Merge branch 'topic/error' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/regulator into regulator-fixed

1 files changed, 164 insertions, 138 deletions

diff --git a/fs/proc/base.c b/fs/proc/base.c
index a11eb7196ec8..c2964d890c9a 100644
--- a/fs/proc/base.c
+++ b/fs/proc/base.c
@@ -400,23 +400,6 @@ static const struct file_operations proc_pid_cmdline_ops = {
 	.llseek	= generic_file_llseek,
 };
 
-static int proc_pid_auxv(struct seq_file *m, struct pid_namespace *ns,
-			 struct pid *pid, struct task_struct *task)
-{
-	struct mm_struct *mm = mm_access(task, PTRACE_MODE_READ_FSCREDS);
-	if (mm && !IS_ERR(mm)) {
-		unsigned int nwords = 0;
-		do {
-			nwords += 2;
-		} while (mm->saved_auxv[nwords - 2] != 0); /* AT_NULL */
-		seq_write(m, mm->saved_auxv, nwords * sizeof(mm->saved_auxv[0]));
-		mmput(mm);
-		return 0;
-	} else
-		return PTR_ERR(mm);
-}
-
-
 #ifdef CONFIG_KALLSYMS
 /*
  * Provides a wchan file via kallsyms in a proper one-value-per-file format.
@@ -483,7 +466,7 @@ static int proc_pid_stack(struct seq_file *m, struct pid_namespace *ns,
 		save_stack_trace_tsk(task, &trace);
 
 		for (i = 0; i < trace.nr_entries; i++) {
-			seq_printf(m, "[<%pK>] %pS\n",
+			seq_printf(m, "[<%pK>] %pB\n",
 				   (void *)entries[i], (void *)entries[i]);
 		}
 		unlock_trace(task);
@@ -579,11 +562,8 @@ static int proc_oom_score(struct seq_file *m, struct pid_namespace *ns,
 	unsigned long totalpages = totalram_pages + total_swap_pages;
 	unsigned long points = 0;
 
-	read_lock(&tasklist_lock);
-	if (pid_alive(task))
-		points = oom_badness(task, NULL, NULL, totalpages) *
-						1000 / totalpages;
-	read_unlock(&tasklist_lock);
+	points = oom_badness(task, NULL, NULL, totalpages) *
+					1000 / totalpages;
 	seq_printf(m, "%lu\n", points);
 
 	return 0;
@@ -712,7 +692,7 @@ int proc_setattr(struct dentry *dentry, struct iattr *attr)
 	if (attr->ia_valid & ATTR_MODE)
 		return -EPERM;
 
-	error = inode_change_ok(inode, attr);
+	error = setattr_prepare(dentry, attr);
 	if (error)
 		return error;
 
@@ -1017,6 +997,30 @@ static const struct file_operations proc_environ_operations = {
 	.release	= mem_release,
 };
 
+static int auxv_open(struct inode *inode, struct file *file)
+{
+	return __mem_open(inode, file, PTRACE_MODE_READ_FSCREDS);
+}
+
+static ssize_t auxv_read(struct file *file, char __user *buf,
+			size_t count, loff_t *ppos)
+{
+	struct mm_struct *mm = file->private_data;
+	unsigned int nwords = 0;
+	do {
+		nwords += 2;
+	} while (mm->saved_auxv[nwords - 2] != 0); /* AT_NULL */
+	return simple_read_from_buffer(buf, count, ppos, mm->saved_auxv,
+				       nwords * sizeof(mm->saved_auxv[0]));
+}
+
+static const struct file_operations proc_auxv_operations = {
+	.open		= auxv_open,
+	.read		= auxv_read,
+	.llseek		= generic_file_llseek,
+	.release	= mem_release,
+};
+
 static ssize_t oom_adj_read(struct file *file, char __user *buf, size_t count,
 			    loff_t *ppos)
 {
@@ -1024,23 +1028,107 @@ static ssize_t oom_adj_read(struct file *file, char __user *buf, size_t count,
 	char buffer[PROC_NUMBUF];
 	int oom_adj = OOM_ADJUST_MIN;
 	size_t len;
-	unsigned long flags;
 
 	if (!task)
 		return -ESRCH;
-	if (lock_task_sighand(task, &flags)) {
-		if (task->signal->oom_score_adj == OOM_SCORE_ADJ_MAX)
-			oom_adj = OOM_ADJUST_MAX;
-		else
-			oom_adj = (task->signal->oom_score_adj * -OOM_DISABLE) /
-				  OOM_SCORE_ADJ_MAX;
-		unlock_task_sighand(task, &flags);
-	}
+	if (task->signal->oom_score_adj == OOM_SCORE_ADJ_MAX)
+		oom_adj = OOM_ADJUST_MAX;
+	else
+		oom_adj = (task->signal->oom_score_adj * -OOM_DISABLE) /
+			  OOM_SCORE_ADJ_MAX;
 	put_task_struct(task);
 	len = snprintf(buffer, sizeof(buffer), "%d\n", oom_adj);
 	return simple_read_from_buffer(buf, count, ppos, buffer, len);
 }
 
