[PATCH 0/3] lib/string_helpers: Add a few string helpers

Lucas De Marchi
2022-01-19T07:24:28Z

Add some helpers under lib/string_helpers.h so they can be used
throughout the kernel. When I started doing this there were 2 other
previous attempts I know of, not counting the iterations each of them
had:

1) https://lore.kernel.org/all/20191023131308.9420-1-jani.nikula@intel.com/
2) https://lore.kernel.org/all/20210215142137.64476-1-andriy.shevchenko@linux.intel.com/#t

Going through the comments I tried to find some common ground and
justification for what is in here, addressing some of the concerns
raised.

a. This version should be a drop-in replacement for what is currently in
the tree, with no change in behavior or binary size. For binary
size what I checked wat that the linked objects in the end have the
same size (gcc 11). From comments in the previous attempts this seems
also the case for earlier compiler versions

b. I didn't change the function name to choice_* as suggested by Andrew
Morton in 20191023155619.43e0013f0c8c673a5c508c1e@linux-foundation.org
because other people argumented in favor of shorter names for these
simple helpers - if they are long and people simply not use due to
that, we failed

c. Use string_helper.h for these helpers - pulling string.h in the
compilations units was one of the concerns and I think re-using this
already existing header is better than creating a new string-choice.h

d. This doesn't bring onoff() helper as there are some places in the
kernel with onoff as variable - another name is probably needed for
this function in order not to shadow the variable, or those variables
could be renamed. Or if people wanting <someprefix>
try to find a short one

e. One alternative to all of this suggested by Christian König
(43456ba7-c372-84cc-4949-dcb817188e21@amd.com) would be to add a
printk format. But besides the comment, he also seemed to like
the common function. This brought the argument from others that the
simple yesno()/enabledisable() already used in the code is easier to
remember and use than e.g. %py[DOY]

Last patch also has some additional conversion of open coded cases. I
preferred starting with drm/ since this is "closer to home".

I hope this is a good summary of the previous attempts and a way we can
move forward.

Andrew Morton, Petr Mladek, Andy Shevchenko: if this is accepted, my
proposal is to take first 2 patches either through mm tree or maybe
vsprintf. Last patch can be taken later through drm.

thanks
Lucas De Marchi

Cc: Alex Deucher <alexander.deucher@amd.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Andy Shevchenko <andy.shevchenko@gmail.com>
Cc: Ben Skeggs <bskeggs@redhat.com>
Cc: Christian König <christian.koenig@amd.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Daniel Vetter <daniel@ffwll.ch>
Cc: David Airlie <airlied@linux.ie>
Cc: David S. Miller <davem@davemloft.net>
Cc: Emma Anholt <emma@anholt.net>
Cc: Eryk Brol <eryk.brol@amd.com>
Cc: Francis Laniel <laniel_francis@privacyrequired.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Harry Wentland <harry.wentland@amd.com>
Cc: Jakub Kicinski <kuba@kernel.org>
Cc: Jani Nikula <jani.nikula@linux.intel.com>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Cc: Julia Lawall <julia.lawall@lip6.fr>
Cc: Kentaro Takeda <takedakn@nttdata.co.jp>
Cc: Leo Li <sunpeng.li@amd.com>
Cc: Mikita Lipski <mikita.lipski@amd.com>
Cc: Petr Mladek <pmladek@suse.com>
Cc: Rahul Lakkireddy <rahul.lakkireddy@chelsio.com>
Cc: Raju Rangoju <rajur@chelsio.com>
Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Cc: Rodrigo Vivi <rodrigo.vivi@intel.com>
Cc: Sakari Ailus <sakari.ailus@linux.intel.com>
Cc: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Vishal Kulkarni <vishal@chelsio.com>

Lucas De Marchi (3):
lib/string_helpers: Consolidate yesno() implementation
lib/string_helpers: Add helpers for enable[d]/disable[d]
drm: Convert open yes/no strings to yesno()

drivers/gpu/drm/amd/amdgpu/atom.c | 3 ++-
.../amd/display/amdgpu_dm/amdgpu_dm_debugfs.c | 6 +-----
drivers/gpu/drm/drm_client_modeset.c | 3 ++-
drivers/gpu/drm/drm_dp_helper.c | 3 ++-
drivers/gpu/drm/drm_gem.c | 3 ++-
drivers/gpu/drm/i915/i915_utils.h | 15 ---------------
drivers/gpu/drm/nouveau/nvkm/subdev/i2c/aux.c | 4 +++-
drivers/gpu/drm/radeon/atom.c | 3 ++-
drivers/gpu/drm/v3d/v3d_debugfs.c | 11 ++++++-----
drivers/gpu/drm/virtio/virtgpu_debugfs.c | 3 ++-
.../net/ethernet/chelsio/cxgb4/cxgb4_debugfs.c | 11 -----------
include/linux/string_helpers.h | 4 ++++
security/tomoyo/audit.c | 2 +-
security/tomoyo/common.c | 18 ++++--------------
security/tomoyo/common.h | 1 -
15 files changed, 31 insertions(+), 59 deletions(-)

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2.34.1