diff options
Diffstat (limited to 'arch/powerpc/kernel/process.c')
| -rw-r--r-- | arch/powerpc/kernel/process.c | 24 |
1 files changed, 2 insertions, 22 deletions
diff --git a/arch/powerpc/kernel/process.c b/arch/powerpc/kernel/process.c index 9c21288f8645..8479c762aef2 100644 --- a/arch/powerpc/kernel/process.c +++ b/arch/powerpc/kernel/process.c @@ -1228,7 +1228,8 @@ struct task_struct *__switch_to(struct task_struct *prev, * mappings, we must issue a cp_abort to clear any state and * prevent snooping, corruption or a covert channel. */ - if (current->thread.used_vas) + if (current->mm && + atomic_read(¤t->mm->context.vas_windows)) asm volatile(PPC_CP_ABORT); } #endif /* CONFIG_PPC_BOOK3S_64 */ @@ -1467,27 +1468,6 @@ void arch_setup_new_exec(void) } #endif -int set_thread_uses_vas(void) -{ -#ifdef CONFIG_PPC_BOOK3S_64 - if (!cpu_has_feature(CPU_FTR_ARCH_300)) - return -EINVAL; - - current->thread.used_vas = 1; - - /* - * Even a process that has no foreign real address mapping can use - * an unpaired COPY instruction (to no real effect). Issue CP_ABORT - * to clear any pending COPY and prevent a covert channel. - * - * __switch_to() will issue CP_ABORT on future context switches. - */ - asm volatile(PPC_CP_ABORT); - -#endif /* CONFIG_PPC_BOOK3S_64 */ - return 0; -} - #ifdef CONFIG_PPC64 /** * Assign a TIDR (thread ID) for task @t and set it in the thread |