powerpc: Copy back TIF flags on return from softirq stack

We already did it for hard IRQs but it looks like we forgot
to do it for softirqs. Without this, we would lose flags
such as TIF_NEED_RESCHED set using current_thread_info()
by something running of a softirq.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

diff --git a/arch/powerpc/kernel/irq.c b/arch/powerpc/kernel/irq.c
index 346cc4a396fefc5a7fc7fc6257c6426052a70cb6..d281fb6f12f36e291c50c492774d8325c61b3081 100644 (file)
--- a/arch/powerpc/kernel/irq.c
+++ b/arch/powerpc/kernel/irq.c
@@ -451,11 +451,18 @@ static inline void do_softirq_onstack(void)
        curtp = current_thread_info();
        irqtp = softirq_ctx[smp_processor_id()];
        irqtp->task = curtp->task;
+       irqtp->flags = 0;
        current->thread.ksp_limit = (unsigned long)irqtp +
                                    _ALIGN_UP(sizeof(struct thread_info), 16);
        call_do_softirq(irqtp);
        current->thread.ksp_limit = saved_sp_limit;
        irqtp->task = NULL;
+
+       /* Set any flag that may have been set on the
+        * alternate stack
+        */
+       if (irqtp->flags)
+               set_bits(irqtp->flags, &curtp->flags);
 }
 
 void do_softirq(void)