From: Thomas Gleixner Date: Wed, 5 Jul 2023 08:59:23 +0000 (+0200) Subject: x86/smp: Don't send INIT to boot CPU X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=b1472a60a584;p=linux.git x86/smp: Don't send INIT to boot CPU Parking CPUs in INIT works well, except for the crash case when the CPU which invokes smp_park_other_cpus_in_init() is not the boot CPU. Sending INIT to the boot CPU resets the whole machine. Prevent this by validating that this runs on the boot CPU. If not fall back and let CPUs hang in HLT. Fixes: 45e34c8af58f ("x86/smp: Put CPUs into INIT on shutdown if possible") Reported-by: Baokun Li Signed-off-by: Thomas Gleixner Tested-by: Baokun Li Link: https://lore.kernel.org/r/87ttui91jo.ffs@tglx --- diff --git a/arch/x86/kernel/smpboot.c b/arch/x86/kernel/smpboot.c index 4ee43396b9102..7417d9b55b219 100644 --- a/arch/x86/kernel/smpboot.c +++ b/arch/x86/kernel/smpboot.c @@ -1473,6 +1473,14 @@ bool smp_park_other_cpus_in_init(void) if (apic->wakeup_secondary_cpu_64 || apic->wakeup_secondary_cpu) return false; + /* + * If this is a crash stop which does not execute on the boot CPU, + * then this cannot use the INIT mechanism because INIT to the boot + * CPU will reset the machine. + */ + if (this_cpu) + return false; + for_each_present_cpu(cpu) { if (cpu == this_cpu) continue;