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author | Linus Torvalds <torvalds@linux-foundation.org> | 2020-06-09 09:54:46 -0700 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2020-06-09 09:54:46 -0700 |
commit | a5ad5742f671de906adbf29fbedf0a04705cebad (patch) | |
tree | 88d1a4c18e2025a5a8335dbbc9dea8bebeba5789 /drivers/vfio/pci/vfio_pci.c | |
parent | 013b2deba9a6b80ca02f4fafd7dedf875e9b4450 (diff) | |
parent | 4fa7252338a56fbc90220e6330f136a379175a7a (diff) | |
download | linux-a5ad5742f671de906adbf29fbedf0a04705cebad.tar.gz linux-a5ad5742f671de906adbf29fbedf0a04705cebad.tar.bz2 linux-a5ad5742f671de906adbf29fbedf0a04705cebad.zip |
Merge branch 'akpm' (patches from Andrew)
Merge even more updates from Andrew Morton:
- a kernel-wide sweep of show_stack()
- pagetable cleanups
- abstract out accesses to mmap_sem - prep for mmap_sem scalability work
- hch's user acess work
Subsystems affected by this patch series: debug, mm/pagemap, mm/maccess,
mm/documentation.
* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (93 commits)
include/linux/cache.h: expand documentation over __read_mostly
maccess: return -ERANGE when probe_kernel_read() fails
x86: use non-set_fs based maccess routines
maccess: allow architectures to provide kernel probing directly
maccess: move user access routines together
maccess: always use strict semantics for probe_kernel_read
maccess: remove strncpy_from_unsafe
tracing/kprobes: handle mixed kernel/userspace probes better
bpf: rework the compat kernel probe handling
bpf:bpf_seq_printf(): handle potentially unsafe format string better
bpf: handle the compat string in bpf_trace_copy_string better
bpf: factor out a bpf_trace_copy_string helper
maccess: unify the probe kernel arch hooks
maccess: remove probe_read_common and probe_write_common
maccess: rename strnlen_unsafe_user to strnlen_user_nofault
maccess: rename strncpy_from_unsafe_strict to strncpy_from_kernel_nofault
maccess: rename strncpy_from_unsafe_user to strncpy_from_user_nofault
maccess: update the top of file comment
maccess: clarify kerneldoc comments
maccess: remove duplicate kerneldoc comments
...
Diffstat (limited to 'drivers/vfio/pci/vfio_pci.c')
-rw-r--r-- | drivers/vfio/pci/vfio_pci.c | 22 |
1 files changed, 11 insertions, 11 deletions
diff --git a/drivers/vfio/pci/vfio_pci.c b/drivers/vfio/pci/vfio_pci.c index 3fc198f3eeb5..7c0779018b1b 100644 --- a/drivers/vfio/pci/vfio_pci.c +++ b/drivers/vfio/pci/vfio_pci.c @@ -1185,7 +1185,7 @@ reset_info_exit: /* * We need to get memory_lock for each device, but devices - * can share mmap_sem, therefore we need to zap and hold + * can share mmap_lock, therefore we need to zap and hold * the vma_lock for each device, and only then get each * memory_lock. */ @@ -1375,26 +1375,26 @@ static int vfio_pci_zap_and_vma_lock(struct vfio_pci_device *vdev, bool try) /* * Lock ordering: - * vma_lock is nested under mmap_sem for vm_ops callback paths. + * vma_lock is nested under mmap_lock for vm_ops callback paths. * The memory_lock semaphore is used by both code paths calling * into this function to zap vmas and the vm_ops.fault callback * to protect the memory enable state of the device. * - * When zapping vmas we need to maintain the mmap_sem => vma_lock + * When zapping vmas we need to maintain the mmap_lock => vma_lock * ordering, which requires using vma_lock to walk vma_list to - * acquire an mm, then dropping vma_lock to get the mmap_sem and + * acquire an mm, then dropping vma_lock to get the mmap_lock and * reacquiring vma_lock. This logic is derived from similar * requirements in uverbs_user_mmap_disassociate(). * - * mmap_sem must always be the top-level lock when it is taken. + * mmap_lock must always be the top-level lock when it is taken. * Therefore we can only hold the memory_lock write lock when - * vma_list is empty, as we'd need to take mmap_sem to clear + * vma_list is empty, as we'd need to take mmap_lock to clear * entries. vma_list can only be guaranteed empty when holding * vma_lock, thus memory_lock is nested under vma_lock. * * This enables the vm_ops.fault callback to acquire vma_lock, * followed by memory_lock read lock, while already holding - * mmap_sem without risk of deadlock. + * mmap_lock without risk of deadlock. */ while (1) { struct mm_struct *mm = NULL; @@ -1422,17 +1422,17 @@ static int vfio_pci_zap_and_vma_lock(struct vfio_pci_device *vdev, bool try) mutex_unlock(&vdev->vma_lock); if (try) { - if (!down_read_trylock(&mm->mmap_sem)) { + if (!mmap_read_trylock(mm)) { mmput(mm); return 0; } } else { - down_read(&mm->mmap_sem); + mmap_read_lock(mm); } if (mmget_still_valid(mm)) { if (try) { if (!mutex_trylock(&vdev->vma_lock)) { - up_read(&mm->mmap_sem); + mmap_read_unlock(mm); mmput(mm); return 0; } @@ -1454,7 +1454,7 @@ static int vfio_pci_zap_and_vma_lock(struct vfio_pci_device *vdev, bool try) } mutex_unlock(&vdev->vma_lock); } - up_read(&mm->mmap_sem); + mmap_read_unlock(mm); mmput(mm); } } |