sh: Fix mmap2 for handling differing PAGE_SIZEs.

mmap2 uses a fixed page shift of 12, regardless of the PAGE_SIZE setting.
Fix up the mmap2 code to add some sanity checks on the mapping, and to
update pgoff accordingly.

Error handling bits based on 4280e3126f641898f0ed1a931645373d3489e2a6
("frv: fix mmap2 error handling").

Signed-off-by: Toshinobu Sugioka <sugioka@itonet.co.jp>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>

diff --git a/arch/sh/kernel/sys_sh.c b/arch/sh/kernel/sys_sh.c
index 58dfc02c7af13bd92431cf16dfc44d8ea9c75f31..e3a7e36639efd9a352488e347585f67635ee0916 100644 (file)
--- a/arch/sh/kernel/sys_sh.c
+++ b/arch/sh/kernel/sys_sh.c
@@ -63,6 +63,15 @@ asmlinkage long sys_mmap2(unsigned long addr, unsigned long len,
        unsigned long prot, unsigned long flags,
        unsigned long fd, unsigned long pgoff)
 {
+       /*
+        * The shift for mmap2 is constant, regardless of PAGE_SIZE
+        * setting.
+        */
+       if (pgoff & ((1 << (PAGE_SHIFT - 12)) - 1))
+               return -EINVAL;
+
+       pgoff >>= PAGE_SHIFT - 12;
+
        return do_mmap2(addr, len, prot, flags, fd, pgoff);
 }