AArch64 Linux kernel port

This set of patches implements the core Linux support for the AArch64
(64-bit ARM) architecture.


ARM introduced AArch64 as part of the ARMv8 architecture and consists of
a substantially revised exception model (with 4 exception levels: EL0 -
user, EL1 - kernel, EL2 - hypervisor, EL3 - secure monitor), new A64
instruction set based on larger register file, new FP/SIMD instructions.
The new ABI is LP64 and takes advantage of the larger register file and
mandates FP.

AArch64 documentation currently available (publicly, though
click-through agreement required):

- Instruction Set Overview:
http://infocenter.arm.com/help/topic/com.arm.doc.genc0101...

- ABI (PCS, ELF, DWARF, C++):
http://infocenter.arm.com/help/topic/com.arm.doc.ihi0059a...

These patches are also available on this branch:

git://git.kernel.org/pub/scm/linux/kernel/git/cmarinas/linux-aarch64.git upstream

Check For Memory Leaks In Programs

#include 
 
  void f(void)
  {
     int* x = malloc(10 * sizeof(int));
     x[10] = 0;        // problem 1: heap block overrun
  }                    // problem 2: memory leak -- x not freed
 
  int main(void)
  {
     f();
     return 0;
  }

You can compile and run it as follows to detect problems:
gcc test.c
valgrind --log-file=output.file --leak-check=yes --tool=memcheck ./a.out
vi output.file

How Do I use Valgrind?

If you normally run your program like this:
./a.out arg1 arg2
OR
/path/to/myapp arg1 arg2
Use this command line to turn on the detailed memory leak detector:
valgrind --leak-check=yes ./a.out arg1 arg2
valgrind --leak-check=yes /path/to/myapp arg1 arg2
You can also set logfile:
valgrind --log-file=output.file --leak-check=yes --tool=memcheck ./a.out arg1 arg2
Most error messages look like the following:
cat output.file

Detecting kernel memory leaks


http://lwn.net/Articles/187979/

CACHE CRAZY STUFF

ARMv8 :

http://www.arm.com/support/training/arm-training-courses/armv8-a-software-development.php

129 주차 진도

• 128 주차 진도를 복습하였습니다.
• vfs_caches_init()
  
  • start_kernel 1 ~/kernel/iamroot/linux-stable/init/main.c
  • vfs_caches_init 925 ~/kernel/iamroot/linux-stable/init/main.c
  • mnt_init 3807 ~/kernel/iamroot/linux-stable/fs/dcache.c
  • sysfs_init 3496 err = sysfs_init();
  • kern_mount 824 ~/kernel/iamroot/linux-stable/fs/sysfs/mount.c
  • kern_mount_data 1962 ~/kernel/iamroot/linux-stable/include/linux/fs.h
  • vfs_kern_mount 3949 mnt = vfs_kern_mount(type, MS_KERNMOUNT, type->name, data);
• 128주차 함수 호출 구조
• call: start_kernel()->vfs_caches_init()
• vfs_caches_init()
  
  • min()
  • kmem_cache_create() : names_caches
  • dcache_init()
  • inode_init()
  • files_init(): mempages
  • mnt_init()
  • kmem_cache_create(): mnt_cache
  • alloc_large_system_hash() : Mount_cache
  • alloc_large_system_hash() : Mountpoint-cache
  • INIT_HLIST_HEAD() : &mount_hashtable[u]
  • INIT_HLIST_HEAD() : &mountpoint_hashtable[u]
  • sysfs_init()
• sysfs_init()
  
  • kmem_cache_create(): sysfs_dir_cache
  • sysfs_inode_init()
  • register_filesystem(): sysfs_fs_type
  • kern_mount() : kern_mount_data()
    • vfs_kern_mount()
• vfs_kern_mount()
  
  • alloc_vfsmnt(): sysfs
    • kmem_cache_zalloc()
    • mnt_alloc_id()
    • alloc_percpu()
    • INIT_HLIST_NODE(): mnt_hash
    • INIT_LIST_HEAD(): mnt_child
    • INIT_LIST_HEAD(): mnt_mounts
    • INIT_LIST_HEAD(): mnt_list
    • INIT_LIST_HEAD(): mnt_expire
    • INIT_LIST_HEAD(): mnt_share
    • INIT_LIST_HEAD(): mnt_slave_list
    • INIT_LIST_HEAD(): mnt_slave
    • INIT_LIST_HEAD(): mnt_fsnotify_marks
  • mount_fs(): sysfs
• mount_fs(): sysfs_mount()
  
  • kzalloc(): sysfs_super_info
  • sget()
    • spin_lock(): sb_lock
    • hlist_for_eash_entry()
    • spin_unlock()
    • alloc_super()
    • kzalloc(): super_block
    • security_sb_alloc()
    • percpu_counter_init()
    • lockdep_init_map()
    • init_waitqueue_head(): s_writers.wait
    • init_waitqueue_head: s_writers.wait_unfrozen
    • INIT_HLIST_NODE(): s_instances
    • INIT_HLIST_BL_HEAD(): s_anon
    • INIT_LIST_HEAD: s_inodes
    • list_lru_init(): s_dentry_lru
    • list_lru_init(): s_inode_lru
    • INIT_LIST_HEAD: s_mounts
    • init_rwsem(): s_umount
    • lockdep_set_class(): s_umount
    • down_write_nested(): s_umount
    • atomic_set(): s_active
    • mutext_init(): s_vfs_rename_mutex
    • lockdep_set_class(): s_vfs_rename_key
    • mutex_init(): s_dquot.dpio_mutex
    • mutext_init(): s_dquot.dqonoff_mutex
    • init_rwsem(): s_dquot.dqptr_sem
    • set()
    • strlcpy(): s_id, sysfs
    • list_add_tail(): s_list
    • hlist_add_head(): s_instances
    • spin_unlock(): sb_lock
    • get_filesystem(type)
    • register_shrinker()
  • IS_ERR(): sb
  • sysfs_fill_super()
    • mutex_lock(): sysfs_mutex
    • sysfs_get_inode(): super_block
    • iget_locked(): super_block
      • spin_lock(): inode_hash_lock
      • find_inode_fast()
      • spin_unlock: inode_hash_lock
      • alloc_inode()
      • kmem_cache_alloc(): inode
      • inode_init_always(): inode
        • atomic_set(): i_count
        • i_uid_write()
        • i_gid_write()
        • atomic_set: i_writecount
        • security_inode_alloc(): inode
        • spin_lock_init(): i_lock
        • spinlock_check()
        • raw_spin_lock_init()
        • lockdep_set_class(): s_type->i_lock_key
        • mutex_init(): i_mutex
        • lockdep_set_class(): s_type->i_mutex
        • atomic_set(): i_dio_count
        • mapping_set_gfp_mask(): inode
        • INIT_HLIST_HEAD(): inode->i_dentry
        • this_cpu_inc()
      • spin_lock(): inode_hash_lock
      • fine_inode_fast()
      • spin_lock(): inode->i_lock
      • hlist_add_head(): inode->i_hash
      • spin_unlock(): inode->i_lock
    • sysfs_init_inode(): sysfs_root
    • mutex_unlock()
    • d_make_root()
    • _dalloc(): super_block
      • kmem_cache_alloc(): dentry
      • memcpy(): d_iname: name->name, (&name)->name: "/", (&name)->len
      • swp_wmb()
      • spin_lock_init(): dentry_d_lock
      • seqcount_init(): d_seq
      • INIT_HLIST_BL_NODE(): dentry->d_fsdata
      • INIT_LIST_HEAD(): dentry->d_lru
      • INIT_LIST_HEAD(): dentry->d_subdirs
      • INIT_HLIST_NODE(): dentry->d_alias
      • INIT_LIST_HEAD(): dentry->d_u.d_child
      • d_set_d_op(): dentry->d_sb->s_d_op
      • this_cpu_inc()
    • d_instantiate(): dentry
      • BUG_ON: hlist_unhased(): entry->d_alias
      • sping_lock(): inode->i_lock
      • _dinstantiate()
      • spin_lock(): dentry->d_lock
      • hlist_add_head(): dentry->d_alias
      • dentry_rcuwalk_barrier(): dentry
        • assert_spin_locked(): assert_raw_spin_locked() : BUG_ON(!raw_spin_is_locked(x))
        • write_seqcount_barrier()
        • swp_wmb()
        • spin_unlock(): dentry->d_lock
        • fsnotify_d_instantiate()
      • spin_unlock()
    • mutext_lock(): sysfs_mutex
    • sysfs_get_inode(): sfsfs_get_inode
    • iget_locked(): super_block
      • spin_lock(): inode_hash_lock
      • find_inode_fast(): super_block
      • spin_unlock(): inode_hash_lock
      • alloc_inode()
        • kmem_cache_alloc(): inode
        • inode_init_always(): inode
        • atomic_set(): i_count
        • i_uid_write()
        • i_gid_write()
        • atomic_set: i_writecount
        • security_inode_alloc(): inode
        • spin_lock_init(): i_lock
          • spinlock_check()
          • raw_spin_lock_init()
        • lockdep_set_class(): s_type->i_lock_key
        • mutex_init(): i_mutex
        • lockdep_set_class(): s_type->i_mutex
        • atomic_set(): i_dio_count
        • mapping_set_gfp_mask(): inode
        • INIT_HLIST_HEAD(): inode->i_dentry
        • this_cpu_inc()
      • spin_lock(): inode_hash_lock
      • find_inode_fast()
      • spin_lock(): i_lock
      • hlist_add_head(): i_hash
      • spin_unlock(): i_lock
      • inode_sb_list_add(): inode
      • spin_unlock(): inode_hash_lock
      • sysfs_init_inode(): sysfs_root
      • sysfs_get(): sysfs_root
      • set_default_inode_attr()
      • sysfs_refresh_inode(): sysfs_root
      • sysfs_type(): sysfs_root
      • unlock_new_inode(): inode
  • dget(): s_root
    • lockref_get(): dentry->d_lockref
• vfs_kern_mount()
  
