Revert "sched/autogroup: Fix crash on reboot when autogroup is disabled" (c1ad41f1) · Commits · 戴 / test

fs/proc/base.c

+78 −0

Original line number	Diff line number	Diff line
		@@ -1272,6 +1272,81 @@ static const struct file_operations proc_pid_sched_operations = {

		#endif

		#ifdef CONFIG_SCHED_AUTOGROUP
		/*
		* Print out autogroup related information:
		*/
		static int sched_autogroup_show(struct seq_file m, void v)
		{
		struct inode *inode = m->private;
		struct task_struct *p;

		p = get_proc_task(inode);
		if (!p)
		return -ESRCH;
		proc_sched_autogroup_show_task(p, m);

		put_task_struct(p);

		return 0;
		}

		static ssize_t
		sched_autogroup_write(struct file file, const char __user buf,
		size_t count, loff_t *offset)
		{
		struct inode *inode = file->f_path.dentry->d_inode;
		struct task_struct *p;
		char buffer[PROC_NUMBUF];
		int nice;
		int err;

		memset(buffer, 0, sizeof(buffer));
		if (count > sizeof(buffer) - 1)
		count = sizeof(buffer) - 1;
		if (copy_from_user(buffer, buf, count))
		return -EFAULT;

		err = kstrtoint(strstrip(buffer), 0, &nice);
		if (err < 0)
		return err;

		p = get_proc_task(inode);
		if (!p)
		return -ESRCH;

		err = proc_sched_autogroup_set_nice(p, nice);
		if (err)
		count = err;

		put_task_struct(p);

		return count;
		}

		static int sched_autogroup_open(struct inode inode, struct file filp)
		{
		int ret;

		ret = single_open(filp, sched_autogroup_show, NULL);
		if (!ret) {
		struct seq_file *m = filp->private_data;

		m->private = inode;
		}
		return ret;
		}

		static const struct file_operations proc_pid_sched_autogroup_operations = {
		.open = sched_autogroup_open,
		.read = seq_read,
		.write = sched_autogroup_write,
		.llseek = seq_lseek,
		.release = single_release,
		};

		#endif /* CONFIG_SCHED_AUTOGROUP */

		static ssize_t comm_write(struct file file, const char __user buf,
		size_t count, loff_t *offset)
		{
		@@ -2582,6 +2657,9 @@ static const struct pid_entry tgid_base_stuff[] = {
		INF("limits", S_IRUGO, proc_pid_limits),
		#ifdef CONFIG_SCHED_DEBUG
		REG("sched", S_IRUGO\|S_IWUSR, proc_pid_sched_operations),
		#endif
		#ifdef CONFIG_SCHED_AUTOGROUP
		REG("autogroup", S_IRUGO\|S_IWUSR, proc_pid_sched_autogroup_operations),
		#endif
		REG("comm", S_IRUGO\|S_IWUSR, proc_pid_set_comm_operations),
		#ifdef CONFIG_HAVE_ARCH_TRACEHOOK

kernel/sched/auto_group.c

+57 −11

Original line number	Diff line number	Diff line
		@@ -110,9 +110,6 @@ out_fail:

		bool task_wants_autogroup(struct task_struct p, struct task_group tg)
		{
		if (!sysctl_sched_autogroup_enabled)
		return false;

		if (tg != &root_task_group)
		return false;

		@@ -146,11 +143,15 @@ autogroup_move_group(struct task_struct p, struct autogroup ag)

		p->signal->autogroup = autogroup_kref_get(ag);

		if (!ACCESS_ONCE(sysctl_sched_autogroup_enabled))
		goto out;

		t = p;
		do {
		sched_move_task(t);
		} while_each_thread(p, t);

		out:
		unlock_task_sighand(p, &flags);
		autogroup_kref_put(prev);
		}
		@@ -158,11 +159,8 @@ autogroup_move_group(struct task_struct p, struct autogroup ag)
		/* Allocates GFP_KERNEL, cannot be called under any spinlock */
		void sched_autogroup_create_attach(struct task_struct *p)
		{
		struct autogroup *ag;
		struct autogroup *ag = autogroup_create();

