diff options
| -rw-r--r-- | arch/s390/include/asm/system.h | 20 |
1 files changed, 12 insertions, 8 deletions
diff --git a/arch/s390/include/asm/system.h b/arch/s390/include/asm/system.h index 1f2ebc4afd8..c35d0a383f0 100644 --- a/arch/s390/include/asm/system.h +++ b/arch/s390/include/asm/system.h @@ -85,14 +85,18 @@ static inline void restore_access_regs(unsigned int *acrs) asm volatile("lam 0,15,%0" : : "Q" (*acrs)); } -#define switch_to(prev,next,last) do { \ - if (prev == next) \ - break; \ - save_fp_regs(&prev->thread.fp_regs); \ - restore_fp_regs(&next->thread.fp_regs); \ - save_access_regs(&prev->thread.acrs[0]); \ - restore_access_regs(&next->thread.acrs[0]); \ - prev = __switch_to(prev,next); \ +#define switch_to(prev,next,last) do { \ + if (prev == next) \ + break; \ + if (prev->mm) { \ + save_fp_regs(&prev->thread.fp_regs); \ + save_access_regs(&prev->thread.acrs[0]); \ + } \ + if (next->mm) { \ + restore_fp_regs(&next->thread.fp_regs); \ + restore_access_regs(&next->thread.acrs[0]); \ + } \ + prev = __switch_to(prev,next); \ } while (0) extern void account_vtime(struct task_struct *, struct task_struct *); |