  • alloc_vfsmnt(): sysfs
    • kmem_cache_zalloc()
    • mnt_alloc_id()
    • alloc_percpu()
    • INIT_HLIST_NODE(): mnt_hash
    • INIT_LIST_HEAD(): mnt_child
    • INIT_LIST_HEAD(): mnt_mounts
    • INIT_LIST_HEAD(): mnt_list
    • INIT_LIST_HEAD(): mnt_expire
    • INIT_LIST_HEAD(): mnt_share
    • INIT_LIST_HEAD(): mnt_slave_list
    • INIT_LIST_HEAD(): mnt_slave
    • INIT_LIST_HEAD(): mnt_fsnotify_marks
  • mount_fs(): sysfs
  • IS_ERR(): root
  • BUG_ON(): super_block
  • WARN_ON(): super_block->s_bdi
  • WARN_ON(): super_block->s_bdi == default_backing_dev_info
  • security_sb_kern_mount()
  • WARN(): super_block->s_maxbytes
  • up_write(): super_block->s_umount
  • free_secdata()

main.c::start_kernel()

• call: start_kernel()->vfs_caches_init()

asmlinkage void __init start_kernel(void)
{
 char * command_line;
 extern const struct kernel_param __start___param[], __stop___param[];
 // ATAG,DTB 정보로 사용

...

    proc_caches_init();
// sighand_struct, signal_struct, files_struct, fs_struct, mm_struct, vm_area_struct, nsproxy
// 를 사용하기 위한 kmem_cache 할당자 및 percpu list 초기화 수행

buffer_init();
// buffer_head 를 사용하기 위한 kmem_cache 할당자 및 max_buffer_heads 값 초기화 수행

key_init(); // null funtion
security_init(); // null funtion
dbg_late_init(); // null funtion

// totalram_pages: 총 free된 page 수
vfs_caches_init(totalram_pages);

## dcache.c::vfs_cache_init() * call: start_kernel() - vfs_caches_init()

// ARM10C 20151003
// totalram_pages: 총 free된 page 수
void __init vfs_caches_init(unsigned long mempages)
{
 unsigned long reserve;

    // mempages: 총 free된 page 수, nr_free_pages(): 현재의 free pages 수
reserve = min((mempages - nr_free_pages()) * 3/2, mempages - 1);
// reserve: XXX

// mempages: 총 free된 page 수, reserve: XXX
mempages -= reserve;
// mempages: 총 free된 page 수 - XXX

// PATH_MAX: 4096
// SLAB_HWCACHE_ALIGN: 0x00002000UL, SLAB_PANIC: 0x00040000UL
// kmem_cache_create("names_cache", 4096, 0, 0x42000, NULL): kmem_cache#6
names_cachep = kmem_cache_create("names_cache", PATH_MAX, 0,
  SLAB_HWCACHE_ALIGN|SLAB_PANIC, NULL);
// names_cachep: kmem_cache#6

dcache_init();

inode_init();

// mempages: 총 free된 page 수 - XXX
files_init(mempages);

mnt_init();

## namespace.c::mnt_init() * call: start_kernel()->vfs_caches_init() - mnt_init()

// ARM10C 20151024
void __init mnt_init(void)
{
 unsigned u;
 int err;
 // sizeof(struct mount): 152 bytes, SLAB_HWCACHE_ALIGN: 0x00002000UL, SLAB_PANIC: 0x00040000UL
 // kmem_cache_create("mnt_cache", 152, 0, 0x42000, NULL): kmem_cache#2
 mnt_cache = kmem_cache_create("mnt_cache", sizeof(struct mount),
   0, SLAB_HWCACHE_ALIGN | SLAB_PANIC, NULL);
 // mnt_cache: kmem_cache#2

    // sizeof(struct hlist_head): 4 bytes, mhash_entries: 0
// alloc_large_system_hash("Mount-cache", 4, 0, 19, 0, &m_hash_shift, &m_hash_mask, 0, 0): 16kB만큼 할당받은 메모리 주소
mount_hashtable = alloc_large_system_hash("Mount-cache",
   sizeof(struct hlist_head),
   mhash_entries, 19,
   0,
   &m_hash_shift, &m_hash_mask, 0, 0);
// mount_hashtable: 16kB만큼 할당받은 메모리 주소

// sizeof(struct hlist_head): 4 bytes, mphash_entries: 0
// alloc_large_system_hash("Mountpoint-cache", 4, 0, 19, 0, &m_hash_shift, &m_hash_mask, 0, 0): 16kB만큼 할당받은 메모리 주소
mountpoint_hashtable = alloc_large_system_hash("Mountpoint-cache",
   sizeof(struct hlist_head),
   mphash_entries, 19,
   0,
   &mp_hash_shift, &mp_hash_mask, 0, 0);
// mountpoint_hashtable: 16kB만큼 할당받은 메모리 주소

// mount_hashtable: 16kB만큼 할당받은 메모리 주소, mountpoint_hashtable: 16kB만큼 할당받은 메모리 주소
if (!mount_hashtable || !mountpoint_hashtable)
 panic("Failed to allocate mount hash table\n");

// m_hash_mask: 0xFFF
for (u = 0; u <= m_hash_mask; u++)
 // u: 0
 INIT_HLIST_HEAD(&mount_hashtable[u]);

 // INIT_HLIST_HEAD 에서 한일:
 // ((&mount_hashtable[0])->first = NULL)

 // u: 1...4095 까지 loop 수행

// mp_hash_mask: 0xFFF
for (u = 0; u <= mp_hash_mask; u++)
 // u: 0
 INIT_HLIST_HEAD(&mountpoint_hashtable[u]);

 // INIT_HLIST_HEAD 에서 한일:
 // ((&mountpoint_hashtable[0])->first = NULL)

 // u: 1...4095 까지 loop 수행

// sysfs_init(): 0
err = sysfs_init();
// err: 0

// err: 0
if (err)
 printk(KERN_WARNING "%s: sysfs_init error: %d\n",
  __func__, err);
fs_kobj = kobject_create_and_add("fs", NULL);

## kobject.c::kobject_create_and_add() * call: start_kernel()->vfs_caches_init()->mnt_init() - kmem_cache_create() - alloc_large_system_hash() : mnt_cache - alloc_large_system_hash() : Mount-cache - alloc_large_system_hash() : Mountpoint-cache - INIT_HLIST_HEAD() : &mount_hashtable[u] - INIT_HLIST_HEAD() : &mountpoint_hashtable[u] - sysfs_init() - kobject_create_and_add() : fs

