linux-kernel - Re: [PATCH v3 4/4] mm/page_owner: Record task command name

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

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

Message-ID: <YfhMd5LTzTHu9zMD@carbon.dhcp.thefacebook.com>
Date:   Mon, 31 Jan 2022 12:54:15 -0800
From:   Roman Gushchin <guro@...com>
To:     Waiman Long <longman@...hat.com>
CC:     Johannes Weiner <hannes@...xchg.org>,
        Michal Hocko <mhocko@...nel.org>,
        Vladimir Davydov <vdavydov.dev@...il.com>,
        Andrew Morton <akpm@...ux-foundation.org>,
        Petr Mladek <pmladek@...e.com>,
        Steven Rostedt <rostedt@...dmis.org>,
        Sergey Senozhatsky <senozhatsky@...omium.org>,
        Andy Shevchenko <andriy.shevchenko@...ux.intel.com>,
        Rasmus Villemoes <linux@...musvillemoes.dk>,
        <linux-kernel@...r.kernel.org>, <cgroups@...r.kernel.org>,
        <linux-mm@...ck.org>, Ira Weiny <ira.weiny@...el.com>,
        Mike Rapoport <rppt@...nel.org>,
        David Rientjes <rientjes@...gle.com>,
        Rafael Aquini <aquini@...hat.com>
Subject: Re: [PATCH v3 4/4] mm/page_owner: Record task command name

On Mon, Jan 31, 2022 at 02:23:08PM -0500, Waiman Long wrote:
> The page_owner information currently includes the pid of the calling
> task. That is useful as long as the task is still running. Otherwise,
> the number is meaningless. To have more information about the allocating
> tasks that had exited by the time the page_owner information is
> retrieved, we need to store the command name of the task.
> 
> Add a new comm field into page_owner structure to store the command name
> and display it when the page_owner information is retrieved. Only the
> first 15 characters of the command name will be copied, but that should
> be enough in most cases. Even for those commands with longer names,
> it shouldn't be hard to guess what they are.
> 
> Signed-off-by: Waiman Long <longman@...hat.com>
> ---
>  mm/page_owner.c | 16 ++++++++++++----
>  1 file changed, 12 insertions(+), 4 deletions(-)
> 
> diff --git a/mm/page_owner.c b/mm/page_owner.c
> index a471c74c7fe0..8b2b381fd986 100644
> --- a/mm/page_owner.c
> +++ b/mm/page_owner.c
> @@ -20,6 +20,7 @@
>   * to use off stack temporal storage
>   */
>  #define PAGE_OWNER_STACK_DEPTH (16)
> +#define PAGE_OWNER_COMM_LEN	16

Not sure I understand why not simply use TASK_COMM_LEN ?