Re: [PATCH v2 19/24] xtensa/cpu: Make sure cpu_die() doesn't return
From: Philippe Mathieu-Daudé <hidden>
Date: 2023-02-14 07:56:16
Also in:
linux-mips, linux-sh, lkml, loongarch, sparclinux
Hi Josh, On 14/2/23 08:05, Josh Poimboeuf wrote:
quoted hunk ↗ jump to hunk
cpu_die() 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/xtensa/kernel/smp.c | 2 ++ 1 file changed, 2 insertions(+)diff --git a/arch/xtensa/kernel/smp.c b/arch/xtensa/kernel/smp.c index 4dc109dd6214..7bad78495536 100644 --- a/arch/xtensa/kernel/smp.c +++ b/arch/xtensa/kernel/smp.c
Can you update the documentation along? Currently we have:
/*
* Called from the idle thread for the CPU which has been shutdown.
*
* Note that we disable IRQs here, but do not re-enable them
* before returning to the caller. This is also the behaviour
* of the other hotplug-cpu capable cores, so presumably coming
* out of idle fixes this.
*/
quoted hunk ↗ jump to hunk
@@ -341,6 +341,8 @@ void __ref cpu_die(void) __asm__ __volatile__( " movi a2, cpu_restart\n" " jx a2\n"); + + BUG(); } #endif /* CONFIG_HOTPLUG_CPU */