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From: Carlos O'Donell <carlos@redhat.com>
To: Adhemerval Zanella <adhemerval.zanella@linaro.org>,
	libc-alpha@sourceware.org
Cc: Richard Purdie <richard.purdie@linuxfoundation.org>
Subject: Re: [PATCH 0/3] Remove prelink support
Date: Wed, 26 Jan 2022 23:59:58 -0500	[thread overview]
Message-ID: <6756d321-a537-48f1-931c-c68a12dd2309@redhat.com> (raw)
In-Reply-To: <20220121172951.285848-1-adhemerval.zanella@linaro.org>

On 1/21/22 12:29, Adhemerval Zanella via Libc-alpha wrote:
> As discussed recently on maillist [1], prelink is deprecated in
> practice:

This goes in the right direction.

I think we should review this for glibc 2.36.

Leaving glibc 2.35 as the last release with prelink support.

I've reviewed your NEWS entry for the removal note.
 
>   * There is no active development neither maintainace.
>   * It misses supports for some architectures, even for architecture
>     wildly deployed such as aarch64 [2].
>   * It does not work with recent security hardening such as PIE.
>   * Nor it will work on future ABI additions such as DT_RELR.
>   * Even when PIE is not enabled its coverity if flacky, with some
>     binaries showing corrupted state [3].
>   * Recent glibc changes to support different tools (such as lld)
>     showed inherent issue with current prelink support.
> 
> The first patch removes both prelink support by the loader and the
> LD_TRACE_PRELINKING.
> 
> The remove of mtrace TRACE_PRELINKING usage is on its own patch
> because it changes LD_TRACE_LOADED_OBJECTS semantic to support
> dumping the executable loading address and fixes mtrace for non
> PIE similar to BZ#22716.
> 
> Finally the third part removed LD_USE_LOAD_BIAS, which is used
> solely for try support prelink with PIE.
> 
> [1] https://sourceware.org/pipermail/libc-alpha/2022-January/135520.html
> [2] https://sourceware.org/pipermail/libc-alpha/2022-January/135522.html
> [3] https://embed.endfa.net/yocto-cross-prelink-1/
> 
> Adhemerval Zanella (3):
>   elf: Remove prelink support
>   malloc: Remove LD_TRACE_PRELINKING usage from mtrace
>   elf: Remove LD_USE_LOAD_BIAS
> 
>  NEWS                                   |   6 +
>  elf/Makefile                           |  16 --
>  elf/dl-conflict.c                      |  77 -------
>  elf/dl-deps.c                          |  66 ------
>  elf/dl-error-skeleton.c                |   4 +-
>  elf/dl-load.c                          |   3 +-
>  elf/dl-lookup.c                        | 161 --------------
>  elf/dl-main.h                          |   3 +
>  elf/dl-map-segments.h                  |   3 +-
>  elf/dl-support.c                       |   1 -
>  elf/do-rel.h                           |   3 -
>  elf/rtld.c                             | 283 ++++++-------------------
>  elf/tst-prelink-cmp.c                  |  49 -----
>  elf/tst-prelink.c                      |  29 ---
>  malloc/mtrace.pl                       |  55 ++---
>  sysdeps/alpha/dl-machine.h             |  15 --
>  sysdeps/arm/dl-machine.h               |   4 -
>  sysdeps/generic/ldsodefs.h             |  16 --
>  sysdeps/generic/unsecvars.h            |   1 -
>  sysdeps/i386/dl-machine.h              |  16 +-
>  sysdeps/or1k/dl-machine.h              |   4 -
>  sysdeps/powerpc/powerpc32/dl-machine.h |  31 +--
>  sysdeps/powerpc/powerpc64/dl-machine.h |  37 ----
>  sysdeps/s390/s390-32/dl-machine.h      |  22 +-
>  sysdeps/s390/s390-64/dl-machine.h      |  22 +-
>  sysdeps/sh/dl-machine.h                |   2 +-
>  sysdeps/sparc/sparc32/dl-machine.h     |  52 +----
>  sysdeps/sparc/sparc64/dl-machine.h     |  72 +------
>  sysdeps/x86_64/dl-machine.h            |  48 ++---
>  29 files changed, 167 insertions(+), 934 deletions(-)
>  delete mode 100644 elf/dl-conflict.c
>  delete mode 100644 elf/tst-prelink-cmp.c
>  delete mode 100644 elf/tst-prelink.c
> 


-- 
Cheers,
Carlos.


  parent reply	other threads:[~2022-01-27  5:00 UTC|newest]

Thread overview: 9+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-01-21 17:29 Adhemerval Zanella
2022-01-21 17:29 ` [PATCH 1/3] elf: " Adhemerval Zanella
2022-01-21 17:29 ` [PATCH 2/3] malloc: Remove LD_TRACE_PRELINKING usage from mtrace Adhemerval Zanella
2022-01-21 18:05   ` Siddhesh Poyarekar
2022-01-21 17:29 ` [PATCH 3/3] elf: Remove LD_USE_LOAD_BIAS Adhemerval Zanella
2022-01-24 18:55 ` [PATCH 0/3] Remove prelink support Adhemerval Zanella
2022-01-27  4:59 ` Carlos O'Donell [this message]
2022-02-03 15:29   ` Richard Purdie
2022-02-03 16:30     ` Adhemerval Zanella

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