linux-kernel - Re: [PATCH v7 0/8]/[PULL REQUEST] Trim unused exported kernel symbols

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Message-ID: <alpine.LFD.2.20.1604182326490.27452@knanqh.ubzr>
Date:	Mon, 18 Apr 2016 23:32:20 -0400 (EDT)
From:	Nicolas Pitre <nicolas.pitre@...aro.org>
To:	Michal Marek <mmarek@...e.com>
cc:	linux-kbuild@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH v7 0/8]/[PULL REQUEST] Trim unused exported kernel
 symbols

Ping !

/me only hears back empty cave echoes ...


On Wed, 6 Apr 2016, Nicolas Pitre wrote:

> 
> Gentle ping...
> 
> If possible, I'd like for those patches to be sorted out before the 
> opening of the merge window gets too close like last time.
> 
> 
> On Tue, 29 Mar 2016, Nicolas Pitre wrote:
> 
> > This patch series provides the option to omit exported symbols from
> > the kernel and modules that are never referenced by any of the selected
> > modules in the current kernel configuration. this allows for optimizing
> > the compiled code and reducing final binaries' size. When using LTO the
> > binary size reduction is even more effective. It could also be argued
> > that this could bring some security advantages.
> > 
> > The original cover letter with lots of test results can be found here:
> > 
> > 	https://lkml.org/lkml/2016/2/8/813
> > 
> > Please consider for merging into your tree.
> > 
> > Alternately, the following branch can be pulled:
> > 
> > 	http://git.linaro.org/people/nicolas.pitre/linux.git autoksyms
> > 
> > Thanks.
> > 
> > Changes from v6:
> > 
> > - Rebased on v4.6-rc1, including adjustments to the recently introduced
> >   rule_as_o_S.
> > 
> > - Explicitly ignored more if_changed_dep callers for which no EXPORT_SYMBOL
> >   can be parsed.
> > 
> > Changes from v5:
> > 
> > - Disable automatic dependency file generation during the preprocessor
> >   pass when gathering exported symbol names.  Not only it is redundant
> >   but in some conditions this crashes fixdep that might be reading the
> >   previous dependency file at the same time. Reported by Michal Marek.
> > 
> > - Redirect error messages to stderr rather than pass it as a symbol name
> >   dependency.
> > 
> > Changes from v4:
> > 
> > - Correctness changes plus small cleanup to adjust_autoksyms.sh as
> >   suggested by Michal Marek.
> > 
> > - Changed ksym build dependency generation by re-running the preprocessor
> >   rather than collecting those dependencies as warnings through stderr
> >   which was too fragile.
> > 
> > Changes from v3:
> > 
> > - Shell portability changes to adjust_autoksyms.sh, partly from
> >   suggestions by Zev Weiss.
> > 
> > - Fix sample modules by building them before adjust_autoksyms.sh is run.
> > 
> > Changes from v2:
> > 
> > - Generating the build dependencies by parsing the source with fixdep
> >   turned out to be unreliable due to all the EXPORT_SYMBOL() variants,
> >   and especially their use within macros where the actual symbol name
> >   is known only after running the preprocessor. This list of symbol names
> >   is now obtained from the preprocessor directly, fixing allmodconfig
> >   builds.
> > 
> > Changes from v1:
> > 
> > - Replaced "exp" that doesn't convey the right meaning as noted by
> >   Sam Ravnborg. The "ksym" identifier is actually what the kernel
> >   already uses for this. Therefore:
> >   - CONFIG_TRIM_UNUSED_EXPSYMS --> CONFIG_TRIM_UNUSED_KSYMS
> >   - include/generated/expsyms.h --> include/generated/autoksyms.h
> >   - #define __EXPSYM_* --> #define __KSYM_*
> > 
> > - Some sed regexp improvements as suggested by Al Viro.
> > 
> > - Renamed vmlinux_recursive target to autoksyms_recursive.
> > 
> > - Accept EXPORT_SYMBOL variants with a prefix, e.g. ACPI_EXPORT_SYMBOL.
> > 
> > - Minor commit log clarifications.
> > 
> > - Added Rusty's ACK.
> > 
> > diffstat:
> > 
> >  Makefile                    |  23 +++++++--
> >  include/linux/export.h      |  33 ++++++++++++-
> >  init/Kconfig                |  16 ++++++
> >  scripts/Kbuild.include      |  32 +++++++++++-
> >  scripts/Makefile.build      |  32 ++++++------
> >  scripts/adjust_autoksyms.sh | 101 ++++++++++++++++++++++++++++++++++++++
> >  scripts/basic/fixdep.c      |  61 +++++++++++++++++------
> >  7 files changed, 261 insertions(+), 37 deletions(-)
> > 
> > 
> 
>