From de4ee728465f7c0c29241550e083139b2ce9159c Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Wed, 24 Jul 2019 08:52:55 +0200 Subject: nouveau: unlock mmap_sem on all errors from nouveau_range_fault Currently nouveau_svm_fault expects nouveau_range_fault to never unlock mmap_sem, but the latter unlocks it for a random selection of error codes. Fix this up by always unlocking mmap_sem for non-zero return values in nouveau_range_fault, and only unlocking it in the caller for successful returns. Link: https://lore.kernel.org/r/20190724065258.16603-5-hch@lst.de Tested-by: Ralph Campbell Signed-off-by: Christoph Hellwig Reviewed-by: Jason Gunthorpe Signed-off-by: Jason Gunthorpe --- drivers/gpu/drm/nouveau/nouveau_svm.c | 11 ++++++----- 1 file changed, 6 insertions(+), 5 deletions(-) (limited to 'drivers') diff --git a/drivers/gpu/drm/nouveau/nouveau_svm.c b/drivers/gpu/drm/nouveau/nouveau_svm.c index e3097492b4ad..a835cebb6d90 100644 --- a/drivers/gpu/drm/nouveau/nouveau_svm.c +++ b/drivers/gpu/drm/nouveau/nouveau_svm.c @@ -495,8 +495,10 @@ nouveau_range_fault(struct hmm_mirror *mirror, struct hmm_range *range) ret = hmm_range_register(range, mirror, range->start, range->end, PAGE_SHIFT); - if (ret) + if (ret) { + up_read(&range->vma->vm_mm->mmap_sem); return (int)ret; + } if (!hmm_range_wait_until_valid(range, HMM_RANGE_DEFAULT_TIMEOUT)) { up_read(&range->vma->vm_mm->mmap_sem); @@ -505,10 +507,9 @@ nouveau_range_fault(struct hmm_mirror *mirror, struct hmm_range *range) ret = hmm_range_fault(range, true); if (ret <= 0) { - if (ret == -EBUSY || !ret) { - up_read(&range->vma->vm_mm->mmap_sem); + if (ret == 0) ret = -EBUSY; - } + up_read(&range->vma->vm_mm->mmap_sem); hmm_range_unregister(range); return ret; } @@ -706,8 +707,8 @@ again: NULL); svmm->vmm->vmm.object.client->super = false; mutex_unlock(&svmm->mutex); + up_read(&svmm->mm->mmap_sem); } - up_read(&svmm->mm->mmap_sem); /* Cancel any faults in the window whose pages didn't manage * to keep their valid bit, or stay writeable when required. -- cgit v1.2.3