+static int __set_oom_adj(struct file *file, int oom_adj, bool legacy)
+{
+	static DEFINE_MUTEX(oom_adj_mutex);
+	struct mm_struct *mm = NULL;
+	struct task_struct *task;
+	int err = 0;
+
+	task = get_proc_task(file_inode(file));
+	if (!task)
+		return -ESRCH;
+
+	mutex_lock(&oom_adj_mutex);
+	if (legacy) {
+		if (oom_adj < task->signal->oom_score_adj &&
+				!capable(CAP_SYS_RESOURCE)) {
+			err = -EACCES;
+			goto err_unlock;
+		}
+		/*
+		 * /proc/pid/oom_adj is provided for legacy purposes, ask users to use
+		 * /proc/pid/oom_score_adj instead.
+		 */
+		pr_warn_once("%s (%d): /proc/%d/oom_adj is deprecated, please use /proc/%d/oom_score_adj instead.\n",
+			  current->comm, task_pid_nr(current), task_pid_nr(task),
+			  task_pid_nr(task));
+	} else {
+		if ((short)oom_adj < task->signal->oom_score_adj_min &&
+				!capable(CAP_SYS_RESOURCE)) {
+			err = -EACCES;
+			goto err_unlock;
+		}
+	}
+
+	/*
+	 * Make sure we will check other processes sharing the mm if this is
+	 * not vfrok which wants its own oom_score_adj.
+	 * pin the mm so it doesn't go away and get reused after task_unlock
+	 */
+	if (!task->vfork_done) {
+		struct task_struct *p = find_lock_task_mm(task);
+
+		if (p) {
+			if (atomic_read(&p->mm->mm_users) > 1) {
+				mm = p->mm;
+				atomic_inc(&mm->mm_count);
+			}
+			task_unlock(p);
+		}
+	}
+
+	task->signal->oom_score_adj = oom_adj;
+	if (!legacy && has_capability_noaudit(current, CAP_SYS_RESOURCE))
+		task->signal->oom_score_adj_min = (short)oom_adj;
+	trace_oom_score_adj_update(task);
+
+	if (mm) {
+		struct task_struct *p;
+
+		rcu_read_lock();
+		for_each_process(p) {
+			if (same_thread_group(task, p))
+				continue;
+
+			/* do not touch kernel threads or the global init */
+			if (p->flags & PF_KTHREAD || is_global_init(p))
+				continue;
+
+			task_lock(p);
+			if (!p->vfork_done && process_shares_mm(p, mm)) {
+				pr_info("updating oom_score_adj for %d (%s) from %d to %d because it shares mm with %d (%s). Report if this is unexpected.\n",
+						task_pid_nr(p), p->comm,
+						p->signal->oom_score_adj, oom_adj,
+						task_pid_nr(task), task->comm);
+				p->signal->oom_score_adj = oom_adj;
+				if (!legacy && has_capability_noaudit(current, CAP_SYS_RESOURCE))
+					p->signal->oom_score_adj_min = (short)oom_adj;
+			}
+			task_unlock(p);
+		}
+		rcu_read_unlock();
+		mmdrop(mm);
+	}
+err_unlock:
+	mutex_unlock(&oom_adj_mutex);
+	put_task_struct(task);
+	return err;
+}
+
 /*
  * /proc/pid/oom_adj exists solely for backwards compatibility with previous
  * kernels.  The effective policy is defined by oom_score_adj, which has a
@@ -1054,10 +1142,8 @@ static ssize_t oom_adj_read(struct file *file, char __user *buf, size_t count,
 static ssize_t oom_adj_write(struct file *file, const char __user *buf,
 			     size_t count, loff_t *ppos)
 {
-	struct task_struct *task;
 	char buffer[PROC_NUMBUF];
 	int oom_adj;
-	unsigned long flags;
 	int err;
 
 	memset(buffer, 0, sizeof(buffer));
@@ -1077,23 +1163,6 @@ static ssize_t oom_adj_write(struct file *file, const char __user *buf,
 		goto out;
 	}
 
