diff options
| author | Thomas Gleixner <tglx@linutronix.de> | 2023-06-15 22:34:00 +0200 |
|---|---|---|
| committer | Thomas Gleixner <tglx@linutronix.de> | 2023-06-20 14:51:47 +0200 |
| commit | 45e34c8af58f23db4474e2bfe79183efec09a18b (patch) | |
| tree | 9b0394979b5e07d83f76699ce2c79ddd95e5f692 /arch/x86/include/asm/smp.h | |
| parent | 6087dd5e86ff03a8cd4cffdf463a7f457e65cbff (diff) | |
x86/smp: Put CPUs into INIT on shutdown if possible
Parking CPUs in a HLT loop is not completely safe vs. kexec() as HLT can
resume execution due to NMI, SMI and MCE, which has the same issue as the
MWAIT loop.
Kicking the secondary CPUs into INIT makes this safe against NMI and SMI.
A broadcast MCE will take the machine down, but a broadcast MCE which makes
HLT resume and execute overwritten text, pagetables or data will end up in
a disaster too.
So chose the lesser of two evils and kick the secondary CPUs into INIT
unless the system has installed special wakeup mechanisms which are not
using INIT.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Ashok Raj <ashok.raj@intel.com>
Reviewed-by: Borislav Petkov (AMD) <bp@alien8.de>
Link: https://lore.kernel.org/r/20230615193330.608657211@linutronix.de
Diffstat (limited to 'arch/x86/include/asm/smp.h')
| -rw-r--r-- | arch/x86/include/asm/smp.h | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/arch/x86/include/asm/smp.h b/arch/x86/include/asm/smp.h index d4ce5cb5c953..5906aa914220 100644 --- a/arch/x86/include/asm/smp.h +++ b/arch/x86/include/asm/smp.h @@ -139,6 +139,8 @@ void native_send_call_func_ipi(const struct cpumask *mask); void native_send_call_func_single_ipi(int cpu); void x86_idle_thread_init(unsigned int cpu, struct task_struct *idle); +bool smp_park_other_cpus_in_init(void); + void smp_store_boot_cpu_info(void); void smp_store_cpu_info(int id); |