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From: Alan Modra <amodra@gmail.com>
To: Tulio Magno Quites Machado Filho <tuliom@linux.ibm.com>
Cc: libc-alpha@sourceware.org
Subject: Re: [PATCH v2 4/4] powerpc64: Enable static-pie
Date: Thu, 14 Apr 2022 10:46:14 +0930	[thread overview]
Message-ID: <Yld13vIqJwzILjfb@squeak.grove.modra.org> (raw)
In-Reply-To: <87wnfz199a.fsf@linux.ibm.com>

On Fri, Apr 08, 2022 at 07:49:05PM -0300, Tulio Magno Quites Machado Filho wrote:
> Alan Modra via Libc-alpha <libc-alpha@sourceware.org> writes:
> 
> > 	* sysdeps/powerpc/powerpc64/configure.ac (SUPPORT_STATIC_PIE): Define.
> > 	(PI_STATIC_AND_HIDDEN): Define.
> > 	* sysdeps/powerpc/powerpc64/configure: Regenerate.
> 
> While the code in this patch is perfect, I'm slightly inclined to think its
> merge should be delayed until the failures on both powerpc64-linux and
> powerpc64le-linux are fixed.
> 
> Another option would be to restrict this code to powerpc64le-linux only,
> although I haven't had the success you mentioned in the cover letter.
> 
> Anyway, in one of my tests in particular (powerpc64le-linux, GCC 8, Binutils
> 2.30, without --enable-static-pie) I noticed many tests failing.  I'm still
> investigating what happened.

binutils-2.30 is too old.  You'll find __rela_iplt_start and
__rela_iplt_end symbols being defined in PIEs.  Those symbols are
supposed to mark out IFUNC relocs in ET_EXEC static binaries.  Their
presence in ET_DYN static binaries is bad, especially since it seems
they have garbage values not pointing at the correct set of
relocations.  I suspect, but haven't checked, that the garbage values
are due to -z combreloc.  This bug in ld was fixed with commit
795e3bb7de9, so you'll need at least binutils-2.33 for static-pie.

I'll note that static-pie is enabled in glibc without any user
--enable-static-pie, ie. it is the default if SUPPORT_STATIC_PIE is
set.  SUPPORT_STATIC_PIE is enabled unconditionally for x86 and
aarch64 without any toolchain checks, and I foolishly followed that
precedent.  Likely x86 would fail the glibc testsuite all over the
place with an old binutils too.

-- 
Alan Modra
Australia Development Lab, IBM

  reply	other threads:[~2022-04-14  1:16 UTC|newest]

Thread overview: 35+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-01-23 12:42 [PowerPC64] Use medium model toc accesses throughout Alan Modra
2022-01-24  3:47 ` [PATCH 2/5] [PowerPC64] Set up thread register for _dl_relocate_static_pie Alan Modra
2022-02-16 23:02   ` Paul E Murphy
2022-02-19  0:49     ` Alan Modra
2022-01-24  3:50 ` [PATCH 3/5] [PowerPC] Relocate stinfo->main Alan Modra
2022-01-24  4:48   ` H.J. Lu
2022-01-24  6:51     ` Alan Modra
2022-01-24  3:52 ` [PATCH 4/5] Constify a variable in dl_vdso_vsym Alan Modra
2022-01-24  4:06 ` [PATCH 5/5] Enable static-pie on powerpc64 Alan Modra
2022-01-27 18:39   ` Florian Weimer
2022-01-28  8:45     ` Alan Modra
2022-01-28 17:48 ` [PowerPC64] Use medium model toc accesses throughout Paul E Murphy
2022-01-29  1:24   ` Alan Modra
2022-02-28  6:40 ` [PATCH v2 0/4] PowerPC64 static-pie Alan Modra
2022-02-28  6:40   ` [PATCH v2 1/4] powerpc64: Use medium model toc accesses throughout Alan Modra
2022-04-08 22:28     ` Tulio Magno Quites Machado Filho
2022-02-28  6:40   ` [PATCH v2 2/4] powerpc64: Set up thread register for _dl_relocate_static_pie Alan Modra
2022-04-08 22:28     ` Tulio Magno Quites Machado Filho
2022-02-28  6:40   ` [PATCH v2 3/4] powerpc: Relocate stinfo->main Alan Modra
2022-04-08 22:32     ` Tulio Magno Quites Machado Filho
2022-02-28  6:40   ` [PATCH v2 4/4] powerpc64: Enable static-pie Alan Modra
2022-04-08 22:49     ` Tulio Magno Quites Machado Filho
2022-04-14  1:16       ` Alan Modra [this message]
2022-04-14  3:42         ` Fangrui Song
2022-04-20  7:21         ` [PATCH v3] " Alan Modra
2022-03-04 12:48   ` [PATCH v2 0/4] PowerPC64 static-pie Alan Modra
2022-04-08  8:06     ` Alan Modra
2022-04-09  0:14       ` Fangrui Song
2022-04-14  0:33         ` Alan Modra
2022-04-14  1:54           ` DT_RELR without libc.so dependency H.J. Lu
2022-04-14  3:43             ` Fangrui Song
2022-04-14  5:18             ` Alan Modra
2022-04-14 17:55               ` H.J. Lu
2022-04-08 22:27   ` [PATCH v2 0/4] PowerPC64 static-pie Tulio Magno Quites Machado Filho
2022-04-11  1:38     ` Alan Modra

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