linux-kernel - Re: [PATCH v3 2/3] perf tool: add PERF_RECORD_NAMESPACES to include namespaces related info

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 for Android: free password hash cracker in your pocket

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

Date:   Tue, 13 Dec 2016 10:51:56 +1300
From:   ebiederm@...ssion.com (Eric W. Biederman)
To:     Hari Bathini <hbathini@...ux.vnet.ibm.com>
Cc:     ast@...com, peterz@...radead.org,
        lkml <linux-kernel@...r.kernel.org>, acme@...nel.org,
        alexander.shishkin@...ux.intel.com, mingo@...hat.com,
        daniel@...earbox.net, rostedt@...dmis.org,
        Ananth N Mavinakayanahalli <ananth@...ux.vnet.ibm.com>,
        sargun@...gun.me, Aravinda Prasad <aravinda@...ux.vnet.ibm.com>,
        brendan.d.gregg@...il.com
Subject: Re: [PATCH v3 2/3] perf tool: add PERF_RECORD_NAMESPACES to include namespaces related info

Hari Bathini <hbathini@...ux.vnet.ibm.com> writes:

> This patch updates perf tool to examine PERF_RECORD_NAMESPACES events
> emitted by the kernel when fork, clone, setns or unshare are invoked.
> Also, it synthesizes PERF_RECORD_NAMESPACES events for processes that
> were running prior to invocation of perf record, the data for which
> is taken from /proc/$PID/ns. These changes make way for analyzing
> events with regard to namespaces.

> diff --git a/tools/perf/util/event.h b/tools/perf/util/event.h
> index 8d363d5..a73bc8e 100644
> --- a/tools/perf/util/event.h
> +++ b/tools/perf/util/event.h
> @@ -39,6 +39,13 @@ struct comm_event {
>  	char comm[16];
>  };
>  
> +struct namespaces_event {
> +	struct perf_event_header header;
> +	u32 pid, tid;
> +	u64 dev_num;
> +	u64 inode_num[NAMESPACES_MAX];
> +};

This suffers from the same issue I pointed out with the
kernel interface.  We need one device number per inode.
Today we only have one device number but that may change in
the future.  These are st_dev and st_inode from stat, and
you need both of them per namespace to be unique.

I do not want to get into a situation where I have to implement a
namespace of namespaces in the future.

Eric