From: Vineet Gupta <vgupta@synopsys.com>
Date: Thu, 26 Sep 2013 13:20:40 +0000 (+0530)
Subject: ARC: Fix 32-bit wrap around in access_ok()
X-Git-Tag: v3.12-rc4~41^2~2
X-Git-Url: http://git.openpandora.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=0752adfda15f0eca9859a76da3db1800e129ad43;p=pandora-kernel.git

ARC: Fix 32-bit wrap around in access_ok()

Anton reported

 | LTP tests syscalls/process_vm_readv01 and process_vm_writev01 fail
 | similarly in one testcase test_iov_invalid -> lvec->iov_base.
 | Testcase expects errno EFAULT and return code -1,
 | but it gets return code 1 and ERRNO is 0 what means success.

Essentially test case was passing a pointer of -1 which access_ok()
was not catching. It was doing [@addr + @sz <= TASK_SIZE] which would
pass for @addr == -1

Fixed that by rewriting as [@addr <= TASK_SIZE - @sz]

Reported-by: Anton Kolesov <Anton.Kolesov@synopsys.com>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
---

Reading git-diff-tree failed