From: Andreas Schwab <schwab@linux-m68k.org>
To: Fangrui Song <maskray@google.com>
Cc: libc-alpha@sourceware.org,
Adhemerval Zanella <adhemerval.zanella@linaro.org>
Subject: Re: [PATCH] elf: Move post-relocation code of _dl_start into _dl_start_final
Date: Mon, 25 Apr 2022 17:14:12 +0200 [thread overview]
Message-ID: <87a6c95h6j.fsf@igel.home> (raw)
In-Reply-To: <20220424014529.347497-1-maskray@google.com> (Fangrui Song's message of "Sat, 23 Apr 2022 18:45:29 -0700")
On Apr 23 2022, Fangrui Song wrote:
> On non-PI_STATIC_AND_HIDDEN architectures, getting the address of
> _rtld_local_ro (for GLRO (dl_final_object)) goes through a GOT entry.
> The GOT load may be reordered before self relocation, leading to an
> unrelocated/incorrect _rtld_local_ro address.
>
> 84e02af1ebc9988126eebe60bf19226cea835623 tickled GCC powerpc32 to
> reorder the GOT load before relative relocations, leading to ld.so
> crash. This is similar to the m68k issue fixed by
> a8e9b5b8079d18116ca69c9797e77804ecf2ee7e.
>
> Move code after self relocation into _dl_start_final to avoid the
> reordering. This fixes powerpc32 and may help other architectures when
> ELF_DYNAMIC_RELOCATE is simplified in the future.
Ok.
--
Andreas Schwab, schwab@linux-m68k.org
GPG Key fingerprint = 7578 EB47 D4E5 4D69 2510 2552 DF73 E780 A9DA AEC1
"And now for something completely different."
prev parent reply other threads:[~2022-04-25 15:14 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-04-24 1:45 Fangrui Song
2022-04-25 15:14 ` Andreas Schwab [this message]
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