linux-kernel - Re: [PATCH] kdb: Replace deprecated strcpy() with strscpy()

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Message-Id: <55A7B251-8E1B-4935-B33F-B12DF1A2B382@linux.dev>
Date: Thu, 14 Aug 2025 17:17:52 +0200
From: Thorsten Blum <thorsten.blum@...ux.dev>
To: Greg Kroah-Hartman <gregkh@...uxfoundation.org>
Cc: Jason Wessel <jason.wessel@...driver.com>,
 Daniel Thompson <danielt@...nel.org>,
 Douglas Anderson <dianders@...omium.org>,
 Nir Lichtman <nir@...htman.org>,
 Yuran Pereira <yuran.pereira@...mail.com>,
 linux-hardening@...r.kernel.org,
 Daniel Thompson <daniel@...cstar.com>,
 kgdb-bugreport@...ts.sourceforge.net,
 linux-kernel@...r.kernel.org
Subject: Re: [PATCH] kdb: Replace deprecated strcpy() with strscpy()

Hi Greg,

On 14. Aug 2025, at 16:35, Greg Kroah-Hartman wrote:
> On Thu, Aug 14, 2025 at 02:35:56PM +0200, Greg Kroah-Hartman wrote:
>> On Thu, Aug 14, 2025 at 02:03:37PM +0200, Thorsten Blum wrote:
>>> [...]
>>> -	strcpy(kdb_grep_string, cp);
>>> +	strscpy(kdb_grep_string, cp);
>> 
>> If this was just a search/replace, it would have been done already, so
>> why is this ok?
> 
> I missed that strscpy() can now handle 2 arguments like this, so yes,
> this should be ok.
> 
> BUT, you just checked the length above this line, which now isn't
> needed, right?  So this function can get simpler?

Yes, this could just be

	memcpy(kdb_grep_string, cp, len + 1);

because we already know the length which strscpy() would just recompute
before calling memcpy() internally. I'll submit a v2.

>>> -		strscpy(cmd_cur, cmd_hist[cmdptr], CMD_BUFLEN);
>>> +		strscpy(cmd_cur, cmd_hist[cmdptr]);
>> 
>> Same here.  And other places...
> 
> Sorry, this should also be ok, BUT it's really just doing the same exact
> thing, right?

Yes, it's the same because sizeof(cmd_cur) equals CMD_BUFLEN.

Thanks,
Thorsten