Re: [PATCH 00/10] mm: adjust get_user_pages* functions to explicitly pass FOLL_* flags

Christian König
2016-10-13T07:32:51Z

Am 13.10.2016 um 02:20 schrieb Lorenzo Stoakes:
> This patch series adjusts functions in the get_user_pages* family such that
> desired FOLL_* flags are passed as an argument rather than implied by flags.
>
> The purpose of this change is to make the use of FOLL_FORCE explicit so it is
> easier to grep for and clearer to callers that this flag is being used. The use
> of FOLL_FORCE is an issue as it overrides missing VM_READ/VM_WRITE flags for the
> VMA whose pages we are reading from/writing to, which can result in surprising
> behaviour.
>
> The patch series came out of the discussion around commit 38e0885, which
> addressed a BUG_ON() being triggered when a page was faulted in with PROT_NONE
> set but having been overridden by FOLL_FORCE. do_numa_page() was run on the
> assumption the page _must_ be one marked for NUMA node migration as an actual
> PROT_NONE page would have been dealt with prior to this code path, however
> FOLL_FORCE introduced a situation where this assumption did not hold.
>
> See https://marc.info/?l=linux-mm&m=147585445805166 for the patch proposal.
>
> Lorenzo Stoakes (10):
> mm: remove write/force parameters from __get_user_pages_locked()
> mm: remove write/force parameters from __get_user_pages_unlocked()
> mm: replace get_user_pages_unlocked() write/force parameters with gup_flags
> mm: replace get_user_pages_locked() write/force parameters with gup_flags
> mm: replace get_vaddr_frames() write/force parameters with gup_flags
> mm: replace get_user_pages() write/force parameters with gup_flags
> mm: replace get_user_pages_remote() write/force parameters with gup_flags
> mm: replace __access_remote_vm() write parameter with gup_flags
> mm: replace access_remote_vm() write parameter with gup_flags
> mm: replace access_process_vm() write parameter with gup_flags

Patch number 6 in this series (which touches drivers I co-maintain) is
Acked-by: Christian König <christian.koenig@amd.com>.

In general looks like a very nice cleanup to me, but I'm not enlightened
enough to full judge.

Regards,
Christian.

>
> arch/alpha/kernel/ptrace.c | 9 ++--
> arch/blackfin/kernel/ptrace.c | 5 ++-
> arch/cris/arch-v32/drivers/cryptocop.c | 4 +-
> arch/cris/arch-v32/kernel/ptrace.c | 4 +-
> arch/ia64/kernel/err_inject.c | 2 +-
> arch/ia64/kernel/ptrace.c | 14 +++---
> arch/m32r/kernel/ptrace.c | 15 ++++---
> arch/mips/kernel/ptrace32.c | 5 ++-
> arch/mips/mm/gup.c | 2 +-
> arch/powerpc/kernel/ptrace32.c | 5 ++-
> arch/s390/mm/gup.c | 3 +-
> arch/score/kernel/ptrace.c | 10 +++--
> arch/sh/mm/gup.c | 3 +-
> arch/sparc/kernel/ptrace_64.c | 24 +++++++----
> arch/sparc/mm/gup.c | 3 +-
> arch/x86/kernel/step.c | 3 +-
> arch/x86/mm/gup.c | 2 +-
> arch/x86/mm/mpx.c | 5 +--
> arch/x86/um/ptrace_32.c | 3 +-
> arch/x86/um/ptrace_64.c | 3 +-
> drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c | 7 ++-
> drivers/gpu/drm/etnaviv/etnaviv_gem.c | 7 ++-
> drivers/gpu/drm/exynos/exynos_drm_g2d.c | 3 +-
> drivers/gpu/drm/i915/i915_gem_userptr.c | 6 ++-
> drivers/gpu/drm/radeon/radeon_ttm.c | 3 +-
> drivers/gpu/drm/via/via_dmablit.c | 4 +-
> drivers/infiniband/core/umem.c | 6 ++-
> drivers/infiniband/core/umem_odp.c | 7 ++-
> drivers/infiniband/hw/mthca/mthca_memfree.c | 2 +-
> drivers/infiniband/hw/qib/qib_user_pages.c | 3 +-
> drivers/infiniband/hw/usnic/usnic_uiom.c | 5 ++-
> drivers/media/pci/ivtv/ivtv-udma.c | 4 +-
> drivers/media/pci/ivtv/ivtv-yuv.c | 5 ++-
> drivers/media/platform/omap/omap_vout.c | 2 +-
> drivers/media/v4l2-core/videobuf-dma-sg.c | 7 ++-
> drivers/media/v4l2-core/videobuf2-memops.c | 6 ++-
> drivers/misc/mic/scif/scif_rma.c | 3 +-
> drivers/misc/sgi-gru/grufault.c | 2 +-
> drivers/platform/goldfish/goldfish_pipe.c | 3 +-
> drivers/rapidio/devices/rio_mport_cdev.c | 3 +-
> drivers/scsi/st.c | 5 +--
> .../interface/vchiq_arm/vchiq_2835_arm.c | 3 +-
> .../vc04_services/interface/vchiq_arm/vchiq_arm.c | 3 +-
> drivers/video/fbdev/pvr2fb.c | 4 +-
> drivers/virt/fsl_hypervisor.c | 4 +-
> fs/exec.c | 9 +++-
> fs/proc/base.c | 19 +++++---
> include/linux/mm.h | 18 ++++----
> kernel/events/uprobes.c | 6 ++-
> kernel/ptrace.c | 16 ++++---
> mm/frame_vector.c | 9 ++--
> mm/gup.c | 50 ++++++++++------------
> mm/memory.c | 16 ++++---
> mm/mempolicy.c | 2 +-
> mm/nommu.c | 38 +++++++---------
> mm/process_vm_access.c | 7 ++-
> mm/util.c | 8 ++--
> net/ceph/pagevec.c | 2 +-
> security/tomoyo/domain.c | 2 +-
> virt/kvm/async_pf.c | 3 +-
> virt/kvm/kvm_main.c | 11 +++--
> 61 files changed, 260 insertions(+), 187 deletions(-)
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