--- zzzz-none-000/linux-3.10.107/fs/proc/namespaces.c 2017-06-27 09:49:32.000000000 +0000 +++ scorpion-7490-727/linux-3.10.107/fs/proc/namespaces.c 2021-02-04 17:41:59.000000000 +0000 @@ -1,10 +1,6 @@ #include #include -#include #include -#include -#include -#include #include #include #include @@ -34,151 +30,46 @@ &mntns_operations, }; -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.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 = iget_locked(sb, ns_ops->inum(ns)); - if (!inode) { - dput(dentry); - ns_ops->put(ns); - return ERR_PTR(-ENOMEM); - } - - ei = PROC_I(inode); - if (inode->i_state & I_NEW) { - 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.ns_ops = ns_ops; - ei->ns.ns = ns; - unlock_new_inode(inode); - } else { - ns_ops->put(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) +static const char *proc_ns_follow_link(struct dentry *dentry, void **cookie) { - struct inode *inode = dentry->d_inode; - struct super_block *sb = inode->i_sb; - struct proc_inode *ei = PROC_I(inode); + struct inode *inode = d_inode(dentry); + const struct proc_ns_operations *ns_ops = PROC_I(inode)->ns_ops; struct task_struct *task; struct path ns_path; void *error = ERR_PTR(-EACCES); task = get_proc_task(inode); if (!task) - goto out; - - if (!ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS)) - goto out_put_task; + return error; - ns_path.dentry = proc_ns_get_dentry(sb, task, ei->ns.ns_ops); - if (IS_ERR(ns_path.dentry)) { - error = ERR_CAST(ns_path.dentry); - goto out_put_task; + if (ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS)) { + error = ns_get_path(&ns_path, task, ns_ops); + if (!error) + nd_jump_link(&ns_path); } - - ns_path.mnt = mntget(nd->path.mnt); - nd_jump_link(nd, &ns_path); - 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.ns_ops; + struct inode *inode = d_inode(dentry); + const struct proc_ns_operations *ns_ops = PROC_I(inode)->ns_ops; struct task_struct *task; - void *ns; char name[50]; - int len = -EACCES; + int res = -EACCES; task = get_proc_task(inode); if (!task) - goto out; + return res; - if (!ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS)) - goto out_put_task; - - len = -ENOENT; - ns = ns_ops->get(task); - if (!ns) - goto out_put_task; - - snprintf(name, sizeof(name), "%s:[%u]", ns_ops->name, ns_ops->inum(ns)); - len = strlen(name); - - if (len > buflen) - len = buflen; - if (copy_to_user(buffer, name, len)) - len = -EFAULT; - - ns_ops->put(ns); -out_put_task: + if (ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS)) { + res = ns_get_name(name, sizeof(name), task, ns_ops); + if (res >= 0) + res = readlink_copy(buffer, buflen, name); + } put_task_struct(task); -out: - return len; + return res; } static const struct inode_operations proc_ns_link_inode_operations = { @@ -187,13 +78,12 @@ .setattr = proc_setattr, }; -static struct dentry *proc_ns_instantiate(struct inode *dir, +static int proc_ns_instantiate(struct inode *dir, struct dentry *dentry, struct task_struct *task, const void *ptr) { const struct proc_ns_operations *ns_ops = ptr; struct inode *inode; struct proc_inode *ei; - struct dentry *error = ERR_PTR(-ENOENT); inode = proc_pid_make_inode(dir->i_sb, task); if (!inode) @@ -202,96 +92,58 @@ ei = PROC_I(inode); inode->i_mode = S_IFLNK|S_IRWXUGO; inode->i_op = &proc_ns_link_inode_operations; - ei->ns.ns_ops = ns_ops; + ei->ns_ops = ns_ops; d_set_d_op(dentry, &pid_dentry_operations); d_add(dentry, inode); /* Close the race of the process dying before we return the dentry */ if (pid_revalidate(dentry, 0)) - error = NULL; + return 0; out: - return error; -} - -static int proc_ns_fill_cache(struct file *filp, void *dirent, - filldir_t filldir, struct task_struct *task, - const struct proc_ns_operations *ops) -{ - return proc_fill_cache(filp, dirent, filldir, - ops->name, strlen(ops->name), - proc_ns_instantiate, task, ops); + return -ENOENT; } -static int proc_ns_dir_readdir(struct file *filp, void *dirent, - filldir_t filldir) +static int proc_ns_dir_readdir(struct file *file, struct dir_context *ctx) { - int i; - struct dentry *dentry = filp->f_path.dentry; - struct inode *inode = dentry->d_inode; - struct task_struct *task = get_proc_task(inode); + struct task_struct *task = get_proc_task(file_inode(file)); const struct proc_ns_operations **entry, **last; - ino_t ino; - int ret; - ret = -ENOENT; if (!task) - goto out_no_task; + return -ENOENT; - ret = 0; - i = filp->f_pos; - switch (i) { - case 0: - ino = inode->i_ino; - if (filldir(dirent, ".", 1, i, ino, DT_DIR) < 0) - goto out; - i++; - filp->f_pos++; - /* fall through */ - case 1: - ino = parent_ino(dentry); - if (filldir(dirent, "..", 2, i, ino, DT_DIR) < 0) - goto out; - i++; - filp->f_pos++; - /* fall through */ - default: - i -= 2; - if (i >= ARRAY_SIZE(ns_entries)) { - ret = 1; - goto out; - } - entry = ns_entries + i; - last = &ns_entries[ARRAY_SIZE(ns_entries) - 1]; - while (entry <= last) { - if (proc_ns_fill_cache(filp, dirent, filldir, - task, *entry) < 0) - goto out; - filp->f_pos++; - entry++; - } + if (!dir_emit_dots(file, ctx)) + goto out; + if (ctx->pos >= 2 + ARRAY_SIZE(ns_entries)) + goto out; + entry = ns_entries + (ctx->pos - 2); + last = &ns_entries[ARRAY_SIZE(ns_entries) - 1]; + while (entry <= last) { + const struct proc_ns_operations *ops = *entry; + if (!proc_fill_cache(file, ctx, ops->name, strlen(ops->name), + proc_ns_instantiate, task, ops)) + break; + ctx->pos++; + entry++; } - - ret = 1; out: put_task_struct(task); -out_no_task: - return ret; + return 0; } const struct file_operations proc_ns_dir_operations = { .read = generic_read_dir, - .readdir = proc_ns_dir_readdir, + .iterate = proc_ns_dir_readdir, }; static struct dentry *proc_ns_dir_lookup(struct inode *dir, struct dentry *dentry, unsigned int flags) { - struct dentry *error; + int error; struct task_struct *task = get_proc_task(dir); const struct proc_ns_operations **entry, **last; unsigned int len = dentry->d_name.len; - error = ERR_PTR(-ENOENT); + error = -ENOENT; if (!task) goto out_no_task; @@ -310,7 +162,7 @@ out: put_task_struct(task); out_no_task: - return error; + return ERR_PTR(error); } const struct inode_operations proc_ns_dir_inode_operations = { @@ -318,31 +170,3 @@ .getattr = pid_getattr, .setattr = proc_setattr, }; - -struct file *proc_ns_fget(int fd) -{ - struct file *file; - - file = fget(fd); - if (!file) - return ERR_PTR(-EBADF); - - if (file->f_op != &ns_file_operations) - goto out_invalid; - - return file; - -out_invalid: - fput(file); - return ERR_PTR(-EINVAL); -} - -struct proc_ns *get_proc_ns(struct inode *inode) -{ - return &PROC_I(inode)->ns; -} - -bool proc_ns_inode(struct inode *inode) -{ - return inode->i_fop == &ns_file_operations; -}