good idea to enforce type-safety in general, so let's change this file to not cause a warning if we do that. I don't know why the warning did not appear on MIPS. Fixes: 2667f50e8b81 ("mm: introduce a general RCU get_user_pages_fast()") Link: http://lkml.kernel.org/r/20170421162659.3314521-1-arnd@arndb.de Signed-off-by: Arnd Bergmann <arnd@arndb.de> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Acked-by: Ingo Molnar <mingo@kernel.org> Cc: Michal Hocko <mhocko@suse.com> Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> Cc: Lorenzo Stoakes <lstoakes@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Revert "x86/mm/gup: Switch GUP to the generic get_user_page_fast() ↵Ingo Molnar2017-04-231-5/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | implementation" This reverts commit 2947ba054a4dabbd82848728d765346886050029. Dan Williams reported dax-pmem kernel warnings with the following signature: WARNING: CPU: 8 PID: 245 at lib/percpu-refcount.c:155 percpu_ref_switch_to_atomic_rcu+0x1f5/0x200 percpu ref (dax_pmem_percpu_release [dax_pmem]) <= 0 (0) after switching to atomic ... and bisected it to this commit, which suggests possible memory corruption caused by the x86 fast-GUP conversion. He also pointed out: " This is similar to the backtrace when we were not properly handling pud faults and was fixed with this commit: 220ced1676c4 "mm: fix get_user_pages() vs device-dax pud mappings" I've found some missing _devmap checks in the generic get_user_pages_fast() path, but this does not fix the regression [...] " So given that there are known bugs, and a pretty robust looking bisection points to this commit suggesting that are unknown bugs in the conversion as well, revert it for the time being - we'll re-try in v4.13. Reported-by: Dan Williams <dan.j.williams@intel.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Michal Hocko <mhocko@suse.cz> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rik van Riel <riel@redhat.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: aneesh.kumar@linux.vnet.ibm.com Cc: dann.frazier@canonical.com Cc: dave.hansen@intel.com Cc: steve.capper@linaro.org Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
* x86/mm/gup: Switch GUP to the generic get_user_page_fast() implementationKirill A. Shutemov2017-03-181-5/+5
| | | | | | | | | | | | | | | | | | | | | | | | | This patch provides all required callbacks required by the generic get_user_pages_fast() code and switches x86 over - and removes the platform specific implementation. Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Aneesh Kumar K . V <aneesh.kumar@linux.vnet.ibm.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Dann Frazier <dann.frazier@canonical.com> Cc: Dave Hansen <dave.hansen@intel.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rik van Riel <riel@redhat.com> Cc: Steve Capper <steve.capper@linaro.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-arch@vger.kernel.org Cc: linux-mm@kvack.org Link: http://lkml.kernel.org/r/20170316213906.89528-1-kirill.shutemov@linux.intel.com [ Minor readability edits. ] Signed-off-by: Ingo Molnar <mingo@kernel.org>
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