kernel/git/stable/linux.git/arch/xtensa, branch linux-4.11.y

mm: larger stack guard gap, between vmas

2017-06-24T05:06:22+00:00

commit 1be7107fbe18eed3e319a6c3e83c78254b693acb upstream. 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 Original-patch-by: Michal Hocko Signed-off-by: Hugh Dickins Acked-by: Michal Hocko Tested-by: Helge Deller # parisc Signed-off-by: Linus Torvalds [wt: backport to 4.11: adjust context] Signed-off-by: Willy Tarreau Signed-off-by: Greg Kroah-Hartman

xtensa: don't use linux IRQ #0

2017-06-17T04:44:18+00:00

commit e5c86679d5e864947a52fb31e45a425dea3e7fa9 upstream. Linux IRQ #0 is reserved for error reporting and may not be used. Increase NR_IRQS for one additional slot and increase irq_domain_add_legacy parameter first_irq value to 1, so that linux IRQ #0 is not associated with hardware IRQ #0 in legacy IRQ domains. Introduce macro XTENSA_PIC_LINUX_IRQ for static translation of xtensa PIC hardware IRQ # to linux IRQ #. Use this macro in XTFPGA platform data definitions. This fixes inability to use hardware IRQ #0 in configurations that don't use device tree and allows for non-identity mapping between linux IRQ # and hardware IRQ #. Signed-off-by: Max Filippov Signed-off-by: Greg Kroah-Hartman

xtensa: wire up statx system call

2017-03-31T23:26:21+00:00

Signed-off-by: Max Filippov

xtensa: fix stack dump output

2017-03-31T22:58:40+00:00

Use %pB in pr_cont format string instead of calling print_symbol separately. It turns [ 19.166249] Call Trace: [ 19.167265] [] [ 19.167843] __warn+0x92/0xa0 [ 19.169656] [] [ 19.170059] warn_slowpath_fmt+0x3c/0x40 [ 19.171934] [] back into [ 18.123240] Call Trace: [ 18.125039] [] __warn+0x92/0xa0 [ 18.126961] [] warn_slowpath_fmt+0x3c/0x40 Signed-off-by: Max Filippov

xtensa: make __pa work with uncached KSEG addresses

2017-03-30T20:29:20+00:00

When __pa is applied to virtual address in uncached KSEG region the result is incorrect. Fix it by checking if the original address is in the uncached KSEG and adjusting the result. It looks better than masking off bits because pfn_valid would correctly work with new __pa results and it may be made working in noMMU case, once we get definition for uncached memory view. This is required for the dma_common_mmap and DMA debug code to work correctly: they both indirectly use __pa with coherent DMA addresses. In case of DMA debug the visible effect is false reports that an address mapped for DMA is accessed by CPU. Cc: stable@vger.kernel.org Tested-by: Boris Brezillon Reviewed-by: Boris Brezillon Signed-off-by: Max Filippov

arch, mm: convert all architectures to use 5level-fixup.h

2017-03-09T19:48:47+00:00

If an architecture uses 4level-fixup.h we don't need to do anything as it includes 5level-fixup.h. If an architecture uses pgtable-nop*d.h, define __ARCH_USE_5LEVEL_HACK before inclusion of the header. It makes asm-generic code to use 5level-fixup.h. If an architecture has 4-level paging or folds levels on its own, include 5level-fixup.h directly. Signed-off-by: Kirill A. Shutemov Acked-by: Michal Hocko Signed-off-by: Linus Torvalds

Merge tag 'xtensa-20170303' of git://github.com/jcmvbkbc/linux-xtensa

2017-03-04T00:17:55+00:00

Pull Xtensa updates from Max Filippov: - clean up bootable image build targets: provide separate 'Image', 'zImage' and 'uImage' make targets that only build corresponding image type. Make 'all' build all images appropriate for a platform - allow merging vectors code into .text section as a preparation step for XIP support - fix handling external FDT when the kernel is built without BLK_DEV_INITRD support * tag 'xtensa-20170303' of git://github.com/jcmvbkbc/linux-xtensa: xtensa: allow merging vectors into .text section xtensa: clean up bootable image build targets xtensa: move parse_tag_fdt out of #ifdef CONFIG_BLK_DEV_INITRD

