From 4d45e75a9955ade5c2f49bd96fc4173b2cec9a72 Mon Sep 17 00:00:00 2001 From: Jann Horn Date: Thu, 15 Oct 2020 20:13:00 -0700 Subject: mm: remove the now-unnecessary mmget_still_valid() hack The preceding patches have ensured that core dumping properly takes the mmap_lock. Thanks to that, we can now remove mmget_still_valid() and all its users. Signed-off-by: Jann Horn Signed-off-by: Andrew Morton Acked-by: Linus Torvalds Cc: Christoph Hellwig Cc: Alexander Viro Cc: "Eric W . Biederman" Cc: Oleg Nesterov Cc: Hugh Dickins Link: http://lkml.kernel.org/r/20200827114932.3572699-8-jannh@google.com Signed-off-by: Linus Torvalds --- drivers/vfio/pci/vfio_pci.c | 38 ++++++++++++++++++-------------------- 1 file changed, 18 insertions(+), 20 deletions(-) (limited to 'drivers/vfio') diff --git a/drivers/vfio/pci/vfio_pci.c b/drivers/vfio/pci/vfio_pci.c index 1ab1f5cda4ac..b0f4b92a87ed 100644 --- a/drivers/vfio/pci/vfio_pci.c +++ b/drivers/vfio/pci/vfio_pci.c @@ -1480,31 +1480,29 @@ static int vfio_pci_zap_and_vma_lock(struct vfio_pci_device *vdev, bool try) } else { mmap_read_lock(mm); } - if (mmget_still_valid(mm)) { - if (try) { - if (!mutex_trylock(&vdev->vma_lock)) { - mmap_read_unlock(mm); - mmput(mm); - return 0; - } - } else { - mutex_lock(&vdev->vma_lock); + if (try) { + if (!mutex_trylock(&vdev->vma_lock)) { + mmap_read_unlock(mm); + mmput(mm); + return 0; } - list_for_each_entry_safe(mmap_vma, tmp, - &vdev->vma_list, vma_next) { - struct vm_area_struct *vma = mmap_vma->vma; + } else { + mutex_lock(&vdev->vma_lock); + } + list_for_each_entry_safe(mmap_vma, tmp, + &vdev->vma_list, vma_next) { + struct vm_area_struct *vma = mmap_vma->vma; - if (vma->vm_mm != mm) - continue; + if (vma->vm_mm != mm) + continue; - list_del(&mmap_vma->vma_next); - kfree(mmap_vma); + list_del(&mmap_vma->vma_next); + kfree(mmap_vma); - zap_vma_ptes(vma, vma->vm_start, - vma->vm_end - vma->vm_start); - } - mutex_unlock(&vdev->vma_lock); + zap_vma_ptes(vma, vma->vm_start, + vma->vm_end - vma->vm_start); } + mutex_unlock(&vdev->vma_lock); mmap_read_unlock(mm); mmput(mm); } -- cgit v1.2.3