Re: [PATCH v2 0/5] firmware: add SmPL grammar to avoid issues

From: Luis R. Rodriguez
Date: Wed Jul 06 2016 - 20:56:55 EST


On Thu, Jun 16, 2016 at 03:54:16PM -0700, Luis R. Rodriguez wrote:
> The firmware API has had some issues a while ago, some of this is
> not well documented, and its still hard to grasp. This documents
> some of these issues, adds SmPL grammar rules to enable us to hunt
> for issues, and annotations to help us with our effort to finally
> compartamentalize that pesky usermode helper.
>
> Previously this was just one patch, the grammar rule to help
> find request firmware API users on init or probe, this series
> extends that effort with usermode helper grammar rules, and some
> annotations and documentation on the firmware_class driver to
> avoid further issues. Documenting the usermode helper and making
> it clear why we cannot remove it is important for analysis for
> the next series which adds the new flexible sysdata firmware API.
>
> This series depends on the coccicheck series which enables
> annotations on coccinelle patches to require a specific
> version of coccinelle [0], as such coordination with Michal is
> in order.

Michal is out until July 11, and upon further thought such coordination
is not need, the annotation is in place as comments and as such
merging this now won't have any negative effects other than the version
check. Also the patches in question for the coccicheck change are all
acked now and I expect them to be merged anyway.

Which tree should firmware changes go through ?

> This series is also further extended next with the new sydata
> API, the full set of changes is available on my linux-next tree [1].
>
> Perhaps now a good time to discuss -- if 0-day should enable the rule
> scripts/coccinelle/api/request_firmware-usermode.cocci to be called on
> every 0-day iteration, it runs rather fast and it should help police
> against avoiding futher explicit users of the usermode helper.

And if we are going to merge this anyone oppose enabling hunting
for further explicit users of the usermode helper using grammar through
0-day ?

Luis

>
> [0] https://lkml.kernel.org/r/1466116292-21843-1-git-send-email-mcgrof@xxxxxxxxxx
> [1] https://git.kernel.org/cgit/linux/kernel/git/mcgrof/linux-next.git/log/?h=20160616-sysdata-v2
>
> Luis R. Rodriguez (5):
> MAINTAINERS: extend firmware_class maintainer list
> firmware: annotate thou shalt not request fw on init or probe
> firmware: update usermode helper docs and add SmPL report
> firmware: add usermode helper DECLARE_FW_LOADER_USER() annotation
> firmware: fix fw cache to avoid usermode helper on suspend
>
> Documentation/firmware_class/README | 59 +++++++++-
> MAINTAINERS | 1 +
> drivers/base/Kconfig | 2 +-
> drivers/base/firmware_class.c | 2 +-
> drivers/firmware/dell_rbu.c | 1 +
> drivers/leds/leds-lp55xx-common.c | 1 +
> include/linux/firmware.h | 7 ++
> .../request_firmware-avoid-init-probe-init.cocci | 130 +++++++++++++++++++++
> .../coccinelle/api/request_firmware-usermode.cocci | 44 +++++++
> 9 files changed, 240 insertions(+), 7 deletions(-)
> create mode 100644 scripts/coccinelle/api/request_firmware-avoid-init-probe-init.cocci
> create mode 100644 scripts/coccinelle/api/request_firmware-usermode.cocci
>
> --
> 2.8.2
>
>

--
Luis Rodriguez, SUSE LINUX GmbH
Maxfeldstrasse 5; D-90409 Nuernberg