// ARM10C 20160109
// "fs", NULL
struct kobject *kobject_create_and_add(const char *name, struct kobject *parent)
{
 struct kobject *kobj;
 int retval;

    // kobject_create(): kmem_cache#30-oX (struct kobject)
kobj = kobject_create();

## kobject.c::kobject_create() * call: start_kernel()->vfs_caches_init()->mnt_init() - kmem_cache_create() - alloc_large_system_hash() : mnt_cache - alloc_large_system_hash() : Mount-cache - alloc_large_system_hash() : Mountpoint-cache - INIT_HLIST_HEAD() : &mount_hashtable[u] - INIT_HLIST_HEAD() : &mountpoint_hashtable[u] - sysfs_init() - kobject_create_and_add() : fs - kobject_create()

// ARM10C 20160109
struct kobject *kobject_create(void)
{
 struct kobject *kobj;

    // sizeof(struct kobject): 36 bytes, GFP_KERNEL: 0xD0
// kzalloc(36, GFP_KERNEL: 0xD0): kmem_cache#30-oX (struct kobject)
kobj = kzalloc(sizeof(*kobj), GFP_KERNEL);
// kobj: kmem_cache#30-oX (struct kobject)

// kobj: kmem_cache#30-oX (struct kobject)
if (!kobj)
 return NULL;

// kobj: kmem_cache#30-oX (struct kobject)
kobject_init(kobj, &dynamic_kobj_ktype);

## kobject.c::kobject_create() * call: start_kernel()->vfs_caches_init()->mnt_init() - kmem_cache_create() - alloc_large_system_hash() : mnt_cache - alloc_large_system_hash() : Mount-cache - alloc_large_system_hash() : Mountpoint-cache - INIT_HLIST_HEAD() : &mount_hashtable[u] - INIT_HLIST_HEAD() : &mountpoint_hashtable[u] - sysfs_init() - kobject_create_and_add() : fs - kobject_create()

// ARM10C 20160109
struct kobject *kobject_create(void)
{
 struct kobject *kobj;

    // sizeof(struct kobject): 36 bytes, GFP_KERNEL: 0xD0
// kzalloc(36, GFP_KERNEL: 0xD0): kmem_cache#30-oX (struct kobject)
kobj = kzalloc(sizeof(*kobj), GFP_KERNEL);
// kobj: kmem_cache#30-oX (struct kobject)

// kobj: kmem_cache#30-oX (struct kobject)
if (!kobj)
 return NULL;

// kobj: kmem_cache#30-oX (struct kobject)
kobject_init(kobj, &dynamic_kobj_ktype);

## kobject.c::kobject_init() * call: start_kernel()->vfs_caches_init()->mnt_init() - kmem_cache_create() - alloc_large_system_hash() : mnt_cache - alloc_large_system_hash() : Mount-cache - alloc_large_system_hash() : Mountpoint-cache - INIT_HLIST_HEAD() : &mount_hashtable[u] - INIT_HLIST_HEAD() : &mountpoint_hashtable[u] - sysfs_init() - kobject_create_and_add() : fs - kobject_create() - kobject_init()

// ARM10C 20160109
// kobj: kmem_cache#30-oX (struct kobject), &dynamic_kobj_ktype
void kobject_init(struct kobject *kobj, struct kobj_type *ktype)
{
 char *err_str;

    // kobj: kmem_cache#30-oX (struct kobject)
if (!kobj) {
 err_str = "invalid kobject pointer!";
 goto error;
}

// ktype: &dynamic_kobj_ktype
if (!ktype) {
 err_str = "must have a ktype to be initialized properly!\n";
 goto error;
}

// kobj->state_initialized: (kmem_cache#30-oX (struct kobject))->state_initialized: 0
if (kobj->state_initialized) {
 /* do not error out as sometimes we can recover */
 printk(KERN_ERR "kobject (%p): tried to init an initialized "
        "object, something is seriously wrong.\n", kobj);
 dump_stack();
}

// kobj: kmem_cache#30-oX (struct kobject)
kobject_init_internal(kobj);

## kobject.c::kobject_init_internal() * call: start_kernel()->vfs_caches_init()->mnt_init() - kmem_cache_create() - alloc_large_system_hash() : mnt_cache - alloc_large_system_hash() : Mount-cache - alloc_large_system_hash() : Mountpoint-cache - INIT_HLIST_HEAD() : &mount_hashtable[u] - INIT_HLIST_HEAD() : &mountpoint_hashtable[u] - sysfs_init() - kobject_create_and_add() : fs - kobject_create() - kobject_init() - kobject_init_internal() : kobj

// ARM10C 20160109
// kobj: kmem_cache#30-oX (struct kobject)
static void kobject_init_internal(struct kobject *kobj)
{
 // kobj: kmem_cache#30-oX (struct kobject)
 if (!kobj)
  return;

    // &kobj->kref: &(kmem_cache#30-oX (struct kobject))->kref
kref_init(&kobj->kref);

* kref_init()

// ARM10C 20160109
// &kobj->kref: &(kmem_cache#30-oX (struct kobject))->kref
static inline void kref_init(struct kref *kref)
{
 atomic_set(&kref->refcount, 1);
}

* kref_init에서 한일: - (&(kmem_cache#30-oX (struct kobject))->kref)->refcount: 1 * INIT_LIST_HEAD에서 한일: - (&(kmem_cache#30-oX (struct kobject))->entry)->next: &(kmem_cache#30-oX (struct kobject))->entry - (&(kmem_cache#30-oX (struct kobject))->entry)->prev: &(kmem_cache#30-oX (struct kobject))->entry

// ARM10C 20160109
// kobj: kmem_cache#30-oX (struct kobject)
static void kobject_init_internal(struct kobject *kobj)
{
 // kobj: kmem_cache#30-oX (struct kobject)
 if (!kobj)
  return;

    // &kobj->kref: &(kmem_cache#30-oX (struct kobject))->kref
kref_init(&kobj->kref);

// kref_init에서 한일:
// (&(kmem_cache#30-oX (struct kobject))->kref)->refcount: 1

// &kobj->entry: &(kmem_cache#30-oX (struct kobject))->entry
INIT_LIST_HEAD(&kobj->entry);

// INIT_LIST_HEAD에서 한일:
// (&(kmem_cache#30-oX (struct kobject))->entry)->next: &(kmem_cache#30-oX (struct kobject))->entry
// (&(kmem_cache#30-oX (struct kobject))->entry)->prev: &(kmem_cache#30-oX (struct kobject))->entry

// kobj->state_in_sysfs: (kmem_cache#30-oX (struct kobject))->state_in_sysfs
kobj->state_in_sysfs = 0;
// kobj->state_in_sysfs: (kmem_cache#30-oX (struct kobject))->state_in_sysfs: 0

// kobj->state_add_uevent_sent: (kmem_cache#30-oX (struct kobject))->state_add_uevent_sent
kobj->state_add_uevent_sent = 0;
// kobj->state_add_uevent_sent: (kmem_cache#30-oX (struct kobject))->state_add_uevent_sent: 0

// kobj->state_remove_uevent_sent: (kmem_cache#30-oX (struct kobject))->state_remove_uevent_sent
kobj->state_remove_uevent_sent = 0;
// kobj->state_remove_uevent_sent: (kmem_cache#30-oX (struct kobject))->state_remove_uevent_sent: 0

// kobj->state_initialized: (kmem_cache#30-oX (struct kobject))->state_initialized
kobj->state_initialized = 1;
// kobj->state_initialized: (kmem_cache#30-oX (struct kobject))->state_initialized: 1
}

