Modified: trunk/drivers/char/mem.c (6526 => 6527)
--- trunk/drivers/char/mem.c 2009-06-02 00:35:33 UTC (rev 6526)
+++ trunk/drivers/char/mem.c 2009-06-02 05:07:49 UTC (rev 6527)
@@ -25,6 +25,7 @@
#include <linux/backing-dev.h>
#include <linux/bootmem.h>
#include <linux/splice.h>
+#include <linux/pfn.h>
#include <linux/smp_lock.h>
#include <asm/uaccess.h>
@@ -180,7 +181,7 @@
return read;
}
-static ssize_t write_mem(struct file * file, const char __user * buf,
+static ssize_t write_mem(struct file * file, const char __user * buf,
size_t count, loff_t *ppos)
{
unsigned long p = *ppos;
@@ -285,6 +286,19 @@
return (unsigned long) -EINVAL;
return pgoff << PAGE_SHIFT;
}
+
+/* can't do an in-place private mapping if there's no MMU */
+static inline int private_mapping_ok(struct vm_area_struct *vma)
+{
+ return vma->vm_flags & VM_MAYSHARE;
+}
+#else
+#define get_unmapped_area_mem NULL
+
+static inline int private_mapping_ok(struct vm_area_struct *vma)
+{
+ return 1;
+}
#endif
void __attribute__((weak))
@@ -326,11 +340,8 @@
if (!valid_mmap_phys_addr_range(vma->vm_pgoff, size))
return -EINVAL;
-#ifndef CONFIG_MMU
- /* can't do an in-place private mapping if there's no MMU */
- if (!(vma->vm_flags & VM_MAYSHARE))
+ if (!private_mapping_ok(vma))
return -ENOSYS;
-#endif
if (!range_is_allowed(vma->vm_pgoff, size))
return -EPERM;
@@ -421,7 +432,7 @@
/*
* This function reads the *virtual* memory as seen by the kernel.
*/
-static ssize_t read_kmem(struct file *file, char __user *buf,
+static ssize_t read_kmem(struct file *file, char __user *buf,
size_t count, loff_t *ppos)
{
unsigned long p = *ppos;
@@ -568,7 +579,7 @@
/*
* This function writes to the *virtual* memory as seen by the kernel.
*/
-static ssize_t write_kmem(struct file * file, const char __user * buf,
+static ssize_t write_kmem(struct file * file, const char __user * buf,
size_t count, loff_t *ppos)
{
unsigned long p = *ppos;
@@ -632,10 +643,10 @@
char __user *tmp = buf;
if (!access_ok(VERIFY_WRITE, buf, count))
- return -EFAULT;
+ return -EFAULT;
while (count-- > 0 && i < 65536) {
- if (__put_user(inb(i),tmp) < 0)
- return -EFAULT;
+ if (__put_user(inb(i),tmp) < 0)
+ return -EFAULT;
i++;
tmp++;
}
@@ -691,7 +702,7 @@
return splice_from_pipe(pipe, out, ppos, len, flags, pipe_to_null);
}
-static ssize_t read_zero(struct file * file, char __user * buf,
+static ssize_t read_zero(struct file * file, char __user * buf,
size_t count, loff_t *ppos)
{
size_t written;
@@ -834,17 +845,15 @@
.mmap = mmap_zero,
};
+/*
+ * capabilities for /dev/zero
+ * - permits private mappings, "copies" are taken of the source of zeros
+ */
static struct backing_dev_info zero_bdi = {
.capabilities = BDI_CAP_MAP_COPY,
};
-static struct backing_dev_info mem_bdi = {
- .capabilities = (/*BDI_CAP_MAP_COPY |*/ BDI_CAP_MAP_DIRECT |
- BDI_CAP_READ_MAP | BDI_CAP_WRITE_MAP |
- BDI_CAP_EXEC_MAP),
-};
-
-static struct file_operations full_fops = {
+static const struct file_operations full_fops = {
.llseek = full_lseek,
.read = read_full,
.write = write_full,
@@ -890,12 +899,14 @@
switch (iminor(inode)) {
case 1:
filp->f_op = &mem_fops;
- filp->f_mapping->backing_dev_info = &mem_bdi;
+ filp->f_mapping->backing_dev_info =
+ &directly_mappable_cdev_bdi;
break;
#ifdef CONFIG_DEVKMEM
case 2:
filp->f_op = &kmem_fops;
- filp->f_mapping->backing_dev_info = &mem_bdi;
+ filp->f_mapping->backing_dev_info =
+ &directly_mappable_cdev_bdi;
break;
#endif
case 3:
