9 files changed, 176 insertions, 19 deletions

diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt
index 0b3f6711d2f1..0072fabb1dd1 100644
--- a/Documentation/kernel-parameters.txt
+++ b/Documentation/kernel-parameters.txt
@@ -918,6 +918,10 @@ and is between 256 and 4096 characters. It is defined in the file
 
         inttest=        [IA64]
 
+        iomem=          Disable strict checking of access to MMIO memory
+                strict  regions from userspace.
+                relaxed
+
         iommu=          [x86]
                 off
                 force
diff --git a/arch/x86/mm/init_32.c b/arch/x86/mm/init_32.c
index 544d724caeee..88f1b10de3be 100644
--- a/arch/x86/mm/init_32.c
+++ b/arch/x86/mm/init_32.c
@@ -328,6 +328,8 @@ int devmem_is_allowed(unsigned long pagenr)
 {
         if (pagenr <= 256)
                 return 1;
+        if (iomem_is_exclusive(pagenr << PAGE_SHIFT))
+                return 0;
         if (!page_is_ram(pagenr))
                 return 1;
         return 0;
diff --git a/arch/x86/mm/init_64.c b/arch/x86/mm/init_64.c
index 54c437e96541..23f68e77ad1f 100644
--- a/arch/x86/mm/init_64.c
+++ b/arch/x86/mm/init_64.c
@@ -888,6 +888,8 @@ int devmem_is_allowed(unsigned long pagenr)
 {
         if (pagenr <= 256)
                 return 1;
+        if (iomem_is_exclusive(pagenr << PAGE_SHIFT))
+                return 0;
         if (!page_is_ram(pagenr))
                 return 1;
         return 0;
diff --git a/drivers/net/e1000e/netdev.c b/drivers/net/e1000e/netdev.c
index d4639facd1bd..91817d0afcaf 100644
--- a/drivers/net/e1000e/netdev.c
+++ b/drivers/net/e1000e/netdev.c
@@ -4807,7 +4807,7 @@ static int __devinit e1000_probe(struct pci_dev *pdev,
                 }
         }
 
-        err = pci_request_selected_regions(pdev,
+        err = pci_request_selected_regions_exclusive(pdev,
                                           pci_select_bars(pdev, IORESOURCE_MEM),
                                           e1000e_driver_name);
         if (err)
diff --git a/drivers/pci/pci-sysfs.c b/drivers/pci/pci-sysfs.c
index 388440e0d222..d5cdccf27a69 100644
--- a/drivers/pci/pci-sysfs.c
+++ b/drivers/pci/pci-sysfs.c
@@ -620,6 +620,9 @@ pci_mmap_resource(struct kobject *kobj, struct bin_attribute *attr,
         vma->vm_pgoff += start >> PAGE_SHIFT;
         mmap_type = res->flags & IORESOURCE_MEM ? pci_mmap_mem : pci_mmap_io;
 
+        if (res->flags & IORESOURCE_MEM && iomem_is_exclusive(start))
+                return -EINVAL;
+
         return pci_mmap_page_range(pdev, vma, mmap_type, write_combine);
 }
 
diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
index 2cfa41e367a7..47663dc0daf7 100644
--- a/drivers/pci/pci.c
+++ b/drivers/pci/pci.c
@@ -1395,7 +1395,8 @@ void pci_release_region(struct pci_dev *pdev, int bar)
  *      Returns 0 on success, or %EBUSY on error.  A warning
  *      message is also printed on failure.
  */
-int pci_request_region(struct pci_dev *pdev, int bar, const char *res_name)
+static int __pci_request_region(struct pci_dev *pdev, int bar, const char *res_name,
+                                                                        int exclusive)
 {
         struct pci_devres *dr;
 
@@ -1408,8 +1409,9 @@ int pci_request_region(struct pci_dev *pdev, int bar, const char *res_name)
                         goto err_out;
         }
         else if (pci_resource_flags(pdev, bar) & IORESOURCE_MEM) {
-                if (!request_mem_region(pci_resource_start(pdev, bar),
-                                        pci_resource_len(pdev, bar), res_name))
+                if (!__request_mem_region(pci_resource_start(pdev, bar),
+                                        pci_resource_len(pdev, bar), res_name,
+                                        exclusive))
                         goto err_out;
         }
 
