#include <linux/proc_fs.h>
#include <linux/stat.h>
#include <linux/init.h>
+#include <linux/capability.h>
#include <linux/file.h>
#include <linux/string.h>
#include <linux/seq_file.h>
#include <linux/seccomp.h>
#include <linux/cpuset.h>
#include <linux/audit.h>
+#include <linux/poll.h>
#include "internal.h"
/*
PROC_TGID_NUMA_MAPS,
PROC_TGID_MOUNTS,
PROC_TGID_WCHAN,
+#ifdef CONFIG_MMU
PROC_TGID_SMAPS,
+#endif
#ifdef CONFIG_SCHEDSTATS
PROC_TGID_SCHEDSTAT,
#endif
PROC_TID_NUMA_MAPS,
PROC_TID_MOUNTS,
PROC_TID_WCHAN,
+#ifdef CONFIG_MMU
PROC_TID_SMAPS,
+#endif
#ifdef CONFIG_SCHEDSTATS
PROC_TID_SCHEDSTAT,
#endif
E(PROC_TGID_ROOT, "root", S_IFLNK|S_IRWXUGO),
E(PROC_TGID_EXE, "exe", S_IFLNK|S_IRWXUGO),
E(PROC_TGID_MOUNTS, "mounts", S_IFREG|S_IRUGO),
+#ifdef CONFIG_MMU
E(PROC_TGID_SMAPS, "smaps", S_IFREG|S_IRUGO),
+#endif
#ifdef CONFIG_SECURITY
E(PROC_TGID_ATTR, "attr", S_IFDIR|S_IRUGO|S_IXUGO),
#endif
E(PROC_TID_ROOT, "root", S_IFLNK|S_IRWXUGO),
E(PROC_TID_EXE, "exe", S_IFLNK|S_IRWXUGO),
E(PROC_TID_MOUNTS, "mounts", S_IFREG|S_IRUGO),
+#ifdef CONFIG_MMU
E(PROC_TID_SMAPS, "smaps", S_IFREG|S_IRUGO),
+#endif
#ifdef CONFIG_SECURITY
E(PROC_TID_ATTR, "attr", S_IFDIR|S_IRUGO|S_IXUGO),
#endif
return result;
}
+
+/* Same as proc_root_link, but this addionally tries to get fs from other
+ * threads in the group */
+static int proc_task_root_link(struct inode *inode, struct dentry **dentry,
+ struct vfsmount **mnt)
+{
+ struct fs_struct *fs;
+ int result = -ENOENT;
+ struct task_struct *leader = proc_task(inode);
+
+ task_lock(leader);
+ fs = leader->fs;
+ if (fs) {
+ atomic_inc(&fs->count);
+ task_unlock(leader);
+ } else {
+ /* Try to get fs from other threads */
+ task_unlock(leader);
+ read_lock(&tasklist_lock);
+ if (pid_alive(leader)) {
+ struct task_struct *task = leader;
+
+ while ((task = next_thread(task)) != leader) {
+ task_lock(task);
+ fs = task->fs;
+ if (fs) {
+ atomic_inc(&fs->count);
+ task_unlock(task);
+ break;
+ }
+ task_unlock(task);
+ }
+ }
+ read_unlock(&tasklist_lock);
+ }
+
+ if (fs) {
+ read_lock(&fs->lock);
+ *mnt = mntget(fs->rootmnt);
+ *dentry = dget(fs->root);
+ read_unlock(&fs->lock);
+ result = 0;
+ put_fs_struct(fs);
+ }
+ return result;
+}
+
+
#define MAY_PTRACE(task) \
(task == current || \
(task->parent == current && \
/* permission checks */
-static int proc_check_root(struct inode *inode)
+/* If the process being read is separated by chroot from the reading process,
+ * don't let the reader access the threads.
