Re: Build regressions/improvements in v5.6

From: Vineet Gupta
Date: Mon Mar 30 2020 - 17:18:34 EST


On 3/30/20 1:40 PM, Alexey Brodkin wrote:
> Hi Andy, Geert,
>
>> -----Original Message-----
>> From: Andy Shevchenko <andy.shevchenko@xxxxxxxxx>
>> Sent: Monday, March 30, 2020 4:28 PM
>> To: Geert Uytterhoeven <geert@xxxxxxxxxxxxxx>; Alexey Brodkin <abrodkin@xxxxxxxxxxxx>
>> Cc: Linux Kernel Mailing List <linux-kernel@xxxxxxxxxxxxxxx>
>> Subject: Re: Build regressions/improvements in v5.6
>>
>> On Mon, Mar 30, 2020 at 4:26 PM Geert Uytterhoeven <geert@xxxxxxxxxxxxxx> wrote:
>>>
>>> Hi Andy,
>>>
>>> On Mon, Mar 30, 2020 at 3:08 PM Andy Shevchenko
>>> <andy.shevchenko@xxxxxxxxx> wrote:
>>>> On Mon, Mar 30, 2020 at 12:00 PM Geert Uytterhoeven
>>>> <geert@xxxxxxxxxxxxxx> wrote:
>>>>> Below is the list of build error/warning regressions/improvements in
>>>>> v5.6[1] compared to v5.5[2].
>>>>
>>>>> + /kisskb/src/include/linux/dev_printk.h: warning: format '%zu' expects argument of type
>> 'size_t', but argument 8 has type 'unsigned int' [-Wformat=]: => 232:23
>>>>
>>>> This is interesting... I checked all dev_WARN_ONCE() and didn't find an issue.
>>>
>>> arcv2/axs103_smp_defconfig
>>>
>>> It's probably due to a broken configuration for the arc toolchain.
>>
>> Alexey, do have any insight?
>
> I think I do have some but first I'd like to get it reproduced myself.
> I just built v5.6 with help of both GCC 8.3.1- & 9.3.1-based toolchains
> and didn't see a single warning. So I guess I was doing something wrong.
>
> FWIW
>
> 1. My GCC 8.3.1 toolchain was exactly this:
> https://github.com/foss-for-synopsys-dwc-arc-processors/toolchain/releases/download/arc-2019.09-release/arc_gnu_2019.09_prebuilt_uclibc_le_archs_linux_install.tar.gz
>
> 2. Linux kernel is vanilla v5.6.0
>
> 3. Configured and built as simple as:
> make axs103_smp_defconfig && make

It seems the build service is using a arc toolchain built in 2016 :-)

# < /opt/cross/kisskb/br-arcle-hs38-full-2016.08-613-ge98b4dd/bin/arc-linux-gcc

Call it Murphy's law, same year a little later I'd fixed the same issue in gcc [1]

[1] http://lists.infradead.org/pipermail/linux-snps-arc/2016-October/001661.html

@Guenter could you please consider updating the ARC tools. FWIW you can build
stuff off upstream gcc/binutils using build system of your choice.

Thx,
-Vineet