Linux-Fsdevel Archive on lore.kernel.org
help / color / mirror / Atom feed
From: Jann Horn <jannh@google.com>
To: Christoph Hellwig <hch@lst.de>
Cc: Andrew Morton <akpm@linux-foundation.org>,
	Linus Torvalds <torvalds@linux-foundation.org>,
	kernel list <linux-kernel@vger.kernel.org>,
	Linux-MM <linux-mm@kvack.org>,
	linux-fsdevel <linux-fsdevel@vger.kernel.org>,
	Alexander Viro <viro@zeniv.linux.org.uk>,
	"Eric W . Biederman" <ebiederm@xmission.com>,
	Oleg Nesterov <oleg@redhat.com>,
	Russell King <linux@armlinux.org.uk>,
	Linux ARM <linux-arm-kernel@lists.infradead.org>,
	Mark Salter <msalter@redhat.com>,
	Aurelien Jacquiot <jacquiot.aurelien@gmail.com>,
	linux-c6x-dev@linux-c6x.org,
	Yoshinori Sato <ysato@users.sourceforge.jp>,
	Rich Felker <dalias@libc.org>,
	Linux-sh list <linux-sh@vger.kernel.org>
Subject: Re: [PATCH v2 1/5] binfmt_elf_fdpic: Stop using dump_emit() on user pointers on !MMU
Date: Tue, 5 May 2020 13:42:12 +0200	[thread overview]
Message-ID: <CAG48ez3F70-UXwdHmO4CnR0bAForn-SBtstW5WAYjcrLFwS_9A@mail.gmail.com> (raw)
In-Reply-To: <20200505104805.GA17400@lst.de>

On Tue, May 5, 2020 at 12:48 PM Christoph Hellwig <hch@lst.de> wrote:
> On Wed, Apr 29, 2020 at 11:49:50PM +0200, Jann Horn wrote:
> > dump_emit() is for kernel pointers, and VMAs describe userspace memory.
> > Let's be tidy here and avoid accessing userspace pointers under KERNEL_DS,
> > even if it probably doesn't matter much on !MMU systems - especially given
> > that it looks like we can just use the same get_dump_page() as on MMU if
> > we move it out of the CONFIG_MMU block.
>
> Looks sensible.  Did you get a chance to test this with a nommu setup?

Nope. Do you happen to have a recommendation for a convenient
environment I can use with QEMU, or something like that? I'm guessing
that just running a standard armel Debian userspace with a !mmu ARM
kernel wouldn't work so well?

  reply	other threads:[~2020-05-05 11:42 UTC|newest]

Thread overview: 28+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-04-29 21:49 [PATCH v2 0/5] Fix ELF / FDPIC ELF core dumping, and use mmap_sem properly in there Jann Horn
2020-04-29 21:49 ` [PATCH v2 1/5] binfmt_elf_fdpic: Stop using dump_emit() on user pointers on !MMU Jann Horn
2020-05-05 10:48   ` Christoph Hellwig
2020-05-05 11:42     ` Jann Horn [this message]
2020-05-05 12:15       ` Christoph Hellwig
2020-08-11  3:05         ` Jann Horn
2020-04-29 21:49 ` [PATCH v2 2/5] coredump: Let dump_emit() bail out on short writes Jann Horn
2020-04-29 21:49 ` [PATCH v2 3/5] coredump: Refactor page range dumping into common helper Jann Horn
2020-05-05 10:50   ` Christoph Hellwig
2020-05-05 11:44     ` Jann Horn
2020-04-29 21:49 ` [PATCH v2 4/5] binfmt_elf, binfmt_elf_fdpic: Use a VMA list snapshot Jann Horn
2020-05-05 11:03   ` Christoph Hellwig
2020-05-05 12:11     ` Jann Horn
2020-04-29 21:49 ` [PATCH v2 5/5] mm/gup: Take mmap_sem in get_dump_page() Jann Horn
2020-04-29 21:56 ` [PATCH v2 0/5] Fix ELF / FDPIC ELF core dumping, and use mmap_sem properly in there Russell King - ARM Linux admin
2020-04-29 23:03   ` Linus Torvalds
2020-04-30  1:27     ` Nicolas Pitre
2020-04-30 14:10     ` Greg Ungerer
2020-04-30 14:51       ` Rich Felker
2020-04-30 21:13         ` Rob Landley
2020-05-01  6:00         ` Greg Ungerer
2020-05-01 19:09           ` Rob Landley
2020-04-30 16:54       ` Linus Torvalds
2020-04-30 19:07         ` Eric W. Biederman
2020-05-01  5:44           ` Greg Ungerer
2020-05-01 11:13             ` Eric W. Biederman
2020-05-01  7:14         ` Greg Ungerer
2020-04-30  1:59   ` Nicolas Pitre

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=CAG48ez3F70-UXwdHmO4CnR0bAForn-SBtstW5WAYjcrLFwS_9A@mail.gmail.com \
    --to=jannh@google.com \
    --cc=akpm@linux-foundation.org \
    --cc=dalias@libc.org \
    --cc=ebiederm@xmission.com \
    --cc=hch@lst.de \
    --cc=jacquiot.aurelien@gmail.com \
    --cc=linux-arm-kernel@lists.infradead.org \
    --cc=linux-c6x-dev@linux-c6x.org \
    --cc=linux-fsdevel@vger.kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-mm@kvack.org \
    --cc=linux-sh@vger.kernel.org \
    --cc=linux@armlinux.org.uk \
    --cc=msalter@redhat.com \
    --cc=oleg@redhat.com \
    --cc=torvalds@linux-foundation.org \
    --cc=viro@zeniv.linux.org.uk \
    --cc=ysato@users.sourceforge.jp \
    --subject='Re: [PATCH v2 1/5] binfmt_elf_fdpic: Stop using dump_emit() on user pointers on '\!'MMU' \
    /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

This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).