From: Christoph Hellwig <hch@lst.de>
To: "Dan Williams" <dan.j.williams@intel.com>,
"Jérôme Glisse" <jglisse@redhat.com>,
"Jason Gunthorpe" <jgg@mellanox.com>,
"Ben Skeggs" <bskeggs@redhat.com>
Cc: Ira Weiny <ira.weiny@intel.com>,
linux-mm@kvack.org, nouveau@lists.freedesktop.org,
dri-devel@lists.freedesktop.org, linux-nvdimm@lists.01.org,
linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: [PATCH 21/22] nouveau: unlock mmap_sem on all errors from nouveau_range_fault
Date: Mon, 1 Jul 2019 08:20:19 +0200 [thread overview]
Message-ID: <20190701062020.19239-22-hch@lst.de> (raw)
In-Reply-To: <20190701062020.19239-1-hch@lst.de>
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.
Signed-off-by: Christoph Hellwig <hch@lst.de>
---
drivers/gpu/drm/nouveau/nouveau_svm.c | 15 ++++++++-------
1 file changed, 8 insertions(+), 7 deletions(-)
diff --git a/drivers/gpu/drm/nouveau/nouveau_svm.c b/drivers/gpu/drm/nouveau/nouveau_svm.c
index e831f4184a17..c0cf7aeaefb3 100644
--- a/drivers/gpu/drm/nouveau/nouveau_svm.c
+++ b/drivers/gpu/drm/nouveau/nouveau_svm.c
@@ -500,8 +500,10 @@ 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, NOUVEAU_RANGE_FAULT_TIMEOUT)) {
/*
@@ -515,15 +517,14 @@ nouveau_range_fault(struct hmm_mirror *mirror, struct hmm_range *range,
ret = hmm_range_fault(range, block);
if (ret <= 0) {
- if (ret == -EBUSY || !ret) {
- /* Same as above, drop mmap_sem to match old API. */
- up_read(&range->vma->vm_mm->mmap_sem);
- ret = -EBUSY;
- } else if (ret == -EAGAIN)
+ if (ret == 0)
ret = -EBUSY;
+ if (ret != -EAGAIN)
+ up_read(&range->vma->vm_mm->mmap_sem);
hmm_range_unregister(range);
return ret;
}
+
return 0;
}
@@ -718,8 +719,8 @@ nouveau_svm_fault(struct nvif_notify *notify)
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.
--
2.20.1
next prev parent reply other threads:[~2019-07-01 6:21 UTC|newest]
Thread overview: 40+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-07-01 6:19 dev_pagemap related cleanups v4 Christoph Hellwig
2019-07-01 6:19 ` [PATCH 01/22] mm/hmm.c: suppress compilation warnings when CONFIG_HUGETLB_PAGE is not set Christoph Hellwig
2019-07-01 6:20 ` [PATCH 02/22] mm/hmm: update HMM documentation Christoph Hellwig
2019-07-01 6:20 ` [PATCH 03/22] mm/hmm: clean up some coding style and comments Christoph Hellwig
2019-07-01 6:20 ` [PATCH 04/22] mm/hmm: support automatic NUMA balancing Christoph Hellwig
2019-07-01 6:20 ` [PATCH 05/22] mm/hmm: Only set FAULT_FLAG_ALLOW_RETRY for non-blocking Christoph Hellwig
2019-07-01 6:20 ` [PATCH 06/22] mm/hmm: fix use after free with struct hmm in the mmu notifiers Christoph Hellwig
2019-07-01 6:20 ` [PATCH 07/22] mm/hmm: Use hmm_mirror not mm as an argument for hmm_range_register Christoph Hellwig
2019-07-01 6:20 ` [PATCH 08/22] mm/hmm: Hold a mmgrab from hmm to mm Christoph Hellwig
2019-07-01 6:20 ` [PATCH 09/22] mm/hmm: Simplify hmm_get_or_create and make it reliable Christoph Hellwig
2019-07-01 6:20 ` [PATCH 10/22] mm/hmm: Remove duplicate condition test before wait_event_timeout Christoph Hellwig
2019-07-01 6:20 ` [PATCH 11/22] mm/hmm: Do not use list*_rcu() for hmm->ranges Christoph Hellwig
2019-07-01 6:20 ` [PATCH 12/22] mm/hmm: Hold on to the mmget for the lifetime of the range Christoph Hellwig
2019-07-01 6:20 ` [PATCH 13/22] mm/hmm: Use lockdep instead of comments Christoph Hellwig
2019-07-01 6:20 ` [PATCH 14/22] mm/hmm: Remove racy protection against double-unregistration Christoph Hellwig
2019-07-01 6:20 ` [PATCH 15/22] mm/hmm: Poison hmm_range during unregister Christoph Hellwig
2019-07-01 6:20 ` [PATCH 16/22] mm/hmm: Remove confusing comment and logic from hmm_release Christoph Hellwig
2019-07-01 6:20 ` [PATCH 17/22] mm/hmm: Fix error flows in hmm_invalidate_range_start Christoph Hellwig
2019-07-01 6:20 ` [PATCH 18/22] mm: return valid info from hmm_range_unregister Christoph Hellwig
2019-07-03 17:22 ` Ralph Campbell
2019-07-01 6:20 ` [PATCH 19/22] mm: always return EBUSY for invalid ranges in hmm_range_{fault,snapshot} Christoph Hellwig
2019-07-02 21:43 ` Kuehling, Felix
2019-07-03 17:32 ` Ralph Campbell
2019-07-01 6:20 ` [PATCH 20/22] mm: move hmm_vma_fault to nouveau Christoph Hellwig
2019-07-03 17:48 ` Ralph Campbell
2019-07-03 17:50 ` [Nouveau] " Ilia Mirkin
2019-07-03 18:03 ` Jason Gunthorpe
2019-07-03 18:05 ` Christoph Hellwig
2019-07-03 18:13 ` Jason Gunthorpe
2019-07-01 6:20 ` Christoph Hellwig [this message]
2019-07-01 6:20 ` [PATCH 22/22] mm: remove the legacy hmm_pfn_* APIs Christoph Hellwig
2019-07-03 18:01 ` Jason Gunthorpe
2019-07-03 18:03 ` Christoph Hellwig
2019-07-03 18:15 ` Jason Gunthorpe
2019-07-01 8:25 ` dev_pagemap related cleanups v4 Christoph Hellwig
2019-07-02 18:42 ` Jason Gunthorpe
2019-07-02 22:45 ` Weiny, Ira
2019-07-02 22:47 ` Christoph Hellwig
2019-07-02 23:17 ` Dan Williams
2019-07-03 1:08 ` Jason Gunthorpe
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