From: Sergio Durigan Junior <sergiodj@redhat.com>
To: Oleg Nesterov <oleg@redhat.com>
Cc: Jan Kratochvil <jan.kratochvil@redhat.com>,
GDB Patches <gdb-patches@sourceware.org>,
Pedro Alves <palves@redhat.com>
Subject: Re: [PATCH] Improve corefile generation by using /proc/PID/coredump_filter (PR corefile/16902)
Date: Thu, 12 Mar 2015 17:37:00 -0000 [thread overview]
Message-ID: <878uf2p162.fsf@redhat.com> (raw)
In-Reply-To: <20150312150024.GA4817@redhat.com> (Oleg Nesterov's message of "Thu, 12 Mar 2015 16:00:24 +0100")
On Thursday, March 12 2015, Oleg Nesterov wrote:
>> Probably gdb doesn't need to dump this vma, but see below.
>
> Probably yes. Note that it has VM_DONTDUMP ("dd" in "VmFlags:" field).
The fact that the region has VM_DONTDUMP is enough for GDB to ignore
it. IMO, as discussed in the other thread with Andy, the Linux kernel
is bogus in this case and should also be ignoring this.
> However. If (for any reason) you decide to dump this region, gdb can
> look into /proc/self/maps, find its own "vvar" mapping, and simply read
> this memory. Unlike "vdso", "vvar" has the same content for every process.
Yeah, but I don't think this is worth the effort. As Pedro mentioned,
things can get more complicated when we consider remote scenarios.
> (just in case, "vdso" is the same too but it is MAYWRITE, so it can have
> anonymous pages. Say, breakpoints installed by gdb).
Also, [vdso] doesn't have the VM_DONTDUMP flag. My patch is already
dumping it inconditionally.
--
Sergio
GPG key ID: 0x65FC5E36
Please send encrypted e-mail if possible
http://sergiodj.net/
next prev parent reply other threads:[~2015-03-12 17:37 UTC|newest]
Thread overview: 46+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-03-05 3:48 Sergio Durigan Junior
2015-03-05 15:48 ` Jan Kratochvil
2015-03-05 20:53 ` Sergio Durigan Junior
2015-03-05 20:57 ` Jan Kratochvil
2015-03-11 20:02 ` Oleg Nesterov
2015-03-12 11:31 ` Sergio Durigan Junior
2015-03-12 14:36 ` vvar, gup && coredump Oleg Nesterov
2015-03-12 16:29 ` Andy Lutomirski
2015-03-12 16:56 ` Oleg Nesterov
2015-03-12 17:18 ` Andy Lutomirski
2015-03-12 17:40 ` Oleg Nesterov
2015-03-12 17:45 ` Sergio Durigan Junior
2015-03-12 18:04 ` Oleg Nesterov
2015-03-13 4:50 ` Sergio Durigan Junior
2015-03-13 15:06 ` Oleg Nesterov
2015-03-12 17:56 ` Andy Lutomirski
2015-03-12 18:28 ` Oleg Nesterov
2015-03-12 17:48 ` Oleg Nesterov
2015-03-12 17:55 ` Andy Lutomirski
2015-03-12 18:16 ` Oleg Nesterov
2015-03-12 18:23 ` Sergio Durigan Junior
2015-03-12 18:20 ` Pedro Alves
2015-03-12 18:26 ` Andy Lutomirski
2015-03-16 19:03 ` install_special_mapping && vm_pgoff (Was: vvar, gup && coredump) Oleg Nesterov
2015-03-16 19:20 ` Andy Lutomirski
2015-03-16 19:46 ` Oleg Nesterov
2015-03-17 13:45 ` Oleg Nesterov
2015-03-18 1:45 ` Andy Lutomirski
2015-03-18 18:08 ` Oleg Nesterov
2015-03-16 19:40 ` Pedro Alves
2015-03-12 15:02 ` [PATCH] Improve corefile generation by using /proc/PID/coredump_filter (PR corefile/16902) Oleg Nesterov
2015-03-12 15:46 ` Pedro Alves
2015-03-12 15:57 ` Jan Kratochvil
2015-03-12 16:19 ` Pedro Alves
2015-03-12 16:07 ` Oleg Nesterov
2015-03-12 16:28 ` Pedro Alves
2015-03-12 17:37 ` Sergio Durigan Junior [this message]
2015-03-12 21:39 ` [PATCH v2] " Sergio Durigan Junior
2015-03-13 19:34 ` Pedro Alves
2015-03-16 23:53 ` Sergio Durigan Junior
2015-03-18 19:10 ` Pedro Alves
2015-03-18 19:39 ` Sergio Durigan Junior
2015-03-14 9:40 ` Eli Zaretskii
2015-03-16 2:42 ` Sergio Durigan Junior
2015-03-13 19:37 ` [PATCH] " Pedro Alves
2015-03-13 19:48 ` Pedro Alves
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=878uf2p162.fsf@redhat.com \
--to=sergiodj@redhat.com \
--cc=gdb-patches@sourceware.org \
--cc=jan.kratochvil@redhat.com \
--cc=oleg@redhat.com \
--cc=palves@redhat.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox