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Commit dd5619cb authored by Kenji Kaneshige's avatar Kenji Kaneshige Committed by Greg Kroah-Hartman
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pciehp - add missing locking 



This patch fixes the problem that system will panic if multiple power
on/off operations are issued to the same slot in parallel. This
problem can be easily reproduced by commands below.

    # while true; do echo 1 > power; echo 0 > power; done &
    # while true; do echo 1 > power; echo 0 > power; done &

The cause is lack of locking for enable/disable operations. This patch
fixes this problem.

Signed-off-by: default avatarKenji Kaneshige <kaneshige.kenji@jp.fujitsu.com>
Signed-off-by: default avatarKristen Carlson Accardi <kristen.c.accardi@intel.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@suse.de>
parent 49ed2b49

drivers/pci/hotplug/pciehp.h

+1 −0
Original line number Diff line number Diff line
@@ -92,6 +92,7 @@ struct php_ctlr_state_s { 
struct controller {

	struct controller *next;

	struct mutex crit_sect;		/* critical section mutex */

	struct mutex ctrl_lock;		/* controller lock */

	struct php_ctlr_state_s *hpc_ctlr_handle; /* HPC controller handle */

	int num_slots;			/* Number of slots on ctlr */

	int slot_num_inc;		/* 1 or -1 */

drivers/pci/hotplug/pciehp_core.c

+3 −3
Original line number Diff line number Diff line
@@ -448,7 +448,7 @@ static int pciehp_probe(struct pcie_device *dev, const struct pcie_port_service_ 
	}



	/* Wait for exclusive access to hardware */

	mutex_lock(&ctrl->crit_sect);

	mutex_lock(&ctrl->ctrl_lock);



	t_slot->hpc_ops->get_adapter_status(t_slot, &value); /* Check if slot is occupied */
@@ -456,7 +456,7 @@ static int pciehp_probe(struct pcie_device *dev, const struct pcie_port_service_ 
		rc = t_slot->hpc_ops->power_off_slot(t_slot); /* Power off slot if not occupied*/

		if (rc) {

			/* Done with exclusive hardware access */

			mutex_unlock(&ctrl->crit_sect);

			mutex_unlock(&ctrl->ctrl_lock);

			goto err_out_free_ctrl_slot;

		} else

			/* Wait for the command to complete */
@@ -464,7 +464,7 @@ static int pciehp_probe(struct pcie_device *dev, const struct pcie_port_service_ 
	}



	/* Done with exclusive hardware access */

	mutex_unlock(&ctrl->crit_sect);

	mutex_unlock(&ctrl->ctrl_lock);



	return 0;

drivers/pci/hotplug/pciehp_ctrl.c

+27 −27
Original line number Diff line number Diff line
@@ -234,13 +234,13 @@ u8 pciehp_handle_power_fault(u8 hp_slot, void *inst_id) 
static void set_slot_off(struct controller *ctrl, struct slot * pslot)

{

	/* Wait for exclusive access to hardware */

	mutex_lock(&ctrl->crit_sect);

	mutex_lock(&ctrl->ctrl_lock);



	/* turn off slot, turn on Amber LED, turn off Green LED if supported*/

	if (POWER_CTRL(ctrl->ctrlcap)) {

		if (pslot->hpc_ops->power_off_slot(pslot)) {   

			err("%s: Issue of Slot Power Off command failed\n", __FUNCTION__);

			mutex_unlock(&ctrl->crit_sect);

			mutex_unlock(&ctrl->ctrl_lock);

			return;

		}

		wait_for_ctrl_irq (ctrl);
@@ -254,14 +254,14 @@ static void set_slot_off(struct controller *ctrl, struct slot * pslot) 
	if (ATTN_LED(ctrl->ctrlcap)) { 

		if (pslot->hpc_ops->set_attention_status(pslot, 1)) {   

			err("%s: Issue of Set Attention Led command failed\n", __FUNCTION__);

			mutex_unlock(&ctrl->crit_sect);

			mutex_unlock(&ctrl->ctrl_lock);

			return;

		}

		wait_for_ctrl_irq (ctrl);

	}



	/* Done with exclusive hardware access */

	mutex_unlock(&ctrl->crit_sect);

	mutex_unlock(&ctrl->ctrl_lock);

}



/**
@@ -284,13 +284,13 @@ static int board_added(struct slot *p_slot) 
			ctrl->slot_device_offset, hp_slot);



