From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mx3-rdu2.redhat.com ([66.187.233.73]:59422 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1750970AbeEUTQD (ORCPT ); Mon, 21 May 2018 15:16:03 -0400 From: Steve Grubb To: linux-audit@redhat.com Cc: Richard Guy Briggs , cgroups@vger.kernel.org, containers@lists.linux-foundation.org, linux-api@vger.kernel.org, linux-fsdevel@vger.kernel.org, LKML , netdev@vger.kernel.org, ebiederm@xmission.com, luto@kernel.org, jlayton@redhat.com, carlos@redhat.com, dhowells@redhat.com, viro@zeniv.linux.org.uk, simo@redhat.com, eparis@parisplace.org, serge@hallyn.com Subject: Re: [RFC PATCH ghak32 V2 13/13] debug audit: read container ID of a process Date: Mon, 21 May 2018 15:16:01 -0400 Message-ID: <3001737.MkQ41rgtZF@x2> In-Reply-To: <1081821010c124fe4e35984ec3dac1654453bb7c.1521179281.git.rgb@redhat.com> References: <1081821010c124fe4e35984ec3dac1654453bb7c.1521179281.git.rgb@redhat.com> MIME-Version: 1.0 Content-Transfer-Encoding: 7Bit Content-Type: text/plain; charset="us-ascii" Sender: linux-fsdevel-owner@vger.kernel.org List-ID: On Friday, March 16, 2018 5:00:40 AM EDT Richard Guy Briggs wrote: > Add support for reading the container ID from the proc filesystem. I think this could be useful in general. Please consider this to be part of the full patch set and not something merely used to debug the patches. -Steve > This is a read from the proc entry of the form /proc/PID/containerid > where PID is the process ID of the task whose container ID is sought. > > The read expects up to a u64 value (unset: 18446744073709551615). > > Signed-off-by: Richard Guy Briggs > --- > fs/proc/base.c | 20 ++++++++++++++++++-- > 1 file changed, 18 insertions(+), 2 deletions(-) > > diff --git a/fs/proc/base.c b/fs/proc/base.c > index 6ce4fbe..f66d1e2 100644 > --- a/fs/proc/base.c > +++ b/fs/proc/base.c > @@ -1300,6 +1300,21 @@ static ssize_t proc_sessionid_read(struct file * > file, char __user * buf, .llseek = generic_file_llseek, > }; > > +static ssize_t proc_containerid_read(struct file *file, char __user *buf, > + size_t count, loff_t *ppos) > +{ > + struct inode *inode = file_inode(file); > + struct task_struct *task = get_proc_task(inode); > + ssize_t length; > + char tmpbuf[TMPBUFLEN*2]; > + > + if (!task) > + return -ESRCH; > + length = scnprintf(tmpbuf, TMPBUFLEN*2, "%llu", > audit_get_containerid(task)); + put_task_struct(task); > + return simple_read_from_buffer(buf, count, ppos, tmpbuf, length); > +} > + > static ssize_t proc_containerid_write(struct file *file, const char __user > *buf, size_t count, loff_t *ppos) > { > @@ -1330,6 +1345,7 @@ static ssize_t proc_containerid_write(struct file > *file, const char __user *buf, } > > static const struct file_operations proc_containerid_operations = { > + .read = proc_containerid_read, > .write = proc_containerid_write, > .llseek = generic_file_llseek, > }; > @@ -2996,7 +3012,7 @@ static int proc_pid_patch_state(struct seq_file *m, > struct pid_namespace *ns, #ifdef CONFIG_AUDITSYSCALL > REG("loginuid", S_IWUSR|S_IRUGO, proc_loginuid_operations), > REG("sessionid", S_IRUGO, proc_sessionid_operations), > - REG("containerid", S_IWUSR, proc_containerid_operations), > + REG("containerid", S_IWUSR|S_IRUSR, proc_containerid_operations), > #endif > #ifdef CONFIG_FAULT_INJECTION > REG("make-it-fail", S_IRUGO|S_IWUSR, proc_fault_inject_operations), > @@ -3391,7 +3407,7 @@ static int proc_tid_comm_permission(struct inode > *inode, int mask) #ifdef CONFIG_AUDITSYSCALL > REG("loginuid", S_IWUSR|S_IRUGO, proc_loginuid_operations), > REG("sessionid", S_IRUGO, proc_sessionid_operations), > - REG("containerid", S_IWUSR, proc_containerid_operations), > + REG("containerid", S_IWUSR|S_IRUSR, proc_containerid_operations), > #endif > #ifdef CONFIG_FAULT_INJECTION > REG("make-it-fail", S_IRUGO|S_IWUSR, proc_fault_inject_operations),