[PATCH] RCU signal handling (e56d0903) · Commits · e / devices / android_kernel_oneplus_sm7250

fs/exec.c

+2 −2

Original line number	Original line	Diff line number	Diff line
	@@ -760,7 +760,7 @@ static inline int de_thread(struct task_struct *tsk)
	spin_lock(&oldsighand->siglock);		spin_lock(&oldsighand->siglock);
	spin_lock(&newsighand->siglock);		spin_lock(&newsighand->siglock);

	current->sighand = newsighand;		rcu_assign_pointer(current->sighand, newsighand);
	recalc_sigpending();		recalc_sigpending();

	spin_unlock(&newsighand->siglock);		spin_unlock(&newsighand->siglock);
	@@ -768,7 +768,7 @@ static inline int de_thread(struct task_struct *tsk)
	write_unlock_irq(&tasklist_lock);		write_unlock_irq(&tasklist_lock);

	if (atomic_dec_and_test(&oldsighand->count))		if (atomic_dec_and_test(&oldsighand->count))
	kmem_cache_free(sighand_cachep, oldsighand);		sighand_free(oldsighand);
	}		}

	BUG_ON(!thread_group_leader(current));		BUG_ON(!thread_group_leader(current));

include/linux/sched.h

+30 −2

Original line number	Original line	Diff line number	Diff line
	@@ -34,6 +34,7 @@
	#include <linux/percpu.h>		#include <linux/percpu.h>
	#include <linux/topology.h>		#include <linux/topology.h>
	#include <linux/seccomp.h>		#include <linux/seccomp.h>
			#include <linux/rcupdate.h>

	#include <linux/auxvec.h> /* For AT_VECTOR_SIZE */		#include <linux/auxvec.h> /* For AT_VECTOR_SIZE */

	@@ -350,8 +351,16 @@ struct sighand_struct {
	atomic_t count;		atomic_t count;
	struct k_sigaction action[_NSIG];		struct k_sigaction action[_NSIG];
	spinlock_t siglock;		spinlock_t siglock;
			struct rcu_head rcu;
	};		};

			extern void sighand_free_cb(struct rcu_head *rhp);

			static inline void sighand_free(struct sighand_struct *sp)
			{
			call_rcu(&sp->rcu, sighand_free_cb);
			}

	/*		/*
	* NOTE! "signal_struct" does not have it's own		* NOTE! "signal_struct" does not have it's own
	* locking, because a shared signal_struct always		* locking, because a shared signal_struct always
	@@ -844,6 +853,7 @@ struct task_struct {
	int cpuset_mems_generation;		int cpuset_mems_generation;
	#endif		#endif
	atomic_t fs_excl; /* holding fs exclusive resources */		atomic_t fs_excl; /* holding fs exclusive resources */
			struct rcu_head rcu;
	};		};

	static inline pid_t process_group(struct task_struct *tsk)		static inline pid_t process_group(struct task_struct *tsk)
	@@ -867,8 +877,26 @@ static inline int pid_alive(struct task_struct *p)
	extern void free_task(struct task_struct *tsk);		extern void free_task(struct task_struct *tsk);
	extern void __put_task_struct(struct task_struct *tsk);		extern void __put_task_struct(struct task_struct *tsk);
	#define get_task_struct(tsk) do { atomic_inc(&(tsk)->usage); } while(0)		#define get_task_struct(tsk) do { atomic_inc(&(tsk)->usage); } while(0)
	#define put_task_struct(tsk) \
	do { if (atomic_dec_and_test(&(tsk)->usage)) __put_task_struct(tsk); } while(0)		static inline int get_task_struct_rcu(struct task_struct *t)
			{
			int oldusage;

			do {
			oldusage = atomic_read(&t->usage);
			if (oldusage == 0)
			return 0;
			} while (cmpxchg(&t->usage.counter, oldusage, oldusage+1) != oldusage);
			return 1;
			}

			extern void __put_task_struct_cb(struct rcu_head *rhp);

			static inline void put_task_struct(struct task_struct *t)
			{
			if (atomic_dec_and_test(&t->usage))
			call_rcu(&t->rcu, __put_task_struct_cb);
			}

	/*		/*
	* Per process flags		* Per process flags

kernel/exit.c

+0 −1

Original line number	Original line	Diff line number	Diff line
	@@ -72,7 +72,6 @@ void release_task(struct task_struct * p)
	__ptrace_unlink(p);		__ptrace_unlink(p);
	BUG_ON(!list_empty(&p->ptrace_list) \|\| !list_empty(&p->ptrace_children));		BUG_ON(!list_empty(&p->ptrace_list) \|\| !list_empty(&p->ptrace_children));
	__exit_signal(p);		__exit_signal(p);
	__exit_sighand(p);
	/*		/*
	* Note that the fastpath in sys_times depends on __exit_signal having		* Note that the fastpath in sys_times depends on __exit_signal having
	* updated the counters before a task is removed from the tasklist of		* updated the counters before a task is removed from the tasklist of

kernel/fork.c

+9 −1

Original line number	Original line	Diff line number	Diff line
	@@ -743,6 +743,14 @@ int unshare_files(void)

