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From: Michael Ellerman <patch-notifications@ellerman.id.au>
To: Nicholas Piggin <npiggin@gmail.com>, linuxppc-dev@lists.ozlabs.org
Cc: Athira Rajeev <atrajeev@linux.vnet.ibm.com>
Subject: Re: [PATCH] powerpc/64s: prevent recursive replay_soft_interrupts causing superfluous interrupt
Date: Wed,  3 Feb 2021 22:46:16 +1100 (AEDT)	[thread overview]
Message-ID: <161235275142.1521894.15184732734416488851.b4-ty@ellerman.id.au> (raw)
In-Reply-To: <20210123061244.2076145-1-npiggin@gmail.com>

On Sat, 23 Jan 2021 16:12:44 +1000, Nicholas Piggin wrote:
> When an asynchronous interrupt calls irq_exit, it checks for softirqs
> that may have been created, and runs them. Running softirqs enables
> local irqs, which can replay pending interrupts causing recursion in
> replay_soft_interrupts. This abridged trace shows how this can occur:
> 
> ! NIP replay_soft_interrupts
>   LR  interrupt_exit_kernel_prepare
>   Call Trace:
>     interrupt_exit_kernel_prepare (unreliable)
>     interrupt_return
>   --- interrupt: ea0 at __rb_reserve_next
>   NIP __rb_reserve_next
>   LR __rb_reserve_next
>   Call Trace:
>     ring_buffer_lock_reserve
>     trace_function
>     function_trace_call
>     ftrace_call
>     __do_softirq
>     irq_exit
>     timer_interrupt
> !   replay_soft_interrupts
>     interrupt_exit_kernel_prepare
>     interrupt_return
>   --- interrupt: ea0 at arch_local_irq_restore
> 
> [...]

Applied to powerpc/fixes.

[1/1] powerpc/64s: prevent recursive replay_soft_interrupts causing superfluous interrupt
      https://git.kernel.org/powerpc/c/4025c784c573cab7e3f84746cc82b8033923ec62

cheers

      parent reply	other threads:[~2021-02-03 13:27 UTC|newest]

Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-01-23  6:12 [PATCH] powerpc/64s: prevent recursive replay_soft_interrupts causing superfluous interrupt Nicholas Piggin
2021-01-27  8:32 ` Athira Rajeev
2021-02-03 11:46 ` Michael Ellerman [this message]

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