From: Guo Ren <guoren@kernel.org>
To: Josh Poimboeuf <jpoimboe@kernel.org>
Cc: linux-kernel@vger.kernel.org, jgross@suse.com,
richard.henderson@linaro.org, ink@jurassic.park.msu.ru,
mattst88@gmail.com, linux-alpha@vger.kernel.org,
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bsegall@google.com, mgorman@suse.de, bristot@redhat.com,
vschneid@redhat.com, paulmck@kernel.org
Subject: Re: [PATCH 05/22] csky/cpu: Make sure arch_cpu_idle_dead() doesn't return
Date: Sat, 4 Feb 2023 09:12:31 +0800 [thread overview]
Message-ID: <CAJF2gTSKe3ve4_rsOYpmSBOyUSU5rpLHyijn9i2-i+WfLqxzYw@mail.gmail.com> (raw)
In-Reply-To: <f860f3a1c1a53c437a99abc53e8f1a798aef6881.1675461757.git.jpoimboe@kernel.org>
On Sat, Feb 4, 2023 at 6:05 AM Josh Poimboeuf <jpoimboe@kernel.org> wrote:
>
> arch_cpu_idle_dead() doesn't return. Make that more explicit with a
> BUG().
>
> BUG() is preferable to unreachable() because BUG() is a more explicit
> failure mode and avoids undefined behavior like falling off the edge of
> the function into whatever code happens to be next.
>
> Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
> ---
> arch/csky/kernel/smp.c | 2 ++
> 1 file changed, 2 insertions(+)
>
> diff --git a/arch/csky/kernel/smp.c b/arch/csky/kernel/smp.c
> index b45d1073307f..0ec20efaf5fd 100644
> --- a/arch/csky/kernel/smp.c
> +++ b/arch/csky/kernel/smp.c
> @@ -317,5 +317,7 @@ void arch_cpu_idle_dead(void)
> "jmpi csky_start_secondary"
> :
> : "r" (secondary_stack));
> +
> + BUG();
Why not:
diff --git a/kernel/sched/idle.c b/kernel/sched/idle.c
index f26ab2675f7d..1d3bf903add2 100644
--- a/kernel/sched/idle.c
+++ b/kernel/sched/idle.c
@@ -285,6 +285,7 @@ static void do_idle(void)
tick_nohz_idle_stop_tick();
cpuhp_report_idle_dead();
arch_cpu_idle_dead();
+ BUG();
}
arch_cpu_idle_enter();
> }
> #endif
> --
> 2.39.0
>
--
Best Regards
Guo Ren
next prev parent reply other threads:[~2023-02-04 1:12 UTC|newest]
Thread overview: 32+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-02-03 22:05 [PATCH 00/22] cpu,sched: Mark arch_cpu_idle_dead() __noreturn Josh Poimboeuf
2023-02-03 22:05 ` [PATCH 01/22] alpha/cpu: Expose arch_cpu_idle_dead()'s prototype declaration Josh Poimboeuf
2023-02-03 22:05 ` [PATCH 02/22] alpha/cpu: Make sure arch_cpu_idle_dead() doesn't return Josh Poimboeuf
2023-02-03 22:05 ` [PATCH 03/22] arm/cpu: " Josh Poimboeuf
2023-02-03 22:05 ` [PATCH 04/22] arm64/cpu: Mark cpu_die() __noreturn Josh Poimboeuf
2023-02-03 22:05 ` [PATCH 05/22] csky/cpu: Make sure arch_cpu_idle_dead() doesn't return Josh Poimboeuf
2023-02-04 1:12 ` Guo Ren [this message]
2023-02-04 2:29 ` Josh Poimboeuf
2023-02-06 3:11 ` Guo Ren
2023-02-03 22:05 ` [PATCH 06/22] ia64/cpu: Mark play_dead() __noreturn Josh Poimboeuf
2023-02-03 22:05 ` [PATCH 07/22] loongarch/cpu: Make sure play_dead() doesn't return Josh Poimboeuf
2023-02-03 22:05 ` [PATCH 08/22] loongarch/cpu: Mark play_dead() __noreturn Josh Poimboeuf
2023-02-03 22:05 ` [PATCH 09/22] mips/cpu: Expose play_dead()'s prototype definition Josh Poimboeuf
2023-02-06 22:36 ` Florian Fainelli
2023-02-03 22:05 ` [PATCH 10/22] mips/cpu: Make sure play_dead() doesn't return Josh Poimboeuf
2023-02-06 22:36 ` Florian Fainelli
2023-02-03 22:05 ` [PATCH 11/22] mips/cpu: Mark play_dead() __noreturn Josh Poimboeuf
2023-02-06 22:36 ` Florian Fainelli
2023-02-03 22:05 ` [PATCH 12/22] powerpc/cpu: Mark start_secondary_resume() __noreturn Josh Poimboeuf
2023-02-06 11:10 ` Michael Ellerman
2023-02-06 22:22 ` Josh Poimboeuf
2023-02-03 22:05 ` [PATCH 13/22] sh/cpu: Make sure play_dead() doesn't return Josh Poimboeuf
2023-02-03 22:05 ` [PATCH 14/22] sh/cpu: Mark play_dead() __noreturn Josh Poimboeuf
2023-02-03 22:05 ` [PATCH 15/22] sh/cpu: Expose arch_cpu_idle_dead()'s prototype definition Josh Poimboeuf
2023-02-03 22:05 ` [PATCH 16/22] sparc/cpu: Mark cpu_play_dead() __noreturn Josh Poimboeuf
2023-02-03 22:05 ` [PATCH 17/22] x86/cpu: Make sure play_dead() doesn't return Josh Poimboeuf
2023-02-03 22:05 ` [PATCH 18/22] x86/cpu: Mark play_dead() __noreturn Josh Poimboeuf
2023-02-03 22:05 ` [PATCH 19/22] xtensa/cpu: Make sure cpu_die() doesn't return Josh Poimboeuf
2023-02-03 22:05 ` [PATCH 20/22] xtensa/cpu: Mark cpu_die() __noreturn Josh Poimboeuf
2023-02-03 22:05 ` [PATCH 21/22] sched/idle: Make sure weak version of arch_cpu_idle_dead() doesn't return Josh Poimboeuf
2023-02-03 22:05 ` [PATCH 22/22] sched/idle: Mark arch_cpu_idle_dead() __noreturn Josh Poimboeuf
2023-02-07 17:33 ` [PATCH v1.1 " Josh Poimboeuf
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