kernel-hardening - Re: [PATCH v6 07/10] proc: flush task dcache entries from all procfs instances

Follow @Openwall on Twitter for new release announcements and other news

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <8d85ba43-0759-358e-137d-246107bac747@gmail.com>
Date: Mon, 30 Dec 2019 14:03:29 -0800
From: J Freyensee <why2jjj.linux@...il.com>
To: Alexey Gladkov <gladkov.alexey@...il.com>,
 LKML <linux-kernel@...r.kernel.org>,
 Kernel Hardening <kernel-hardening@...ts.openwall.com>,
 Linux API <linux-api@...r.kernel.org>,
 Linux FS Devel <linux-fsdevel@...r.kernel.org>,
 Linux Security Module <linux-security-module@...r.kernel.org>
Cc: Akinobu Mita <akinobu.mita@...il.com>,
 Alexander Viro <viro@...iv.linux.org.uk>,
 Alexey Dobriyan <adobriyan@...il.com>,
 Andrew Morton <akpm@...ux-foundation.org>, Andy Lutomirski
 <luto@...nel.org>, Daniel Micay <danielmicay@...il.com>,
 Djalal Harouni <tixxdz@...il.com>, "Dmitry V . Levin" <ldv@...linux.org>,
 "Eric W . Biederman" <ebiederm@...ssion.com>,
 Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
 Ingo Molnar <mingo@...nel.org>, "J . Bruce Fields" <bfields@...ldses.org>,
 Jeff Layton <jlayton@...chiereds.net>, Jonathan Corbet <corbet@....net>,
 Kees Cook <keescook@...omium.org>,
 Linus Torvalds <torvalds@...ux-foundation.org>,
 Oleg Nesterov <oleg@...hat.com>, Solar Designer <solar@...nwall.com>,
 Stephen Rothwell <sfr@...b.auug.org.au>
Subject: Re: [PATCH v6 07/10] proc: flush task dcache entries from all procfs
 instances

snip

.

.

.

>   
> +#ifdef CONFIG_PROC_FS
> +static inline void pidns_proc_lock(struct pid_namespace *pid_ns)
> +{
> +	down_write(&pid_ns->rw_proc_mounts);
> +}
> +
> +static inline void pidns_proc_unlock(struct pid_namespace *pid_ns)
> +{
> +	up_write(&pid_ns->rw_proc_mounts);
> +}
> +
> +static inline void pidns_proc_lock_shared(struct pid_namespace *pid_ns)
> +{
> +	down_read(&pid_ns->rw_proc_mounts);
> +}
> +
> +static inline void pidns_proc_unlock_shared(struct pid_namespace *pid_ns)
> +{
> +	up_read(&pid_ns->rw_proc_mounts);
> +}
> +#else /* !CONFIG_PROC_FS */
> +
Apologies for my newbie question. I couldn't help but notice all these 
function calls are assuming that the parameter struct pid_namespace 
*pid_ns will never be NULL.  Is that a good assumption?

I don't have the background in this code to answer on my own, but I 
thought I'd raise the question.

Thanks,
Jay

Confused about mailing lists and their use? Read about mailing lists on Wikipedia and check out these guidelines on proper formatting of your messages.