user/sven/linux.git, branch v4.9.138

Linux 4.9.138

2018-11-21T08:26:04Z

KVM: arm64: Fix caching of host MDCR_EL2 value

2018-11-21T08:26:04Z

commit da5a3ce66b8bb51b0ea8a89f42aac153903f90fb upstream. At boot time, KVM stashes the host MDCR_EL2 value, but only does this when the kernel is not running in hyp mode (i.e. is non-VHE). In these cases, the stashed value of MDCR_EL2.HPMN happens to be zero, which can lead to CONSTRAINED UNPREDICTABLE behaviour. Since we use this value to derive the MDCR_EL2 value when switching to/from a guest, after a guest have been run, the performance counters do not behave as expected. This has been observed to result in accesses via PMXEVTYPER_EL0 and PMXEVCNTR_EL0 not affecting the relevant counters, resulting in events not being counted. In these cases, only the fixed-purpose cycle counter appears to work as expected. Fix this by always stashing the host MDCR_EL2 value, regardless of VHE. Cc: Christopher Dall Cc: James Morse Cc: Will Deacon Cc: stable@vger.kernel.org Fixes: 1e947bad0b63b351 ("arm64: KVM: Skip HYP setup when already running in HYP") Tested-by: Robin Murphy Signed-off-by: Mark Rutland Signed-off-by: Marc Zyngier Signed-off-by: Greg Kroah-Hartman

drm/i915/execlists: Force write serialisation into context image vs execution

2018-11-21T08:26:04Z

commit 0a823e8fd4fd67726697854578f3584ee3a49b1d upstream. Ensure that the writes into the context image are completed prior to the register mmio to trigger execution. Although previously we were assured by the SDM that all writes are flushed before an uncached memory transaction (our mmio write to submit the context to HW for execution), we have empirical evidence to believe that this is not actually the case. Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=108656 References: https://bugs.freedesktop.org/show_bug.cgi?id=108315 References: https://bugs.freedesktop.org/show_bug.cgi?id=106887 Signed-off-by: Chris Wilson Cc: Mika Kuoppala Cc: Tvrtko Ursulin Acked-by: Mika Kuoppala Link: https://patchwork.freedesktop.org/patch/msgid/20181108081740.25615-1-chris@chris-wilson.co.uk Cc: stable@vger.kernel.org (cherry picked from commit 987abd5c62f92ee4970b45aa077f47949974e615) Signed-off-by: Joonas Lahtinen Signed-off-by: Greg Kroah-Hartman

drm/i915/hdmi: Add HDMI 2.0 audio clock recovery N values

2018-11-21T08:26:04Z

commit 6503493145cba4413ecd3d4d153faeef4a1e9b85 upstream. HDMI 2.0 594Mhz modes were incorrectly selecting 25.200Mhz Automatic N value mode instead of HDMI specification values. V2: Fix 88.2 Hz N value Cc: Jani Nikula Cc: stable@vger.kernel.org Signed-off-by: Clint Taylor Signed-off-by: Jani Nikula Link: https://patchwork.freedesktop.org/patch/msgid/1540493521-1746-2-git-send-email-clinton.a.taylor@intel.com (cherry picked from commit 5a400aa3c562c4a726b4da286e63c96db905ade1) Signed-off-by: Joonas Lahtinen Signed-off-by: Greg Kroah-Hartman

drm/dp_mst: Check if primary mstb is null

2018-11-21T08:26:03Z

commit 23d8003907d094f77cf959228e2248d6db819fa7 upstream. Unfortunately drm_dp_get_mst_branch_device which is called from both drm_dp_mst_handle_down_rep and drm_dp_mst_handle_up_rep seem to rely on that mgr->mst_primary is not NULL, which seem to be wrong as it can be cleared with simultaneous mode set, if probing fails or in other case. mgr->lock mutex doesn't protect against that as it might just get assigned to NULL right before, not simultaneously. There are currently bugs 107738, 108616 bugs which crash in drm_dp_get_mst_branch_device, caused by this issue. v2: Refactored the code, as it was nicely noticed. Fixed Bugzilla bug numbers(second was 108616, but not 108816) and added links. [changed title and added stable cc] Signed-off-by: Lyude Paul Signed-off-by: Stanislav Lisovskiy Cc: stable@vger.kernel.org Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=108616 Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=107738 Link: https://patchwork.freedesktop.org/patch/msgid/20181109090012.24438-1-stanislav.lisovskiy@intel.com Signed-off-by: Greg Kroah-Hartman