* kobject_init_internal에서 한일: - (&(kmem_cache#30-oX (struct kobject))->kref)->refcount: 1 - (&(kmem_cache#30-oX (struct kobject))->entry)->next: &(kmem_cache#30-oX (struct kobject))->entry - (&(kmem_cache#30-oX (struct kobject))->entry)->prev: &(kmem_cache#30-oX (struct kobject))->entry - (kmem_cache#30-oX (struct kobject))->state_in_sysfs: 0 - (kmem_cache#30-oX (struct kobject))->state_add_uevent_sent: 0 - (kmem_cache#30-oX (struct kobject))->state_remove_uevent_sent: 0 - (kmem_cache#30-oX (struct kobject))->state_initialized: 1 ## kobject.c::kobject_init() * call: start_kernel()->vfs_caches_init()->mnt_init() - kmem_cache_create() - alloc_large_system_hash() : mnt_cache - alloc_large_system_hash() : Mount-cache - alloc_large_system_hash() : Mountpoint-cache - INIT_HLIST_HEAD() : &mount_hashtable[u] - INIT_HLIST_HEAD() : &mountpoint_hashtable[u] - sysfs_init() - kobject_create_and_add() : fs - kobject_create() - kobject_init() - kobject_init_internal() : kobj

// ARM10C 20160109
// kobj: kmem_cache#30-oX (struct kobject), &dynamic_kobj_ktype
void kobject_init(struct kobject *kobj, struct kobj_type *ktype)
{
 char *err_str;

    // kobj: kmem_cache#30-oX (struct kobject)
if (!kobj) {
 err_str = "invalid kobject pointer!";
 goto error;
}

// ktype: &dynamic_kobj_ktype
if (!ktype) {
 err_str = "must have a ktype to be initialized properly!\n";
 goto error;
}

// kobj->state_initialized: (kmem_cache#30-oX (struct kobject))->state_initialized: 0
if (kobj->state_initialized) {
 /* do not error out as sometimes we can recover */
 printk(KERN_ERR "kobject (%p): tried to init an initialized "
        "object, something is seriously wrong.\n", kobj);
 dump_stack();
}

// kobj: kmem_cache#30-oX (struct kobject)
kobject_init_internal(kobj);

// kobj->ktype: (kmem_cache#30-oX (struct kobject))->ktype, ktype: &dynamic_kobj_ktype
kobj->ktype = ktype;
// kobj->ktype: (kmem_cache#30-oX (struct kobject))->ktype: &dynamic_kobj_ktype

return;
// return
error:
 printk(KERN_ERR "kobject (%p): %s\n", kobj, err_str);
 dump_stack();
}
EXPORT_SYMBOL(kobject_init);

* kobject_init에서 한일: - (&(kmem_cache#30-oX (struct kobject))->kref)->refcount: 1 - (&(kmem_cache#30-oX (struct kobject))->entry)->next: &(kmem_cache#30-oX (struct kobject))->entry - (&(kmem_cache#30-oX (struct kobject))->entry)->prev: &(kmem_cache#30-oX (struct kobject))->entry - (kmem_cache#30-oX (struct kobject))->state_in_sysfs: 0 - (kmem_cache#30-oX (struct kobject))->state_add_uevent_sent: 0 - (kmem_cache#30-oX (struct kobject))->state_remove_uevent_sent: 0 - (kmem_cache#30-oX (struct kobject))->state_initialized: 1 - (kmem_cache#30-oX (struct kobject))->ktype: &dynamic_kobj_ktype ## kobject.c::kobject_create() * call: start_kernel()->vfs_caches_init()->mnt_init() - kmem_cache_create() - alloc_large_system_hash() : mnt_cache - alloc_large_system_hash() : Mount-cache - alloc_large_system_hash() : Mountpoint-cache - INIT_HLIST_HEAD() : &mount_hashtable[u] - INIT_HLIST_HEAD() : &mountpoint_hashtable[u] - sysfs_init() - kobject_create_and_add() : fs - kobject_create() - kobject_init() - kobject_init_internal() : kobj

// ARM10C 20160109
struct kobject *kobject_create(void)
{
 struct kobject *kobj;

    // sizeof(struct kobject): 36 bytes, GFP_KERNEL: 0xD0
// kzalloc(36, GFP_KERNEL: 0xD0): kmem_cache#30-oX (struct kobject)
kobj = kzalloc(sizeof(*kobj), GFP_KERNEL);
// kobj: kmem_cache#30-oX (struct kobject)

// kobj: kmem_cache#30-oX (struct kobject)
if (!kobj)
 return NULL;

// kobj: kmem_cache#30-oX (struct kobject)
kobject_init(kobj, &dynamic_kobj_ktype);

// kobj: kmem_cache#30-oX (struct kobject)
return kobj;
// return kmem_cache#30-oX (struct kobject)
}

* return kmem_cache#30-oX (struct kobject) * kobject_create에서 한일: - struct kobject의 메모리를 할당받음 kmem_cache#30-oX (struct kobject) - (&(kmem_cache#30-oX (struct kobject))->kref)->refcount: 1 - (&(kmem_cache#30-oX (struct kobject))->entry)->next: &(kmem_cache#30-oX (struct kobject))->entry - (&(kmem_cache#30-oX (struct kobject))->entry)->prev: &(kmem_cache#30-oX (struct kobject))->entry - (kmem_cache#30-oX (struct kobject))->state_in_sysfs: 0 - (kmem_cache#30-oX (struct kobject))->state_add_uevent_sent: 0 - (kmem_cache#30-oX (struct kobject))->state_remove_uevent_sent: 0 - (kmem_cache#30-oX (struct kobject))->state_initialized: 1 - (kmem_cache#30-oX (struct kobject))->ktype: &dynamic_kobj_ktype ## kobject.c::kobject_create_and_add() * call: start_kernel()->vfs_caches_init()->mnt_init() - kmem_cache_create() - alloc_large_system_hash() : mnt_cache - alloc_large_system_hash() : Mount-cache - alloc_large_system_hash() : Mountpoint-cache - INIT_HLIST_HEAD() : &mount_hashtable[u] - INIT_HLIST_HEAD() : &mountpoint_hashtable[u] - sysfs_init() - kobject_create_and_add() : fs - kobject_create() - kobject_init() - kobject_init_internal() : kobj

// ARM10C 20160109
// "fs", NULL
struct kobject *kobject_create_and_add(const char *name, struct kobject *parent)
{
 struct kobject *kobj;
 int retval;

    // kobject_create(): kmem_cache#30-oX (struct kobject)
kobj = kobject_create();
// kobj: kmem_cache#30-oX (struct kobject)

// kobj: kmem_cache#30-oX (struct kobject)
if (!kobj)
 return NULL;

// kobj: kmem_cache#30-oX (struct kobject), parent: NULL, name: "fs"
retval = kobject_add(kobj, parent, "%s", name);

## kobject.c::kobject_create_and_add() * call: start_kernel()->vfs_caches_init()->mnt_init() - kmem_cache_create() - alloc_large_system_hash() : mnt_cache - alloc_large_system_hash() : Mount-cache - alloc_large_system_hash() : Mountpoint-cache - INIT_HLIST_HEAD() : &mount_hashtable[u] - INIT_HLIST_HEAD() : &mountpoint_hashtable[u] - sysfs_init() - kobject_create_and_add() : fs - kobject_create() - kobject_init() - kobject_init_internal() : kobj - kobject_add()

// ARM10C 20160109
// kobj: kmem_cache#30-oX (struct kobject), parent: NULL, "%s", name: "fs"
int kobject_add(struct kobject *kobj, struct kobject *parent,
  const char *fmt, ...)
{
 va_list args;
 int retval;

    // kobj: kmem_cache#30-oX (struct kobject)
if (!kobj)
 return -EINVAL;

// kobj->state_initialized: (kmem_cache#30-oX (struct kobject))->state_initialized: 1
if (!kobj->state_initialized) {
 printk(KERN_ERR "kobject '%s' (%p): tried to add an "
        "uninitialized object, something is seriously wrong.\n",
        kobject_name(kobj), kobj);
 dump_stack();
 return -EINVAL;
}

// fmt: "%s"
va_start(args, fmt);

## acenv.h::va_start() * call: start_kernel()->vfs_caches_init()->mnt_init() - kmem_cache_create() - alloc_large_system_hash() : mnt_cache - alloc_large_system_hash() : Mount-cache - alloc_large_system_hash() : Mountpoint-cache - INIT_HLIST_HEAD() : &mount_hashtable[u] - INIT_HLIST_HEAD() : &mountpoint_hashtable[u] - sysfs_init() - kobject_create_and_add() : fs - kobject_create() - kobject_init() - kobject_init_internal() : kobj - kobject_add() - va_start()

