Merge tag 'y2038' of git://git.kernel.org/pub/scm/linux/kernel/git/arnd/playground into timers/core

Pull more y2038 work from Arnd Bergman:

y2038: convert more syscalls

Here is another set of system call changes to prepare the change over to
64-bit time_t. As before, the strategy is to change system calls that
take a 'struct timespec' argument over to 'struct __kernel_timespec',
which for now is defined to be the same but will get redefined to use a
64-bit time_t argument once we are ready to modify the system call tables.

The major change from previous patches is that the plan is no longer
to directly use the 'compat' system calls for providing compatibility
with the existing 32-bit time_t based entry points. Instead, we rename
the compat code to something that makes more sense on 32-bit architectures,
e.g. compat_timespec becomes old_timespec32.

With the renamed types in place, change over the 'stat' and 'utimes'
families of system calls, sched_rr_get_interval, recvmmsg and
rt_sigtimedwait. Another series for poll, select and io_pgetevents is
currently being tested.

1 files changed, 103 insertions, 32 deletions

diff --git a/kernel/fork.c b/kernel/fork.c
index 9440d61b925c..d896e9ca38b0 100644
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -303,11 +303,37 @@ struct kmem_cache *files_cachep;
 struct kmem_cache *fs_cachep;
 
 /* SLAB cache for vm_area_struct structures */
-struct kmem_cache *vm_area_cachep;
+static struct kmem_cache *vm_area_cachep;
 
 /* SLAB cache for mm_struct structures (tsk->mm) */
 static struct kmem_cache *mm_cachep;
 
+struct vm_area_struct *vm_area_alloc(struct mm_struct *mm)
+{
+	struct vm_area_struct *vma;
+
+	vma = kmem_cache_alloc(vm_area_cachep, GFP_KERNEL);
+	if (vma)
+		vma_init(vma, mm);
+	return vma;
+}
+
+struct vm_area_struct *vm_area_dup(struct vm_area_struct *orig)
+{
+	struct vm_area_struct *new = kmem_cache_alloc(vm_area_cachep, GFP_KERNEL);
+
+	if (new) {
+		*new = *orig;
+		INIT_LIST_HEAD(&new->anon_vma_chain);
+	}
+	return new;
+}
+
+void vm_area_free(struct vm_area_struct *vma)
+{
+	kmem_cache_free(vm_area_cachep, vma);
+}
+
 static void account_kernel_stack(struct task_struct *tsk, int account)
 {
 	void *stack = task_stack_page(tsk);
@@ -455,11 +481,9 @@ static __latent_entropy int dup_mmap(struct mm_struct *mm,
 				goto fail_nomem;
 			charge = len;
 		}
-		tmp = kmem_cache_alloc(vm_area_cachep, GFP_KERNEL);
+		tmp = vm_area_dup(mpnt);
 		if (!tmp)
 			goto fail_nomem;
-		*tmp = *mpnt;
-		INIT_LIST_HEAD(&tmp->anon_vma_chain);
 		retval = vma_dup_policy(mpnt, tmp);
 		if (retval)
 			goto fail_nomem_policy;
@@ -539,7 +563,7 @@ fail_uprobe_end:
 fail_nomem_anon_vma_fork:
 	mpol_put(vma_policy(tmp));
 fail_nomem_policy:
-	kmem_cache_free(vm_area_cachep, tmp);
+	vm_area_free(tmp);
 fail_nomem:
 	retval = -ENOMEM;
 	vm_unacct_memory(charge);
@@ -843,6 +867,14 @@ static struct task_struct *dup_task_struct(struct task_struct *orig, int node)
 	tsk->fail_nth = 0;
 #endif
 
+#ifdef CONFIG_BLK_CGROUP
+	tsk->throttle_queue = NULL;
+	tsk->use_memdelay = 0;
+#endif
+
+#ifdef CONFIG_MEMCG
+	tsk->active_memcg = NULL;
+#endif
 	return tsk;
 
 free_stack:
@@ -1270,6 +1302,7 @@ static int copy_mm(unsigned long clone_flags, struct task_struct *tsk)
 	tsk->nvcsw = tsk->nivcsw = 0;
 #ifdef CONFIG_DETECT_HUNG_TASK
 	tsk->last_switch_count = tsk->nvcsw + tsk->nivcsw;
+	tsk->last_switch_time = 0;
 #endif
 
 	tsk->mm = NULL;
@@ -1394,7 +1427,9 @@ static int copy_sighand(unsigned long clone_flags, struct task_struct *tsk)
 		return -ENOMEM;
 
 	atomic_set(&sig->count, 1);
+	spin_lock_irq(&current->sighand->siglock);
 	memcpy(sig->action, current->sighand->action, sizeof(sig->action));
+	spin_unlock_irq(&current->sighand->siglock);
 	return 0;
 }
 
