From: Sheng Yang <sheng@linux.intel.com>
To: Jan Kiszka <jan.kiszka@web.de>
Cc: Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
kvm <kvm@vger.kernel.org>, Avi Kivity <avi@redhat.com>,
Marcelo Tosatti <mtosatti@redhat.com>,
iommu@lists.linux-foundation.org,
David Woodhouse <dwmw2@infradead.org>
Subject: Re: [PATCH] intel-iommu: Fix use after release during device attach
Date: Tue, 2 Nov 2010 15:31:22 +0800 [thread overview]
Message-ID: <201011021531.22886.sheng@linux.intel.com> (raw)
In-Reply-To: <4CCFB84F.6050102@web.de>
On Tuesday 02 November 2010 15:05:51 Jan Kiszka wrote:
> From: Jan Kiszka <jan.kiszka@siemens.com>
>
> Obtail the new pgd pointer before releasing the page containing this
> value.
>
> Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
> ---
>
> Who is taking care of this? The kvm tree?
>
> drivers/pci/intel-iommu.c | 2 +-
> 1 files changed, 1 insertions(+), 1 deletions(-)
>
> diff --git a/drivers/pci/intel-iommu.c b/drivers/pci/intel-iommu.c
> index 4789f8e..35463dd 100644
> --- a/drivers/pci/intel-iommu.c
> +++ b/drivers/pci/intel-iommu.c
> @@ -3627,9 +3627,9 @@ static int intel_iommu_attach_device(struct
> iommu_domain *domain,
>
> pte = dmar_domain->pgd;
> if (dma_pte_present(pte)) {
> - free_pgtable_page(dmar_domain->pgd);
> dmar_domain->pgd = (struct dma_pte *)
> phys_to_virt(dma_pte_addr(pte));
> + free_pgtable_page(pte);
> }
> dmar_domain->agaw--;
> }
Reviewed-by: Sheng Yang <sheng@linux.intel.com>
CC iommu mailing list and David.
OK, Jan, I got your meaning now. And it's not the exactly swap. :)
I think the old code is safe, seems it's broken(exposed) by:
commit 1a8bd481bfba30515b54368d90a915db3faf302f
Author: David Woodhouse <David.Woodhouse@intel.com>
Date: Tue Aug 10 01:38:53 2010 +0100
intel-iommu: Fix 32-bit build warning with __cmpxchg()
drivers/pci/intel-iommu.c: In function 'dma_pte_addr':
drivers/pci/intel-iommu.c:239: warning: passing argument 1 of '__cmpxchg64'
from incompatible pointer typ
It seems that __cmpxchg64() now cares about the type of its pointer argument,
so give it a (uint64_t *) instead of a pointer to a structure which contains
only that.
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
diff --git a/drivers/pci/intel-iommu.c b/drivers/pci/intel-iommu.c
index c9171be..603cdc0 100644
--- a/drivers/pci/intel-iommu.c
+++ b/drivers/pci/intel-iommu.c
@@ -236,7 +236,7 @@ static inline u64 dma_pte_addr(struct dma_pte *pte)
return pte->val & VTD_PAGE_MASK;
#else
/* Must have a full atomic 64-bit read */
- return __cmpxchg64(pte, 0ULL, 0ULL) & VTD_PAGE_MASK;
+ return __cmpxchg64(&pte->val, 0ULL, 0ULL) & VTD_PAGE_MASK;
#endif
}
Seems here is the only affected code?
--
regards
Yang, Sheng
next prev parent reply other threads:[~2010-11-02 7:31 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-11-02 7:05 [PATCH] intel-iommu: Fix use after release during device attach Jan Kiszka
2010-11-02 7:31 ` Sheng Yang [this message]
2010-11-02 7:46 ` Jan Kiszka
2010-11-02 7:57 ` Sheng Yang
2010-11-02 8:00 ` Sheng Yang
2010-11-14 9:18 ` Jan Kiszka
2010-12-10 8:36 ` Jan Kiszka
2010-12-10 18:44 ` Chris Wright
2011-01-04 10:42 ` Jan Kiszka
2011-04-21 12:32 ` [PATCH v2] " Jan Kiszka
2011-04-21 14:02 ` Chris Wright
2011-04-21 14:28 ` Alex Williamson
2011-04-21 15:42 ` David Woodhouse
2011-04-21 16:14 ` Alex Williamson
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