// ARM10C 20160109
// _AUPBND: 3
// _bnd("%s",3): 4
//
// #define va_start(args, "%s"):
// (void) ((args) = (((char *) &("%s")) + 4))
#define va_start(ap, A)         (void) ((ap) = (((char *) &(A)) + (_bnd (A,_AUPBND))))

// ARM10C 20160109
// #define _bnd("%s", 3):
// (((sizeof ("%s")) + (3)) & (~(3)))
#define _bnd(X, bnd)            (((sizeof (X)) + (bnd)) & (~(bnd)))

// ARM10C 20160109
#define va_end(ap)              (ap = (va_list) NULL)

* va_start에서 한일: - (args): (((char *) &("%s")) + 4): "fs" ## kobject.c::kobject_add() * call: start_kernel()->vfs_caches_init()->mnt_init() - kmem_cache_create() - alloc_large_system_hash() : mnt_cache - alloc_large_system_hash() : Mount-cache - alloc_large_system_hash() : Mountpoint-cache - INIT_HLIST_HEAD() : &mount_hashtable[u] - INIT_HLIST_HEAD() : &mountpoint_hashtable[u] - sysfs_init() - kobject_create_and_add() : fs - kobject_create() - kobject_init() - kobject_init_internal() : kobj - kobject_add() - va_start()

// ARM10C 20160109
// kobj: kmem_cache#30-oX (struct kobject), parent: NULL, "%s", name: "fs"
int kobject_add(struct kobject *kobj, struct kobject *parent,
  const char *fmt, ...)
{
 va_list args;
 int retval;

    // kobj: kmem_cache#30-oX (struct kobject)
if (!kobj)
 return -EINVAL;

// kobj->state_initialized: (kmem_cache#30-oX (struct kobject))->state_initialized: 1
if (!kobj->state_initialized) {
 printk(KERN_ERR "kobject '%s' (%p): tried to add an "
        "uninitialized object, something is seriously wrong.\n",
        kobject_name(kobj), kobj);
 dump_stack();
 return -EINVAL;
}

// fmt: "%s"
va_start(args, fmt);

// va_start에서 한일:
// (args): (((char *) &("%s")) + 4): "fs"

// kobj: kmem_cache#30-oX (struct kobject), parent: NULL, fmt: "%s", args: "fs"
retval = kobject_add_varg(kobj, parent, fmt, args);

## kobject.c::kobject_add() * call: start_kernel()->vfs_caches_init()->mnt_init() - kmem_cache_create() - alloc_large_system_hash() : mnt_cache - alloc_large_system_hash() : Mount-cache - alloc_large_system_hash() : Mountpoint-cache - INIT_HLIST_HEAD() : &mount_hashtable[u] - INIT_HLIST_HEAD() : &mountpoint_hashtable[u] - sysfs_init() - kobject_create_and_add() : fs - kobject_create() - kobject_init() - kobject_init_internal() : kobj - kobject_add() - va_start() - kobject_add_varg() : kobj, fs

// ARM10C 20160109
// kobj: kmem_cache#30-oX (struct kobject), parent: NULL, fmt: "%s", args: "fs"
static int kobject_add_varg(struct kobject *kobj, struct kobject *parent,
       const char *fmt, va_list vargs)
{
 int retval;

    // kobj: kmem_cache#30-oX (struct kobject), fmt: "%s", vargs: "fs"
retval = kobject_set_name_vargs(kobj, fmt, vargs);

## kobject.c::kobject_set_name_vargs() * call: start_kernel()->vfs_caches_init()->mnt_init() - kmem_cache_create() - alloc_large_system_hash() : mnt_cache - alloc_large_system_hash() : Mount-cache - alloc_large_system_hash() : Mountpoint-cache - INIT_HLIST_HEAD() : &mount_hashtable[u] - INIT_HLIST_HEAD() : &mountpoint_hashtable[u] - sysfs_init() - kobject_create_and_add() : fs - kobject_create() - kobject_init() - kobject_init_internal() : kobj - kobject_add() - va_start() - kobject_add_varg() : kobj, fs - kobject_set_name_vargs()

int kobject_set_name_vargs(struct kobject *kobj, const char *fmt,
      va_list vargs)
{
 // kobj->name: (kmem_cache#30-oX (struct kobject))->name: NULL
 const char *old_name = kobj->name;
 // old_name: NULL

    char *s;

// kobj->name: (kmem_cache#30-oX (struct kobject))->name: NULL, fmt: "%s"
if (kobj->name && !fmt)
 return 0;

// kobj->name: (kmem_cache#30-oX (struct kobject))->name: NULL
// GFP_KERNEL: 0xD0, fmt: "%s", vargs: "fs"
// kvasprintf(GFP_KERNEL: 0xD0, "%s", "fs"): kmem_cache#30-oX: "fs"
kobj->name = kvasprintf(GFP_KERNEL, fmt, vargs);

## kasprintf.c::kvasspintf() * call: start_kernel()->vfs_caches_init() - mnt_init() - kmem_cache_create() - alloc_large_system_hash() : mnt_cache - alloc_large_system_hash() : Mount-cache - alloc_large_system_hash() : Mountpoint-cache - INIT_HLIST_HEAD() : &mount_hashtable[u] - INIT_HLIST_HEAD() : &mountpoint_hashtable[u] - sysfs_init() - kobject_create_and_add() : fs - kobject_create() - kobject_init() - kobject_init_internal() : kobj - kobject_add() - va_start() - kobject_add_vargs() : kobj, fs - kobject_set_name_vargs() - kvasprintf()

// ARM10C 20160109
// GFP_KERNEL: 0xD0, fmt: "%s", vargs: "fs"
char *kvasprintf(gfp_t gfp, const char *fmt, va_list ap)
{
 unsigned int len;
 char *p;
 va_list aq;

    // ap: "fs"
va_copy(aq, ap);

* va_copy() 에서 한일 - aq: "fs" ## vspirntf.c:: kvasprintf() * call: start_kernel()->vfs_caches_init() - mnt_init() - kmem_cache_create() - alloc_large_system_hash() : mnt_cache - alloc_large_system_hash() : Mount-cache - alloc_large_system_hash() : Mountpoint-cache - INIT_HLIST_HEAD() : &mount_hashtable[u] - INIT_HLIST_HEAD() : &mountpoint_hashtable[u] - sysfs_init() - kobject_create_and_add() : fs - kobject_create() - kobject_init() - kobject_init_internal() : kobj - kobject_add() - va_start() - kobject_add_vargs() : kobj, fs - kobject_set_name_vargs() - kvasprintf()

// ARM10C 20160109
// GFP_KERNEL: 0xD0, fmt: "%s", vargs: "fs"
char *kvasprintf(gfp_t gfp, const char *fmt, va_list ap)
{
 unsigned int len;
 char *p;
 va_list aq;

    // ap: "fs"
va_copy(aq, ap);

// va_copy에서 한일:
// aq: "fs"

// fmt: "%s", aq: "fs"
// vsnprintf(NULL, 0, "%s", "fs"): 2
len = vsnprintf(NULL, 0, fmt, aq);

## vsprintf.c::kvasprintf() * call: start_kernel()->vfs_caches_init() - mnt_init() - kmem_cache_create() - alloc_large_system_hash() : mnt_cache - alloc_large_system_hash() : Mount-cache - alloc_large_system_hash() : Mountpoint-cache - INIT_HLIST_HEAD() : &mount_hashtable[u] - INIT_HLIST_HEAD() : &mountpoint_hashtable[u] - sysfs_init() - kobject_create_and_add() : fs - kobject_create() - kobject_init() - kobject_init_internal() : kobj - kobject_add() - va_start() - kobject_add_vargs() : kobj, fs - kobject_set_name_vargs() - kvasprintf()

// ARM10C 20160109
// p: kmem_cache#30-oX, len: 2, fmt: "%s", ap: "fs"
int vsnprintf(char *buf, size_t size, const char *fmt, va_list args)
{
 unsigned long long num;
 char *str, *end;
 struct printf_spec spec = {0};

