linux-kernel - Re: [PATCH V11 4/5] vsprintf: add printk specifier %px

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Message-ID: <20171206041924.GA2959@avx2>
Date:   Wed, 6 Dec 2017 07:19:24 +0300
From:   Alexey Dobriyan <adobriyan@...il.com>
To:     sergey.senozhatsky.work@...il.com
Cc:     linux-kernel@...r.kernel.org, torvalds@...ux-foundation.org,
        me@...in.cc
Subject: Re: [PATCH V11 4/5] vsprintf: add printk specifier %px

> more %p grepping [filtering out all `%ps %pf %pb' variants] gives
> a huge number of print outs that potentially can be broken now

Because people who introduce this stupid %p hashing can't be bothered
to actually audit users:

	static int show_timer(struct seq_file *m, void *v)
	{
		...
	        seq_printf(m, "signal: %d/%p\n",
                   timer->sigq->info.si_signo,
                   timer->sigq->info.si_value.sival_ptr);

Overall, this %px thing doesn't matter. Developers will quickly learn
than %p gives some useless irreversible values and start using %px
everywhere. Soon someone will use %px in the wrong place and new
non-standard format specifier will be added.