1 files changed, 114 insertions, 33 deletions

diff --git a/fs/proc/base.c b/fs/proc/base.c
index bd3e9e68125b..b1755b23893e 100644
--- a/fs/proc/base.c
+++ b/fs/proc/base.c
@@ -403,7 +403,7 @@ static const struct file_operations proc_pid_cmdline_ops = {
 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);
+	struct mm_struct *mm = mm_access(task, PTRACE_MODE_READ_FSCREDS);
 	if (mm && !IS_ERR(mm)) {
 		unsigned int nwords = 0;
 		do {
@@ -430,10 +430,11 @@ static int proc_pid_wchan(struct seq_file *m, struct pid_namespace *ns,
 
 	wchan = get_wchan(task);
 
-	if (wchan && ptrace_may_access(task, PTRACE_MODE_READ) && !lookup_symbol_name(wchan, symname))
+	if (wchan && ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS)
+			&& !lookup_symbol_name(wchan, symname))
 		seq_printf(m, "%s", symname);
 	else
-		seq_putc(m, '0');
+		seq_puts(m, "0\n");
 
 	return 0;
 }
@@ -444,7 +445,7 @@ static int lock_trace(struct task_struct *task)
 	int err = mutex_lock_killable(&task->signal->cred_guard_mutex);
 	if (err)
 		return err;
-	if (!ptrace_may_access(task, PTRACE_MODE_ATTACH)) {
+	if (!ptrace_may_access(task, PTRACE_MODE_ATTACH_FSCREDS)) {
 		mutex_unlock(&task->signal->cred_guard_mutex);
 		return -EPERM;
 	}
@@ -697,7 +698,7 @@ static int proc_fd_access_allowed(struct inode *inode)
 	 */
 	task = get_proc_task(inode);
 	if (task) {
-		allowed = ptrace_may_access(task, PTRACE_MODE_READ);
+		allowed = ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS);
 		put_task_struct(task);
 	}
 	return allowed;
@@ -732,7 +733,7 @@ static bool has_pid_permissions(struct pid_namespace *pid,
 		return true;
 	if (in_group_p(pid->pid_gid))
 		return true;
-	return ptrace_may_access(task, PTRACE_MODE_READ);
+	return ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS);
 }
 
 
@@ -809,7 +810,7 @@ struct mm_struct *proc_mem_open(struct inode *inode, unsigned int mode)
 	struct mm_struct *mm = ERR_PTR(-ESRCH);
 
 	if (task) {
-		mm = mm_access(task, mode);
+		mm = mm_access(task, mode | PTRACE_MODE_FSCREDS);
 		put_task_struct(task);
 
 		if (!IS_ERR_OR_NULL(mm)) {
@@ -952,6 +953,7 @@ static ssize_t environ_read(struct file *file, char __user *buf,
 	unsigned long src = *ppos;
 	int ret = 0;
 	struct mm_struct *mm = file->private_data;
+	unsigned long env_start, env_end;
 
 	if (!mm)
 		return 0;
@@ -963,19 +965,25 @@ static ssize_t environ_read(struct file *file, char __user *buf,
 	ret = 0;
 	if (!atomic_inc_not_zero(&mm->mm_users))
 		goto free;
+
+	down_read(&mm->mmap_sem);
+	env_start = mm->env_start;
+	env_end = mm->env_end;
+	up_read(&mm->mmap_sem);
+
 	while (count > 0) {
 		size_t this_len, max_len;
 		int retval;
 
-		if (src >= (mm->env_end - mm->env_start))
+		if (src >= (env_end - env_start))
 			break;
 
-		this_len = mm->env_end - (mm->env_start + src);
+		this_len = env_end - (env_start + src);
 
 		max_len = min_t(size_t, PAGE_SIZE, count);
 		this_len = min(max_len, this_len);
 
-		retval = access_remote_vm(mm, (mm->env_start + src),
+		retval = access_remote_vm(mm, (env_start + src),
 			page, this_len, 0);
 
 		if (retval <= 0) {
@@ -1564,12 +1572,16 @@ static int proc_exe_link(struct dentry *dentry, struct path *exe_path)
 		return -ENOENT;
 }
 
