Merge tag 'init_task-20180117' of git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs

Pull init_task initializer cleanups from David Howells:
 "It doesn't seem useful to have the init_task in a header file rather
  than in a normal source file. We could consolidate init_task handling
  instead and expand out various macros.

  Here's a series of patches that consolidate init_task handling:

   (1) Make THREAD_SIZE available to vmlinux.lds for cris, hexagon and
       openrisc.

   (2) Alter the INIT_TASK_DATA linker script macro to set
       init_thread_union and init_stack rather than defining these in C.

       Insert init_task and init_thread_into into the init_stack area in
       the linker script as appropriate to the configuration, with
       different section markers so that they end up correctly ordered.

       We can then get merge ia64's init_task.c into the main one.

       We then have a bunch of single-use INIT_*() macros that seem only
       to be macros because they used to be used per-arch. We can then
       expand these in place of the user and get rid of a few lines and
       a lot of backslashes.

   (3) Expand INIT_TASK() in place.

   (4) Expand in place various small INIT_*() macros that are defined
       conditionally. Expand them and surround them by #if[n]def/#endif
       in the .c file as it takes fewer lines.

   (5) Expand INIT_SIGNALS() and INIT_SIGHAND() in place.

   (6) Expand INIT_STRUCT_PID in place.

  These macros can then be discarded"

* tag 'init_task-20180117' of git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs:
  Expand INIT_STRUCT_PID and remove
  Expand the INIT_SIGNALS and INIT_SIGHAND macros and remove
  Expand various INIT_* macros and remove
  Expand INIT_TASK() in init/init_task.c and remove
  Construct init thread stack in the linker script rather than by union
  openrisc: Make THREAD_SIZE available to vmlinux.lds
  hexagon: Make THREAD_SIZE available to vmlinux.lds
  cris: Make THREAD_SIZE available to vmlinux.lds

2 files changed, 163 insertions, 9 deletions

diff --git a/init/Makefile b/init/Makefile
index 1dbb23787290..a3e5ce2bcf08 100644
--- a/init/Makefile
+++ b/init/Makefile
@@ -13,9 +13,7 @@ obj-$(CONFIG_BLK_DEV_INITRD)   += initramfs.o
 endif
 obj-$(CONFIG_GENERIC_CALIBRATE_DELAY) += calibrate.o
 
-ifneq ($(CONFIG_ARCH_INIT_TASK),y)
 obj-y                          += init_task.o
-endif
 
 mounts-y			:= do_mounts.o
 mounts-$(CONFIG_BLK_DEV_RAM)	+= do_mounts_rd.o
diff --git a/init/init_task.c b/init/init_task.c
index 9325fee7dc82..3ac6e754cf64 100644
--- a/init/init_task.c
+++ b/init/init_task.c
@@ -13,19 +13,175 @@
 #include <asm/pgtable.h>
 #include <linux/uaccess.h>
 
-static struct signal_struct init_signals = INIT_SIGNALS(init_signals);
-static struct sighand_struct init_sighand = INIT_SIGHAND(init_sighand);
+static struct signal_struct init_signals = {
+	.nr_threads	= 1,
+	.thread_head	= LIST_HEAD_INIT(init_task.thread_node),
+	.wait_chldexit	= __WAIT_QUEUE_HEAD_INITIALIZER(init_signals.wait_chldexit),
+	.shared_pending	= {
+		.list = LIST_HEAD_INIT(init_signals.shared_pending.list),
+		.signal =  {{0}}
+	},
+	.rlim		= INIT_RLIMITS,
+	.cred_guard_mutex = __MUTEX_INITIALIZER(init_signals.cred_guard_mutex),
+#ifdef CONFIG_POSIX_TIMERS
+	.posix_timers = LIST_HEAD_INIT(init_signals.posix_timers),
+	.cputimer	= {
+		.cputime_atomic	= INIT_CPUTIME_ATOMIC,
+		.running	= false,
+		.checking_timer = false,
+	},
+#endif
+	INIT_CPU_TIMERS(init_signals)
+	INIT_PREV_CPUTIME(init_signals)
+};
+
+static struct sighand_struct init_sighand = {
+	.count		= ATOMIC_INIT(1),
+	.action		= { { { .sa_handler = SIG_DFL, } }, },
+	.siglock	= __SPIN_LOCK_UNLOCKED(init_sighand.siglock),
+	.signalfd_wqh	= __WAIT_QUEUE_HEAD_INITIALIZER(init_sighand.signalfd_wqh),
+};
 