@@ -1428,6 +1430,47 @@ err_out:
 }
 
 /**
+ *      pci_request_region - Reserved PCI I/O and memory resource
+ *      @pdev: PCI device whose resources are to be reserved
+ *      @bar: BAR to be reserved
+ *      @res_name: Name to be associated with resource.
+ *
+ *      Mark the PCI region associated with PCI device @pdev BR @bar as
+ *      being reserved by owner @res_name.  Do not access any
+ *      address inside the PCI regions unless this call returns
+ *      successfully.
+ *
+ *      Returns 0 on success, or %EBUSY on error.  A warning
+ *      message is also printed on failure.
+ */
+int pci_request_region(struct pci_dev *pdev, int bar, const char *res_name)
+{
+        return __pci_request_region(pdev, bar, res_name, 0);
+}
+
+/**
+ *      pci_request_region_exclusive - Reserved PCI I/O and memory resource
+ *      @pdev: PCI device whose resources are to be reserved
+ *      @bar: BAR to be reserved
+ *      @res_name: Name to be associated with resource.
+ *
+ *      Mark the PCI region associated with PCI device @pdev BR @bar as
+ *      being reserved by owner @res_name.  Do not access any
+ *      address inside the PCI regions unless this call returns
+ *      successfully.
+ *
+ *      Returns 0 on success, or %EBUSY on error.  A warning
+ *      message is also printed on failure.
+ *
+ *      The key difference that _exclusive makes it that userspace is
+ *      explicitly not allowed to map the resource via /dev/mem or
+ *      sysfs.
+ */
+int pci_request_region_exclusive(struct pci_dev *pdev, int bar, const char *res_name)
+{
+        return __pci_request_region(pdev, bar, res_name, IORESOURCE_EXCLUSIVE);
+}
+/**
  * pci_release_selected_regions - Release selected PCI I/O and memory resources
  * @pdev: PCI device whose resources were previously reserved
  * @bars: Bitmask of BARs to be released
@@ -1444,20 +1487,14 @@ void pci_release_selected_regions(struct pci_dev *pdev, int bars)
                         pci_release_region(pdev, i);
 }
 
-/**
- * pci_request_selected_regions - Reserve selected PCI I/O and memory resources
- * @pdev: PCI device whose resources are to be reserved
- * @bars: Bitmask of BARs to be requested
- * @res_name: Name to be associated with resource
- */
-int pci_request_selected_regions(struct pci_dev *pdev, int bars,
-                                 const char *res_name)
+int __pci_request_selected_regions(struct pci_dev *pdev, int bars,
+                                 const char *res_name, int excl)
 {
         int i;
 
         for (i = 0; i < 6; i++)
                 if (bars & (1 << i))
-                        if(pci_request_region(pdev, i, res_name))
+                        if (__pci_request_region(pdev, i, res_name, excl))
                                 goto err_out;
         return 0;
 
@@ -1469,6 +1506,26 @@ err_out:
         return -EBUSY;
 }
 
+
+/**
+ * pci_request_selected_regions - Reserve selected PCI I/O and memory resources
+ * @pdev: PCI device whose resources are to be reserved
+ * @bars: Bitmask of BARs to be requested
+ * @res_name: Name to be associated with resource
+ */
+int pci_request_selected_regions(struct pci_dev *pdev, int bars,
+                                 const char *res_name)
+{
+        return __pci_request_selected_regions(pdev, bars, res_name, 0);
+}
+
+int pci_request_selected_regions_exclusive(struct pci_dev *pdev,
+                                 int bars, const char *res_name)
+{
+        return __pci_request_selected_regions(pdev, bars, res_name,
+                        IORESOURCE_EXCLUSIVE);
+}
+
 /**
  *      pci_release_regions - Release reserved PCI I/O and memory resources
  *      @pdev: PCI device whose resources were previously reserved by pci_request_regions
@@ -1502,6 +1559,29 @@ int pci_request_regions(struct pci_dev *pdev, const char *res_name)
 }
 