-	task = get_proc_task(file_inode(file));
-	if (!task) {
-		err = -ESRCH;
-		goto out;
-	}
-
-	task_lock(task);
-	if (!task->mm) {
-		err = -EINVAL;
-		goto err_task_lock;
-	}
-
-	if (!lock_task_sighand(task, &flags)) {
-		err = -ESRCH;
-		goto err_task_lock;
-	}
-
 	/*
 	 * Scale /proc/pid/oom_score_adj appropriately ensuring that a maximum
 	 * value is always attainable.
@@ -1103,27 +1172,7 @@ static ssize_t oom_adj_write(struct file *file, const char __user *buf,
 	else
 		oom_adj = (oom_adj * OOM_SCORE_ADJ_MAX) / -OOM_DISABLE;
 
-	if (oom_adj < task->signal->oom_score_adj &&
-	    !capable(CAP_SYS_RESOURCE)) {
-		err = -EACCES;
-		goto err_sighand;
-	}
-
-	/*
-	 * /proc/pid/oom_adj is provided for legacy purposes, ask users to use
-	 * /proc/pid/oom_score_adj instead.
-	 */
-	pr_warn_once("%s (%d): /proc/%d/oom_adj is deprecated, please use /proc/%d/oom_score_adj instead.\n",
-		  current->comm, task_pid_nr(current), task_pid_nr(task),
-		  task_pid_nr(task));
-
-	task->signal->oom_score_adj = oom_adj;
-	trace_oom_score_adj_update(task);
-err_sighand:
-	unlock_task_sighand(task, &flags);
-err_task_lock:
-	task_unlock(task);
-	put_task_struct(task);
+	err = __set_oom_adj(file, oom_adj, true);
 out:
 	return err < 0 ? err : count;
 }
@@ -1140,15 +1189,11 @@ static ssize_t oom_score_adj_read(struct file *file, char __user *buf,
 	struct task_struct *task = get_proc_task(file_inode(file));
 	char buffer[PROC_NUMBUF];
 	short oom_score_adj = OOM_SCORE_ADJ_MIN;
-	unsigned long flags;
 	size_t len;
 
 	if (!task)
 		return -ESRCH;
-	if (lock_task_sighand(task, &flags)) {
-		oom_score_adj = task->signal->oom_score_adj;
-		unlock_task_sighand(task, &flags);
-	}
+	oom_score_adj = task->signal->oom_score_adj;
 	put_task_struct(task);
 	len = snprintf(buffer, sizeof(buffer), "%hd\n", oom_score_adj);
 	return simple_read_from_buffer(buf, count, ppos, buffer, len);
@@ -1157,9 +1202,7 @@ static ssize_t oom_score_adj_read(struct file *file, char __user *buf,
 static ssize_t oom_score_adj_write(struct file *file, const char __user *buf,
 					size_t count, loff_t *ppos)
 {
-	struct task_struct *task;
 	char buffer[PROC_NUMBUF];
-	unsigned long flags;
 	int oom_score_adj;
 	int err;
 
@@ -1180,39 +1223,7 @@ static ssize_t oom_score_adj_write(struct file *file, const char __user *buf,
 		goto out;
 	}
 
-	task = get_proc_task(file_inode(file));
-	if (!task) {
-		err = -ESRCH;
-		goto out;
-	}
-
-	task_lock(task);
-	if (!task->mm) {
-		err = -EINVAL;
-		goto err_task_lock;
-	}
-
-	if (!lock_task_sighand(task, &flags)) {
-		err = -ESRCH;
-		goto err_task_lock;
-	}
-
-	if ((short)oom_score_adj < task->signal->oom_score_adj_min &&
-			!capable(CAP_SYS_RESOURCE)) {
-		err = -EACCES;
-		goto err_sighand;
-	}
-
-	task->signal->oom_score_adj = (short)oom_score_adj;
-	if (has_capability_noaudit(current, CAP_SYS_RESOURCE))
-		task->signal->oom_score_adj_min = (short)oom_score_adj;
-	trace_oom_score_adj_update(task);
-
-err_sighand:
-	unlock_task_sighand(task, &flags);
-err_task_lock:
-	task_unlock(task);
-	put_task_struct(task);
+	err = __set_oom_adj(file, oom_score_adj, false);
 out:
 	return err < 0 ? err : count;
 }
@@ -1552,18 +1563,13 @@ static const struct file_operations proc_pid_set_comm_operations = {
 static int proc_exe_link(struct dentry *dentry, struct path *exe_path)
 {
 	struct task_struct *task;
-	struct mm_struct *mm;
 	struct file *exe_file;
 
