linux-kernel - Re: timing of module MODULE_STATE

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:	Mon, 31 Aug 2015 11:06:22 +0930
From:	Rusty Russell <rusty@...tcorp.com.au>
To:	"Frank Ch. Eigler" <fche@...hat.com>
Cc:	linux-kernel@...r.kernel.org
Subject: Re: timing of module MODULE_STATE_COMING notifier

"Frank Ch. Eigler" <fche@...hat.com> writes:
> Hi, Rusty -
>
> We just [1] came across your patch [2] from last year (merged into
> 3.17), wherein the RO/NX mapping settings for module sections were
> moved to an earlier point in the module-loading sequence.
>
> That patch also moved the MODULE_STATE_COMING notifier call to
> complete_formation(), which is relatively early to its former
> do_init_module() call site.  It now precedes the parse_args(),
> mod_sysfs_setup(), and trace_module_load() steps.

Yes, parse_args() can enter the module, so you really want it before
then.

> Was the latter part of the change intended & necessary?  It is
> negatively impacting systemtap, which was relying on
> MODULE_STATE_COMING being called from a fairly complete module state -
> just before the actual initializer function call.

Notifiers suck for stuff like this :(

Module state has many steps, so my preference has been to open-code
explicit hooks.  This would seem to reinforce that preference...

Thanks,
Rusty.
--
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/