mm: use may_adjust_brk helper

Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Cc: Kees Cook <keescook@chromium.org>
Cc: Tejun Heo <tj@kernel.org>
Cc: Andrew Vagin <avagin@openvz.org>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Acked-by: Serge Hallyn <serge.hallyn@canonical.com>
Cc: Pavel Emelyanov <xemul@parallels.com>
Cc: Vasiliy Kulikov <segoon@openwall.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Michael Kerrisk <mtk.manpages@gmail.com>
Cc: Julien Tinnes <jln@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 4 insertions, 7 deletions

diff --git a/kernel/sys.c b/kernel/sys.c
index ce8129192a26..7879729bd3bd 100644
--- a/kernel/sys.c
+++ b/kernel/sys.c
@@ -1693,7 +1693,6 @@ exit:
 static int prctl_set_mm(int opt, unsigned long addr,
                         unsigned long arg4, unsigned long arg5)
 {
-        unsigned long rlim = rlimit(RLIMIT_DATA);
         struct mm_struct *mm = current->mm;
         struct vm_area_struct *vma;
         int error;
@@ -1733,9 +1732,8 @@ static int prctl_set_mm(int opt, unsigned long addr,
                 if (addr <= mm->end_data)
                         goto out;
 
-                if (rlim < RLIM_INFINITY &&
-                    (mm->brk - addr) +
-                    (mm->end_data - mm->start_data) > rlim)
+                if (check_data_rlimit(rlimit(RLIMIT_DATA), mm->brk, addr,
+                                      mm->end_data, mm->start_data))
                         goto out;
 
                 mm->start_brk = addr;
@@ -1745,9 +1743,8 @@ static int prctl_set_mm(int opt, unsigned long addr,
                 if (addr <= mm->end_data)
                         goto out;
 
-                if (rlim < RLIM_INFINITY &&
-                    (addr - mm->start_brk) +
-                    (mm->end_data - mm->start_data) > rlim)
+                if (check_data_rlimit(rlimit(RLIMIT_DATA), addr, mm->start_brk,
+                                      mm->end_data, mm->start_data))
                         goto out;
 
                 mm->brk = addr;