linux-kernel - Re: [PATCH V2 2/3] riscv: Fixup lockdep_assert_held with wrong param cpu_running

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Date:   Tue, 29 Sep 2020 15:12:33 -0700
From:   Atish Patra <atishp@...shpatra.org>
To:     Guo Ren <guoren@...nel.org>
Cc:     Palmer Dabbelt <palmerdabbelt@...gle.com>,
        Paul Walmsley <paul.walmsley@...ive.com>,
        Anup Patel <anup@...infault.org>,
        Greentime Hu <greentime.hu@...ive.com>,
        Zong Li <zong.li@...ive.com>,
        Albert Ou <aou@...s.berkeley.edu>,
        Thomas Gleixner <tglx@...utronix.de>, tycho@...ho.ws,
        Nick Hu <nickhu@...estech.com>,
        linux-riscv <linux-riscv@...ts.infradead.org>,
        Guo Ren <guoren@...ux.alibaba.com>,
        "linux-kernel@...r.kernel.org List" <linux-kernel@...r.kernel.org>,
        linux-csky@...r.kernel.org
Subject: Re: [PATCH V2 2/3] riscv: Fixup lockdep_assert_held with wrong param cpu_running

On Sat, Jun 27, 2020 at 6:58 AM <guoren@...nel.org> wrote:
>
> From: Zong Li <zong.li@...ive.com>
>
> The cpu_running is not a lock-class, it lacks the dep_map member in
> completion. It causes the error as follow:
>
> arch/riscv/kernel/smpboot.c: In function '__cpu_up':
> ./include/linux/lockdep.h:364:52: error: 'struct completion' has no member named 'dep_map'
>   364 | #define lockdep_is_held(lock)  lock_is_held(&(lock)->dep_map)
>       |                                                    ^~
> ./include/asm-generic/bug.h:113:25: note: in definition of macro 'WARN_ON'
>   113 |  int __ret_warn_on = !!(condition);    \
>       |                         ^~~~~~~~~
> ./include/linux/lockdep.h:390:27: note: in expansion of macro 'lockdep_is_held'
>   390 |   WARN_ON(debug_locks && !lockdep_is_held(l)); \
>       |                           ^~~~~~~~~~~~~~~
> arch/riscv/kernel/smpboot.c:118:2: note: in expansion of macro 'lockdep_assert_held'
>   118 |  lockdep_assert_held(&cpu_running);
>
> There are a lot of archs which use cpu_running in smpboot.c (arm,
> arm64, openrisc, xtensa, s390, x86, mips), but none of them try
> lockdep_assert_held(&cpu_running.wait.lock). So Just remove it.
>
> Signed-off-by: Zong Li <zong.li@...ive.com>
> Signed-off-by: Guo Ren <guoren@...ux.alibaba.com>
> ---
>  arch/riscv/kernel/smpboot.c | 1 -
>  1 file changed, 1 deletion(-)
>
> diff --git a/arch/riscv/kernel/smpboot.c b/arch/riscv/kernel/smpboot.c
> index 4e99227..defc4e1 100644
> --- a/arch/riscv/kernel/smpboot.c
> +++ b/arch/riscv/kernel/smpboot.c
> @@ -121,7 +121,6 @@ int __cpu_up(unsigned int cpu, struct task_struct *tidle)
>
>         ret = start_secondary_cpu(cpu, tidle);
>         if (!ret) {
> -               lockdep_assert_held(&cpu_running);
>                 wait_for_completion_timeout(&cpu_running,
>                                             msecs_to_jiffies(1000));
>
> --
> 2.7.4
>
>
> _______________________________________________
> linux-riscv mailing list
> linux-riscv@...ts.infradead.org
> http://lists.infradead.org/mailman/listinfo/linux-riscv

Thanks for catching this.

Reviewed-by: Atish Patra <atish.patra@....com>

-- 
Regards,
Atish

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