linux-kernel - Re: [PATCH v4 4/9] vsprintf: Consolidate handling of unknown pointer specifiers

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Date:   Sat, 7 Apr 2018 08:52:14 +0900
From:   Sergey Senozhatsky <sergey.senozhatsky@...il.com>
To:     Joe Perches <joe@...ches.com>
Cc:     Rasmus Villemoes <linux@...musvillemoes.dk>,
        Petr Mladek <pmladek@...e.com>,
        Linus Torvalds <torvalds@...ux-foundation.org>,
        Andy Shevchenko <andriy.shevchenko@...ux.intel.com>,
        "Tobin C . Harding" <me@...in.cc>,
        Andrew Morton <akpm@...ux-foundation.org>,
        Michal Hocko <mhocko@...e.cz>,
        Sergey Senozhatsky <sergey.senozhatsky@...il.com>,
        Steven Rostedt <rostedt@...dmis.org>,
        Sergey Senozhatsky <sergey.senozhatsky.work@...il.com>,
        linux-kernel@...r.kernel.org
Subject: Re: [PATCH v4 4/9] vsprintf: Consolidate handling of unknown pointer
 specifiers

On (04/05/18 16:55), Joe Perches wrote:
> On Thu, 2018-04-05 at 16:45 -0700, Joe Perches wrote:
> > On Thu, 2018-04-05 at 16:25 +0200, Rasmus Villemoes wrote:
> > > Even just git grep -1 -E '%p"$' finds %pt and %po
> > > which should get fixed before somebody claims those extensions.
> > 
> > Neither %pt nor %po is used in a vsprintf
> > in the kernel.
> 
> Nope, you are right, both are defectively used in the
> kernel via string concatenation.
> 
> Also there's a missing space in a concatenation adjacent.

Can we tweak checkpatch to catch such things?


Hm... *Probably* also wouldn't hurt if checkpatch can require at least
one character after pointer format specifiers:

	printk("string %p"          vs       printk("string %p "
	       " Object\n", ptr);                   "Object\n", ptr);

Especially if we can have a "potential" %px, like here

               dev_vdbg(&md->input->dev,
                       "%s: *axis=%02X(%d) size=%d max=%08X xy_data=%p"
                       " xy_data[%d]=%02X(%d) bofs=%d\n",

or here

       dev_vdbg(&md->input->dev,
               "%s: *axis=%02X(%d) size=%d max=%08X xy_data=%p"
               " xy_data[%d]=%02X(%d)\n",

Opinions?

	-ss