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Date:   Wed, 10 Mar 2021 11:16:49 +1000
From:   Nicholas Piggin <npiggin@gmail.com>
Subject: Re: [PATCH v2 01/43] powerpc/traps: unrecoverable_exception() is not
 an interrupt handler
To:     Benjamin Herrenschmidt <benh@kernel.crashing.org>,
        Christophe Leroy <christophe.leroy@csgroup.eu>,
        Michael Ellerman <mpe@ellerman.id.au>,
        Paul Mackerras <paulus@samba.org>
Cc:     linux-kernel@vger.kernel.org, linuxppc-dev@lists.ozlabs.org
References: <cover.1615291471.git.christophe.leroy@csgroup.eu>
        <ae96c59fa2cb7f24a8929c58cfa2c909cb8ff1f1.1615291471.git.christophe.leroy@csgroup.eu>
In-Reply-To: <ae96c59fa2cb7f24a8929c58cfa2c909cb8ff1f1.1615291471.git.christophe.leroy@csgroup.eu>
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Excerpts from Christophe Leroy's message of March 9, 2021 10:09 pm:
> unrecoverable_exception() is called from interrupt handlers or
> after an interrupt handler has failed.
>=20
> Make it a standard function to avoid doubling the actions
> performed on interrupt entry (e.g.: user time accounting).
>=20
> Fixes: 3a96570ffceb ("powerpc: convert interrupt handlers to use wrappers=
")
> Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>

Reviewed-by: Nicholas Piggin <npiggin@gmail.com>

This should go in as a fix for this release I think.

> ---
>  arch/powerpc/include/asm/interrupt.h | 3 ++-
>  arch/powerpc/kernel/interrupt.c      | 1 -
>  arch/powerpc/kernel/traps.c          | 2 +-
>  3 files changed, 3 insertions(+), 3 deletions(-)
>=20
> diff --git a/arch/powerpc/include/asm/interrupt.h b/arch/powerpc/include/=
asm/interrupt.h
> index aedfba29e43a..e8d09a841373 100644
> --- a/arch/powerpc/include/asm/interrupt.h
> +++ b/arch/powerpc/include/asm/interrupt.h
> @@ -410,7 +410,6 @@ DECLARE_INTERRUPT_HANDLER(altivec_assist_exception);
>  DECLARE_INTERRUPT_HANDLER(CacheLockingException);
>  DECLARE_INTERRUPT_HANDLER(SPEFloatingPointException);
>  DECLARE_INTERRUPT_HANDLER(SPEFloatingPointRoundException);
> -DECLARE_INTERRUPT_HANDLER(unrecoverable_exception);
>  DECLARE_INTERRUPT_HANDLER(WatchdogException);
>  DECLARE_INTERRUPT_HANDLER(kernel_bad_stack);
> =20
> @@ -437,6 +436,8 @@ DECLARE_INTERRUPT_HANDLER_NMI(hmi_exception_realmode)=
;
> =20
>  DECLARE_INTERRUPT_HANDLER_ASYNC(TAUException);
> =20
> +void unrecoverable_exception(struct pt_regs *regs);
> +
>  void replay_system_reset(void);
>  void replay_soft_interrupts(void);
> =20
> diff --git a/arch/powerpc/kernel/interrupt.c b/arch/powerpc/kernel/interr=
upt.c
> index 398cd86b6ada..b8e7d25be31b 100644
> --- a/arch/powerpc/kernel/interrupt.c
> +++ b/arch/powerpc/kernel/interrupt.c
> @@ -436,7 +436,6 @@ notrace unsigned long interrupt_exit_user_prepare(str=
uct pt_regs *regs, unsigned
>  	return ret;
>  }
> =20
> -void unrecoverable_exception(struct pt_regs *regs);
>  void preempt_schedule_irq(void);
> =20
>  notrace unsigned long interrupt_exit_kernel_prepare(struct pt_regs *regs=
, unsigned long msr)
> diff --git a/arch/powerpc/kernel/traps.c b/arch/powerpc/kernel/traps.c
> index 1583fd1c6010..a44a30b0688c 100644
> --- a/arch/powerpc/kernel/traps.c
> +++ b/arch/powerpc/kernel/traps.c
> @@ -2170,7 +2170,7 @@ DEFINE_INTERRUPT_HANDLER(SPEFloatingPointRoundExcep=
tion)
>   * in the MSR is 0.  This indicates that SRR0/1 are live, and that
>   * we therefore lost state by taking this exception.
>   */
> -DEFINE_INTERRUPT_HANDLER(unrecoverable_exception)
> +void unrecoverable_exception(struct pt_regs *regs)
>  {
>  	pr_emerg("Unrecoverable exception %lx at %lx (msr=3D%lx)\n",
>  		 regs->trap, regs->nip, regs->msr);
> --=20
> 2.25.0
>=20
>=20