@@ -1456,6 +1491,7 @@ static int copy_signal(unsigned long clone_flags, struct task_struct *tsk)
 	init_waitqueue_head(&sig->wait_chldexit);
 	sig->curr_target = tsk;
 	init_sigpending(&sig->shared_pending);
+	INIT_HLIST_HEAD(&sig->multiprocess);
 	seqlock_init(&sig->stats_lock);
 	prev_cputime_init(&sig->prev_cputime);
 
@@ -1549,10 +1585,22 @@ static void posix_cpu_timers_init(struct task_struct *tsk)
 static inline void posix_cpu_timers_init(struct task_struct *tsk) { }
 #endif
 
+static inline void init_task_pid_links(struct task_struct *task)
+{
+	enum pid_type type;
+
+	for (type = PIDTYPE_PID; type < PIDTYPE_MAX; ++type) {
+		INIT_HLIST_NODE(&task->pid_links[type]);
+	}
+}
+
 static inline void
 init_task_pid(struct task_struct *task, enum pid_type type, struct pid *pid)
 {
-	 task->pids[type].pid = pid;
+	if (type == PIDTYPE_PID)
+		task->thread_pid = pid;
+	else
+		task->signal->pids[type] = pid;
 }
 
 static inline void rcu_copy_process(struct task_struct *p)
@@ -1590,6 +1638,7 @@ static __latent_entropy struct task_struct *copy_process(
 {
 	int retval;
 	struct task_struct *p;
+	struct multiprocess_signals delayed;
 
 	/*
 	 * Don't allow sharing the root directory with processes in a different
@@ -1637,6 +1686,24 @@ static __latent_entropy struct task_struct *copy_process(
 			return ERR_PTR(-EINVAL);
 	}
 
+	/*
+	 * Force any signals received before this point to be delivered
+	 * before the fork happens.  Collect up signals sent to multiple
+	 * processes that happen during the fork and delay them so that
+	 * they appear to happen after the fork.
+	 */
+	sigemptyset(&delayed.signal);
+	INIT_HLIST_NODE(&delayed.node);
+
+	spin_lock_irq(&current->sighand->siglock);
+	if (!(clone_flags & CLONE_THREAD))
+		hlist_add_head(&delayed.node, &current->signal->multiprocess);
+	recalc_sigpending();
+	spin_unlock_irq(&current->sighand->siglock);
+	retval = -ERESTARTNOINTR;
+	if (signal_pending(current))
+		goto fork_out;
+
 	retval = -ENOMEM;
 	p = dup_task_struct(current, node);
 	if (!p)
@@ -1910,29 +1977,26 @@ static __latent_entropy struct task_struct *copy_process(
 
 	rseq_fork(p, clone_flags);
 
-	/*
-	 * Process group and session signals need to be delivered to just the
-	 * parent before the fork or both the parent and the child after the
-	 * fork. Restart if a signal comes in before we add the new process to
-	 * it's process group.
-	 * A fatal signal pending means that current will exit, so the new
-	 * thread can't slip out of an OOM kill (or normal SIGKILL).
-	*/
-	recalc_sigpending();
-	if (signal_pending(current)) {
-		retval = -ERESTARTNOINTR;
-		goto bad_fork_cancel_cgroup;
-	}
+	/* Don't start children in a dying pid namespace */
 	if (unlikely(!(ns_of_pid(pid)->pid_allocated & PIDNS_ADDING))) {
 		retval = -ENOMEM;
 		goto bad_fork_cancel_cgroup;
 	}
 
+	/* Let kill terminate clone/fork in the middle */
+	if (fatal_signal_pending(current)) {
+		retval = -EINTR;
+		goto bad_fork_cancel_cgroup;
+	}
+
+
+	init_task_pid_links(p);
 	if (likely(p->pid)) {
 		ptrace_init_task(p, (clone_flags & CLONE_PTRACE) || trace);
 
 		init_task_pid(p, PIDTYPE_PID, pid);
 		if (thread_group_leader(p)) {
+			init_task_pid(p, PIDTYPE_TGID, pid);
 			init_task_pid(p, PIDTYPE_PGID, task_pgrp(current));
 			init_task_pid(p, PIDTYPE_SID, task_session(current));
 
