From: "H.J. Lu" <hjl.tools@gmail.com>
To: Alan Modra <amodra@gmail.com>
Cc: Binutils <binutils@sourceware.org>, Kaylee Blake <klkblake@gmail.com>
Subject: Re: RFC: [PATCH] ELF: Don't require section header on ELF objects
Date: Sun, 8 Mar 2020 17:02:11 -0700 [thread overview]
Message-ID: <CAMe9rOqH6x-0vLDBWgC26x+_e4-n-vaq5HKGSyUhSJj2=13kfQ@mail.gmail.com> (raw)
In-Reply-To: <CAMe9rOoREuJBwSeFQ_2J28V3=_jr4jZPdE98Ycq1PS6y7qXjgw@mail.gmail.com>
On Sun, Mar 8, 2020 at 4:46 PM H.J. Lu <hjl.tools@gmail.com> wrote:
>
> On Sun, Mar 8, 2020 at 4:35 PM Alan Modra <amodra@gmail.com> wrote:
> >
> > On Sun, Mar 08, 2020 at 11:06:33AM -0700, H.J. Lu wrote:
> > > On Sun, Mar 8, 2020 at 10:59 AM H.J. Lu <hjl.tools@gmail.com> wrote:
> > > >
> > > > Any comments?
> > > >
> > > > Kaylee, do you have copyright paper with FSF?
> > > >
> > > > H.J.
> > > > ---
> > > > Section header isn't mandatory on ELF executable nor shared library.
> > > > This patch adds a new linker option, -z nosectionheader, to omit ELF
> > > > section header when building an executable or shared library, adds
> > > > an objcopy and strip option, --remove-section-header, to remove ELF
> > > > section header from an executable or shared library.
> > > >
> > > > The PT_DYNAMIC segment contains DT_HASH/DT_GNU_HASH/DT_MIPS_XHASH,
> > > > DT_STRTAB, DT_SYMTAB, DT_STRSZ and DT_SYMENT, which can be used to
> > > > reconstruct dynamic symbol table when section header isn't available.
> > > > For DT_HASH, the number of dynamic symbol table entries equals the
> > > > number of chains. For DT_GNU_HASH/DT_MIPS_XHASH, only defined symbols
> > > > with non-STB_LOCAL indings are in hash table. Since in dynamic symbol
> > > > table, all symbols with STB_LOCAL binding are placed before symbols with
> > > > other bindings and all defined symbols are placed before undefined ones,
> > >
> > > It should read
> > >
> > > ---
> > > all symbols with STB_LOCAL binding are placed
> > > before symbols with other bindings and all undefined symbols are placed
> > > before defined ones,
> > > ---
> >
> > That's new to me. I don't think there is any ordering in .dynsym
> > among non-local symbols.
>
> I will get clarification from gABI group.
FYI,
https://groups.google.com/forum/#!topic/generic-abi/oDQ3Z3IDYuU
--
H.J.
next prev parent reply other threads:[~2020-03-09 0:02 UTC|newest]
Thread overview: 37+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-03-08 17:59 H.J. Lu
2020-03-08 18:06 ` H.J. Lu
2020-03-08 23:35 ` Alan Modra
2020-03-08 23:46 ` H.J. Lu
2020-03-09 0:02 ` H.J. Lu [this message]
2020-03-09 0:02 ` Kaylee Blake
2020-03-09 0:05 ` Alan Modra
2020-03-09 1:36 ` H.J. Lu
2020-03-09 1:59 ` Kaylee Blake
2020-03-09 2:23 ` Alan Modra
2020-03-09 2:35 ` H.J. Lu
2020-03-09 4:14 ` H.J. Lu
2020-03-09 4:59 ` Kaylee Blake
2020-03-09 11:56 ` Alan Modra
2020-03-08 23:24 ` Kaylee Blake
2020-03-08 23:29 ` H.J. Lu
2020-03-08 23:38 ` Alan Modra
2020-03-08 23:45 ` H.J. Lu
2020-03-12 2:14 ` Fangrui Song
2020-03-09 8:13 ` Florian Weimer
2020-03-09 12:54 ` Kaylee Blake
2020-03-09 13:06 ` Florian Weimer
2020-03-09 13:14 ` Kaylee Blake
2020-03-09 13:16 ` Florian Weimer
2020-03-09 13:28 ` Kaylee Blake
2020-03-09 13:29 ` Florian Weimer
2020-03-09 13:45 ` Kaylee Blake
2020-03-09 13:54 ` H.J. Lu
2020-03-09 14:02 ` Kaylee Blake
2020-03-09 14:52 ` Florian Weimer
2020-03-09 15:07 ` Kaylee Blake
2020-03-09 15:29 ` Florian Weimer
2020-03-09 13:44 ` Alan Modra
2020-03-09 13:54 ` Kaylee Blake
2020-03-09 22:34 ` Alan Modra
2020-03-10 0:14 ` H.J. Lu
2020-03-09 14:34 ` Michael Matz
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