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From: Sasha Levin <sashal@kernel.org>
To: linux-kernel@vger.kernel.org, stable@vger.kernel.org
Cc: Sasha Levin <sashal@kernel.org>,
	iommu@lists.linux-foundation.org, Frank <fgndev@posteo.de>,
	Joerg Roedel <jroedel@suse.de>
Subject: [PATCH AUTOSEL 5.4 395/459] iommu/vt-d: Remove unnecessary WARN_ON_ONCE()
Date: Fri, 14 Feb 2020 11:00:45 -0500
Message-ID: <20200214160149.11681-395-sashal@kernel.org> (raw)
In-Reply-To: <20200214160149.11681-1-sashal@kernel.org>

From: Lu Baolu <baolu.lu@linux.intel.com>

[ Upstream commit 857f081426e5aa38313426c13373730f1345fe95 ]

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>
Signed-off-by: Joerg Roedel <jroedel@suse.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/iommu/dmar.c | 1 -
 1 file changed, 1 deletion(-)

diff --git a/drivers/iommu/dmar.c b/drivers/iommu/dmar.c
index eecd6a4216672..7196cabafb252 100644
--- a/drivers/iommu/dmar.c
+++ b/drivers/iommu/dmar.c
@@ -1351,7 +1351,6 @@ 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
-- 
2.20.1

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Thread overview: 10+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
     [not found] <20200214160149.11681-1-sashal@kernel.org>
2020-02-14 15:54 ` [PATCH AUTOSEL 5.4 045/459] iommu/vt-d: Fix off-by-one in PASID allocation Sasha Levin
2020-02-14 15:57 ` [PATCH AUTOSEL 5.4 196/459] PCI: Add nr_devfns parameter to pci_add_dma_alias() Sasha Levin
2020-02-14 15:57 ` [PATCH AUTOSEL 5.4 220/459] iommu/amd: Check feature support bit before accessing MSI capability registers Sasha Levin
2020-02-14 15:57 ` [PATCH AUTOSEL 5.4 221/459] iommu/amd: Only support x2APIC with IVHD type 11h/40h Sasha Levin
2020-02-14 15:57 ` [PATCH AUTOSEL 5.4 222/459] iommu/iova: Silence warnings under memory pressure Sasha Levin
2020-02-14 15:58 ` [PATCH AUTOSEL 5.4 253/459] iommu/vt-d: Match CPU and IOMMU paging mode Sasha Levin
2020-02-14 15:58 ` [PATCH AUTOSEL 5.4 254/459] iommu/vt-d: Avoid sending invalid page response Sasha Levin
2020-02-14 15:58 ` [PATCH AUTOSEL 5.4 271/459] iommu/arm-smmu-v3: Populate VMID field for CMDQ_OP_TLBI_NH_VA Sasha Levin
2020-02-14 15:59 ` [PATCH AUTOSEL 5.4 322/459] iommu/arm-smmu-v3: Use WRITE_ONCE() when changing validity of an STE Sasha Levin
2020-02-14 16:00 ` Sasha Levin [this message]

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