-/* Initial task structure */
-struct task_struct init_task = INIT_TASK(init_task);
+/*
+ * Set up the first task table, touch at your own risk!. Base=0,
+ * limit=0x1fffff (=2MB)
+ */
+struct task_struct init_task
+#ifdef CONFIG_ARCH_TASK_STRUCT_ON_STACK
+	__init_task_data
+#endif
+= {
+#ifdef CONFIG_THREAD_INFO_IN_TASK
+	.thread_info	= INIT_THREAD_INFO(init_task),
+	.stack_refcount	= ATOMIC_INIT(1),
+#endif
+	.state		= 0,
+	.stack		= init_stack,
+	.usage		= ATOMIC_INIT(2),
+	.flags		= PF_KTHREAD,
+	.prio		= MAX_PRIO - 20,
+	.static_prio	= MAX_PRIO - 20,
+	.normal_prio	= MAX_PRIO - 20,
+	.policy		= SCHED_NORMAL,
+	.cpus_allowed	= CPU_MASK_ALL,
+	.nr_cpus_allowed= NR_CPUS,
+	.mm		= NULL,
+	.active_mm	= &init_mm,
+	.restart_block	= {
+		.fn = do_no_restart_syscall,
+	},
+	.se		= {
+		.group_node 	= LIST_HEAD_INIT(init_task.se.group_node),
+	},
+	.rt		= {
+		.run_list	= LIST_HEAD_INIT(init_task.rt.run_list),
+		.time_slice	= RR_TIMESLICE,
+	},
+	.tasks		= LIST_HEAD_INIT(init_task.tasks),
+#ifdef CONFIG_SMP
+	.pushable_tasks	= PLIST_NODE_INIT(init_task.pushable_tasks, MAX_PRIO),
+#endif
+#ifdef CONFIG_CGROUP_SCHED
+	.sched_task_group = &root_task_group,
+#endif
+	.ptraced	= LIST_HEAD_INIT(init_task.ptraced),
+	.ptrace_entry	= LIST_HEAD_INIT(init_task.ptrace_entry),
+	.real_parent	= &init_task,
+	.parent		= &init_task,
+	.children	= LIST_HEAD_INIT(init_task.children),
+	.sibling	= LIST_HEAD_INIT(init_task.sibling),
+	.group_leader	= &init_task,
+	RCU_POINTER_INITIALIZER(real_cred, &init_cred),
+	RCU_POINTER_INITIALIZER(cred, &init_cred),
+	.comm		= INIT_TASK_COMM,
+	.thread		= INIT_THREAD,
+	.fs		= &init_fs,
+	.files		= &init_files,
+	.signal		= &init_signals,
+	.sighand	= &init_sighand,
+	.nsproxy	= &init_nsproxy,
+	.pending	= {
+		.list = LIST_HEAD_INIT(init_task.pending.list),
+		.signal = {{0}}
+	},
+	.blocked	= {{0}},
+	.alloc_lock	= __SPIN_LOCK_UNLOCKED(init_task.alloc_lock),
+	.journal_info	= NULL,
+	INIT_CPU_TIMERS(init_task)
+	.pi_lock	= __RAW_SPIN_LOCK_UNLOCKED(init_task.pi_lock),
+	.timer_slack_ns = 50000, /* 50 usec default slack */
+	.pids = {
+		[PIDTYPE_PID]  = INIT_PID_LINK(PIDTYPE_PID),
+		[PIDTYPE_PGID] = INIT_PID_LINK(PIDTYPE_PGID),
+		[PIDTYPE_SID]  = INIT_PID_LINK(PIDTYPE_SID),
+	},
+	.thread_group	= LIST_HEAD_INIT(init_task.thread_group),
+	.thread_node	= LIST_HEAD_INIT(init_signals.thread_head),
+#ifdef CONFIG_AUDITSYSCALL
+	.loginuid	= INVALID_UID,
+	.sessionid	= (unsigned int)-1,
+#endif
+#ifdef CONFIG_PERF_EVENTS
+	.perf_event_mutex = __MUTEX_INITIALIZER(init_task.perf_event_mutex),
+	.perf_event_list = LIST_HEAD_INIT(init_task.perf_event_list),
+#endif
+#ifdef CONFIG_PREEMPT_RCU
+	.rcu_read_lock_nesting = 0,
+	.rcu_read_unlock_special.s = 0,
+	.rcu_node_entry = LIST_HEAD_INIT(init_task.rcu_node_entry),
+	.rcu_blocked_node = NULL,
+#endif
+#ifdef CONFIG_TASKS_RCU
+	.rcu_tasks_holdout = false,
+	.rcu_tasks_holdout_list = LIST_HEAD_INIT(init_task.rcu_tasks_holdout_list),
+	.rcu_tasks_idle_cpu = -1,
+#endif
+#ifdef CONFIG_CPUSETS
+	.mems_allowed_seq = SEQCNT_ZERO(init_task.mems_allowed_seq),
+#endif
+#ifdef CONFIG_RT_MUTEXES
+	.pi_waiters	= RB_ROOT_CACHED,
+	.pi_top_task	= NULL,
+#endif
+	INIT_PREV_CPUTIME(init_task)
+#ifdef CONFIG_VIRT_CPU_ACCOUNTING_GEN
+	.vtime.seqcount	= SEQCNT_ZERO(init_task.vtime_seqcount),
+	.vtime.starttime = 0,
+	.vtime.state	= VTIME_SYS,
+#endif
+#ifdef CONFIG_NUMA_BALANCING
+	.numa_preferred_nid = -1,
+	.numa_group	= NULL,
+	.numa_faults	= NULL,
+#endif
+#ifdef CONFIG_KASAN
+	.kasan_depth	= 1,
+#endif
+#ifdef CONFIG_TRACE_IRQFLAGS
+	.softirqs_enabled = 1,
+#endif
+#ifdef CONFIG_LOCKDEP
+	.lockdep_recursion = 0,
+#endif
+#ifdef CONFIG_FUNCTION_GRAPH_TRACER
+	.ret_stack	= NULL,
+#endif
+#if defined(CONFIG_TRACING) && defined(CONFIG_PREEMPT)
+	.trace_recursion = 0,
+#endif
+#ifdef CONFIG_LIVEPATCH
+	.patch_state	= KLP_UNDEFINED,
+#endif
+#ifdef CONFIG_SECURITY
+	.security	= NULL,
+#endif
+};
 EXPORT_SYMBOL(init_task);
 
 /*
  * Initial thread structure. Alignment of this is handled by a special
  * linker map entry.
  */
-union thread_union init_thread_union __init_task_data = {
 #ifndef CONFIG_THREAD_INFO_IN_TASK
-	INIT_THREAD_INFO(init_task)
+struct thread_info init_thread_info __init_thread_info = INIT_THREAD_INFO(init_task);
 #endif
-};