From: Arnd Bergmann <arnd@arndb.de>
Date: Wed, 3 May 2017 21:56:12 +0000 (-0700)
Subject: mm/gup.c: fix access_ok() argument type
X-Git-Tag: MMI-PSA29.97-13-9~5692^2~12
X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=aa2369f11ff77317b9af388ae3527f1b85981e0d;p=GitHub%2FMotorolaMobilityLLC%2Fkernel-slsi.git

mm/gup.c: fix access_ok() argument type

MIPS just got changed to only accept a pointer argument for access_ok(),
causing one warning in drivers/scsi/pmcraid.c.  I tried changing x86 the
same way and found the same warning in __get_user_pages_fast() and
nowhere else in the kernel during randconfig testing:

  mm/gup.c: In function '__get_user_pages_fast':
  mm/gup.c:1578:6: error: passing argument 1 of '__chk_range_not_ok' makes pointer from integer without a cast [-Werror=int-conversion]

It would probably be a good idea to enforce type-safety in general, so
let's change this file to not cause a warning if we do that.

I don't know why the warning did not appear on MIPS.

Fixes: 2667f50e8b81 ("mm: introduce a general RCU get_user_pages_fast()")
Link: http://lkml.kernel.org/r/20170421162659.3314521-1-arnd@arndb.de
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Acked-by: Ingo Molnar <mingo@kernel.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Lorenzo Stoakes <lstoakes@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
---

diff --git a/mm/gup.c b/mm/gup.c
index 527ec2c6cca3..d9e6fddcc51f 100644
--- a/mm/gup.c
+++ b/mm/gup.c
@@ -1575,7 +1575,7 @@ int __get_user_pages_fast(unsigned long start, int nr_pages, int write,
 	end = start + len;
 
 	if (unlikely(!access_ok(write ? VERIFY_WRITE : VERIFY_READ,
-					start, len)))
+					(void __user *)start, len)))
 		return 0;
 
 	/*