From: Florian Weimer <fweimer@redhat.com>
To: "H.J. Lu" <hjl.tools@gmail.com>
Cc: binutils@sourceware.org, Alan Modra <amodra@gmail.com>,
Nick Clifton <nickc@redhat.com>,
Richard Earnshaw <rearnsha@arm.com>
Subject: Re: [PATCH v3 2/2] elf: Add GNU_PROPERTY_1_NEEDED check
Date: Fri, 25 Jun 2021 16:10:48 +0200 [thread overview]
Message-ID: <87o8bu826v.fsf@oldenburg.str.redhat.com> (raw)
In-Reply-To: <20210624132411.1993105-3-hjl.tools@gmail.com> (H. J. Lu's message of "Thu, 24 Jun 2021 06:24:11 -0700")
* H. J. Lu:
> If GNU_PROPERTY_1_NEEDED_INDIRECT_EXTERN_ACCESS is set on any input
> relocatable files:
>
> 1. Don't generate copy relocations.
> 2. Turn off extern_protected_data since it implies
> GNU_PROPERTY_NO_COPY_ON_PROTECTED.
> 3. Treate reference to protected symbols with indirect external access
> as local.
> 4. Set GNU_PROPERTY_1_NEEDED_INDIRECT_EXTERN_ACCESS on output.
> 5. When generating executable, clear this bit when there are non-GOT or
> non-PLT relocations in input relocatable files without the bit set.
> 6. Add -z [no]indirect-extern-access to control indirect external access.
Should the property be used just for error checking? We would flip the
default unconditionally. Such a behavioral change simply based on some
input file is quite surprising.
For (4), I think we need to set a different flag (or perhaps even
flags), and be really careful about what we do. I think an output file
that is an executable will never require indirect-extern-access, but it
can be incompatible with indirect-extern-access objects at run time.
Shared objects as output files may themselves depend on
indirect-extern-access objects at run time. Ideally, markup would be
applied to the relocations that are affected by the changes in the ABI.
Thanks,
Florian
next prev parent reply other threads:[~2021-06-25 14:10 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-06-24 13:24 [PATCH v3 0/2] elf: Implement indirect external access marker H.J. Lu
2021-06-24 13:24 ` [PATCH v3 1/2] elf: Add GNU_PROPERTY_1_NEEDED H.J. Lu
2021-06-24 13:24 ` [PATCH v3 2/2] elf: Add GNU_PROPERTY_1_NEEDED check H.J. Lu
2021-06-25 14:10 ` Florian Weimer [this message]
2021-06-25 18:52 ` H.J. Lu
2021-06-28 8:46 ` Florian Weimer
2021-06-28 11:55 ` H.J. Lu
2021-07-08 7:27 ` Florian Weimer
2021-07-08 12:26 ` H.J. Lu
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