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From: Matthew Wilcox <willy@infradead.org>
To: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Cc: Timur Tabi <timur@kernel.org>,
	Andrew Morton <akpm@linux-foundation.org>,
	linux-kernel@vger.kernel.org, torvalds@linux-foundation.org,
	Petr Mladek <pmladek@suse.com>,
	roman.fietze@magna.com, keescook@chromium.org,
	Steven Rostedt <rostedt@goodmis.org>,
	John Ogness <john.ogness@linutronix.de>,
	linux-mm@kvack.org, Akinobu Mita <akinobu.mita@gmail.com>
Subject: Re: [PATCH 0/2] introduce DUMP_PREFIX_UNHASHED for hex dumps
Date: Tue, 19 Jan 2021 01:47:25 +0000	[thread overview]
Message-ID: <20210119014725.GH2260413@casper.infradead.org> (raw)
In-Reply-To: <YAYtbbHAHeEwunkW@jagdpanzerIV.localdomain>

On Tue, Jan 19, 2021 at 09:53:01AM +0900, Sergey Senozhatsky wrote:
> On (21/01/18 13:03), Timur Tabi wrote:
> > On 1/18/21 12:26 PM, Matthew Wilcox wrote:
> > > Don't make it easy.  And don't make it look like they're doing
> > > something innocent.  DUMP_PREFIX_SECURITY_HOLE would be OK
> > > by me.  DUMP_PREFIX_LEAK_INFORMATION would work fine too.
> > > DUMP_PREFIX_MAKE_ATTACKERS_LIFE_EASY might be a bit too far.
> > 
> > It's already extremely easy to replace %p with %px in your own printks, so I
> > don't really understand your argument.
> 
> I like the idea of a more radical name, e.g. DUMP_PREFIX_RAW_POINTERS or
> something similar.
> 
> > Seriously, this patch should not be so contentious.  If you want hashed
> > addresses, then nothing changes.  If you need unhashed addresses while
> > debugging, then use DUMP_PREFIX_UNHASHED.  Just like you can use %px in
> > printk.  I never use %p in my printks, but then I never submit code upstream
> > that prints addresses, hashed or unhashed.

I'm glad to hear you never make mistakes.  I make lots of mistakes, so
I prefer them to be big, loud and obvious so they're easy for people
to spot.

> So maybe DUMP_PREFIX_UNHASHED can do the unhashed dump only when
> CONFIG_DEBUG_KERNEL=y and fallback to DUMP_PREFIX_ADDRESS otherwise?

Distros enable CONFIG_DEBUG_KERNEL.  If you want to add
CONFIG_DEBUG_LEAK_ADDRESSES, then that's great, and you won't even have
to change users, you can just change how %p behaves.

  reply	other threads:[~2021-01-19  1:49 UTC|newest]

Thread overview: 37+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-01-16 22:09 [PATCH 0/2] introduce DUMP_PREFIX_UNHASHED for hex dumps Timur Tabi
2021-01-16 22:09 ` [PATCH 1/2] [v2] lib/hexdump: introduce DUMP_PREFIX_UNHASHED for unhashed addresses Timur Tabi
2021-01-18 10:03   ` Andy Shevchenko
2021-01-18 15:57     ` Timur Tabi
2021-01-18 17:14       ` Andy Shevchenko
2021-01-18 17:53         ` Timur Tabi
2021-01-16 22:09 ` [PATCH 2/2] mm/page_poison: use unhashed address in hexdump for check_poison_mem() Timur Tabi
2021-01-18 18:26 ` [PATCH 0/2] introduce DUMP_PREFIX_UNHASHED for hex dumps Matthew Wilcox
2021-01-18 19:03   ` Timur Tabi
2021-01-19  0:53     ` Sergey Senozhatsky
2021-01-19  1:47       ` Matthew Wilcox [this message]
2021-01-19 10:38         ` Sergey Senozhatsky
2021-01-19 19:45           ` Kees Cook
2021-01-26 16:47           ` Vlastimil Babka
2021-01-26 16:59             ` Timur Tabi
2021-01-26 17:14               ` Steven Rostedt
2021-01-26 17:14               ` Vlastimil Babka
2021-01-26 17:30                 ` Timur Tabi
2021-01-26 17:39                   ` Steven Rostedt
2021-01-26 17:40                     ` Steven Rostedt
2021-01-26 19:23                       ` John Ogness
2021-01-27  2:11                         ` Sergey Senozhatsky
2021-01-27  3:22                           ` Timur Tabi
2021-01-27 10:11                       ` Petr Mladek
2021-01-27 10:38                         ` Vlastimil Babka
2021-01-19 19:45         ` Kees Cook
2021-01-19 19:55           ` Timur Tabi
2021-01-19 20:10             ` Steven Rostedt
2021-01-19 20:49               ` Timur Tabi
2021-01-19 21:15                 ` Steven Rostedt
2021-01-19 21:25                   ` Timur Tabi
2021-01-20  9:19             ` Petr Mladek
2021-01-20 12:17               ` Matthew Wilcox
2021-01-20 19:39               ` Linus Torvalds
2021-01-19 20:18           ` Randy Dunlap
2021-01-20 20:28             ` Kees Cook
2021-01-19  2:30       ` Timur Tabi

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