X-Git-Url: http://git.samba.org/samba.git/?a=blobdiff_plain;f=arch%2Fpowerpc%2Fkernel%2Firq.c;h=086b0a74332903c0defecd9c902444b610aca6b9;hb=b12b47249688915e987a9a2a393b522f86f6b7ab;hp=4788522b2b144ecb15be9182199a8a1cf37aaa08;hpb=82d2c16b350f72aa21ac2a6860c542aa4b43a51e;p=sfrench%2Fcifs-2.6.git

diff --git a/arch/powerpc/kernel/irq.c b/arch/powerpc/kernel/irq.c
index 4788522b2b14..086b0a743329 100644
--- a/arch/powerpc/kernel/irq.c
+++ b/arch/powerpc/kernel/irq.c
@@ -181,13 +181,18 @@ void notrace restore_interrupts(void)
 
 void replay_soft_interrupts(void)
 {
+	struct pt_regs regs;
+
 	/*
-	 * We use local_paca rather than get_paca() to avoid all
-	 * the debug_smp_processor_id() business in this low level
-	 * function
+	 * Be careful here, calling these interrupt handlers can cause
+	 * softirqs to be raised, which they may run when calling irq_exit,
+	 * which will cause local_irq_enable() to be run, which can then
+	 * recurse into this function. Don't keep any state across
+	 * interrupt handler calls which may change underneath us.
+	 *
+	 * We use local_paca rather than get_paca() to avoid all the
+	 * debug_smp_processor_id() business in this low level function.
 	 */
-	unsigned char happened = local_paca->irq_happened;
-	struct pt_regs regs;
 
 	ppc_save_regs(&regs);
 	regs.softe = IRQS_ENABLED;
@@ -210,7 +215,7 @@ again:
 	 * This is a higher priority interrupt than the others, so
 	 * replay it first.
 	 */
-	if (IS_ENABLED(CONFIG_PPC_BOOK3S) && (happened & PACA_IRQ_HMI)) {
+	if (IS_ENABLED(CONFIG_PPC_BOOK3S) && (local_paca->irq_happened & PACA_IRQ_HMI)) {
 		local_paca->irq_happened &= ~PACA_IRQ_HMI;
 		regs.trap = 0xe60;
 		handle_hmi_exception(&regs);
@@ -218,7 +223,7 @@ again:
 			hard_irq_disable();
 	}
 
-	if (happened & PACA_IRQ_DEC) {
+	if (local_paca->irq_happened & PACA_IRQ_DEC) {
 		local_paca->irq_happened &= ~PACA_IRQ_DEC;
 		regs.trap = 0x900;
 		timer_interrupt(&regs);
@@ -226,7 +231,7 @@ again:
 			hard_irq_disable();
 	}
 
-	if (happened & PACA_IRQ_EE) {
+	if (local_paca->irq_happened & PACA_IRQ_EE) {
 		local_paca->irq_happened &= ~PACA_IRQ_EE;
 		regs.trap = 0x500;
 		do_IRQ(&regs);
@@ -234,7 +239,7 @@ again:
 			hard_irq_disable();
 	}
 
-	if (IS_ENABLED(CONFIG_PPC_DOORBELL) && (happened & PACA_IRQ_DBELL)) {
+	if (IS_ENABLED(CONFIG_PPC_DOORBELL) && (local_paca->irq_happened & PACA_IRQ_DBELL)) {
 		local_paca->irq_happened &= ~PACA_IRQ_DBELL;
 		if (IS_ENABLED(CONFIG_PPC_BOOK3E))
 			regs.trap = 0x280;
@@ -246,7 +251,7 @@ again:
 	}
 
 	/* Book3E does not support soft-masking PMI interrupts */
-	if (IS_ENABLED(CONFIG_PPC_BOOK3S) && (happened & PACA_IRQ_PMI)) {
+	if (IS_ENABLED(CONFIG_PPC_BOOK3S) && (local_paca->irq_happened & PACA_IRQ_PMI)) {
 		local_paca->irq_happened &= ~PACA_IRQ_PMI;
 		regs.trap = 0xf00;
 		performance_monitor_exception(&regs);
@@ -254,8 +259,7 @@ again:
 			hard_irq_disable();
 	}
 
-	happened = local_paca->irq_happened;
-	if (happened & ~PACA_IRQ_HARD_DIS) {
+	if (local_paca->irq_happened & ~PACA_IRQ_HARD_DIS) {
 		/*
 		 * We are responding to the next interrupt, so interrupt-off
 		 * latencies should be reset here.