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From:   Naresh Kamboju <naresh.kamboju@linaro.org>
Date:   Sat, 5 Dec 2020 00:33:51 +0530
Message-ID: <CA+G9fYsHo-9tmxCKGticDowF8e3d1RkcLamapOgMQqeP6OdEEg@mail.gmail.com>
Subject: BUG: KCSAN: data-race in tick_nohz_next_event / tick_nohz_stop_tick
To:     open list <linux-kernel@vger.kernel.org>,
        kasan-dev <kasan-dev@googlegroups.com>, rcu@vger.kernel.org,
        lkft-triage@lists.linaro.org
Cc:     Marco Elver <elver@google.com>,
        Peter Zijlstra <peterz@infradead.org>,
        "Paul E. McKenney" <paulmck@kernel.org>,
        Ingo Molnar <mingo@kernel.org>,
        Thomas Gleixner <tglx@linutronix.de>, fweisbec@gmail.com,
        Arnd Bergmann <arnd@arndb.de>
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LKFT started testing KCSAN enabled kernel from the linux next tree.
Here we have found BUG: KCSAN: data-race in tick_nohz_next_event /
tick_nohz_stop_tick

This report is from an x86_64 machine clang-11 linux next 20201201.
Since we are running for the first time we do not call this regression.

[   47.811425] BUG: KCSAN: data-race in tick_nohz_next_event /
tick_nohz_stop_tick
[   47.818738]
[   47.820239] write to 0xffffffffa4cbe920 of 4 bytes by task 0 on cpu 2:
[   47.826766]  tick_nohz_stop_tick+0x8b/0x310
[   47.830951]  tick_nohz_idle_stop_tick+0xcb/0x170
[   47.835571]  do_idle+0x193/0x250
[   47.838804]  cpu_startup_entry+0x25/0x30
[   47.842728]  start_secondary+0xa0/0xb0
[   47.846482]  secondary_startup_64_no_verify+0xc2/0xcb
[   47.851531]
[   47.853034] read to 0xffffffffa4cbe920 of 4 bytes by task 0 on cpu 3:
[   47.859473]  tick_nohz_next_event+0x165/0x1e0
[   47.863831]  tick_nohz_get_sleep_length+0x94/0xd0
[   47.868539]  menu_select+0x250/0xac0
[   47.872116]  cpuidle_select+0x47/0x50
[   47.875781]  do_idle+0x17c/0x250
[   47.879015]  cpu_startup_entry+0x25/0x30
[   47.882942]  start_secondary+0xa0/0xb0
[   47.886694]  secondary_startup_64_no_verify+0xc2/0xcb
[   47.891743]
[   47.893234] Reported by Kernel Concurrency Sanitizer on:
[   47.898541] CPU: 3 PID: 0 Comm: swapper/3 Not tainted
5.10.0-rc6-next-20201201 #2
[   47.906017] Hardware name: Supermicro SYS-5019S-ML/X11SSH-F, BIOS
2.2 05/23/2018

metadata:
    git_repo: https://gitlab.com/aroxell/lkft-linux-next
    target_arch: x86
    toolchain: clang-11
    git_describe: next-20201201
    download_url: https://builds.tuxbuild.com/1l8eiWgGMi6W4aDobjAAlOleFVl/

Full test log link,
https://lkft.validation.linaro.org/scheduler/job/2002643#L2019

-- 
Linaro LKFT
https://lkft.linaro.org