sched/headers: Move task->mm handling methods to

2017-03-03T00:43:28+00:00

Move the following task->mm helper APIs into a new header file, , to further reduce the size and complexity of . Here are how the APIs are used in various kernel files: # mm_alloc(): arch/arm/mach-rpc/ecard.c fs/exec.c include/linux/sched/mm.h kernel/fork.c # __mmdrop(): arch/arc/include/asm/mmu_context.h include/linux/sched/mm.h kernel/fork.c # mmdrop(): arch/arm/mach-rpc/ecard.c arch/m68k/sun3/mmu_emu.c arch/x86/mm/tlb.c drivers/gpu/drm/amd/amdkfd/kfd_process.c drivers/gpu/drm/i915/i915_gem_userptr.c drivers/infiniband/hw/hfi1/file_ops.c drivers/vfio/vfio_iommu_spapr_tce.c fs/exec.c fs/proc/base.c fs/proc/task_mmu.c fs/proc/task_nommu.c fs/userfaultfd.c include/linux/mmu_notifier.h include/linux/sched/mm.h kernel/fork.c kernel/futex.c kernel/sched/core.c mm/khugepaged.c mm/ksm.c mm/mmu_context.c mm/mmu_notifier.c mm/oom_kill.c virt/kvm/kvm_main.c # mmdrop_async_fn(): include/linux/sched/mm.h # mmdrop_async(): include/linux/sched/mm.h kernel/fork.c # mmget_not_zero(): fs/userfaultfd.c include/linux/sched/mm.h mm/oom_kill.c # mmput(): arch/arc/include/asm/mmu_context.h arch/arc/kernel/troubleshoot.c arch/frv/mm/mmu-context.c arch/powerpc/platforms/cell/spufs/context.c arch/sparc/include/asm/mmu_context_32.h drivers/android/binder.c drivers/gpu/drm/etnaviv/etnaviv_gem.c drivers/gpu/drm/i915/i915_gem_userptr.c drivers/infiniband/core/umem.c drivers/infiniband/core/umem_odp.c drivers/infiniband/core/uverbs_main.c drivers/infiniband/hw/mlx4/main.c drivers/infiniband/hw/mlx5/main.c drivers/infiniband/hw/usnic/usnic_uiom.c drivers/iommu/amd_iommu_v2.c drivers/iommu/intel-svm.c drivers/lguest/lguest_user.c drivers/misc/cxl/fault.c drivers/misc/mic/scif/scif_rma.c drivers/oprofile/buffer_sync.c drivers/vfio/vfio_iommu_type1.c drivers/vhost/vhost.c drivers/xen/gntdev.c fs/exec.c fs/proc/array.c fs/proc/base.c fs/proc/task_mmu.c fs/proc/task_nommu.c fs/userfaultfd.c include/linux/sched/mm.h kernel/cpuset.c kernel/events/core.c kernel/events/uprobes.c kernel/exit.c kernel/fork.c kernel/ptrace.c kernel/sys.c kernel/trace/trace_output.c kernel/tsacct.c mm/memcontrol.c mm/memory.c mm/mempolicy.c mm/migrate.c mm/mmu_notifier.c mm/nommu.c mm/oom_kill.c mm/process_vm_access.c mm/rmap.c mm/swapfile.c mm/util.c virt/kvm/async_pf.c # mmput_async(): include/linux/sched/mm.h kernel/fork.c mm/oom_kill.c # get_task_mm(): arch/arc/kernel/troubleshoot.c arch/powerpc/platforms/cell/spufs/context.c drivers/android/binder.c drivers/gpu/drm/etnaviv/etnaviv_gem.c drivers/infiniband/core/umem.c drivers/infiniband/core/umem_odp.c drivers/infiniband/hw/mlx4/main.c drivers/infiniband/hw/mlx5/main.c drivers/infiniband/hw/usnic/usnic_uiom.c drivers/iommu/amd_iommu_v2.c drivers/iommu/intel-svm.c drivers/lguest/lguest_user.c drivers/misc/cxl/fault.c drivers/misc/mic/scif/scif_rma.c drivers/oprofile/buffer_sync.c drivers/vfio/vfio_iommu_type1.c drivers/vhost/vhost.c drivers/xen/gntdev.c fs/proc/array.c fs/proc/base.c fs/proc/task_mmu.c include/linux/sched/mm.h kernel/cpuset.c kernel/events/core.c kernel/exit.c kernel/fork.c kernel/ptrace.c kernel/sys.c kernel/trace/trace_output.c kernel/tsacct.c mm/memcontrol.c mm/memory.c mm/mempolicy.c mm/migrate.c mm/mmu_notifier.c mm/nommu.c mm/util.c # mm_access(): fs/proc/base.c include/linux/sched/mm.h kernel/fork.c mm/process_vm_access.c # mm_release(): arch/arc/include/asm/mmu_context.h fs/exec.c include/linux/sched/mm.h include/uapi/linux/sched.h kernel/exit.c kernel/fork.c Acked-by: Linus Torvalds Cc: Mike Galbraith Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar

sched/headers: Prepare to move kstack_end() from to

2017-03-02T07:42:39+00:00

But first update the usage sites with the new header dependency. Acked-by: Linus Torvalds Cc: Mike Galbraith Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar

sched/headers: Prepare to remove the dependency from

2017-03-02T07:42:37+00:00

Update code that relied on sched.h including various MM types for them. This will allow us to remove the include from . Acked-by: Linus Torvalds Cc: Mike Galbraith Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar