From: Aaron Campbell Date: Sun, 3 Jul 2016 00:23:24 +0000 (-0300) Subject: iommu/vt-d: Fix infinite loop in free_all_cpu_cached_iovas X-Git-Url: http://git.cdn.openwrt.org/?a=commitdiff_plain;h=0caa7616a6aca449dd68b58cb29bd491d296c2d5;p=openwrt%2Fstaging%2Fblogic.git iommu/vt-d: Fix infinite loop in free_all_cpu_cached_iovas Per VT-d spec Section 10.4.2 ("Capability Register"), the maximum number of possible domains is 64K; indeed this is the maximum value that the cap_ndoms() macro will expand to. Since the value 65536 will not fix in a u16, the 'did' variable must be promoted to an int, otherwise the test for < 65536 will always be true and the loop will never end. The symptom, in my case, was a hung machine during suspend. Fixes: 3bd4f9112f87 ("iommu/vt-d: Fix overflow of iommu->domains array") Signed-off-by: Aaron Campbell Signed-off-by: Joerg Roedel --- diff --git a/drivers/iommu/intel-iommu.c b/drivers/iommu/intel-iommu.c index cfe410eedaf0..323dac9900ba 100644 --- a/drivers/iommu/intel-iommu.c +++ b/drivers/iommu/intel-iommu.c @@ -4602,13 +4602,13 @@ static void free_all_cpu_cached_iovas(unsigned int cpu) for (i = 0; i < g_num_of_iommus; i++) { struct intel_iommu *iommu = g_iommus[i]; struct dmar_domain *domain; - u16 did; + int did; if (!iommu) continue; for (did = 0; did < cap_ndoms(iommu->cap); did++) { - domain = get_iommu_domain(iommu, did); + domain = get_iommu_domain(iommu, (u16)did); if (!domain) continue;