All of lore.kernel.org
 help / color / mirror / Atom feed
From: Josh Triplett <josh@joshtriplett.org>
To: Riku Voipio <riku.voipio@linaro.org>
Cc: LKML <linux-kernel@vger.kernel.org>,
	Andrew Morton <akpm@linux-foundation.org>
Subject: Re: [PATCH] uselib: default depending if libc5 was used
Date: Fri, 27 Nov 2015 12:04:58 -0800	[thread overview]
Message-ID: <20151127200458.GA17820@x> (raw)
In-Reply-To: <CAAqcGHmPDcP_CK0XTif=9YN3w51icN=8xpuXiC_CKDaBXdkrrg@mail.gmail.com>

On Fri, Nov 27, 2015 at 12:48:29PM +0200, Riku Voipio wrote:
> On 27 November 2015 at 11:33, Josh Triplett <josh@joshtriplett.org> wrote:
> > On Fri, Nov 27, 2015 at 11:11:26AM +0200, Riku Voipio wrote:
> >> uselib hasn't been used since libc5; glibc does not use it.
> >> Deprecate uselib a bit more, by making the default y only
> >> if libc5 was widely used on the plaform.
> >>
> >> This makes arm64 kernel built with defconfig slighly smaller
> >>
> >> bloat-o-meter:
> >> add/remove: 0/3 grow/shrink: 0/2 up/down: 0/-1390 (-1390)
> >> function                                     old     new   delta
> >> kernel_config_data                         18164   18162      -2
> >> uselib_flags                                  20       -     -20
> >> padzero                                      216     192     -24
> >> sys_uselib                                   380       -    -380
> >> load_elf_library                             964       -    -964
> >>
> >> Signed-off-by: Riku Voipio <riku.voipio@linaro.org>
> >> Cc: Josh Triplett <josh@joshtriplett.org>
> >
> > Seems sensible.  Can you also make it only "default y" on 32-bit x86,
> > not 64-bit x86, since the latter never had libc5?
> 
> but running 32bit libc5 apps is possible with X86_64 kernel, so the
> check would become:
> 
> || X86_32 || (X86_64 && IA32_EMULATION)

Fair point.  Seems unlikely that anyone would do so, but certainly possible.

> > With that change:
> > Reviewed-by: Josh Triplett <josh@joshtriplett.org>
> >
> >>  init/Kconfig | 2 +-
> >>  1 file changed, 1 insertion(+), 1 deletion(-)
> >>
> >> diff --git a/init/Kconfig b/init/Kconfig
> >> index c24b6f7..bef326d 100644
> >> --- a/init/Kconfig
> >> +++ b/init/Kconfig
> >> @@ -285,7 +285,7 @@ config FHANDLE
> >>
> >>  config USELIB
> >>       bool "uselib syscall"
> >> -     default y
> >> +     def_bool ALPHA || M68K || SPARC || X86
> >>       help
> >>         This option enables the uselib syscall, a system call used in the
> >>         dynamic linker from libc5 and earlier.  glibc does not use this
> >> --
> >> 2.6.2
> >>

      reply	other threads:[~2015-11-27 20:05 UTC|newest]

Thread overview: 4+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2015-11-27  9:11 [PATCH] uselib: default depending if libc5 was used Riku Voipio
2015-11-27  9:33 ` Josh Triplett
2015-11-27 10:48   ` Riku Voipio
2015-11-27 20:04     ` Josh Triplett [this message]

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20151127200458.GA17820@x \
    --to=josh@joshtriplett.org \
    --cc=akpm@linux-foundation.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=riku.voipio@linaro.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.