linux-kernel - Re: [PATCH] printk: Export struct log size and member offsets through vmcoreinfo

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]

Date:	Wed, 18 Jul 2012 19:27:08 +0200
From:	Kay Sievers <kay@...y.org>
To:	Vivek Goyal <vgoyal@...hat.com>
Cc:	linux kernel mailing list <linux-kernel@...r.kernel.org>,
	Kexec Mailing List <kexec@...ts.infradead.org>,
	"Eric W. Biederman" <ebiederm@...ssion.com>,
	Andrew Morton <akpm@...ux-foundation.org>,
	Greg Kroah-Hartmann <gregkh@...uxfoundation.org>
Subject: Re: [PATCH] printk: Export struct log size and member offsets through vmcoreinfo

On Wed, Jul 18, 2012 at 7:18 PM, Vivek Goyal <vgoyal@...hat.com> wrote:

> Currently I am not exporting log "level" info as that is a bitfield and
> offsetof() bitfields can't be calculated.

We could make the level the lower 3 bits of the byte, export the byte,
and define that only 3 bits of the byte are valid? Would that help?

>  kernel/printk.c |    9 +++++++++
>  1 file changed, 9 insertions(+)

> +       /*
> +        * Export struct log size and field offsets. User space tools can
> +        * parse it and detect any changes to structure down the line.
> +        */
> +       VMCOREINFO_STRUCT_SIZE(log);
> +       VMCOREINFO_OFFSET(log, ts_nsec);
> +       VMCOREINFO_OFFSET(log, len);
> +       VMCOREINFO_OFFSET(log, text_len);
> +       VMCOREINFO_OFFSET(log, dict_len);

Ah, nice, that's how you handle exporting structures, it was still on
my list, to find out how all that should look like.

Cc:ing Greg, to pick it up.

Thanks a lot for taking care of it,
Kay
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/