-static const char *proc_pid_follow_link(struct dentry *dentry, void **cookie)
+static const char *proc_pid_get_link(struct dentry *dentry,
+				     struct inode *inode,
+				     struct delayed_call *done)
 {
-	struct inode *inode = d_inode(dentry);
 	struct path path;
 	int error = -EACCES;
 
+	if (!dentry)
+		return ERR_PTR(-ECHILD);
+
 	/* Are we allowed to snoop on the tasks file descriptors? */
 	if (!proc_fd_access_allowed(inode))
 		goto out;
@@ -1630,7 +1642,7 @@ out:
 
 const struct inode_operations proc_pid_link_inode_operations = {
 	.readlink	= proc_pid_readlink,
-	.follow_link	= proc_pid_follow_link,
+	.get_link	= proc_pid_get_link,
 	.setattr	= proc_setattr,
 };
 
@@ -1856,7 +1868,7 @@ static int map_files_d_revalidate(struct dentry *dentry, unsigned int flags)
 	if (!task)
 		goto out_notask;
 
-	mm = mm_access(task, PTRACE_MODE_READ);
+	mm = mm_access(task, PTRACE_MODE_READ_FSCREDS);
 	if (IS_ERR_OR_NULL(mm))
 		goto out;
 
@@ -1895,7 +1907,7 @@ static const struct dentry_operations tid_map_files_dentry_operations = {
 	.d_delete	= pid_delete_dentry,
 };
 
-static int proc_map_files_get_link(struct dentry *dentry, struct path *path)
+static int map_files_get_link(struct dentry *dentry, struct path *path)
 {
 	unsigned long vm_start, vm_end;
 	struct vm_area_struct *vma;
@@ -1945,20 +1957,22 @@ struct map_files_info {
  * path to the file in question.
  */
 static const char *
-proc_map_files_follow_link(struct dentry *dentry, void **cookie)
+proc_map_files_get_link(struct dentry *dentry,
+			struct inode *inode,
+		        struct delayed_call *done)
 {
 	if (!capable(CAP_SYS_ADMIN))
 		return ERR_PTR(-EPERM);
 
-	return proc_pid_follow_link(dentry, NULL);
+	return proc_pid_get_link(dentry, inode, done);
 }
 
 /*
- * Identical to proc_pid_link_inode_operations except for follow_link()
+ * Identical to proc_pid_link_inode_operations except for get_link()
  */
 static const struct inode_operations proc_map_files_link_inode_operations = {
 	.readlink	= proc_pid_readlink,
-	.follow_link	= proc_map_files_follow_link,
+	.get_link	= proc_map_files_get_link,
 	.setattr	= proc_setattr,
 };
 
@@ -1975,7 +1989,7 @@ proc_map_files_instantiate(struct inode *dir, struct dentry *dentry,
 		return -ENOENT;
 
 	ei = PROC_I(inode);
-	ei->op.proc_get_link = proc_map_files_get_link;
+	ei->op.proc_get_link = map_files_get_link;
 
 	inode->i_op = &proc_map_files_link_inode_operations;
 	inode->i_size = 64;
@@ -2007,7 +2021,7 @@ static struct dentry *proc_map_files_lookup(struct inode *dir,
 		goto out;
 
 	result = -EACCES;
-	if (!ptrace_may_access(task, PTRACE_MODE_READ))
+	if (!ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS))
 		goto out_put_task;
 
 	result = -ENOENT;
@@ -2060,7 +2074,7 @@ proc_map_files_readdir(struct file *file, struct dir_context *ctx)
 		goto out;
 
 	ret = -EACCES;
-	if (!ptrace_may_access(task, PTRACE_MODE_READ))
+	if (!ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS))
 		goto out_put_task;
 
 	ret = 0;
@@ -2144,6 +2158,7 @@ static const struct file_operations proc_map_files_operations = {
 	.llseek		= default_llseek,
 };
 
