From 08ddddda667b3b7aaac10641418283f78118c5cd Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Mon, 16 Mar 2020 20:32:16 +0100 Subject: mm/hmm: check the device private page owner in hmm_range_fault() hmm_range_fault() will succeed for any kind of device private memory, even if it doesn't belong to the calling entity. While nouveau has some crude checks for that, they are broken because they assume nouveau is the only user of device private memory. Fix this by passing in an expected pgmap owner in the hmm_range_fault structure. If a device_private page is found and doesn't match the owner then it is treated as an non-present and non-faultable page. This prevents a bug in amdgpu, where it doesn't know how to handle device_private pages, but hmm_range_fault would return them anyhow. Fixes: 4ef589dc9b10 ("mm/hmm/devmem: device memory hotplug using ZONE_DEVICE") Link: https://lore.kernel.org/r/20200316193216.920734-5-hch@lst.de Signed-off-by: Christoph Hellwig Reviewed-by: Jason Gunthorpe Reviewed-by: Ralph Campbell Signed-off-by: Jason Gunthorpe --- include/linux/hmm.h | 2 ++ 1 file changed, 2 insertions(+) (limited to 'include/linux/hmm.h') diff --git a/include/linux/hmm.h b/include/linux/hmm.h index 5e6034f105c3..bb6be4428633 100644 --- a/include/linux/hmm.h +++ b/include/linux/hmm.h @@ -132,6 +132,7 @@ enum hmm_pfn_value_e { * @pfn_flags_mask: allows to mask pfn flags so that only default_flags matter * @pfn_shifts: pfn shift value (should be <= PAGE_SHIFT) * @valid: pfns array did not change since it has been fill by an HMM function + * @dev_private_owner: owner of device private pages */ struct hmm_range { struct mmu_interval_notifier *notifier; @@ -144,6 +145,7 @@ struct hmm_range { uint64_t default_flags; uint64_t pfn_flags_mask; uint8_t pfn_shift; + void *dev_private_owner; }; /* -- cgit