From: Lu Baolu <baolu.lu@linux.intel.com> To: Joerg Roedel <joro@8bytes.org> Cc: baolu.lu@linux.intel.com, ashok.raj@intel.com, jacob.jun.pan@intel.com, kevin.tian@intel.com, iommu@lists.linux-foundation.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH 1/1] iommu/vt-d: Remove unnecessary WARN_ON_ONCE() Date: Sat, 18 Jan 2020 10:14:11 +0800 [thread overview] Message-ID: <b56e8a8f-acd7-b318-5a1c-f32c5a07657f@linux.intel.com> (raw) In-Reply-To: <20200117095953.GB15760@8bytes.org> Hi Joerg, On 1/17/20 5:59 PM, Joerg Roedel wrote: > On Thu, Jan 16, 2020 at 09:52:36AM +0800, Lu Baolu wrote: >> 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> > > Does this need a Fixes and/or stable tag? > This doesn't cause any errors, just an unnecessary checking of "0 & ((1UL << 64) - 1)" in some cases. > > Regards, > > Joerg Best regards, baolu
WARNING: multiple messages have this Message-ID (diff)
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: Re: [PATCH 1/1] iommu/vt-d: Remove unnecessary WARN_ON_ONCE() Date: Sat, 18 Jan 2020 10:14:11 +0800 [thread overview] Message-ID: <b56e8a8f-acd7-b318-5a1c-f32c5a07657f@linux.intel.com> (raw) In-Reply-To: <20200117095953.GB15760@8bytes.org> Hi Joerg, On 1/17/20 5:59 PM, Joerg Roedel wrote: > On Thu, Jan 16, 2020 at 09:52:36AM +0800, Lu Baolu wrote: >> 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> > > Does this need a Fixes and/or stable tag? > This doesn't cause any errors, just an unnecessary checking of "0 & ((1UL << 64) - 1)" in some cases. > > Regards, > > Joerg Best regards, baolu _______________________________________________ iommu mailing list iommu@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/iommu
next prev parent reply other threads:[~2020-01-18 2:15 UTC|newest] Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top 2020-01-16 1:52 [PATCH 1/1] iommu/vt-d: Remove unnecessary WARN_ON_ONCE() Lu Baolu 2020-01-16 1:52 ` Lu Baolu 2020-01-17 9:59 ` Joerg Roedel 2020-01-17 9:59 ` Joerg Roedel 2020-01-18 2:14 ` Lu Baolu [this message] 2020-01-18 2:14 ` Lu Baolu 2020-01-24 14:36 ` Joerg Roedel 2020-01-24 14:36 ` Joerg Roedel
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