drm/rockchip: Allow driver to be shutdown on reboot/kexec

2018-11-21T08:26:03Z

commit 7f3ef5dedb146e3d5063b6845781ad1bb59b92b5 upstream. Leaving the DRM driver enabled on reboot or kexec has the annoying effect of leaving the display generating transactions whilst the IOMMU has been shut down. In turn, the IOMMU driver (which shares its interrupt line with the VOP) starts warning either on shutdown or when entering the secondary kernel in the kexec case (nothing is expected on that front). A cheap way of ensuring that things are nicely shut down is to register a shutdown callback in the platform driver. Signed-off-by: Marc Zyngier Tested-by: Vicente Bergas Signed-off-by: Heiko Stuebner Link: https://patchwork.freedesktop.org/patch/msgid/20180805124807.18169-1-marc.zyngier@arm.com Cc: stable@vger.kernel.org Signed-off-by: Greg Kroah-Hartman

mm: migration: fix migration of huge PMD shared pages

2018-11-21T08:26:03Z

commit 017b1660df89f5fb4bfe66c34e35f7d2031100c7 upstream. The page migration code employs try_to_unmap() to try and unmap the source page. This is accomplished by using rmap_walk to find all vmas where the page is mapped. This search stops when page mapcount is zero. For shared PMD huge pages, the page map count is always 1 no matter the number of mappings. Shared mappings are tracked via the reference count of the PMD page. Therefore, try_to_unmap stops prematurely and does not completely unmap all mappings of the source page. This problem can result is data corruption as writes to the original source page can happen after contents of the page are copied to the target page. Hence, data is lost. This problem was originally seen as DB corruption of shared global areas after a huge page was soft offlined due to ECC memory errors. DB developers noticed they could reproduce the issue by (hotplug) offlining memory used to back huge pages. A simple testcase can reproduce the problem by creating a shared PMD mapping (note that this must be at least PUD_SIZE in size and PUD_SIZE aligned (1GB on x86)), and using migrate_pages() to migrate process pages between nodes while continually writing to the huge pages being migrated. To fix, have the try_to_unmap_one routine check for huge PMD sharing by calling huge_pmd_unshare for hugetlbfs huge pages. If it is a shared mapping it will be 'unshared' which removes the page table entry and drops the reference on the PMD page. After this, flush caches and TLB. mmu notifiers are called before locking page tables, but we can not be sure of PMD sharing until page tables are locked. Therefore, check for the possibility of PMD sharing before locking so that notifiers can prepare for the worst possible case. Link: http://lkml.kernel.org/r/20180823205917.16297-2-mike.kravetz@oracle.com [mike.kravetz@oracle.com: make _range_in_vma() a static inline] Link: http://lkml.kernel.org/r/6063f215-a5c8-2f0c-465a-2c515ddc952d@oracle.com Fixes: 39dde65c9940 ("shared page table for hugetlb page") Signed-off-by: Mike Kravetz Acked-by: Kirill A. Shutemov Reviewed-by: Naoya Horiguchi Acked-by: Michal Hocko Cc: Vlastimil Babka Cc: Davidlohr Bueso Cc: Jerome Glisse Cc: Mike Kravetz Cc: Signed-off-by: Andrew Morton Signed-off-by: Mike Kravetz Reviewed-by: Jérôme Glisse Acked-by: Michal Hocko Signed-off-by: Greg Kroah-Hartman

hugetlbfs: fix kernel BUG at fs/hugetlbfs/inode.c:444!

