1 files changed, 32 insertions, 1 deletions

diff --git a/arch/x86/mm/pat.c b/arch/x86/mm/pat.c
index ef8b64b89c7d..e7ca7fc48d12 100644
--- a/arch/x86/mm/pat.c
+++ b/arch/x86/mm/pat.c
@@ -16,6 +16,7 @@
 #include <asm/msr.h>
 #include <asm/tlbflush.h>
 #include <asm/processor.h>
+#include <asm/page.h>
 #include <asm/pgtable.h>
 #include <asm/pat.h>
 #include <asm/e820.h>
@@ -334,7 +335,7 @@ int reserve_memtype(u64 start, u64 end, unsigned long req_type,
                                 break;
                         }
 
-                        printk("Overlap at 0x%Lx-0x%Lx\n",
+                        pr_debug("Overlap at 0x%Lx-0x%Lx\n",
                                saved_ptr->start, saved_ptr->end);
                         /* No conflict. Go ahead and add this new entry */
                         list_add(&new_entry->nd, saved_ptr->nd.prev);
@@ -477,6 +478,33 @@ pgprot_t phys_mem_access_prot(struct file *file, unsigned long pfn,
         return vma_prot;
 }
 
+#ifdef CONFIG_NONPROMISC_DEVMEM
+/* This check is done in drivers/char/mem.c in case of NONPROMISC_DEVMEM*/
+static inline int range_is_allowed(unsigned long pfn, unsigned long size)
+{
+        return 1;
+}
+#else
+static inline int range_is_allowed(unsigned long pfn, unsigned long size)
+{
+        u64 from = ((u64)pfn) << PAGE_SHIFT;
+        u64 to = from + size;
+        u64 cursor = from;
+
+        while (cursor < to) {
+                if (!devmem_is_allowed(pfn)) {
+                        printk(KERN_INFO
+                "Program %s tried to access /dev/mem between %Lx->%Lx.\n",
+                                current->comm, from, to);
+                        return 0;
+                }
+                cursor += PAGE_SIZE;
+                pfn++;
+        }
+        return 1;
+}
+#endif /* CONFIG_NONPROMISC_DEVMEM */
+
 int phys_mem_access_prot_allowed(struct file *file, unsigned long pfn,
                                 unsigned long size, pgprot_t *vma_prot)
 {
@@ -485,6 +513,9 @@ int phys_mem_access_prot_allowed(struct file *file, unsigned long pfn,
         unsigned long ret_flags;
         int retval;
 
+        if (!range_is_allowed(pfn, size))
+                return 0;
+
         if (file->f_flags & O_SYNC) {
                 flags = _PAGE_CACHE_UC;
         }