Commit dbf8685c authored by David Howells's avatar David Howells Committed by Linus Torvalds

[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: default avatarDavid Howells <dhowells@redhat.com>
Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
parent d00c7b99
...@@ -116,6 +116,9 @@ FURTHER NOTES ON NO-MMU MMAP ...@@ -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 (*) A list of all the mappings on the system is visible through /proc/maps in
no-MMU mode. no-MMU mode.
(*) A list of all the mappings in use by a process is visible through
/proc/<pid>/maps in no-MMU mode.
(*) Supplying MAP_FIXED or a requesting a particular mapping address will (*) Supplying MAP_FIXED or a requesting a particular mapping address will
result in an error. result in an error.
......
...@@ -28,6 +28,7 @@ do { \ ...@@ -28,6 +28,7 @@ do { \
(vmi)->largest_chunk = 0; \ (vmi)->largest_chunk = 0; \
} while(0) } while(0)
extern int nommu_vma_show(struct seq_file *, struct vm_area_struct *);
#endif #endif
extern void create_seq_entry(char *name, mode_t mode, const struct file_operations *f); extern void create_seq_entry(char *name, mode_t mode, const struct file_operations *f);
......
...@@ -33,19 +33,15 @@ ...@@ -33,19 +33,15 @@
#include "internal.h" #include "internal.h"
/* /*
* display a list of all the VMAs the kernel knows about * display a single VMA to a sequenced file
* - nommu kernals have a single flat list
*/ */
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; unsigned long ino = 0;
struct file *file; struct file *file;
dev_t dev = 0; dev_t dev = 0;
int flags, len; int flags, len;
vma = rb_entry((struct rb_node *) v, struct vm_area_struct, vm_rb);
flags = vma->vm_flags; flags = vma->vm_flags;
file = vma->vm_file; file = vma->vm_file;
...@@ -78,6 +74,18 @@ static int nommu_vma_list_show(struct seq_file *m, void *v) ...@@ -78,6 +74,18 @@ static int nommu_vma_list_show(struct seq_file *m, void *v)
return 0; 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) static void *nommu_vma_list_start(struct seq_file *m, loff_t *_pos)
{ {
struct rb_node *_rb; struct rb_node *_rb;
......
...@@ -138,25 +138,63 @@ out: ...@@ -138,25 +138,63 @@ out:
} }
/* /*
* Albert D. Cahalan suggested to fake entries for the traditional * display mapping lines for a particular process's /proc/pid/maps
* sections here. This might be worth investigating.
*/ */
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) 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; 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, .start = m_start,
.next = m_next, .next = m_next,
.stop = m_stop, .stop = m_stop,
...@@ -165,11 +203,19 @@ static struct seq_operations proc_pid_maps_op = { ...@@ -165,11 +203,19 @@ static struct seq_operations proc_pid_maps_op = {
static int maps_open(struct inode *inode, struct file *file) static int maps_open(struct inode *inode, struct file *file)
{ {
int ret; struct proc_maps_private *priv;
ret = seq_open(file, &proc_pid_maps_op); 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) { if (!ret) {
struct seq_file *m = file->private_data; struct seq_file *m = file->private_data;
m->private = NULL; m->private = priv;
} else {
kfree(priv);
}
} }
return ret; return ret;
} }
...@@ -178,6 +224,6 @@ struct file_operations proc_maps_operations = { ...@@ -178,6 +224,6 @@ struct file_operations proc_maps_operations = {
.open = maps_open, .open = maps_open,
.read = seq_read, .read = seq_read,
.llseek = seq_lseek, .llseek = seq_lseek,
.release = seq_release, .release = seq_release_private,
}; };
...@@ -268,7 +268,9 @@ static inline struct proc_dir_entry *PDE(const struct inode *inode) ...@@ -268,7 +268,9 @@ static inline struct proc_dir_entry *PDE(const struct inode *inode)
struct proc_maps_private { struct proc_maps_private {
struct pid *pid; struct pid *pid;
struct task_struct *task; struct task_struct *task;
#ifdef CONFIG_MMU
struct vm_area_struct *tail_vma; struct vm_area_struct *tail_vma;
#endif
}; };
#endif /* _LINUX_PROC_FS_H */ #endif /* _LINUX_PROC_FS_H */
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