    /* Reject out-of-range values early.  Large positive sizes are
   used for unknown buffer sizes. */
// size: 0
if (WARN_ON_ONCE((int) size < 0))
 return 0;

// buf: NULL
str = buf;
// str: NULL

// buf: NULL
end = buf + size;
// end: NULL

/* Make sure end is always >= buf */
// end: NULL, buf: NULL
if (end < buf) {
 end = ((void *)-1);
 size = end - buf;
}

// *fmt: '%'
while (*fmt) {
 // fmt: "%s"
 const char *old_fmt = fmt;
 // old_fmt: "%s"

 // fmt: "%s", format_decode("%s", &spec): 2
 int read = format_decode(fmt, &spec);

## vsprintf.c::format_decode() * call: start_kernel()->vfs_caches_init() - mnt_init() - kmem_cache_create() - alloc_large_system_hash() : mnt_cache - alloc_large_system_hash() : Mount-cache - alloc_large_system_hash() : Mountpoint-cache - INIT_HLIST_HEAD() : &mount_hashtable[u] - INIT_HLIST_HEAD() : &mountpoint_hashtable[u] - sysfs_init() - kobject_create_and_add() : fs - kobject_create() - kobject_init() - kobject_init_internal() : kobj - kobject_add() - va_start() - kobject_add_vargs() : kobj, fs - kobject_set_name_vargs() - kvasprintf() - format_decode()

// ARM10C 20160109
// fmt: "%s", &spec
static noinline_for_stack
int format_decode(const char *fmt, struct printf_spec *spec)
{
 // fmt: "%s"
 const char *start = fmt;
 // start: "%s"

    /* we finished early by reading the field width */
// spec->type: (&spec)->type: 0, FORMAT_TYPE_WIDTH: 1
if (spec->type == FORMAT_TYPE_WIDTH) {
 if (spec->field_width < 0) {
  spec->field_width = -spec->field_width;
  spec->flags |= LEFT;
 }
 spec->type = FORMAT_TYPE_NONE;
 goto precision;
}

/* we finished early by reading the precision */
// spec->type: (&spec)->type: 0, FORMAT_TYPE_PRECISION: 2
if (spec->type == FORMAT_TYPE_PRECISION) {
 if (spec->precision < 0)
  spec->precision = 0;

 spec->type = FORMAT_TYPE_NONE;
 goto qualifier;
}

/* By default */
// spec->type: (&spec)->type: 0, FORMAT_TYPE_NONE: 0
spec->type = FORMAT_TYPE_NONE;
// spec->type: (&spec)->type: 0

// fmt: "%s"
for (; *fmt ; ++fmt) {
 // *fmt: '%'
 if (*fmt == '%')
  break;
  // break 수행
}

/* Return the current non-format string */
// fmt: "%s", start: "%s", *fmt: '%'
if (fmt != start || !*fmt)
 return fmt - start;

/* Process flags */
// spec->flags: (&spec)->flags
spec->flags = 0;
// spec->flags: (&spec)->flags: 0

while (1) { /* this also skips first '%' */
 bool found = true;
 // found: true

 // fmt: "%s"
 ++fmt;
 // fmt: "s"

 // *fmt: 's'
 switch (*fmt) {
 case '-': spec->flags |= LEFT;    break;
 case '+': spec->flags |= PLUS;    break;
 case ' ': spec->flags |= SPACE;   break;
 case '#': spec->flags |= SPECIAL; break;
 case '0': spec->flags |= ZEROPAD; break;
 default:  found = false;
    // found: false
 }

 // found: false
 if (!found)
  break;
  // break 수행
}

/* get field width */
// spec->field_width: (&spec)->field_width
spec->field_width = -1;
// spec->field_width: (&spec)->field_width: -1

// *fmt: 's', isdigit('s'): 0
if (isdigit(*fmt))
 spec->field_width = skip_atoi(&fmt);
else if (*fmt == '*') {
 /* it's the next argument */
 spec->type = FORMAT_TYPE_WIDTH;
 return ++fmt - start;
}
precision:
 /* get the precision */
 // spec->precision: (&spec)->precision
 spec->precision = -1;
 // spec->precision: (&spec)->precision: -1

    // *fmt: 's'
if (*fmt == '.') {
 ++fmt;
 if (isdigit(*fmt)) {
  spec->precision = skip_atoi(&fmt);
  if (spec->precision < 0)
   spec->precision = 0;
 } else if (*fmt == '*') {
  /* it's the next argument */
  spec->type = FORMAT_TYPE_PRECISION;
  return ++fmt - start;
 }
}
qualifier:
 /* get the conversion qualifier */
 // spec->qualifier: (&spec)->qualifier
 spec->qualifier = -1;
 // spec->qualifier: (&spec)->qualifier: -1

    // *fmt: 's', _tolower('s'): 's'
if (*fmt == 'h' || _tolower(*fmt) == 'l' ||
    _tolower(*fmt) == 'z' || *fmt == 't') {
 spec->qualifier = *fmt++;
 if (unlikely(spec->qualifier == *fmt)) {
  if (spec->qualifier == 'l') {
   spec->qualifier = 'L';
   ++fmt;
  } else if (spec->qualifier == 'h') {
   spec->qualifier = 'H';
   ++fmt;
  }
 }
}

/* default base */
// spec->base: (&spec)->base
spec->base = 10;
// spec->base: (&spec)->base: 10

// *fmt: 's'
switch (*fmt) {
case 'c':
 spec->type = FORMAT_TYPE_CHAR;
 return ++fmt - start;

case 's':
 // spec->type: (&spec)->type, FORMAT_TYPE_STR: 4
 spec->type = FORMAT_TYPE_STR;
 // spec->type: (&spec)->type: 4

 // fmt: "s",  start: "%s"
 return ++fmt - start;
 // return 2

case 'p':
 spec->type = FORMAT_TYPE_PTR;
 return fmt - start;
 /* skip alnum */

case 'n':
 spec->type = FORMAT_TYPE_NRCHARS;
 return ++fmt - start;

case '%':
 spec->type = FORMAT_TYPE_PERCENT_CHAR;
 return ++fmt - start;

/* integer number formats - set up the flags and "break" */
case 'o':
 spec->base = 8;
 break;

case 'x':
 spec->flags |= SMALL;

case 'X':
 spec->base = 16;
 break;

case 'd':
case 'i':
 spec->flags |= SIGN;
case 'u':
 break;

default:
 spec->type = FORMAT_TYPE_INVALID;
 return fmt - start;
}

if (spec->qualifier == 'L')
 spec->type = FORMAT_TYPE_LONG_LONG;
else if (spec->qualifier == 'l') {
 if (spec->flags & SIGN)
  spec->type = FORMAT_TYPE_LONG;
 else
  spec->type = FORMAT_TYPE_ULONG;
} else if (_tolower(spec->qualifier) == 'z') {
 spec->type = FORMAT_TYPE_SIZE_T;
} else if (spec->qualifier == 't') {
 spec->type = FORMAT_TYPE_PTRDIFF;
} else if (spec->qualifier == 'H') {
 if (spec->flags & SIGN)
  spec->type = FORMAT_TYPE_BYTE;
 else
  spec->type = FORMAT_TYPE_UBYTE;
} else if (spec->qualifier == 'h') {
 if (spec->flags & SIGN)
  spec->type = FORMAT_TYPE_SHORT;
 else
  spec->type = FORMAT_TYPE_USHORT;
} else {
 if (spec->flags & SIGN)
  spec->type = FORMAT_TYPE_INT;
 else
  spec->type = FORMAT_TYPE_UINT;
}

return ++fmt - start;
}

* format_decode에서 한일: - - (&spec)->type: 0 - (&spec)->flags: 0 - (&spec)->field_width: -1 - (&spec)->precision: -1 - (&spec)->qualifier: -1 - (&spec)->base: 10 ## vsprintf.c::kvasprintf() * call: start_kernel()->vfs_caches_init() - mnt_init() - kmem_cache_create() - alloc_large_system_hash() : mnt_cache - alloc_large_system_hash() : Mount-cache - alloc_large_system_hash() : Mountpoint-cache - INIT_HLIST_HEAD() : &mount_hashtable[u] - INIT_HLIST_HEAD() : &mountpoint_hashtable[u] - sysfs_init() - kobject_create_and_add() : fs - kobject_create() - kobject_init() - kobject_init_internal() : kobj - kobject_add() - va_start() - kobject_add_vargs() : kobj, fs - kobject_set_name_vargs() - kvasprintf() - format_decode()

