From 245589546060761ed4fd8de96dd2b05eec2069e3 Mon Sep 17 00:00:00 2001
From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Date: Thu, 2 Sep 2021 14:56:43 -0700
Subject: [PATCH] mm: change fault_in_pages_* to have an unsigned size
 parameter

References: bsc#1190208 (MM functional and performance backports)
Patch-mainline: v5.15-rc1
Git-commit: e15710bf04063766f428048f4dad7b73b646203f

fault_in_pages_writeable() and fault_in_pages_readable() treat the size
parameter as unsigned, doing pointer math with the value, so make this
explicit and set it to be a size_t type which all callers currently treat
it as anyway.

This solves the issue where static checkers get nervous seeing pointer
arithmetic happening with a signed value.

Link: https://lkml.kernel.org/r/20210727111136.457638-1-gregkh@linuxfoundation.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reported-by: Jordy Zomer <jordy@pwning.systems>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: David Howells <dhowells@redhat.com>
Cc: William Kucharski <william.kucharski@oracle.com>
Cc: "Darrick J. Wong" <djwong@kernel.org>
Cc: Hugh Dickins <hughd@google.com>
Cc: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Mel Gorman <mgorman@suse.de>
---
 include/linux/pagemap.h | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/include/linux/pagemap.h b/include/linux/pagemap.h
index e2de0c18effd..148129aebe09 100644
--- a/include/linux/pagemap.h
+++ b/include/linux/pagemap.h
@@ -736,7 +736,7 @@ extern void add_page_wait_queue(struct page *page, wait_queue_entry_t *waiter);
 /*
  * Fault everything in given userspace address range in.
  */
-static inline int fault_in_pages_writeable(char __user *uaddr, int size)
+static inline int fault_in_pages_writeable(char __user *uaddr, size_t size)
 {
 	char __user *end = uaddr + size - 1;
 
@@ -763,7 +763,7 @@ static inline int fault_in_pages_writeable(char __user *uaddr, int size)
 	return 0;
 }
 
-static inline int fault_in_pages_readable(const char __user *uaddr, int size)
+static inline int fault_in_pages_readable(const char __user *uaddr, size_t size)
 {
 	volatile char c;
 	const char __user *end = uaddr + size - 1;