		if (!sysctl_sched_autogroup_enabled)
		return;
		ag = autogroup_create();
		autogroup_move_group(p, ag);
		/* drop extra reference added by autogroup_create() */
		autogroup_kref_put(ag);
		@@ -178,15 +176,11 @@ EXPORT_SYMBOL(sched_autogroup_detach);

		void sched_autogroup_fork(struct signal_struct *sig)
		{
		if (!sysctl_sched_autogroup_enabled)
		return;
		sig->autogroup = autogroup_task_get(current);
		}

		void sched_autogroup_exit(struct signal_struct *sig)
		{
		if (!sysctl_sched_autogroup_enabled)
		return;
		autogroup_kref_put(sig->autogroup);
		}

		@@ -199,6 +193,58 @@ static int __init setup_autogroup(char *str)

		__setup("noautogroup", setup_autogroup);

		#ifdef CONFIG_PROC_FS

		int proc_sched_autogroup_set_nice(struct task_struct *p, int nice)
		{
		static unsigned long next = INITIAL_JIFFIES;
		struct autogroup *ag;
		int err;

		if (nice < -20 \|\| nice > 19)
		return -EINVAL;

		err = security_task_setnice(current, nice);
		if (err)
		return err;

		if (nice < 0 && !can_nice(current, nice))
		return -EPERM;

		/* this is a heavy operation taking global locks.. */
		if (!capable(CAP_SYS_ADMIN) && time_before(jiffies, next))
		return -EAGAIN;

		next = HZ / 10 + jiffies;
		ag = autogroup_task_get(p);

		down_write(&ag->lock);
		err = sched_group_set_shares(ag->tg, prio_to_weight[nice + 20]);
		if (!err)
		ag->nice = nice;
		up_write(&ag->lock);

		autogroup_kref_put(ag);

		return err;
		}

		void proc_sched_autogroup_show_task(struct task_struct p, struct seq_file m)
		{
		struct autogroup *ag = autogroup_task_get(p);

		if (!task_group_is_autogroup(ag->tg))
		goto out;

		down_read(&ag->lock);
		seq_printf(m, "/autogroup-%ld nice %d\n", ag->id, ag->nice);
		up_read(&ag->lock);

		out:
		autogroup_kref_put(ag);
		}
		#endif /* CONFIG_PROC_FS */

		#ifdef CONFIG_SCHED_DEBUG
		int autogroup_path(struct task_group tg, char buf, int buflen)
		{

kernel/sched/auto_group.h

+8 −1

Original line number	Diff line number	Diff line
		@@ -4,6 +4,11 @@
		#include <linux/rwsem.h>

		struct autogroup {
		/*
		* reference doesn't mean how many thread attach to this
		* autogroup now. It just stands for the number of task
		* could use this autogroup.
		*/
		struct kref kref;
		struct task_group *tg;
		struct rw_semaphore lock;
		@@ -24,7 +29,9 @@ extern bool task_wants_autogroup(struct task_struct p, struct task_group tg);
		static inline struct task_group *
		autogroup_task_group(struct task_struct p, struct task_group tg)
		{
		if (task_wants_autogroup(p, tg))
		int enabled = ACCESS_ONCE(sysctl_sched_autogroup_enabled);

		if (enabled && task_wants_autogroup(p, tg))
		return p->signal->autogroup->tg;

		return tg;

kernel/sysctl.c

+4 −2

Original line number	Diff line number	Diff line
		@@ -367,8 +367,10 @@ static struct ctl_table kern_table[] = {
		.procname = "sched_autogroup_enabled",
		.data = &sysctl_sched_autogroup_enabled,
		.maxlen = sizeof(unsigned int),
		.mode = 0444,
		.proc_handler = proc_dointvec,
		.mode = 0644,
		.proc_handler = proc_dointvec_minmax,
		.extra1 = &zero,
		.extra2 = &one,
		},
		#endif
		#ifdef CONFIG_CFS_BANDWIDTH

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