1 // SPDX-License-Identifier: GPL-2.0
2 #include <linux/mm_types.h>
3 #include <linux/rbtree.h>
4 #include <linux/rwsem.h>
5 #include <linux/spinlock.h>
6 #include <linux/list.h>
7 #include <linux/cpumask.h>
8 #include <linux/mman.h>
9 #include <linux/pgtable.h>
10
11 #include <linux/atomic.h>
12 #include <linux/user_namespace.h>
13 #include <asm/mmu.h>
14
15 #ifndef INIT_MM_CONTEXT
16 #define INIT_MM_CONTEXT(name)
17 #endif
18
19 /*
20 * For dynamically allocated mm_structs, there is a dynamically sized cpumask
21 * at the end of the structure, the size of which depends on the maximum CPU
22 * number the system can see. That way we allocate only as much memory for
23 * mm_cpumask() as needed for the hundreds, or thousands of processes that
24 * a system typically runs.
25 *
26 * Since there is only one init_mm in the entire system, keep it simple
27 * and size this cpu_bitmask to NR_CPUS.
28 */
29 struct mm_struct init_mm = {
30 .mm_rb = RB_ROOT,
31 .pgd = swapper_pg_dir,
32 .mm_users = ATOMIC_INIT(2),
33 .mm_count = ATOMIC_INIT(1),
34 .write_protect_seq = SEQCNT_ZERO(init_mm.write_protect_seq),
35 MMAP_LOCK_INITIALIZER(init_mm)
36 .page_table_lock = __SPIN_LOCK_UNLOCKED(init_mm.page_table_lock),
37 .arg_lock = __SPIN_LOCK_UNLOCKED(init_mm.arg_lock),
38 .mmlist = LIST_HEAD_INIT(init_mm.mmlist),
39 .user_ns = &init_user_ns,
40 .cpu_bitmap = CPU_BITS_NONE,
41 INIT_MM_CONTEXT(init_mm)
42 };
43
setup_initial_init_mm(void * start_code,void * end_code,void * end_data,void * brk)44 void setup_initial_init_mm(void *start_code, void *end_code,
45 void *end_data, void *brk)
46 {
47 init_mm.start_code = (unsigned long)start_code;
48 init_mm.end_code = (unsigned long)end_code;
49 init_mm.end_data = (unsigned long)end_data;
50 init_mm.brk = (unsigned long)brk;
51 }
52