From: Doug Evans <dje@google.com>
To: "Metzger, Markus T" <markus.t.metzger@intel.com>,
"gdb@sourceware.org" <gdb@sourceware.org>,
"binutils@sourceware.org" <binutils@sourceware.org>
Subject: Re: vdso handling
Date: Wed, 12 Mar 2014 17:34:00 -0000 [thread overview]
Message-ID: <CADPb22SAmK5JB3muW_nCvuHN5L-aOcdyzYNR+OtnM3bA1x_OJg@mail.gmail.com> (raw)
In-Reply-To: <20140312071701.GW26922@bubble.grove.modra.org>
On Wed, Mar 12, 2014 at 12:17 AM, Alan Modra <amodra@gmail.com> wrote:
> On Mon, Mar 10, 2014 at 01:04:33PM +0000, Metzger, Markus T wrote:
>> I noticed that the BFD created for the VDSO (system-provided in-memory
>> DSO) does not contain any BFD sections. Is this intentional? Or has
>> there just been no need for them?
> [snip]
>> The vdso is processed in symbol_file_add_from_memory at
>> gdb/symfile-mem.c:84. It calls bfd_from_remote_memory to create a BFD
>> for the vdso and then processes it.
>
> The underlying cause is that you're trying to debug an ELF binary that
> only contains the execution view. The linking view (of which the
> sections are a part) is not loaded, so bfd_from_remote_memory does not
> have this information. See elfcode.h bfd_from_remote_memory.
>
> You can see similar breakage of gdb and binutils if you zap e_shoff,
> e_shnum, and e_shstrndx of your favourite hello world program.
>
> I suppose one way to provide something that gdb and other tools expect
> would be to treat the vdso like a core file, and create fake sections
> corresponding to the program headers. I'm not really keen on the idea
> though, since I know that will open up a can of worms.
I think a case can be made that gdb should be able to use the
"execution view" of the program here.
As for how to achieve that ... "Discuss." :-)
next prev parent reply other threads:[~2014-03-12 17:34 UTC|newest]
Thread overview: 41+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-03-10 13:05 Metzger, Markus T
2014-03-12 7:17 ` Alan Modra
2014-03-12 11:31 ` Mike Frysinger
2014-03-12 17:34 ` Doug Evans [this message]
2014-03-12 20:23 ` Cary Coutant
2014-03-13 1:01 ` Alan Modra
2014-03-13 8:25 ` Metzger, Markus T
2014-03-13 9:48 ` Metzger, Markus T
2014-03-13 10:07 ` Pedro Alves
2014-03-13 10:46 ` Pedro Alves
2014-06-01 23:45 ` Samuel Bronson
2014-06-06 12:45 ` Pedro Alves
2014-03-13 13:13 ` Alan Modra
2014-03-13 9:52 ` Mark Wielaard
2014-03-13 13:03 ` Alan Modra
2014-03-13 14:38 ` Mark Wielaard
2014-03-13 14:59 ` Pedro Alves
2014-03-13 15:04 ` Pedro Alves
2014-03-13 15:26 ` Pedro Alves
2014-03-13 23:53 ` Alan Modra
2014-03-18 15:14 ` Metzger, Markus T
2014-03-18 23:10 ` Alan Modra
2014-03-19 8:11 ` Metzger, Markus T
2014-03-19 8:31 ` Metzger, Markus T
2014-03-19 12:04 ` Pedro Alves
2014-03-20 2:00 ` Alan Modra
2014-03-21 15:55 ` Pedro Alves
2014-03-26 9:32 ` Metzger, Markus T
2014-03-19 12:03 ` Pedro Alves
2014-03-20 1:33 ` Alan Modra
2014-03-21 8:10 ` Metzger, Markus T
2014-03-21 15:48 ` Pedro Alves
2014-03-28 6:13 ` Alan Modra
2014-03-28 13:38 ` Pedro Alves
2014-03-28 23:00 ` Alan Modra
2014-04-01 13:46 ` Pedro Alves
2014-04-02 1:50 ` Alan Modra
2014-04-02 8:05 ` Metzger, Markus T
2014-04-02 8:04 ` Hans-Peter Nilsson
2014-04-03 1:06 ` Alan Modra
2014-04-03 1:46 ` Alan Modra
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