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Message-ID: <361c2f87-1424-f452-912f-0e4a339f5c46@kernel.org>
Date:   Thu, 22 Jun 2023 12:20:13 +0200
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Subject: Re: [PATCH][next] cgroup: Avoid -Wstringop-overflow warnings
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To:     "Gustavo A. R. Silva" <gustavoars@kernel.org>,
        Tejun Heo <tj@kernel.org>, Zefan Li <lizefan.x@bytedance.com>,
        Johannes Weiner <hannes@cmpxchg.org>
Cc:     cgroups@vger.kernel.org, linux-kernel@vger.kernel.org,
        linux-hardening@vger.kernel.org,
        Linux Next Mailing List <linux-next@vger.kernel.org>,
        Arnd Bergmann <arnd@arndb.de>,
        "linux-samsung-soc@vger.kernel.org" 
        <linux-samsung-soc@vger.kernel.org>
References: <ZIpm3pcs3iCP9UaR@work>
From:   Krzysztof Kozlowski <krzk@kernel.org>
In-Reply-To: <ZIpm3pcs3iCP9UaR@work>
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On 15/06/2023 03:18, Gustavo A. R. Silva wrote:
> Address the following -Wstringop-overflow warnings seen when
> built with ARM architecture and aspeed_g4_defconfig configuration
> (notice that under this configuration CGROUP_SUBSYS_COUNT == 0):
> kernel/cgroup/cgroup.c:1208:16: warning: 'find_existing_css_set' accessing 4 bytes in a region of size 0 [-Wstringop-overflow=]
> kernel/cgroup/cgroup.c:1258:15: warning: 'css_set_hash' accessing 4 bytes in a region of size 0 [-Wstringop-overflow=]
> kernel/cgroup/cgroup.c:6089:18: warning: 'css_set_hash' accessing 4 bytes in a region of size 0 [-Wstringop-overflow=]
> kernel/cgroup/cgroup.c:6153:18: warning: 'css_set_hash' accessing 4 bytes in a region of size 0 [-Wstringop-overflow=]
> 

Hi,

This patch landed in next but causes boot failures on
Exynos ARMv7 board (32 bit) with systemd (exynos_defconfig):

NFS-Mount: 192.168.1.10:/srv/nfs/odroidhc1
Waiting 10 seconds for device /dev/nfs ...
ERROR: device '/dev/nfs' not found. Skipping fsck.
Mount cmd: 
mount.nfs4 -o vers=4,nolock 192.168.1.10:/srv/nfs/odroidhc1 /new_root
:: running cleanup hook [udev]
[   23.752917] systemd[1]: System time before build time, advancing clock.
[   23.851828] systemd[1]: Failed to mount tmpfs at /sys/fs/cgroup: No such file or directory
[   23.868459] systemd[1]: Failed to mount cgroup at /sys/fs/cgroup/systemd: No such file or directory
[!!!!!!] Failed to mount API filesystems.
[   23.914562] systemd[1]: Freezing execution.

Full log:
https://krzk.eu/#/builders/21/builds/4110/steps/15/logs/serial0

Best regards,
Krzysztof