diff options
Diffstat (limited to 'arch/powerpc/kernel/process.c')
| -rw-r--r-- | arch/powerpc/kernel/process.c | 16 |
1 files changed, 9 insertions, 7 deletions
diff --git a/arch/powerpc/kernel/process.c b/arch/powerpc/kernel/process.c index febe9f7cda2f..2a6fadde58b4 100644 --- a/arch/powerpc/kernel/process.c +++ b/arch/powerpc/kernel/process.c @@ -1250,15 +1250,17 @@ struct task_struct *__switch_to(struct task_struct *prev, restore_math(current->thread.regs); /* - * The copy-paste buffer can only store into foreign real - * addresses, so unprivileged processes can not see the - * data or use it in any way unless they have foreign real - * mappings. If the new process has the foreign real address - * mappings, we must issue a cp_abort to clear any state and - * prevent snooping, corruption or a covert channel. + * On POWER9 the copy-paste buffer can only paste into + * foreign real addresses, so unprivileged processes can not + * see the data or use it in any way unless they have + * foreign real mappings. If the new process has the foreign + * real address mappings, we must issue a cp_abort to clear + * any state and prevent snooping, corruption or a covert + * channel. ISA v3.1 supports paste into local memory. */ if (current->mm && - atomic_read(¤t->mm->context.vas_windows)) + (cpu_has_feature(CPU_FTR_ARCH_31) || + atomic_read(¤t->mm->context.vas_windows))) asm volatile(PPC_CP_ABORT); } #endif /* CONFIG_PPC_BOOK3S_64 */ |