binfmt_elf: switch elf_map() to vm_mmap/vm_munmap

No reason to hold ->mmap_sem over the sequence
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

fs/binfmt_elf.c

@@ -329,7 +329,6 @@ static unsigned long elf_map(struct file *filep, unsigned long addr,
 	if (!size)
 		return addr;
 
-	down_write(&current->mm->mmap_sem);
 	/*
 	* total_size is the size of the ELF (interpreter) image.
 	* The _first_ mmap needs to know the full size, otherwise
@@ -340,13 +339,12 @@ static unsigned long elf_map(struct file *filep, unsigned long addr,
 	*/
 	if (total_size) {
 		total_size = ELF_PAGEALIGN(total_size);
-		map_addr = do_mmap(filep, addr, total_size, prot, type, off);
+		map_addr = vm_mmap(filep, addr, total_size, prot, type, off);
 		if (!BAD_ADDR(map_addr))
-			do_munmap(current->mm, map_addr+size, total_size-size);
+			vm_munmap(map_addr+size, total_size-size);
 	} else
-		map_addr = do_mmap(filep, addr, size, prot, type, off);
+		map_addr = vm_mmap(filep, addr, size, prot, type, off);
 
-	up_write(&current->mm->mmap_sem);
 	return(map_addr);
 }