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Diffstat (limited to 'fs/proc')
-rw-r--r--fs/proc/inode.c6
-rw-r--r--fs/proc/namespaces.c169
2 files changed, 152 insertions, 23 deletions
diff --git a/fs/proc/inode.c b/fs/proc/inode.c
index 3b22bbdee9ec..439ae6886507 100644
--- a/fs/proc/inode.c
+++ b/fs/proc/inode.c
@@ -31,6 +31,7 @@ static void proc_evict_inode(struct inode *inode)
struct proc_dir_entry *de;
struct ctl_table_header *head;
const struct proc_ns_operations *ns_ops;
+ void *ns;
truncate_inode_pages(&inode->i_data, 0);
clear_inode(inode);
@@ -49,8 +50,9 @@ static void proc_evict_inode(struct inode *inode)
}
/* Release any associated namespace */
ns_ops = PROC_I(inode)->ns_ops;
- if (ns_ops && ns_ops->put)
- ns_ops->put(PROC_I(inode)->ns);
+ ns = PROC_I(inode)->ns;
+ if (ns_ops && ns)
+ ns_ops->put(ns);
}
static struct kmem_cache * proc_inode_cachep;
diff --git a/fs/proc/namespaces.c b/fs/proc/namespaces.c
index 030250c27d70..7a6d8d69cdb8 100644
--- a/fs/proc/namespaces.c
+++ b/fs/proc/namespaces.c
@@ -38,6 +38,151 @@ static const struct file_operations ns_file_operations = {
.llseek = no_llseek,
};
+static const struct inode_operations ns_inode_operations = {
+ .setattr = proc_setattr,
+};
+
+static int ns_delete_dentry(const struct dentry *dentry)
+{
+ /* Don't cache namespace inodes when not in use */
+ return 1;
+}
+
+static char *ns_dname(struct dentry *dentry, char *buffer, int buflen)
+{
+ struct inode *inode = dentry->d_inode;
+ const struct proc_ns_operations *ns_ops = PROC_I(inode)->ns_ops;
+
+ return dynamic_dname(dentry, buffer, buflen, "%s:[%lu]",
+ ns_ops->name, inode->i_ino);
+}
+
+const struct dentry_operations ns_dentry_operations =
+{
+ .d_delete = ns_delete_dentry,
+ .d_dname = ns_dname,
+};
+
+static struct dentry *proc_ns_get_dentry(struct super_block *sb,
+ struct task_struct *task, const struct proc_ns_operations *ns_ops)
+{
+ struct dentry *dentry, *result;
+ struct inode *inode;
+ struct proc_inode *ei;
+ struct qstr qname = { .name = "", };
+ void *ns;
+
+ ns = ns_ops->get(task);
+ if (!ns)
+ return ERR_PTR(-ENOENT);
+
+ dentry = d_alloc_pseudo(sb, &qname);
+ if (!dentry) {
+ ns_ops->put(ns);
+ return ERR_PTR(-ENOMEM);
+ }
+
+ inode = new_inode(sb);
+ if (!inode) {
+ dput(dentry);
+ ns_ops->put(ns);
+ return ERR_PTR(-ENOMEM);
+ }
+
+ ei = PROC_I(inode);
+ inode->i_ino = get_next_ino();
+ inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME;
+ inode->i_op = &ns_inode_operations;
+ inode->i_mode = S_IFREG | S_IRUGO;
+ inode->i_fop = &ns_file_operations;
+ ei->ns_ops = ns_ops;
+ ei->ns = ns;
+
+ d_set_d_op(dentry, &ns_dentry_operations);
+ result = d_instantiate_unique(dentry, inode);
+ if (result) {
+ dput(dentry);
+ dentry = result;
+ }
+
+ return dentry;
+}
+
+static void *proc_ns_follow_link(struct dentry *dentry, struct nameidata *nd)
+{
+ struct inode *inode = dentry->d_inode;
+ struct super_block *sb = inode->i_sb;
+ struct proc_inode *ei = PROC_I(inode);
+ struct task_struct *task;
+ struct dentry *ns_dentry;
+ void *error = ERR_PTR(-EACCES);
+