	/* Wait for exclusive access to hardware */

	mutex_lock(&ctrl->crit_sect);

	mutex_lock(&ctrl->ctrl_lock);



	if (POWER_CTRL(ctrl->ctrlcap)) {

		/* Power on slot */

		rc = p_slot->hpc_ops->power_on_slot(p_slot);

		if (rc) {

			mutex_unlock(&ctrl->crit_sect);

			mutex_unlock(&ctrl->ctrl_lock);

			return -1;

		}
@@ -306,7 +306,7 @@ static int board_added(struct slot *p_slot) 
	}



	/* Done with exclusive hardware access */

	mutex_unlock(&ctrl->crit_sect);

	mutex_unlock(&ctrl->ctrl_lock);



	/* Wait for ~1 second */

	wait_for_ctrl_irq (ctrl);
@@ -340,7 +340,7 @@ static int board_added(struct slot *p_slot) 
		pci_fixup_device(pci_fixup_final, ctrl->pci_dev);

	if (PWR_LED(ctrl->ctrlcap)) {

		/* Wait for exclusive access to hardware */

  		mutex_lock(&ctrl->crit_sect);

  		mutex_lock(&ctrl->ctrl_lock);



  		p_slot->hpc_ops->green_led_on(p_slot);
@@ -348,7 +348,7 @@ static int board_added(struct slot *p_slot) 
  		wait_for_ctrl_irq (ctrl);

  	

  		/* Done with exclusive hardware access */

  		mutex_unlock(&ctrl->crit_sect);

  		mutex_unlock(&ctrl->ctrl_lock);

  	}

	return 0;
@@ -380,14 +380,14 @@ static int remove_board(struct slot *p_slot) 
	dbg("In %s, hp_slot = %d\n", __FUNCTION__, hp_slot);



	/* Wait for exclusive access to hardware */

	mutex_lock(&ctrl->crit_sect);

	mutex_lock(&ctrl->ctrl_lock);



	if (POWER_CTRL(ctrl->ctrlcap)) {

		/* power off slot */

		rc = p_slot->hpc_ops->power_off_slot(p_slot);

		if (rc) {

			err("%s: Issue of Slot Disable command failed\n", __FUNCTION__);

			mutex_unlock(&ctrl->crit_sect);

			mutex_unlock(&ctrl->ctrl_lock);

			return rc;

		}

		/* Wait for the command to complete */
@@ -403,7 +403,7 @@ static int remove_board(struct slot *p_slot) 
	}



	/* Done with exclusive hardware access */

	mutex_unlock(&ctrl->crit_sect);

	mutex_unlock(&ctrl->ctrl_lock);



	return 0;

}
@@ -450,7 +450,7 @@ static void pciehp_pushbutton_thread(unsigned long slot) 


		if (pciehp_enable_slot(p_slot) && PWR_LED(p_slot->ctrl->ctrlcap)) {

			/* Wait for exclusive access to hardware */

			mutex_lock(&p_slot->ctrl->crit_sect);

			mutex_lock(&p_slot->ctrl->ctrl_lock);



			p_slot->hpc_ops->green_led_off(p_slot);
@@ -458,7 +458,7 @@ static void pciehp_pushbutton_thread(unsigned long slot) 
			wait_for_ctrl_irq (p_slot->ctrl);



			/* Done with exclusive hardware access */

			mutex_unlock(&p_slot->ctrl->crit_sect);

			mutex_unlock(&p_slot->ctrl->ctrl_lock);

		}

		p_slot->state = STATIC_STATE;

	}
@@ -500,7 +500,7 @@ static void pciehp_surprise_rm_thread(unsigned long slot) 


		if (pciehp_enable_slot(p_slot) && PWR_LED(p_slot->ctrl->ctrlcap)) {

			/* Wait for exclusive access to hardware */

			mutex_lock(&p_slot->ctrl->crit_sect);

			mutex_lock(&p_slot->ctrl->ctrl_lock);



			p_slot->hpc_ops->green_led_off(p_slot);
@@ -508,7 +508,7 @@ static void pciehp_surprise_rm_thread(unsigned long slot) 
			wait_for_ctrl_irq (p_slot->ctrl);



			/* Done with exclusive hardware access */

			mutex_unlock(&p_slot->ctrl->crit_sect);

			mutex_unlock(&p_slot->ctrl->ctrl_lock);

		}

		p_slot->state = STATIC_STATE;

