Re: Build regressions/improvements in v6.8-rc2

From: Helge Deller <deller@gmx.de>
To: Guenter Roeck <linux@roeck-us.net>,
	Geert Uytterhoeven <geert@linux-m68k.org>,
	linux-kernel@vger.kernel.org
Cc: sparclinux@vger.kernel.org, linux-parisc@vger.kernel.org,
	linux-hwmon@vger.kernel.org, intel-xe@lists.freedesktop.org
Subject: Re: Build regressions/improvements in v6.8-rc2
Date: Tue, 30 Jan 2024 08:49:32 +0100	[thread overview]
Message-ID: <90cd0f1a-29c0-4c6f-9efd-92b69da194c0@gmx.de> (raw)
In-Reply-To: <56b9c222-4e97-4eda-89af-3e0d0c39acb2@roeck-us.net>

On 1/29/24 15:58, Guenter Roeck wrote:
> On 1/29/24 03:06, Geert Uytterhoeven wrote:
> [ ... ]
>> parisc-gcc1[23]/parisc-{allmod,def}config
>>
>>    + /kisskb/src/drivers/hwmon/pc87360.c: error: writing 1 byte into a region of size 0 [-Werror=stringop-overflow=]:  => 383:51
>>
>
> The "fix" for this problem would be similar to commit 4265eb062a73 ("hwmon: (pc87360)
> Bounds check data->innr usage"). The change would be something like
>
> -               for (i = 0; i < data->tempnr; i++) {
> +               for (i = 0; i < min(data->tempnr, ARRAY_SIZE(data->temp_max)); i++) {
>
> but that would be purely random because the loop accesses several arrays
> indexed with i, and tempnr is never >= ARRAY_SIZE(data->temp_max).
> I kind of resist making such changes to the code just because the compiler
> is clueless.

I agree with your analysis.
But I'm wondering why this warning just seem to appear on parisc.
I would expect gcc on other platforms to complain as well ?!?

Helge

> Are we sprinkling the kernel code with code like this to make the compiler happy ?
>
> Guenter
>
>