VM: add "vm_brk()" helper function
It does the same thing as "do_brk()", except it handles the VM locking
too.
It turns out that all external callers want that anyway, so we can make
do_brk() static to just mm/mmap.c while at it.
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/mm/mmap.c b/mm/mmap.c
index a7bf6a3..df51891 100644
--- a/mm/mmap.c
+++ b/mm/mmap.c
@@ -240,6 +240,8 @@
return next;
}
+static unsigned long do_brk(unsigned long addr, unsigned long len);
+
SYSCALL_DEFINE1(brk, unsigned long, brk)
{
unsigned long rlim, retval;
@@ -2136,7 +2138,7 @@
* anonymous maps. eventually we may be able to do some
* brk-specific accounting here.
*/
-unsigned long do_brk(unsigned long addr, unsigned long len)
+static unsigned long do_brk(unsigned long addr, unsigned long len)
{
struct mm_struct * mm = current->mm;
struct vm_area_struct * vma, * prev;
@@ -2232,7 +2234,17 @@
return addr;
}
-EXPORT_SYMBOL(do_brk);
+unsigned long vm_brk(unsigned long addr, unsigned long len)
+{
+ struct mm_struct *mm = current->mm;
+ unsigned long ret;
+
+ down_write(&mm->mmap_sem);
+ ret = do_brk(addr, len);
+ up_write(&mm->mmap_sem);
+ return ret;
+}
+EXPORT_SYMBOL(vm_brk);
/* Release all mmaps. */
void exit_mmap(struct mm_struct *mm)