@@ -1940,8 +2004,7 @@ static __latent_entropy struct task_struct *copy_process(
 				ns_of_pid(pid)->child_reaper = p;
 				p->signal->flags |= SIGNAL_UNKILLABLE;
 			}
-
-			p->signal->leader_pid = pid;
+			p->signal->shared_pending.signal = delayed.signal;
 			p->signal->tty = tty_kref_get(current->signal->tty);
 			/*
 			 * Inherit has_child_subreaper flag under the same
@@ -1952,6 +2015,7 @@ static __latent_entropy struct task_struct *copy_process(
 							 p->real_parent->signal->is_child_subreaper;
 			list_add_tail(&p->sibling, &p->real_parent->children);
 			list_add_tail_rcu(&p->tasks, &init_task.tasks);
+			attach_pid(p, PIDTYPE_TGID);
 			attach_pid(p, PIDTYPE_PGID);
 			attach_pid(p, PIDTYPE_SID);
 			__this_cpu_inc(process_counts);
@@ -1959,6 +2023,7 @@ static __latent_entropy struct task_struct *copy_process(
 			current->signal->nr_threads++;
 			atomic_inc(&current->signal->live);
 			atomic_inc(&current->signal->sigcnt);
+			task_join_group_stop(p);
 			list_add_tail_rcu(&p->thread_group,
 					  &p->group_leader->thread_group);
 			list_add_tail_rcu(&p->thread_node,
@@ -1967,8 +2032,8 @@ static __latent_entropy struct task_struct *copy_process(
 		attach_pid(p, PIDTYPE_PID);
 		nr_threads++;
 	}
-
 	total_forks++;
+	hlist_del_init(&delayed.node);
 	spin_unlock(&current->sighand->siglock);
 	syscall_tracepoint_update(p);
 	write_unlock_irq(&tasklist_lock);
@@ -2033,16 +2098,19 @@ bad_fork_free:
 	put_task_stack(p);
 	free_task(p);
 fork_out:
+	spin_lock_irq(&current->sighand->siglock);
+	hlist_del_init(&delayed.node);
+	spin_unlock_irq(&current->sighand->siglock);
 	return ERR_PTR(retval);
 }
 
-static inline void init_idle_pids(struct pid_link *links)
+static inline void init_idle_pids(struct task_struct *idle)
 {
 	enum pid_type type;
 
 	for (type = PIDTYPE_PID; type < PIDTYPE_MAX; ++type) {
-		INIT_HLIST_NODE(&links[type].node); /* not really needed */
-		links[type].pid = &init_struct_pid;
+		INIT_HLIST_NODE(&idle->pid_links[type]); /* not really needed */
+		init_task_pid(idle, type, &init_struct_pid);
 	}
 }
 
@@ -2052,7 +2120,7 @@ struct task_struct *fork_idle(int cpu)
 	task = copy_process(CLONE_VM, 0, 0, NULL, &init_struct_pid, 0, 0,
 			    cpu_to_node(cpu));
 	if (!IS_ERR(task)) {
-		init_idle_pids(task->pids);
+		init_idle_pids(task);
 		init_idle(task, cpu);
 	}
 
@@ -2253,6 +2321,8 @@ static void sighand_ctor(void *data)
 
 void __init proc_caches_init(void)
 {
+	unsigned int mm_size;
+
 	sighand_cachep = kmem_cache_create("sighand_cache",
 			sizeof(struct sighand_struct), 0,
 			SLAB_HWCACHE_ALIGN|SLAB_PANIC|SLAB_TYPESAFE_BY_RCU|
@@ -2269,15 +2339,16 @@ void __init proc_caches_init(void)
 			sizeof(struct fs_struct), 0,
 			SLAB_HWCACHE_ALIGN|SLAB_PANIC|SLAB_ACCOUNT,
 			NULL);
+
 	/*
-	 * FIXME! The "sizeof(struct mm_struct)" currently includes the
-	 * whole struct cpumask for the OFFSTACK case. We could change
-	 * this to *only* allocate as much of it as required by the
-	 * maximum number of CPU's we can ever have.  The cpumask_allocation
-	 * is at the end of the structure, exactly for that reason.
+	 * The mm_cpumask is located at the end of mm_struct, and is
+	 * dynamically sized based on the maximum CPU number this system
+	 * can have, taking hotplug into account (nr_cpu_ids).
 	 */
+	mm_size = sizeof(struct mm_struct) + cpumask_size();
+
 	mm_cachep = kmem_cache_create_usercopy("mm_struct",
-			sizeof(struct mm_struct), ARCH_MIN_MMSTRUCT_ALIGN,
+			mm_size, ARCH_MIN_MMSTRUCT_ALIGN,
 			SLAB_HWCACHE_ALIGN|SLAB_PANIC|SLAB_ACCOUNT,
 			offsetof(struct mm_struct, saved_auxv),
 			sizeof_field(struct mm_struct, saved_auxv),