LKML Archive on lore.kernel.org
 help / color / Atom feed
From: Anna-Maria Gleixner <anna-maria@linutronix.de>
To: linux-kernel@vger.kernel.org
Cc: Linus Torvalds <torvalds@linux-foundation.org>,
	Kees Cook <keescook@chromium.org>,
	"Tobin C. Harding" <me@tobin.cc>,
	Steven Rostedt <rostedt@goodmis.org>
Subject: Hashed pointer issues
Date: Mon, 30 Apr 2018 17:50:50 +0200 (CEST)
Message-ID: <alpine.DEB.2.20.1804301741570.3243@hypnos.tec.linutronix.de> (raw)

Hi,

I stumbled over an issue with hashed pointers and tracing. 

I'm using trace points for examination and on error the trace buffers
are dumped. The error occurs when entropy has not been set up, so the
pointers are not hashed and only (ptrval) is printed instead. The
pointers are required to distinguish the different objects in the
trace.

Beside workarounds like patching lib/vsprintf.c helpers before testing
or dumping trace buffers later (given that kernel comes up properly
and entropy is set up), is there a possible generic solution for this
issue? A commandline option for disabling the pointer obfuscation
would be a pretty handy tool.


Thanks,

      Anna-Maria

             reply index

Thread overview: 16+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-04-30 15:50 Anna-Maria Gleixner [this message]
2018-04-30 16:11 ` Kees Cook
2018-04-30 16:31   ` Linus Torvalds
2018-04-30 16:41     ` Steven Rostedt
2018-04-30 16:57       ` Linus Torvalds
2018-04-30 17:01         ` Linus Torvalds
2018-04-30 17:06           ` Randy Dunlap
2018-04-30 17:12             ` Linus Torvalds
2018-05-01  7:05               ` tcharding
2018-05-03  8:41             ` Geert Uytterhoeven
2018-04-30 18:38           ` Kees Cook
2018-04-30 19:00             ` Linus Torvalds
2018-04-30 19:16               ` Kees Cook
2018-04-30 20:01                 ` Linus Torvalds
2018-04-30 20:07                   ` Linus Torvalds
2018-04-30 21:23                 ` Tobin C. Harding

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=alpine.DEB.2.20.1804301741570.3243@hypnos.tec.linutronix.de \
    --to=anna-maria@linutronix.de \
    --cc=keescook@chromium.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=me@tobin.cc \
    --cc=rostedt@goodmis.org \
    --cc=torvalds@linux-foundation.org \
    /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

LKML Archive on lore.kernel.org

Archives are clonable:
	git clone --mirror https://lore.kernel.org/lkml/0 lkml/git/0.git
	git clone --mirror https://lore.kernel.org/lkml/1 lkml/git/1.git
	git clone --mirror https://lore.kernel.org/lkml/2 lkml/git/2.git
	git clone --mirror https://lore.kernel.org/lkml/3 lkml/git/3.git
	git clone --mirror https://lore.kernel.org/lkml/4 lkml/git/4.git
	git clone --mirror https://lore.kernel.org/lkml/5 lkml/git/5.git
	git clone --mirror https://lore.kernel.org/lkml/6 lkml/git/6.git
	git clone --mirror https://lore.kernel.org/lkml/7 lkml/git/7.git
	git clone --mirror https://lore.kernel.org/lkml/8 lkml/git/8.git
	git clone --mirror https://lore.kernel.org/lkml/9 lkml/git/9.git

	# If you have public-inbox 1.1+ installed, you may
	# initialize and index your mirror using the following commands:
	public-inbox-init -V2 lkml lkml/ https://lore.kernel.org/lkml \
		linux-kernel@vger.kernel.org
	public-inbox-index lkml

Example config snippet for mirrors

Newsgroup available over NNTP:
	nntp://nntp.lore.kernel.org/org.kernel.vger.linux-kernel


AGPL code for this site: git clone https://public-inbox.org/public-inbox.git