From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751321AbcJIOhf (ORCPT ); Sun, 9 Oct 2016 10:37:35 -0400 Received: from mail-lf0-f66.google.com ([209.85.215.66]:34191 "EHLO mail-lf0-f66.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750708AbcJIOh0 (ORCPT ); Sun, 9 Oct 2016 10:37:26 -0400 From: Lafcadio Wluiki To: linux-kernel@vger.kernel.org Cc: Kees Cook Subject: [PATCH 1/2] procfs: use an enum for possible hidepid values Date: Sun, 9 Oct 2016 16:36:39 +0200 Message-Id: <1476023800-15333-1-git-send-email-wluikil@gmail.com> X-Mailer: git-send-email 2.7.4 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org (Second, rebased submission, since first submission yielded no replies.) Previously, the hidepid parameter was checked by comparing literal integers 0, 1, 2. Let's add a proper enum for this, to make the checking more expressive: 0 → HIDEPID_OFF 1 → HIDEPID_NO_ACCESS 2 → HIDEPID_INVISIBLE This changes the internal labelling only, the userspace-facing interface remains unmodified, and still works with literal integers 0, 1, 2. No functional changes. Signed-off-by: Lafcadio Wluiki --- fs/proc/base.c | 8 ++++---- fs/proc/inode.c | 2 +- fs/proc/root.c | 3 ++- include/linux/pid_namespace.h | 6 ++++++ 4 files changed, 13 insertions(+), 6 deletions(-) diff --git a/fs/proc/base.c b/fs/proc/base.c index dc7fe5f..2680794 100644 --- a/fs/proc/base.c +++ b/fs/proc/base.c @@ -743,11 +743,11 @@ static int proc_pid_permission(struct inode *inode, int mask) task = get_proc_task(inode); if (!task) return -ESRCH; - has_perms = has_pid_permissions(pid, task, 1); + has_perms = has_pid_permissions(pid, task, HIDEPID_NO_ACCESS); put_task_struct(task); if (!has_perms) { - if (pid->hide_pid == 2) { + if (pid->hide_pid == HIDEPID_INVISIBLE) { /* * Let's make getdents(), stat(), and open() * consistent with each other. If a process @@ -1705,7 +1705,7 @@ int pid_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat) stat->gid = GLOBAL_ROOT_GID; task = pid_task(proc_pid(inode), PIDTYPE_PID); if (task) { - if (!has_pid_permissions(pid, task, 2)) { + if (!has_pid_permissions(pid, task, HIDEPID_INVISIBLE)) { rcu_read_unlock(); /* * This doesn't prevent learning whether PID exists, @@ -3166,7 +3166,7 @@ int proc_pid_readdir(struct file *file, struct dir_context *ctx) iter.tgid += 1, iter = next_tgid(ns, iter)) { char name[PROC_NUMBUF]; int len; - if (!has_pid_permissions(ns, iter.task, 2)) + if (!has_pid_permissions(ns, iter.task, HIDEPID_INVISIBLE)) continue; len = snprintf(name, sizeof(name), "%d", iter.tgid); diff --git a/fs/proc/inode.c b/fs/proc/inode.c index c1b7238..7b28103 100644 --- a/fs/proc/inode.c +++ b/fs/proc/inode.c @@ -107,7 +107,7 @@ static int proc_show_options(struct seq_file *seq, struct dentry *root) if (!gid_eq(pid->pid_gid, GLOBAL_ROOT_GID)) seq_printf(seq, ",gid=%u", from_kgid_munged(&init_user_ns, pid->pid_gid)); - if (pid->hide_pid != 0) + if (pid->hide_pid != HIDEPID_OFF) seq_printf(seq, ",hidepid=%u", pid->hide_pid); return 0; diff --git a/fs/proc/root.c b/fs/proc/root.c index 8d3e484..2989731 100644 --- a/fs/proc/root.c +++ b/fs/proc/root.c @@ -58,7 +58,8 @@ int proc_parse_options(char *options, struct pid_namespace *pid) case Opt_hidepid: if (match_int(&args[0], &option)) return 0; - if (option < 0 || option > 2) { + if (option < HIDEPID_OFF || + option > HIDEPID_INVISIBLE) { pr_err("proc: hidepid value must be between 0 and 2.\n"); return 0; } diff --git a/include/linux/pid_namespace.h b/include/linux/pid_namespace.h index 34cce96..c2a989d 100644 --- a/include/linux/pid_namespace.h +++ b/include/linux/pid_namespace.h @@ -21,6 +21,12 @@ struct pidmap { struct fs_pin; +enum { /* definitions for pid_namespace's hide_pid field */ + HIDEPID_OFF = 0, + HIDEPID_NO_ACCESS = 1, + HIDEPID_INVISIBLE = 2, +}; + struct pid_namespace { struct kref kref; struct pidmap pidmap[PIDMAP_ENTRIES]; -- 2.7.4