From: Alan Modra <amodra@gmail.com>
To: "H.J. Lu" <hjl.tools@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: Mon, 9 Mar 2020 10:05:54 +1030 [thread overview]
Message-ID: <20200308233553.GG5384@bubble.grove.modra.org> (raw)
In-Reply-To: <CAMe9rOpSQtgjXJKWwq9QuOw5ehE7dW0P0cek7ASkU1uWbVvkmw@mail.gmail.com>
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.
The patch looks OK.
--
Alan Modra
Australia Development Lab, IBM
next prev parent reply other threads:[~2020-03-08 23:35 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 [this message]
2020-03-08 23:46 ` H.J. Lu
2020-03-09 0:02 ` H.J. Lu
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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