 /**
+ *      pci_request_regions_exclusive - Reserved PCI I/O and memory resources
+ *      @pdev: PCI device whose resources are to be reserved
+ *      @res_name: Name to be associated with resource.
+ *
+ *      Mark all PCI regions associated with PCI device @pdev as
+ *      being reserved by owner @res_name.  Do not access any
+ *      address inside the PCI regions unless this call returns
+ *      successfully.
+ *
+ *      pci_request_regions_exclusive() will mark the region so that
+ *      /dev/mem and the sysfs MMIO access will not be allowed.
+ *
+ *      Returns 0 on success, or %EBUSY on error.  A warning
+ *      message is also printed on failure.
+ */
+int pci_request_regions_exclusive(struct pci_dev *pdev, const char *res_name)
+{
+        return pci_request_selected_regions_exclusive(pdev,
+                                        ((1 << 6) - 1), res_name);
+}
+
+
+/**
  * pci_set_master - enables bus-mastering for device dev
  * @dev: the PCI device to enable
  *
@@ -2149,10 +2229,13 @@ EXPORT_SYMBOL(pci_find_capability);
 EXPORT_SYMBOL(pci_bus_find_capability);
 EXPORT_SYMBOL(pci_release_regions);
 EXPORT_SYMBOL(pci_request_regions);
+EXPORT_SYMBOL(pci_request_regions_exclusive);
 EXPORT_SYMBOL(pci_release_region);
 EXPORT_SYMBOL(pci_request_region);
+EXPORT_SYMBOL(pci_request_region_exclusive);
 EXPORT_SYMBOL(pci_release_selected_regions);
 EXPORT_SYMBOL(pci_request_selected_regions);
+EXPORT_SYMBOL(pci_request_selected_regions_exclusive);
 EXPORT_SYMBOL(pci_set_master);
 EXPORT_SYMBOL(pci_set_mwi);
 EXPORT_SYMBOL(pci_try_set_mwi);
diff --git a/include/linux/ioport.h b/include/linux/ioport.h
index 041e95aac2bf..f6bb2ca8e3ba 100644
--- a/include/linux/ioport.h
+++ b/include/linux/ioport.h
@@ -49,6 +49,7 @@ struct resource_list {
 #define IORESOURCE_SIZEALIGN    0x00020000      /* size indicates alignment */
 #define IORESOURCE_STARTALIGN   0x00040000      /* start field is alignment */
 
+#define IORESOURCE_EXCLUSIVE    0x08000000      /* Userland may not map this resource */
 #define IORESOURCE_DISABLED     0x10000000
 #define IORESOURCE_UNSET        0x20000000
 #define IORESOURCE_AUTO         0x40000000
@@ -133,13 +134,16 @@ static inline unsigned long resource_type(struct resource *res)
 }
 
 /* Convenience shorthand with allocation */
-#define request_region(start,n,name)    __request_region(&ioport_resource, (start), (n), (name))
-#define request_mem_region(start,n,name) __request_region(&iomem_resource, (start), (n), (name))
+#define request_region(start,n,name)    __request_region(&ioport_resource, (start), (n), (name), 0)
+#define __request_mem_region(start,n,name, excl) __request_region(&iomem_resource, (start), (n), (name), excl)
+#define request_mem_region(start,n,name) __request_region(&iomem_resource, (start), (n), (name), 0)
+#define request_mem_region_exclusive(start,n,name) \
+        __request_region(&iomem_resource, (start), (n), (name), IORESOURCE_EXCLUSIVE)
 #define rename_region(region, newname) do { (region)->name = (newname); } while (0)
 
 extern struct resource * __request_region(struct resource *,
                                         resource_size_t start,
-                                        resource_size_t n, const char *name);
+                                        resource_size_t n, const char *name, int relaxed);
 
 /* Compatibility cruft */
 #define release_region(start,n) __release_region(&ioport_resource, (start), (n))
@@ -175,6 +179,7 @@ extern struct resource * __devm_request_region(struct device *dev,
 extern void __devm_release_region(struct device *dev, struct resource *parent,
                                   resource_size_t start, resource_size_t n);
 extern int iomem_map_sanity_check(resource_size_t addr, unsigned long size);
+extern int iomem_is_exclusive(u64 addr);
 