// ARM10C 20160109
// NULL, 0, fmt: "%s", aq: "fs"
// ARM10C 20160109
// p: kmem_cache#30-oX, len: 2, fmt: "%s", ap: "fs"
int vsnprintf(char *buf, size_t size, const char *fmt, va_list args)
{
 unsigned long long num;
 char *str, *end;
 struct printf_spec spec = {0};

    /* Reject out-of-range values early.  Large positive sizes are
   used for unknown buffer sizes. */
// size: 0
if (WARN_ON_ONCE((int) size < 0))
 return 0;

// buf: NULL
str = buf;
// str: NULL

// buf: NULL
end = buf + size;
// end: NULL

/* Make sure end is always >= buf */
// end: NULL, buf: NULL
if (end < buf) {
 end = ((void *)-1);
 size = end - buf;
}

// *fmt: '%'
while (*fmt) {
 // fmt: "%s"
 const char *old_fmt = fmt;
 // old_fmt: "%s"

 // fmt: "%s", format_decode("%s", &spec): 2
 int read = format_decode(fmt, &spec);
 // read: 2

 // fmt: "%s", read: 2
 fmt += read;
 // fmt: NULL

 // spec.type: 0
 switch (spec.type) {
 case FORMAT_TYPE_NONE: { // FORMAT_TYPE_NONE: 0
  // read: 2
  int copy = read;
  // copy: 2

  // str: NULL, end: NULL
  if (str < end) {
   if (copy > end - str)
    copy = end - str;
   memcpy(str, old_fmt, copy);
  }
  // str: NULL, read: 2
  str += read;
  // str: 2

  break;
  // break 수행
 }

 case FORMAT_TYPE_WIDTH:
  spec.field_width = va_arg(args, int);
  break;

 case FORMAT_TYPE_PRECISION:
  spec.precision = va_arg(args, int);
  break;

 case FORMAT_TYPE_CHAR: {
  char c;

  if (!(spec.flags & LEFT)) {
   while (--spec.field_width > 0) {
    if (str < end)
     *str = ' ';
    ++str;

   }
  }
  c = (unsigned char) va_arg(args, int);
  if (str < end)
   *str = c;
  ++str;
  while (--spec.field_width > 0) {
   if (str < end)
    *str = ' ';
   ++str;
  }
  break;
 }

 case FORMAT_TYPE_STR:
  str = string(str, end, va_arg(args, char *), spec);
  break;

 case FORMAT_TYPE_PTR:
  str = pointer(fmt+1, str, end, va_arg(args, void *),
         spec);
  while (isalnum(*fmt))
   fmt++;
  break;

 case FORMAT_TYPE_PERCENT_CHAR:
  if (str < end)
   *str = '%';
  ++str;
  break;

 case FORMAT_TYPE_INVALID:
  if (str < end)
   *str = '%';
  ++str;
  break;

 case FORMAT_TYPE_NRCHARS: {
  /*
   * Since %n poses a greater security risk than
   * utility, ignore %n and skip its argument.
   */
  void *skip_arg;

  WARN_ONCE(1, "Please remove ignored %%n in '%s'\n",
    old_fmt);

  skip_arg = va_arg(args, void *);
  break;
 }

 default:
  switch (spec.type) {
  case FORMAT_TYPE_LONG_LONG:
   num = va_arg(args, long long);
   break;
  case FORMAT_TYPE_ULONG:
   num = va_arg(args, unsigned long);
   break;
  case FORMAT_TYPE_LONG:
   num = va_arg(args, long);
   break;
  case FORMAT_TYPE_SIZE_T:
   if (spec.flags & SIGN)
    num = va_arg(args, ssize_t);
   else
    num = va_arg(args, size_t);
   break;
  case FORMAT_TYPE_PTRDIFF:
   num = va_arg(args, ptrdiff_t);
   break;
  case FORMAT_TYPE_UBYTE:
   num = (unsigned char) va_arg(args, int);
   break;
  case FORMAT_TYPE_BYTE:
   num = (signed char) va_arg(args, int);
   break;
  case FORMAT_TYPE_USHORT:
   num = (unsigned short) va_arg(args, int);
   break;
  case FORMAT_TYPE_SHORT:
   num = (short) va_arg(args, int);
   break;
  case FORMAT_TYPE_INT:
   num = (int) va_arg(args, int);
   break;
  default:
   num = va_arg(args, unsigned int);
  }

  str = number(str, end, num, spec);
 }
}

// size: 0
if (size > 0) {
 if (str < end)
  *str = '\0';
 else
  end[-1] = '\0';
}

/* the trailing null byte doesn't count towards the total */
// str: 2, buf: NULL
return str-buf;
// return 2
}
EXPORT_SYMBOL(vsnprintf);

## kasprintf.c::kvasprintf() * call: start_kernel()->vfs_caches_init() - mnt_init() - kmem_cache_create() - alloc_large_system_hash() : mnt_cache - alloc_large_system_hash() : Mount-cache - alloc_large_system_hash() : Mountpoint-cache - INIT_HLIST_HEAD() : &mount_hashtable[u] - INIT_HLIST_HEAD() : &mountpoint_hashtable[u] - sysfs_init() - kobject_create_and_add() : fs - kobject_create() - kobject_init() - kobject_init_internal() : kobj - kobject_add() - va_start() - kobject_add_vargs() : kobj, fs - kobject_set_name_vargs() - kvasprintf() - format_decode()

// ARM10C 20160109
// GFP_KERNEL: 0xD0, fmt: "%s", vargs: "fs"
char *kvasprintf(gfp_t gfp, const char *fmt, va_list ap)
{
 unsigned int len;
 char *p;
 va_list aq;

    // ap: "fs"
va_copy(aq, ap);

// va_copy에서 한일:
// aq: "fs"

// fmt: "%s", aq: "fs"
// vsnprintf(NULL, 0, "%s", "fs"): 2
len = vsnprintf(NULL, 0, fmt, aq);
// len: 11 "kmalloc-192"의 길이
// len: 2

// aq: "fs"
va_end(aq);

* va_end(aq);

#define va_end(ap)              (ap = (va_list) NULL)

* va_end에서 한일: - aq: NULL

// ARM10C 20160109
// GFP_KERNEL: 0xD0, fmt: "%s", vargs: "fs"
char *kvasprintf(gfp_t gfp, const char *fmt, va_list ap)
{
 unsigned int len;
 char *p;
 va_list aq;

    // ap: "fs"
va_copy(aq, ap);

// va_copy에서 한일:
// aq: "fs"

// fmt: "%s", aq: "fs"
// vsnprintf(NULL, 0, "%s", "fs"): 2
len = vsnprintf(NULL, 0, fmt, aq);
// len: 11 "kmalloc-192"의 길이
// len: 2

// aq: "fs"
va_end(aq);

// va_end에서 한일:
// aq: NULL

// len: 11, gfp: GFP_NOWAIT: 0
// kmalloc_track_caller(12, GFP_NOWAIT: 0): kmem_cache#30-o0
// len: 2, GFP_KERNEL: 0xD0
p = kmalloc_track_caller(len+1, gfp);

## slab.h::kmalloc_track_caller() * call: start_kernel()->vfs_caches_init() - mnt_init() - kmem_cache_create() - alloc_large_system_hash() : mnt_cache - alloc_large_system_hash() : Mount-cache - alloc_large_system_hash() : Mountpoint-cache - INIT_HLIST_HEAD() : &mount_hashtable[u] - INIT_HLIST_HEAD() : &mountpoint_hashtable[u] - sysfs_init() - kobject_create_and_add() : fs - kobject_create() - kobject_init() - kobject_init_internal() : kobj - kobject_add() - va_start() - kobject_add_vargs() : kobj, fs - kobject_set_name_vargs() - kvasprintf() - va_copy() - vsnprintf() - format_decode() - va_end() - kmalloc_track_caller()