+ task = get_proc_task(inode);
+ if (!task)
+ goto out;
+
+ if (!ptrace_may_access(task, PTRACE_MODE_READ))
+ goto out_put_task;
+
+ ns_dentry = proc_ns_get_dentry(sb, task, ei->ns_ops);
+ if (IS_ERR(ns_dentry)) {
+ error = ERR_CAST(ns_dentry);
+ goto out_put_task;
+ }
+
+ dput(nd->path.dentry);
+ nd->path.dentry = ns_dentry;
+ error = NULL;
+
+out_put_task:
+ put_task_struct(task);
+out:
+ return error;
+}
+
+static int proc_ns_readlink(struct dentry *dentry, char __user *buffer, int buflen)
+{
+ struct inode *inode = dentry->d_inode;
+ struct proc_inode *ei = PROC_I(inode);
+ const struct proc_ns_operations *ns_ops = ei->ns_ops;
+ struct task_struct *task;
+ void *ns;
+ char name[50];
+ int len = -EACCES;
+
+ task = get_proc_task(inode);
+ if (!task)
+ goto out;
+
+ if (!ptrace_may_access(task, PTRACE_MODE_READ))
+ goto out_put_task;
+
+ len = -ENOENT;
+ ns = ns_ops->get(task);
+ if (!ns)
+ goto out_put_task;
+
+ snprintf(name, sizeof(name), "%s", ns_ops->name);
+ len = strlen(name);
+
+ if (len > buflen)
+ len = buflen;
+ if (copy_to_user(buffer, ns_ops->name, len))
+ len = -EFAULT;
+
+ ns_ops->put(ns);
+out_put_task:
+ put_task_struct(task);
+out:
+ return len;
+}
+
+static const struct inode_operations proc_ns_link_inode_operations = {
+ .readlink = proc_ns_readlink,
+ .follow_link = proc_ns_follow_link,
+ .setattr = proc_setattr,
+};
+
static struct dentry *proc_ns_instantiate(struct inode *dir,
struct dentry *dentry, struct task_struct *task, const void *ptr)
{
@@ -45,21 +190,15 @@ static struct dentry *proc_ns_instantiate(struct inode *dir,
struct inode *inode;
struct proc_inode *ei;
struct dentry *error = ERR_PTR(-ENOENT);
- void *ns;
inode = proc_pid_make_inode(dir->i_sb, task);
if (!inode)
goto out;
- ns = ns_ops->get(task);
- if (!ns)
- goto out_iput;
-
ei = PROC_I(inode);
- inode->i_mode = S_IFREG|S_IRUSR;
- inode->i_fop = &ns_file_operations;
- ei->ns_ops = ns_ops;
- ei->ns = ns;
+ inode->i_mode = S_IFLNK|S_IRWXUGO;
+ inode->i_op = &proc_ns_link_inode_operations;
+ ei->ns_ops = ns_ops;
d_set_d_op(dentry, &pid_dentry_operations);
d_add(dentry, inode);
@@ -68,9 +207,6 @@ static struct dentry *proc_ns_instantiate(struct inode *dir,
error = NULL;
out:
return error;
-out_iput:
- iput(inode);
- goto out;
}
static int proc_ns_fill_cache(struct file *filp, void *dirent,
@@ -97,10 +233,6 @@ static int proc_ns_dir_readdir(struct file *filp, void *dirent,
if (!task)
goto out_no_task;
- ret = -EPERM;
- if (!ptrace_may_access(task, PTRACE_MODE_READ))
- goto out;
-
ret = 0;
i = filp->f_pos;
switch (i) {
@@ -160,10 +292,6 @@ static struct dentry *proc_ns_dir_lookup(struct inode *dir,
if (!task)
goto out_no_task;
- error = ERR_PTR(-EPERM);
- if (!ptrace_may_access(task, PTRACE_MODE_READ))
- goto out;
-
last = &ns_entries[ARRAY_SIZE(ns_entries)];
for (entry = ns_entries; entry < last; entry++) {
if (strlen((*entry)->name) != len)
@@ -171,7 +299,6 @@ static struct dentry *proc_ns_dir_lookup(struct inode *dir,
if (!memcmp(dentry->d_name.name, (*entry)->name, len))
break;
}
- error = ERR_PTR(-ENOENT);
if (entry == last)
goto out;