From: David Howells Date: Wed, 27 Sep 2006 08:50:19 +0000 (-0700) Subject: [PATCH] NOMMU: Implement /proc/pid/maps for NOMMU X-Git-Url: http://git.cdn.openwrt.org/?a=commitdiff_plain;h=dbf8685c8e21404e3a8ed244bd0219d3c4b89101;p=openwrt%2Fstaging%2Fblogic.git [PATCH] NOMMU: Implement /proc/pid/maps for NOMMU Implement /proc/pid/maps for NOMMU by reading the vm_area_list attached to current->mm->context.vmlist. Signed-off-by: David Howells Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- diff --git a/Documentation/nommu-mmap.txt b/Documentation/nommu-mmap.txt index b88ebe4d808c..83f4b083d57e 100644 --- a/Documentation/nommu-mmap.txt +++ b/Documentation/nommu-mmap.txt @@ -116,6 +116,9 @@ FURTHER NOTES ON NO-MMU MMAP (*) A list of all the mappings on the system is visible through /proc/maps in no-MMU mode. + (*) A list of all the mappings in use by a process is visible through + /proc//maps in no-MMU mode. + (*) Supplying MAP_FIXED or a requesting a particular mapping address will result in an error. diff --git a/fs/proc/internal.h b/fs/proc/internal.h index 146a434ba944..987c773dbb20 100644 --- a/fs/proc/internal.h +++ b/fs/proc/internal.h @@ -28,6 +28,7 @@ do { \ (vmi)->largest_chunk = 0; \ } while(0) +extern int nommu_vma_show(struct seq_file *, struct vm_area_struct *); #endif extern void create_seq_entry(char *name, mode_t mode, const struct file_operations *f); diff --git a/fs/proc/nommu.c b/fs/proc/nommu.c index cff10ab1af63..d7dbdf9e0f49 100644 --- a/fs/proc/nommu.c +++ b/fs/proc/nommu.c @@ -33,19 +33,15 @@ #include "internal.h" /* - * display a list of all the VMAs the kernel knows about - * - nommu kernals have a single flat list + * display a single VMA to a sequenced file */ -static int nommu_vma_list_show(struct seq_file *m, void *v) +int nommu_vma_show(struct seq_file *m, struct vm_area_struct *vma) { - struct vm_area_struct *vma; unsigned long ino = 0; struct file *file; dev_t dev = 0; int flags, len; - vma = rb_entry((struct rb_node *) v, struct vm_area_struct, vm_rb); - flags = vma->vm_flags; file = vma->vm_file; @@ -78,6 +74,18 @@ static int nommu_vma_list_show(struct seq_file *m, void *v) return 0; } +/* + * display a list of all the VMAs the kernel knows about + * - nommu kernals have a single flat list + */ +static int nommu_vma_list_show(struct seq_file *m, void *v) +{ + struct vm_area_struct *vma; + + vma = rb_entry((struct rb_node *) v, struct vm_area_struct, vm_rb); + return nommu_vma_show(m, vma); +} + static void *nommu_vma_list_start(struct seq_file *m, loff_t *_pos) { struct rb_node *_rb; diff --git a/fs/proc/task_nommu.c b/fs/proc/task_nommu.c index 4616ed50ffcd..091aa8e48e02 100644 --- a/fs/proc/task_nommu.c +++ b/fs/proc/task_nommu.c @@ -138,25 +138,63 @@ out: } /* - * Albert D. Cahalan suggested to fake entries for the traditional - * sections here. This might be worth investigating. + * display mapping lines for a particular process's /proc/pid/maps */ -static int show_map(struct seq_file *m, void *v) +static int show_map(struct seq_file *m, void *_vml) { - return 0; + struct vm_list_struct *vml = _vml; + return nommu_vma_show(m, vml->vma); } + static void *m_start(struct seq_file *m, loff_t *pos) { + struct proc_maps_private *priv = m->private; + struct vm_list_struct *vml; + struct mm_struct *mm; + loff_t n = *pos; + + /* pin the task and mm whilst we play with them */ + priv->task = get_pid_task(priv->pid, PIDTYPE_PID); + if (!priv->task) + return NULL; + + mm = get_task_mm(priv->task); + if (!mm) { + put_task_struct(priv->task); + priv->task = NULL; + return NULL; + } + + down_read(&mm->mmap_sem); + + /* start from the Nth VMA */ + for (vml = mm->context.vmlist; vml; vml = vml->next) + if (n-- == 0) + return vml; return NULL; } -static void m_stop(struct seq_file *m, void *v) + +static void m_stop(struct seq_file *m, void *_vml) { + struct proc_maps_private *priv = m->private; + + if (priv->task) { + struct mm_struct *mm = priv->task->mm; + up_read(&mm->mmap_sem); + mmput(mm); + put_task_struct(priv->task); + } } -static void *m_next(struct seq_file *m, void *v, loff_t *pos) + +static void *m_next(struct seq_file *m, void *_vml, loff_t *pos) { - return NULL; + struct vm_list_struct *vml = _vml; + + (*pos)++; + return vml ? vml->next : NULL; } -static struct seq_operations proc_pid_maps_op = { + +static struct seq_operations proc_pid_maps_ops = { .start = m_start, .next = m_next, .stop = m_stop, @@ -165,11 +203,19 @@ static struct seq_operations proc_pid_maps_op = { static int maps_open(struct inode *inode, struct file *file) { - int ret; - ret = seq_open(file, &proc_pid_maps_op); - if (!ret) { - struct seq_file *m = file->private_data; - m->private = NULL; + 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, &proc_pid_maps_ops); + if (!ret) { + struct seq_file *m = file->private_data; + m->private = priv; + } else { + kfree(priv); + } } return ret; } @@ -178,6 +224,6 @@ struct file_operations proc_maps_operations = { .open = maps_open, .read = seq_read, .llseek = seq_lseek, - .release = seq_release, + .release = seq_release_private, }; diff --git a/include/linux/proc_fs.h b/include/linux/proc_fs.h index 3435ca38dd14..57f70bc8b24b 100644 --- a/include/linux/proc_fs.h +++ b/include/linux/proc_fs.h @@ -268,7 +268,9 @@ static inline struct proc_dir_entry *PDE(const struct inode *inode) struct proc_maps_private { struct pid *pid; struct task_struct *task; +#ifdef CONFIG_MMU struct vm_area_struct *tail_vma; +#endif }; #endif /* _LINUX_PROC_FS_H */