+#ifdef CONFIG_CHECKPOINT_RESTORE
 struct timers_private {
 	struct pid *pid;
 	struct task_struct *task;
@@ -2242,6 +2257,73 @@ static const struct file_operations proc_timers_operations = {
 	.llseek		= seq_lseek,
 	.release	= seq_release_private,
 };
+#endif
+
+static ssize_t timerslack_ns_write(struct file *file, const char __user *buf,
+					size_t count, loff_t *offset)
+{
+	struct inode *inode = file_inode(file);
+	struct task_struct *p;
+	u64 slack_ns;
+	int err;
+
+	err = kstrtoull_from_user(buf, count, 10, &slack_ns);
+	if (err < 0)
+		return err;
+
+	p = get_proc_task(inode);
+	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;
+
+	put_task_struct(p);
+
+	return count;
+}
+
+static int timerslack_ns_show(struct seq_file *m, void *v)
+{
+	struct inode *inode = m->private;
+	struct task_struct *p;
+	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;
+
+	put_task_struct(p);
+
+	return err;
+}
+
+static int timerslack_ns_open(struct inode *inode, struct file *filp)
+{
+	return single_open(filp, timerslack_ns_show, inode);
+}
+
+static const struct file_operations proc_pid_set_timerslack_ns_operations = {
+	.open		= timerslack_ns_open,
+	.read		= seq_read,
+	.write		= timerslack_ns_write,
+	.llseek		= seq_lseek,
+	.release	= single_release,
+};
 
 static int proc_pident_instantiate(struct inode *dir,
 	struct dentry *dentry, struct task_struct *task, const void *ptr)
@@ -2359,7 +2441,7 @@ static ssize_t proc_pid_attr_write(struct file * file, const char __user * buf,
 				   size_t count, loff_t *ppos)
 {
 	struct inode * inode = file_inode(file);
-	char *page;
+	void *page;
 	ssize_t length;
 	struct task_struct *task = get_proc_task(inode);
 
@@ -2374,14 +2456,11 @@ static ssize_t proc_pid_attr_write(struct file * file, const char __user * buf,
 	if (*ppos != 0)
 		goto out;
 
-	length = -ENOMEM;
-	page = (char*)__get_free_page(GFP_TEMPORARY);
-	if (!page)
+	page = memdup_user(buf, count);
+	if (IS_ERR(page)) {
+		length = PTR_ERR(page);
 		goto out;
-
-	length = -EFAULT;
-	if (copy_from_user(page, buf, count))
-		goto out_free;
+	}
 
 	/* Guard against adverse ptrace interaction */
 	length = mutex_lock_interruptible(&task->signal->cred_guard_mutex);
@@ -2390,10 +2469,10 @@ static ssize_t proc_pid_attr_write(struct file * file, const char __user * buf,
 
 	length = security_setprocattr(task,
 				      (char*)file->f_path.dentry->d_name.name,
-				      (void*)page, count);
+				      page, count);
 	mutex_unlock(&task->signal->cred_guard_mutex);
 out_free:
-	free_page((unsigned long) page);
+	kfree(page);
 out:
 	put_task_struct(task);
 out_no_task:
@@ -2494,6 +2573,7 @@ static ssize_t proc_coredump_filter_write(struct file *file,
 	mm = get_task_mm(task);
 	if (!mm)
 		goto out_no_mm;
+	ret = 0;
 
 	for (i = 0, mask = 1; i < MMF_DUMP_FILTER_BITS; i++, mask <<= 1) {
 		if (val & mask)
@@ -2529,7 +2609,7 @@ static int do_io_accounting(struct task_struct *task, struct seq_file *m, int wh
 	if (result)
 		return result;
 
-	if (!ptrace_may_access(task, PTRACE_MODE_READ)) {
+	if (!ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS)) {
 		result = -EACCES;
 		goto out_unlock;
 	}
@@ -2819,6 +2899,7 @@ static const struct pid_entry tgid_base_stuff[] = {
 #ifdef CONFIG_CHECKPOINT_RESTORE
 	REG("timers",	  S_IRUGO, proc_timers_operations),
 #endif
+	REG("timerslack_ns", S_IRUGO|S_IWUGO, proc_pid_set_timerslack_ns_operations),
 };
 
 static int proc_tgid_base_readdir(struct file *file, struct dir_context *ctx)