From: Toshinobu Sugioka <sugioka@itonet.co.jp>
Date: Mon, 20 Apr 2009 22:34:53 +0000 (+0900)
Subject: sh: Fix mmap2 for handling differing PAGE_SIZEs.
X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=8c31813f31cd4403b46802866949a95a6e8fa584;p=GitHub%2FLineageOS%2FG12%2Fandroid_kernel_amlogic_linux-4.9.git

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 58dfc02c7af1..e3a7e36639ef 100644
--- 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);
 }