+ */
+static int proc_check_chroot(struct dentry *root, struct vfsmount *vfsmnt)
{
- struct dentry *de, *base, *root;
- struct vfsmount *our_vfsmnt, *vfsmnt, *mnt;
+ struct dentry *de, *base;
+ struct vfsmount *our_vfsmnt, *mnt;
int res = 0;
-
- if (proc_root_link(inode, &root, &vfsmnt)) /* Ewww... */
- return -ENOENT;
read_lock(¤t->fs->lock);
our_vfsmnt = mntget(current->fs->rootmnt);
base = dget(current->fs->root);
goto exit;
}
+static int proc_check_root(struct inode *inode)
+{
+ struct dentry *root;
+ struct vfsmount *vfsmnt;
+
+ if (proc_root_link(inode, &root, &vfsmnt)) /* Ewww... */
+ return -ENOENT;
+ return proc_check_chroot(root, vfsmnt);
+}
+
static int proc_permission(struct inode *inode, int mask, struct nameidata *nd)
{
if (generic_permission(inode, mask, NULL) != 0)
return proc_check_root(inode);
}
+static int proc_task_permission(struct inode *inode, int mask, struct nameidata *nd)
+{
+ struct dentry *root;
+ struct vfsmount *vfsmnt;
+
+ if (generic_permission(inode, mask, NULL) != 0)
+ return -EACCES;
+
+ if (proc_task_root_link(inode, &root, &vfsmnt))
+ return -ENOENT;
+
+ return proc_check_chroot(root, vfsmnt);
+}
+
extern struct seq_operations proc_pid_maps_op;
static int maps_open(struct inode *inode, struct file *file)
{
};
#endif
+#ifdef CONFIG_MMU
extern struct seq_operations proc_pid_smaps_op;
static int smaps_open(struct inode *inode, struct file *file)
{
.llseek = seq_lseek,
.release = seq_release,
};
+#endif
extern struct seq_operations mounts_op;
+struct proc_mounts {
+ struct seq_file m;
+ int event;
+};
+
static int mounts_open(struct inode *inode, struct file *file)
{
struct task_struct *task = proc_task(inode);
- int ret = seq_open(file, &mounts_op);
+ struct namespace *namespace;
+ struct proc_mounts *p;
+ int ret = -EINVAL;
- if (!ret) {
- struct seq_file *m = file->private_data;
- struct namespace *namespace;
- task_lock(task);
- namespace = task->namespace;
- if (namespace)
- get_namespace(namespace);
- task_unlock(task);
-
- if (namespace)
- m->private = namespace;
- else {
- seq_release(inode, file);
- ret = -EINVAL;
+ task_lock(task);
+ namespace = task->namespace;
+ if (namespace)
+ get_namespace(namespace);
+ task_unlock(task);
+
+ if (namespace) {
+ ret = -ENOMEM;
+ p = kmalloc(sizeof(struct proc_mounts), GFP_KERNEL);
+ if (p) {
+ file->private_data = &p->m;
+ ret = seq_open(file, &mounts_op);
+ if (!ret) {
+ p->m.private = namespace;
+ p->event = namespace->event;
+ return 0;
+ }
+ kfree(p);
}
+ put_namespace(namespace);
}
return ret;
}
return seq_release(inode, file);
}
+static unsigned mounts_poll(struct file *file, poll_table *wait)
+{
+ struct proc_mounts *p = file->private_data;
+ struct namespace *ns = p->m.private;
+ unsigned res = 0;
+
+ poll_wait(file, &ns->poll, wait);
+
+ spin_lock(&vfsmount_lock);
+ if (p->event != ns->event) {
+ p->event = ns->event;
+ res = POLLERR;
+ }
+ spin_unlock(&vfsmount_lock);
+
+ return res;
+}
+
static struct file_operations proc_mounts_operations = {
.open = mounts_open,
.read = seq_read,
.llseek = seq_lseek,
.release = mounts_release,
+ .poll = mounts_poll,
};
#define PROC_BLOCK_SIZE (3*1024) /* 4K page size but our output routines use some slack for overruns */
static struct inode_operations proc_task_inode_operations = {
.lookup = proc_task_lookup,
- .permission = proc_permission,
+ .permission = proc_task_permission,
};
#ifdef CONFIG_SECURITY
case PROC_TGID_MOUNTS:
inode->i_fop = &proc_mounts_operations;
break;
+#ifdef CONFIG_MMU
case PROC_TID_SMAPS:
case PROC_TGID_SMAPS:
inode->i_fop = &proc_smaps_operations;
break;
+#endif
#ifdef CONFIG_SECURITY
case PROC_TID_ATTR:
inode->i_nlink = 2;
projects / cascardo / linux.git / blobdiff