 #endif /* __ASSEMBLY__ */
 #endif  /* _LINUX_IOPORT_H */
diff --git a/include/linux/pci.h b/include/linux/pci.h
index 59a3dc2059d3..bfcb39ca8879 100644
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -686,10 +686,13 @@ void pci_fixup_irqs(u8 (*)(struct pci_dev *, u8 *),
                     int (*)(struct pci_dev *, u8, u8));
 #define HAVE_PCI_REQ_REGIONS    2
 int __must_check pci_request_regions(struct pci_dev *, const char *);
+int __must_check pci_request_regions_exclusive(struct pci_dev *, const char *);
 void pci_release_regions(struct pci_dev *);
 int __must_check pci_request_region(struct pci_dev *, int, const char *);
+int __must_check pci_request_region_exclusive(struct pci_dev *, int, const char *);
 void pci_release_region(struct pci_dev *, int);
 int pci_request_selected_regions(struct pci_dev *, int, const char *);
+int pci_request_selected_regions_exclusive(struct pci_dev *, int, const char *);
 void pci_release_selected_regions(struct pci_dev *, int);
 
 /* drivers/pci/bus.c */
diff --git a/kernel/resource.c b/kernel/resource.c
index e633106b12f6..ca6a1536b205 100644
--- a/kernel/resource.c
+++ b/kernel/resource.c
@@ -623,7 +623,7 @@ resource_size_t resource_alignment(struct resource *res)
  */
 struct resource * __request_region(struct resource *parent,
                                    resource_size_t start, resource_size_t n,
-                                   const char *name)
+                                   const char *name, int flags)
 {
         struct resource *res = kzalloc(sizeof(*res), GFP_KERNEL);
 
@@ -634,6 +634,7 @@ struct resource * __request_region(struct resource *parent,
         res->start = start;
         res->end = start + n - 1;
         res->flags = IORESOURCE_BUSY;
+        res->flags |= flags;
 
         write_lock(&resource_lock);
 
@@ -679,7 +680,7 @@ int __check_region(struct resource *parent, resource_size_t start,
 {
         struct resource * res;
 
-        res = __request_region(parent, start, n, "check-region");
+        res = __request_region(parent, start, n, "check-region", 0);
         if (!res)
                 return -EBUSY;
 
@@ -776,7 +777,7 @@ struct resource * __devm_request_region(struct device *dev,
         dr->start = start;
         dr->n = n;
 
-        res = __request_region(parent, start, n, name);
+        res = __request_region(parent, start, n, name, 0);
         if (res)
                 devres_add(dev, dr);
         else
@@ -876,3 +877,57 @@ int iomem_map_sanity_check(resource_size_t addr, unsigned long size)
 
         return err;
 }
+
+#ifdef CONFIG_STRICT_DEVMEM
+static int strict_iomem_checks = 1;
+#else
+static int strict_iomem_checks;
+#endif
+
+/*
+ * check if an address is reserved in the iomem resource tree
+ * returns 1 if reserved, 0 if not reserved.
+ */
+int iomem_is_exclusive(u64 addr)
+{
+        struct resource *p = &iomem_resource;
+        int err = 0;
+        loff_t l;
+        int size = PAGE_SIZE;
+
+        if (!strict_iomem_checks)
+                return 0;
+
+        addr = addr & PAGE_MASK;
+
+        read_lock(&resource_lock);
+        for (p = p->child; p ; p = r_next(NULL, p, &l)) {
+                /*
+                 * We can probably skip the resources without
+                 * IORESOURCE_IO attribute?
+                 */
+                if (p->start >= addr + size)
+                        break;
+                if (p->end < addr)
+                        continue;
+                if (p->flags & IORESOURCE_BUSY &&
+                     p->flags & IORESOURCE_EXCLUSIVE) {
+                        err = 1;
+                        break;
+                }
+        }
+        read_unlock(&resource_lock);
+
+        return err;
+}
+
+static int __init strict_iomem(char *str)
+{
+        if (strstr(str, "relaxed"))
+                strict_iomem_checks = 0;
+        if (strstr(str, "strict"))
+                strict_iomem_checks = 1;
+        return 1;
+}
+
+__setup("iomem=", strict_iomem);