From: Lu Baolu <baolu.lu@linux.intel.com>
To: Joerg Roedel <joro@8bytes.org>
Cc: kevin.tian@intel.com, ashok.raj@intel.com,
linux-kernel@vger.kernel.org, iommu@lists.linux-foundation.org,
jacob.jun.pan@intel.com
Subject: [PATCH 1/1] iommu/vt-d: Remove unnecessary WARN_ON_ONCE()
Date: Thu, 16 Jan 2020 09:52:36 +0800 [thread overview]
Message-ID: <20200116015236.4458-1-baolu.lu@linux.intel.com> (raw)
Address field in device TLB invalidation descriptor is qualified
by the S field. If S field is zero, a single page at page address
specified by address [63:12] is requested to be invalidated. If S
field is set, the least significant bit in the address field with
value 0b (say bit N) indicates the invalidation address range. The
spec doesn't require the address [N - 1, 0] to be cleared, hence
remove the unnecessary WARN_ON_ONCE().
Otherwise, the caller might set "mask = MAX_AGAW_PFN_WIDTH" in order
to invalidating all the cached mappings on an endpoint, and below
overflow error will be triggered.
[...]
UBSAN: Undefined behaviour in drivers/iommu/dmar.c:1354:3
shift exponent 64 is too large for 64-bit type 'long long unsigned int'
[...]
Reported-and-tested-by: Frank <fgndev@posteo.de>
Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
---
drivers/iommu/dmar.c | 1 -
1 file changed, 1 deletion(-)
diff --git a/drivers/iommu/dmar.c b/drivers/iommu/dmar.c
index 613b7153905d..071bb42bbbc5 100644
--- a/drivers/iommu/dmar.c
+++ b/drivers/iommu/dmar.c
@@ -1354,7 +1354,6 @@ void qi_flush_dev_iotlb(struct intel_iommu *iommu, u16 sid, u16 pfsid,
struct qi_desc desc;
if (mask) {
- WARN_ON_ONCE(addr & ((1ULL << (VTD_PAGE_SHIFT + mask)) - 1));
addr |= (1ULL << (VTD_PAGE_SHIFT + mask - 1)) - 1;
desc.qw1 = QI_DEV_IOTLB_ADDR(addr) | QI_DEV_IOTLB_SIZE;
} else
--
2.17.1
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next reply other threads:[~2020-01-16 1:54 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-01-16 1:52 Lu Baolu [this message]
2020-01-17 9:59 ` [PATCH 1/1] iommu/vt-d: Remove unnecessary WARN_ON_ONCE() Joerg Roedel
2020-01-18 2:14 ` Lu Baolu
2020-01-24 14:36 ` Joerg Roedel
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