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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)	[thread overview]
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	other threads:[~2018-04-30 15:50 UTC|newest]

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 ` Hashed pointer issues 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

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