diff options
| -rw-r--r-- | arch/powerpc/lib/vmx-helper.c | 12 |
1 files changed, 11 insertions, 1 deletions
diff --git a/arch/powerpc/lib/vmx-helper.c b/arch/powerpc/lib/vmx-helper.c index f76a50291fd7..d491da8d1838 100644 --- a/arch/powerpc/lib/vmx-helper.c +++ b/arch/powerpc/lib/vmx-helper.c @@ -36,7 +36,17 @@ int exit_vmx_usercopy(void) { disable_kernel_altivec(); pagefault_enable(); - preempt_enable(); + preempt_enable_no_resched(); + /* + * Must never explicitly call schedule (including preempt_enable()) + * while in a kuap-unlocked user copy, because the AMR register will + * not be saved and restored across context switch. However preempt + * kernels need to be preempted as soon as possible if need_resched is + * set and we are preemptible. The hack here is to schedule a + * decrementer to fire here and reschedule for us if necessary. + */ + if (IS_ENABLED(CONFIG_PREEMPT) && need_resched()) + set_dec(1); return 0; } |