2018-11-21T08:26:03Z

commit 5e41540c8a0f0e98c337dda8b391e5dda0cde7cf upstream. This bug has been experienced several times by the Oracle DB team. The BUG is in remove_inode_hugepages() as follows: /* * If page is mapped, it was faulted in after being * unmapped in caller. Unmap (again) now after taking * the fault mutex. The mutex will prevent faults * until we finish removing the page. * * This race can only happen in the hole punch case. * Getting here in a truncate operation is a bug. */ if (unlikely(page_mapped(page))) { BUG_ON(truncate_op); In this case, the elevated map count is not the result of a race. Rather it was incorrectly incremented as the result of a bug in the huge pmd sharing code. Consider the following: - Process A maps a hugetlbfs file of sufficient size and alignment (PUD_SIZE) that a pmd page could be shared. - Process B maps the same hugetlbfs file with the same size and alignment such that a pmd page is shared. - Process B then calls mprotect() to change protections for the mapping with the shared pmd. As a result, the pmd is 'unshared'. - Process B then calls mprotect() again to chage protections for the mapping back to their original value. pmd remains unshared. - Process B then forks and process C is created. During the fork process, we do dup_mm -> dup_mmap -> copy_page_range to copy page tables. Copying page tables for hugetlb mappings is done in the routine copy_hugetlb_page_range. In copy_hugetlb_page_range(), the destination pte is obtained by: dst_pte = huge_pte_alloc(dst, addr, sz); If pmd sharing is possible, the returned pointer will be to a pte in an existing page table. In the situation above, process C could share with either process A or process B. Since process A is first in the list, the returned pte is a pointer to a pte in process A's page table. However, the check for pmd sharing in copy_hugetlb_page_range is: /* If the pagetables are shared don't copy or take references */ if (dst_pte == src_pte) continue; Since process C is sharing with process A instead of process B, the above test fails. The code in copy_hugetlb_page_range which follows assumes dst_pte points to a huge_pte_none pte. It copies the pte entry from src_pte to dst_pte and increments this map count of the associated page. This is how we end up with an elevated map count. To solve, check the dst_pte entry for huge_pte_none. If !none, this implies PMD sharing so do not copy. Link: http://lkml.kernel.org/r/20181105212315.14125-1-mike.kravetz@oracle.com Fixes: c5c99429fa57 ("fix hugepages leak due to pagetable page sharing") Signed-off-by: Mike Kravetz Reviewed-by: Naoya Horiguchi Cc: Michal Hocko Cc: Hugh Dickins Cc: Andrea Arcangeli Cc: "Kirill A . Shutemov" Cc: Davidlohr Bueso Cc: Prakash Sangappa Cc: Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman

lib/ubsan.c: don't mark __ubsan_handle_builtin_unreachable as noreturn

2018-11-21T08:26:03Z

commit 1c23b4108d716cc848b38532063a8aca4f86add8 upstream. gcc-8 complains about the prototype for this function: lib/ubsan.c:432:1: error: ignoring attribute 'noreturn' in declaration of a built-in function '__ubsan_handle_builtin_unreachable' because it conflicts with attribute 'const' [-Werror=attributes] This is actually a GCC's bug. In GCC internals __ubsan_handle_builtin_unreachable() declared with both 'noreturn' and 'const' attributes instead of only 'noreturn': https://gcc.gnu.org/bugzilla/show_bug.cgi?id=84210 Workaround this by removing the noreturn attribute. [aryabinin: add information about GCC bug in changelog] Link: http://lkml.kernel.org/r/20181107144516.4587-1-aryabinin@virtuozzo.com Signed-off-by: Arnd Bergmann Signed-off-by: Andrey Ryabinin Acked-by: Olof Johansson Cc: Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman

configfs: replace strncpy with memcpy

2018-11-21T08:26:03Z

commit 1823342a1f2b47a4e6f5667f67cd28ab6bc4d6cd upstream. gcc 8.1.0 complains: fs/configfs/symlink.c:67:3: warning: 'strncpy' output truncated before terminating nul copying as many bytes from a string as its length fs/configfs/symlink.c: In function 'configfs_get_link': fs/configfs/symlink.c:63:13: note: length computed here Using strncpy() is indeed less than perfect since the length of data to be copied has already been determined with strlen(). Replace strncpy() with memcpy() to address the warning and optimize the code a little. Signed-off-by: Guenter Roeck Signed-off-by: Christoph Hellwig Signed-off-by: Nobuhiro Iwamatsu Signed-off-by: Greg Kroah-Hartman