linux-kernel - Re: [re: PATCH v2 00/15 - 03/11] dyndbg: disambiguate quoting in a debug msg

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Date: Mon, 18 Dec 2023 17:34:11 +0100
From: Petr Mladek <pmladek@...e.com>
To: Jim Cromie <jim.cromie@...il.com>
Cc: lb@...ihalf.com, linux-kernel@...r.kernel.org,
	akpm@...ux-foundation.org, bleung@...gle.com, contact@...rsion.fr,
	daniel@...ll.ch, dianders@...omium.org, groeck@...gle.com,
	jbaron@...mai.com, john.ogness@...utronix.de, keescook@...omium.org,
	ppaalanen@...il.com, rostedt@...dmis.org, seanpaul@...omium.org,
	sergey.senozhatsky@...il.com, upstream@...ihalf.com,
	vincent.whitchurch@...s.com, yanivt@...gle.com,
	gregkh@...uxfoundation.org
Subject: Re: [re: PATCH v2 00/15 -  03/11] dyndbg: disambiguate quoting in a
 debug msg

On Thu 2023-12-07 17:15:06, Jim Cromie wrote:
> When debugging a query parsing error, the debug message wraps the
> query in escaped-double-quotes.  This is confusing when mixed with any
> quoted args where quotes are stripped by the shell.
> 
> So this replaces the \"%s\" with <%s> in the format string, allowing a
> user to see how the shell strips quotes:
> 
> lx]# echo  module "foo" format ,_ -f > /proc/dynamic_debug/control
> [  716.037430] dyndbg: read 26 bytes from userspace
> [  716.037966] dyndbg: query 0: <module foo format ,_ -f> on module: <*>

Could you provide a real life example, please? It is hard to imagine
what '"foo" format' means in a real life.

Also could you please provide output before and after?

Honestly, Using <> as quotes looks pretty non-standard and confusing
to me. Also this changes only one place but '\"' is used in many
other locations which would make dyndbg messages even more confusing.

I do not understand how this would help. The double quote is gone
even in this variant.

BTW: It is a bit funny that this patch is supposed to make the debug
     message better readable. For me, the echo command is hard
     to read in the first place. I would use:

lx]# echo "module $my_module ,_ -f" > /proc/dynamic_debug/control

Maybe, this change fixes the output to match some personal style.
I wonder how common is the style. I can't remember seeing:

    $> echo param param param

Instead I frequently see:

    $> echo "bla bla bla".

Best Regards,
Petr