	EXPORT_SYMBOL(unshare_files);		EXPORT_SYMBOL(unshare_files);

			void sighand_free_cb(struct rcu_head *rhp)
			{
			struct sighand_struct *sp;

			sp = container_of(rhp, struct sighand_struct, rcu);
			kmem_cache_free(sighand_cachep, sp);
			}

	static inline int copy_sighand(unsigned long clone_flags, struct task_struct * tsk)		static inline int copy_sighand(unsigned long clone_flags, struct task_struct * tsk)
	{		{
	struct sighand_struct *sig;		struct sighand_struct *sig;
	@@ -752,7 +760,7 @@ static inline int copy_sighand(unsigned long clone_flags, struct task_struct * t
	return 0;		return 0;
	}		}
	sig = kmem_cache_alloc(sighand_cachep, GFP_KERNEL);		sig = kmem_cache_alloc(sighand_cachep, GFP_KERNEL);
	tsk->sighand = sig;		rcu_assign_pointer(tsk->sighand, sig);
	if (!sig)		if (!sig)
	return -ENOMEM;		return -ENOMEM;
	spin_lock_init(&sig->siglock);		spin_lock_init(&sig->siglock);

kernel/pid.c

+11 −11

Original line number	Original line	Diff line number	Diff line
	@@ -136,7 +136,7 @@ struct pid * fastcall find_pid(enum pid_type type, int nr)
	struct hlist_node *elem;		struct hlist_node *elem;
	struct pid *pid;		struct pid *pid;

	hlist_for_each_entry(pid, elem,		hlist_for_each_entry_rcu(pid, elem,
	&pid_hash[type][pid_hashfn(nr)], pid_chain) {		&pid_hash[type][pid_hashfn(nr)], pid_chain) {
	if (pid->nr == nr)		if (pid->nr == nr)
	return pid;		return pid;
	@@ -150,15 +150,15 @@ int fastcall attach_pid(task_t *task, enum pid_type type, int nr)

	task_pid = &task->pids[type];		task_pid = &task->pids[type];
	pid = find_pid(type, nr);		pid = find_pid(type, nr);
			task_pid->nr = nr;
	if (pid == NULL) {		if (pid == NULL) {
	hlist_add_head(&task_pid->pid_chain,
	&pid_hash[type][pid_hashfn(nr)]);
	INIT_LIST_HEAD(&task_pid->pid_list);		INIT_LIST_HEAD(&task_pid->pid_list);
			hlist_add_head_rcu(&task_pid->pid_chain,
			&pid_hash[type][pid_hashfn(nr)]);
	} else {		} else {
	INIT_HLIST_NODE(&task_pid->pid_chain);		INIT_HLIST_NODE(&task_pid->pid_chain);
	list_add_tail(&task_pid->pid_list, &pid->pid_list);		list_add_tail_rcu(&task_pid->pid_list, &pid->pid_list);
	}		}
	task_pid->nr = nr;

	return 0;		return 0;
	}		}
	@@ -170,20 +170,20 @@ static fastcall int __detach_pid(task_t *task, enum pid_type type)

	pid = &task->pids[type];		pid = &task->pids[type];
	if (!hlist_unhashed(&pid->pid_chain)) {		if (!hlist_unhashed(&pid->pid_chain)) {
	hlist_del(&pid->pid_chain);

	if (list_empty(&pid->pid_list))		if (list_empty(&pid->pid_list)) {
	nr = pid->nr;		nr = pid->nr;
	else {		hlist_del_rcu(&pid->pid_chain);
			} else {
	pid_next = list_entry(pid->pid_list.next,		pid_next = list_entry(pid->pid_list.next,
	struct pid, pid_list);		struct pid, pid_list);
	/* insert next pid from pid_list to hash */		/* insert next pid from pid_list to hash */
	hlist_add_head(&pid_next->pid_chain,		hlist_replace_rcu(&pid->pid_chain,
	&pid_hash[type][pid_hashfn(pid_next->nr)]);		&pid_next->pid_chain);
	}		}
	}		}

	list_del(&pid->pid_list);		list_del_rcu(&pid->pid_list);
	pid->nr = 0;		pid->nr = 0;

	return nr;		return nr;