diff options
Diffstat (limited to 'fs/proc/task_nommu.c')
-rw-r--r-- | fs/proc/task_nommu.c | 88 |
1 files changed, 61 insertions, 27 deletions
diff --git a/fs/proc/task_nommu.c b/fs/proc/task_nommu.c index 678455d2d68..599ec2e2010 100644 --- a/fs/proc/task_nommu.c +++ b/fs/proc/task_nommu.c @@ -123,6 +123,25 @@ unsigned long task_statm(struct mm_struct *mm, return size; } +static pid_t pid_of_stack(struct proc_maps_private *priv, + struct vm_area_struct *vma, bool is_pid) +{ + struct inode *inode = priv->inode; + struct task_struct *task; + pid_t ret = 0; + + rcu_read_lock(); + task = pid_task(proc_pid(inode), PIDTYPE_PID); + if (task) { + task = task_of_stack(task, vma, is_pid); + if (task) + ret = task_pid_nr_ns(task, inode->i_sb->s_fs_info); + } + rcu_read_unlock(); + + return ret; +} + /* * display a single VMA to a sequenced file */ @@ -163,7 +182,7 @@ static int nommu_vma_show(struct seq_file *m, struct vm_area_struct *vma, seq_pad(m, ' '); seq_path(m, &file->f_path, ""); } else if (mm) { - pid_t tid = vm_is_stack(priv->task, vma, is_pid); + pid_t tid = pid_of_stack(priv, vma, is_pid); if (tid != 0) { seq_pad(m, ' '); @@ -212,22 +231,22 @@ static void *m_start(struct seq_file *m, loff_t *pos) loff_t n = *pos; /* pin the task and mm whilst we play with them */ - priv->task = get_pid_task(priv->pid, PIDTYPE_PID); + priv->task = get_proc_task(priv->inode); if (!priv->task) return ERR_PTR(-ESRCH); - mm = mm_access(priv->task, PTRACE_MODE_READ); - if (!mm || IS_ERR(mm)) { - put_task_struct(priv->task); - priv->task = NULL; - return mm; - } - down_read(&mm->mmap_sem); + mm = priv->mm; + if (!mm || !atomic_inc_not_zero(&mm->mm_users)) + return NULL; + down_read(&mm->mmap_sem); /* start from the Nth VMA */ for (p = rb_first(&mm->mm_rb); p; p = rb_next(p)) if (n-- == 0) return p; + + up_read(&mm->mmap_sem); + mmput(mm); return NULL; } @@ -235,11 +254,13 @@ static void m_stop(struct seq_file *m, void *_vml) { struct proc_maps_private *priv = m->private; + if (!IS_ERR_OR_NULL(_vml)) { + up_read(&priv->mm->mmap_sem); + mmput(priv->mm); + } if (priv->task) { - struct mm_struct *mm = priv->task->mm; - up_read(&mm->mmap_sem); - mmput(mm); put_task_struct(priv->task); + priv->task = NULL; } } @@ -269,20 +290,33 @@ static int maps_open(struct inode *inode, struct file *file, const struct seq_operations *ops) { struct proc_maps_private *priv; - int ret = -ENOMEM; - - priv = kzalloc(sizeof(*priv), GFP_KERNEL); - if (priv) { - priv->pid = proc_pid(inode); - ret = seq_open(file, ops); - if (!ret) { - struct seq_file *m = file->private_data; - m->private = priv; - } else { - kfree(priv); - } + + priv = __seq_open_private(file, ops, sizeof(*priv)); + if (!priv) + return -ENOMEM; + + priv->inode = inode; + priv->mm = proc_mem_open(inode, PTRACE_MODE_READ); + if (IS_ERR(priv->mm)) { + int err = PTR_ERR(priv->mm); + + seq_release_private(inode, file); + return err; } - return ret; + + return 0; +} + + +static int map_release(struct inode *inode, struct file *file) +{ + struct seq_file *seq = file->private_data; + struct proc_maps_private *priv = seq->private; + + if (priv->mm) + mmdrop(priv->mm); + + return seq_release_private(inode, file); } static int pid_maps_open(struct inode *inode, struct file *file) @@ -299,13 +333,13 @@ const struct file_operations proc_pid_maps_operations = { .open = pid_maps_open, .read = seq_read, .llseek = seq_lseek, - .release = seq_release_private, + .release = map_release, }; const struct file_operations proc_tid_maps_operations = { .open = tid_maps_open, .read = seq_read, .llseek = seq_lseek, - .release = seq_release_private, + .release = map_release, }; |