	}
@@ -621,7 +621,7 @@ static void interrupt_event_handler(struct controller *ctrl) 
					switch (p_slot->state) {

					case BLINKINGOFF_STATE:

						/* Wait for exclusive access to hardware */

						mutex_lock(&ctrl->crit_sect);

						mutex_lock(&ctrl->ctrl_lock);

						

						if (PWR_LED(ctrl->ctrlcap)) {

							p_slot->hpc_ops->green_led_on(p_slot);
@@ -635,11 +635,11 @@ static void interrupt_event_handler(struct controller *ctrl) 
							wait_for_ctrl_irq (ctrl);

						}

						/* Done with exclusive hardware access */

						mutex_unlock(&ctrl->crit_sect);

						mutex_unlock(&ctrl->ctrl_lock);

						break;

					case BLINKINGON_STATE:

						/* Wait for exclusive access to hardware */

						mutex_lock(&ctrl->crit_sect);

						mutex_lock(&ctrl->ctrl_lock);



						if (PWR_LED(ctrl->ctrlcap)) {

							p_slot->hpc_ops->green_led_off(p_slot);
@@ -652,7 +652,7 @@ static void interrupt_event_handler(struct controller *ctrl) 
							wait_for_ctrl_irq (ctrl);

						}

						/* Done with exclusive hardware access */

						mutex_unlock(&ctrl->crit_sect);

						mutex_unlock(&ctrl->ctrl_lock);



						break;

					default:
@@ -681,7 +681,7 @@ static void interrupt_event_handler(struct controller *ctrl) 
						}



						/* Wait for exclusive access to hardware */

						mutex_lock(&ctrl->crit_sect);

						mutex_lock(&ctrl->ctrl_lock);



						/* blink green LED and turn off amber */

						if (PWR_LED(ctrl->ctrlcap)) {
@@ -698,7 +698,7 @@ static void interrupt_event_handler(struct controller *ctrl) 
						}



						/* Done with exclusive hardware access */

						mutex_unlock(&ctrl->crit_sect);

						mutex_unlock(&ctrl->ctrl_lock);



						init_timer(&p_slot->task_event);

						p_slot->task_event.expires = jiffies + 5 * HZ;   /* 5 second delay */
@@ -713,7 +713,7 @@ static void interrupt_event_handler(struct controller *ctrl) 
					if (POWER_CTRL(ctrl->ctrlcap)) {

						dbg("power fault\n");

						/* Wait for exclusive access to hardware */

						mutex_lock(&ctrl->crit_sect);

						mutex_lock(&ctrl->ctrl_lock);



						if (ATTN_LED(ctrl->ctrlcap)) {

							p_slot->hpc_ops->set_attention_status(p_slot, 1);
@@ -726,7 +726,7 @@ static void interrupt_event_handler(struct controller *ctrl) 
						}



						/* Done with exclusive hardware access */

						mutex_unlock(&ctrl->crit_sect);

						mutex_unlock(&ctrl->ctrl_lock);

					}

				}

				/***********SURPRISE REMOVAL********************/
@@ -789,7 +789,6 @@ int pciehp_enable_slot(struct slot *p_slot) 
			return -EINVAL;

		}

	}

	mutex_unlock(&p_slot->ctrl->crit_sect);



	p_slot->hpc_ops->get_latch_status(p_slot, &getstatus);
@@ -801,6 +800,7 @@ int pciehp_enable_slot(struct slot *p_slot) 
	if (p_slot)

		update_slot_info(p_slot);



	mutex_unlock(&p_slot->ctrl->crit_sect);

	return rc;

}
@@ -846,10 +846,10 @@ int pciehp_disable_slot(struct slot *p_slot) 
		}

	}



	mutex_unlock(&p_slot->ctrl->crit_sect);



	ret = remove_board(p_slot);

	update_slot_info(p_slot);



	mutex_unlock(&p_slot->ctrl->crit_sect);

	return ret;

}

drivers/pci/hotplug/pciehp_hpc.c

+2 −0
Original line number Diff line number Diff line
@@ -1402,6 +1402,8 @@ int pcie_init(struct controller * ctrl, struct pcie_device *dev) 
		pdev->subsystem_vendor, pdev->subsystem_device);



	mutex_init(&ctrl->crit_sect);

	mutex_init(&ctrl->ctrl_lock);



	/* setup wait queue */

	init_waitqueue_head(&ctrl->queue);