netns xfrm: fix "ip xfrm state|policy count" misreport

[safe/jmp/linux-2.6] / mm / maccess.c

diff --git a/mm/maccess.c b/mm/maccess.c
index 24f81b9..4e348db 100644 (file)
--- a/mm/maccess.c
+++ b/mm/maccess.c
@@ -14,14 +14,21 @@
  * Safely read from address @src to the buffer at @dst.  If a kernel fault
  * happens, handle that and return -EFAULT.
  */
-long probe_kernel_read(void *dst, void *src, size_t size)
+
+long __weak probe_kernel_read(void *dst, void *src, size_t size)
+    __attribute__((alias("__probe_kernel_read")));
+
+long __probe_kernel_read(void *dst, void *src, size_t size)
 {
        long ret;
+       mm_segment_t old_fs = get_fs();
 
+       set_fs(KERNEL_DS);
        pagefault_disable();
        ret = __copy_from_user_inatomic(dst,
                        (__force const void __user *)src, size);
        pagefault_enable();
+       set_fs(old_fs);
 
        return ret ? -EFAULT : 0;
 }
@@ -36,13 +43,19 @@ EXPORT_SYMBOL_GPL(probe_kernel_read);
  * Safely write to address @dst from the buffer at @src.  If a kernel fault
  * happens, handle that and return -EFAULT.
  */
-long probe_kernel_write(void *dst, void *src, size_t size)
+long __weak probe_kernel_write(void *dst, void *src, size_t size)
+    __attribute__((alias("__probe_kernel_write")));
+
+long __probe_kernel_write(void *dst, void *src, size_t size)
 {
        long ret;
+       mm_segment_t old_fs = get_fs();
 
+       set_fs(KERNEL_DS);
        pagefault_disable();
        ret = __copy_to_user_inatomic((__force void __user *)dst, src, size);
        pagefault_enable();
+       set_fs(old_fs);
 
        return ret ? -EFAULT : 0;
 }