mm: change fault_in_pages_* to have an unsigned size parameter

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: Stephen Rothwell <sfr@canb.auug.org.au>

diff --git a/include/linux/pagemap.h b/include/linux/pagemap.h
index b071babc66299f824d37bc1a62e08c2665bd7fca..45f5ab7496cc6d6488ce6803a0ba20575005b8c9 100644 (file)
--- a/include/linux/pagemap.h
+++ b/include/linux/pagemap.h
@@ -786,7 +786,7 @@ 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;
 
@@ -813,7 +813,7 @@ 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;