// ARM10C 20160109
// len: 3, GFP_KERNEL: 0xD0
#define kmalloc_track_caller(size, flags) \
 __kmalloc_track_caller(size, flags, _RET_IP_)

// ARM10C 20160109
// len: 3, GFP_KERNEL: 0xD0, _RET_IP_
void *__kmalloc_track_caller(size_t size, gfp_t gfpflags, unsigned long caller)
{
 struct kmem_cache *s;
 void *ret;

    // size: 16, KMALLOC_MAX_CACHE_SIZE: 0x2000
if (unlikely(size > KMALLOC_MAX_CACHE_SIZE))
 return kmalloc_large(size, gfpflags);

// size: 16, gfpflags: GFP_KERNEL: 0xD0
// kmalloc_slab(16, 0xD0): kmem_cache#30
s = kmalloc_slab(size, gfpflags);
// s: kmem_cache#30

// s: kmem_cache#30, ZERO_OR_NULL_PTR(kmem_cache#30): 0
if (unlikely(ZERO_OR_NULL_PTR(s)))
 return s;

// s: kmem_cache#30, gfpflags: GFP_KERNEL: 0xD0, _RET_IP_
// slab_alloc(kmem_cache#30, GFP_NOWAIT: 0, _RET_IP_):
// kmem_cache#30-oX
ret = slab_alloc(s, gfpflags, caller);
// ret: kmem_cache#30-o17

/* Honor the call site pointer we received. */
trace_kmalloc(caller, ret, size, s->size, gfpflags);

// ret: kmem_cache#30-o17
return ret;
// return kmem_cache#30-o17
}

## kasprintf.c::kvasprintf() * call: start_kernel()->vfs_caches_init() - mnt_init() - kmem_cache_create() - alloc_large_system_hash() : mnt_cache - alloc_large_system_hash() : Mount-cache - alloc_large_system_hash() : Mountpoint-cache - INIT_HLIST_HEAD() : &mount_hashtable[u] - INIT_HLIST_HEAD() : &mountpoint_hashtable[u] - sysfs_init() - kobject_create_and_add() : fs - kobject_create() - kobject_init() - kobject_init_internal() : kobj - kobject_add() - va_start() - kobject_add_vargs() : kobj, fs - kobject_set_name_vargs() - kvasprintf() - va_copy() - vsnprintf() - format_decode() - va_end() - kmalloc_track_caller() - kvasprintf()

// ARM10C 20160109
// GFP_KERNEL: 0xD0, fmt: "%s", vargs: "fs"
char *kvasprintf(gfp_t gfp, const char *fmt, va_list ap)
{
 unsigned int len;
 char *p;
 va_list aq;

    // ap: "fs"
va_copy(aq, ap);

// va_copy에서 한일:
// aq: "fs"

// fmt: "%s", aq: "fs"
// vsnprintf(NULL, 0, "%s", "fs"): 2
len = vsnprintf(NULL, 0, fmt, aq);
// len: 11 "kmalloc-192"의 길이
// len: 2

// aq: "fs"
va_end(aq);

// va_end에서 한일:
// aq: NULL

// len: 11, gfp: GFP_NOWAIT: 0
// kmalloc_track_caller(12, GFP_NOWAIT: 0): kmem_cache#30-o0
// len: 2, GFP_KERNEL: 0xD0
p = kmalloc_track_caller(len+1, gfp);
// p: kmem_cache#30-o0
// p: kmem_cache#30-oX

// p: kmem_cache#30-o0
// p: kmem_cache#30-oX
if (!p)
 return NULL;

// p: kmem_cache#30-oX, len: 2, fmt: "%s", ap: "fs"
vsnprintf(p, len+1, fmt, ap);

// vsnprintf에서 한일:
// p: kmem_cache#30-oX: "fs"

// p: kmem_cache#30-o0
// p: kmem_cache#30-oX: "fs"
return p;
// return kmem_cache#30-o0
// return kmem_cache#30-oX: "fs"
}
EXPORT_SYMBOL(kvasprintf);

## kobject.c::kobject_set_name_vargs() * call: start_kernel()->vfs_caches_init() - mnt_init() - kmem_cache_create() - alloc_large_system_hash() : mnt_cache - alloc_large_system_hash() : Mount-cache - alloc_large_system_hash() : Mountpoint-cache - INIT_HLIST_HEAD() : &mount_hashtable[u] - INIT_HLIST_HEAD() : &mountpoint_hashtable[u] - sysfs_init() - kobject_create_and_add() : fs - kobject_create() - kobject_init() - kobject_init_internal() : kobj - kobject_add() - va_start() - kobject_add_vargs() : kobj, fs - kobject_set_name_vargs() - kvasprintf() - va_copy() - vsnprintf() - format_decode() - va_end() - kmalloc_track_caller() - kvasprintf() - ret: kobject_set_name_vargs()

// ARM10C 20160109
// kobj: kmem_cache#30-oX (struct kobject), fmt: "%s", vargs: "fs"
int kobject_set_name_vargs(struct kobject *kobj, const char *fmt,
      va_list vargs)
{
 // kobj->name: (kmem_cache#30-oX (struct kobject))->name: NULL
 const char *old_name = kobj->name;
 // old_name: NULL

    char *s;

// kobj->name: (kmem_cache#30-oX (struct kobject))->name: NULL, fmt: "%s"
if (kobj->name && !fmt)
 return 0;

// kobj->name: (kmem_cache#30-oX (struct kobject))->name: NULL
// GFP_KERNEL: 0xD0, fmt: "%s", vargs: "fs"
// kvasprintf(GFP_KERNEL: 0xD0, "%s", "fs"): kmem_cache#30-oX: "fs"
kobj->name = kvasprintf(GFP_KERNEL, fmt, vargs);
// kobj->name: (kmem_cache#30-oX (struct kobject))->name: kmem_cache#30-oX: "fs"

// kobj->name: (kmem_cache#30-oX (struct kobject))->name: kmem_cache#30-oX: "fs"
if (!kobj->name)
 return -ENOMEM;
// 2016/01/09 종료

* kernel object - .ko로 확장자로 끝나는 파일들. - kernel 2.6 이후 사용. ## log * 1st log

c68141d..7b4f179  master     -> origin/master
Updating c68141d..7b4f179
Fast-forward
fs/dcache.c                           | 276 ++++++++++++++++++++++-----------------------
fs/inode.c                            | 458 +++++++++++++++++++++++++++++++++++++-------------------------------------
fs/mount.h                            |  24 ++++
fs/namespace.c                        | 626 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++------------------
fs/super.c                            | 218 ++++++++++++++++++------------------
fs/sysfs/inode.c                      | 222 ++++++++++++++++++------------------
fs/sysfs/mount.c                      | 814 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++-------------------------------------
include/linux/err.h                   |   9 ++
include/linux/fs.h                    |   1 +
include/linux/kernel.h                |   1 +
include/linux/list.h                  |   2 +
include/linux/lockdep.h               |   2 +
include/linux/seqlock.h               | 126 +++++++++++++++++++++
include/linux/spinlock.h              |   4 +
include/linux/spinlock_types.h        |  12 ++
include/uapi/asm-generic/errno-base.h |   1 +
16 files changed, 1872 insertions(+), 924 deletions(-)

* 2nd log

7b4f179..f8705f2  master     -> origin/master
Updating 7b4f179..f8705f2
Fast-forward
README.md                         |   3 +
fs/namespace.c                    | 425 ++++++++++++++++++++++++++++++++++++++
include/acpi/actypes.h            |   5 +-
include/acpi/platform/acenv.h     |  14 ++
include/acpi/platform/aclinux.h   |   3 +
include/asm-generic/bitsperlong.h |   1 +
include/linux/ctype.h             |  13 ++
include/linux/gfp.h               |   1 +
include/linux/kobject.h           |   2 +
include/linux/kref.h              |   2 +
include/linux/list.h              |   2 +
include/linux/slab.h              |   4 +
lib/ctype.c                       |   1 +
lib/kasprintf.c                   |  25 +++
lib/kobject.c                     | 118 +++++++++++
lib/vsprintf.c                    |  91 +++++++-
mm/slub.c                         |   2 +
17 files changed, 708 insertions(+), 4 deletions(-)