 	task = get_proc_task(d_inode(dentry));
 	if (!task)
 		return -ENOENT;
-	mm = get_task_mm(task);
+	exe_file = get_task_exe_file(task);
 	put_task_struct(task);
-	if (!mm)
-		return -ENOENT;
-	exe_file = get_mm_exe_file(mm);
-	mmput(mm);
 	if (exe_file) {
 		*exe_path = exe_file->f_path;
 		path_get(&exe_file->f_path);
@@ -1665,7 +1671,7 @@ struct inode *proc_pid_make_inode(struct super_block * sb, struct task_struct *t
 	/* Common stuff */
 	ei = PROC_I(inode);
 	inode->i_ino = get_next_ino();
-	inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME;
+	inode->i_mtime = inode->i_atime = inode->i_ctime = current_time(inode);
 	inode->i_op = &proc_def_inode_operations;
 
 	/*
@@ -2281,16 +2287,27 @@ static ssize_t timerslack_ns_write(struct file *file, const char __user *buf,
 	if (!p)
 		return -ESRCH;
 
-	if (ptrace_may_access(p, PTRACE_MODE_ATTACH_FSCREDS)) {
-		task_lock(p);
-		if (slack_ns == 0)
-			p->timer_slack_ns = p->default_timer_slack_ns;
-		else
-			p->timer_slack_ns = slack_ns;
-		task_unlock(p);
-	} else
-		count = -EPERM;
+	if (p != current) {
+		if (!capable(CAP_SYS_NICE)) {
+			count = -EPERM;
+			goto out;
+		}
 
+		err = security_task_setscheduler(p);
+		if (err) {
+			count = err;
+			goto out;
+		}
+	}
+
+	task_lock(p);
+	if (slack_ns == 0)
+		p->timer_slack_ns = p->default_timer_slack_ns;
+	else
+		p->timer_slack_ns = slack_ns;
+	task_unlock(p);
+
+out:
 	put_task_struct(p);
 
 	return count;
@@ -2300,19 +2317,28 @@ static int timerslack_ns_show(struct seq_file *m, void *v)
 {
 	struct inode *inode = m->private;
 	struct task_struct *p;
-	int err =  0;
+	int err = 0;
 
 	p = get_proc_task(inode);
 	if (!p)
 		return -ESRCH;
 
-	if (ptrace_may_access(p, PTRACE_MODE_ATTACH_FSCREDS)) {
-		task_lock(p);
-		seq_printf(m, "%llu\n", p->timer_slack_ns);
-		task_unlock(p);
-	} else
-		err = -EPERM;
+	if (p != current) {
+
+		if (!capable(CAP_SYS_NICE)) {
+			err = -EPERM;
+			goto out;
+		}
+		err = security_task_getscheduler(p);
+		if (err)
+			goto out;
+	}
 
+	task_lock(p);
+	seq_printf(m, "%llu\n", p->timer_slack_ns);
+	task_unlock(p);
+
+out:
 	put_task_struct(p);
 
 	return err;
@@ -2823,7 +2849,7 @@ static const struct pid_entry tgid_base_stuff[] = {
 	DIR("net",        S_IRUGO|S_IXUGO, proc_net_inode_operations, proc_net_operations),
 #endif
 	REG("environ",    S_IRUSR, proc_environ_operations),
-	ONE("auxv",       S_IRUSR, proc_pid_auxv),
+	REG("auxv",       S_IRUSR, proc_auxv_operations),
 	ONE("status",     S_IRUGO, proc_pid_status),
 	ONE("personality", S_IRUSR, proc_pid_personality),
 	ONE("limits",	  S_IRUGO, proc_pid_limits),
@@ -3211,7 +3237,7 @@ static const struct pid_entry tid_base_stuff[] = {
 	DIR("net",        S_IRUGO|S_IXUGO, proc_net_inode_operations, proc_net_operations),
 #endif
 	REG("environ",   S_IRUSR, proc_environ_operations),
-	ONE("auxv",      S_IRUSR, proc_pid_auxv),
+	REG("auxv",      S_IRUSR, proc_auxv_operations),
 	ONE("status",    S_IRUGO, proc_pid_status),
 	ONE("personality", S_IRUSR, proc_pid_personality),
 	ONE("limits",	 S_IRUGO, proc_pid_limits),