From 95ee14e4379c5e19c0897c872350570402014742 Mon Sep 17 00:00:00 2001 From: "H. Peter Anvin" Date: Tue, 9 Jun 2009 18:20:39 -0700 Subject: [PATCH] x86: cap iomem_resource to addressable physical memory iomem_resource is by default initialized to -1, which means 64 bits of physical address space if 64-bit resources are enabled. However, x86 CPUs cannot address 64 bits of physical address space. Thus, we want to cap the physical address space to what the union of all CPU can actually address. Without this patch, we may end up assigning inaccessible values to uninitialized 64-bit PCI memory resources. Signed-off-by: H. Peter Anvin Cc: Matthew Wilcox Cc: Jesse Barnes Cc: Martin Mares Cc: stable@kernel.org --- arch/x86/kernel/cpu/common.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c index 3ffdcfa9abdf..5b9cb8839cae 100644 --- a/arch/x86/kernel/cpu/common.c +++ b/arch/x86/kernel/cpu/common.c @@ -853,6 +853,9 @@ static void __cpuinit identify_cpu(struct cpuinfo_x86 *c) #if defined(CONFIG_NUMA) && defined(CONFIG_X86_64) numa_add_cpu(smp_processor_id()); #endif + + /* Cap the iomem address space to what is addressable on all CPUs */ + iomem_resource.end &= (1ULL << c->x86_phys_bits) - 1; } #ifdef CONFIG_X86_64 -- 2.20.1