From: Jiang Liu <jiang.liu@xxxxxxxxxx> Function acpi_bus_get_device() return an ACPI device without holding a reference count the device, which is not safe to ACPI hotplug operations. So change acpi_bus_get_device() to hold a reference count on the returned ACPI device and introduces acpi_get_device()/acpi_put_device() to manage ACPI device reference count. This patch is still incomplete, need to check and modify all callers of acpi_bus_get_device(). Signed-off-by: Jiang Liu <liuj97@xxxxxxxxx> --- drivers/acpi/bus.c | 22 +++++++++++++++++++--- drivers/acpi/internal.h | 3 +++ drivers/acpi/scan.c | 6 ++++++ drivers/gpu/drm/i915/intel_opregion.c | 2 ++ drivers/gpu/drm/nouveau/nouveau_acpi.c | 1 + drivers/pci/hotplug/acpiphp_glue.c | 9 +++++++-- drivers/pci/hotplug/acpiphp_ibm.c | 5 ++++- drivers/pci/hotplug/sgi_hotplug.c | 6 +++++- drivers/platform/x86/thinkpad_acpi.c | 2 ++ drivers/pnp/pnpacpi/core.c | 23 ++++++++++------------- include/acpi/acpi_bus.h | 16 +++++++++++++++- 11 files changed, 74 insertions(+), 21 deletions(-) diff --git a/drivers/acpi/bus.c b/drivers/acpi/bus.c index adceafd..e13dcbc 100644 --- a/drivers/acpi/bus.c +++ b/drivers/acpi/bus.c @@ -89,26 +89,42 @@ static struct dmi_system_id dsdt_dmi_table[] __initdata = { Device Management -------------------------------------------------------------------------- */ -int acpi_bus_get_device(acpi_handle handle, struct acpi_device **device) +bool acpi_bus_has_device(acpi_handle handle) { - acpi_status status = AE_OK; + acpi_status status; + struct acpi_device *device = NULL; + + down_read(&acpi_device_data_handler_sem); + status = acpi_get_data(handle, acpi_bus_data_handler, (void **)&device); + up_read(&acpi_device_data_handler_sem); + + return ACPI_SUCCESS(status) && device; +} +EXPORT_SYMBOL(acpi_bus_has_device); +int acpi_bus_get_device(acpi_handle handle, struct acpi_device **device) +{ + acpi_status status; if (!device) return -EINVAL; /* TBD: Support fixed-feature devices */ + down_read(&acpi_device_data_handler_sem); status = acpi_get_data(handle, acpi_bus_data_handler, (void **)device); if (ACPI_FAILURE(status) || !*device) { + up_read(&acpi_device_data_handler_sem); ACPI_DEBUG_PRINT((ACPI_DB_INFO, "No context for object [%p]\n", handle)); return -ENODEV; + } else { + get_device(&(*device)->dev); + up_read(&acpi_device_data_handler_sem); } return 0; } - EXPORT_SYMBOL(acpi_bus_get_device); acpi_status acpi_bus_get_status_handle(acpi_handle handle, diff --git a/drivers/acpi/internal.h b/drivers/acpi/internal.h index ca75b9c..70843c0 100644 --- a/drivers/acpi/internal.h +++ b/drivers/acpi/internal.h @@ -93,4 +93,7 @@ static inline int suspend_nvs_save(void) { return 0; } static inline void suspend_nvs_restore(void) {} #endif +extern struct rw_semaphore acpi_device_data_handler_sem; +void acpi_bus_data_handler(acpi_handle handle, void *context); + #endif /* _ACPI_INTERNAL_H_ */ diff --git a/drivers/acpi/scan.c b/drivers/acpi/scan.c index 459593a..28408af 100644 --- a/drivers/acpi/scan.c +++ b/drivers/acpi/scan.c @@ -10,6 +10,7 @@ #include <linux/signal.h> #include <linux/kthread.h> #include <linux/dmi.h> +#include <linux/sem.h> #include <acpi/acpi_drivers.h> #include <linux/idr.h> @@ -33,6 +34,7 @@ static LIST_HEAD(acpi_device_list); static LIST_HEAD(acpi_bus_id_list); DEFINE_MUTEX(acpi_device_lock); LIST_HEAD(acpi_wakeup_device_list); +DECLARE_RWSEM(acpi_device_data_handler_sem); struct acpi_device_bus_id{ char bus_id[15]; @@ -564,7 +566,9 @@ static void acpi_device_unregister(struct acpi_device *device, int type) acpi_device_release_id(device); mutex_unlock(&acpi_device_lock); + down_write(&acpi_device_data_handler_sem); acpi_detach_data(device->handle, acpi_bus_data_handler); + up_write(&acpi_device_data_handler_sem); acpi_device_remove_files(device); device_unregister(&device->dev); @@ -1227,8 +1231,10 @@ static int acpi_device_set_context(struct acpi_device *device) if (!device->handle) return 0; + down_write(&acpi_device_data_handler_sem); status = acpi_attach_data(device->handle, acpi_bus_data_handler, device); + up_write(&acpi_device_data_handler_sem); if (ACPI_SUCCESS(status)) return 0; diff --git a/drivers/gpu/drm/i915/intel_opregion.c b/drivers/gpu/drm/i915/intel_opregion.c index 18bd0af..da7dd48 100644 --- a/drivers/gpu/drm/i915/intel_opregion.c +++ b/drivers/gpu/drm/i915/intel_opregion.c @@ -359,6 +359,8 @@ static void intel_didl_outputs(struct drm_device *dev) } } + acpi_device_put(acpi_dev); + if (!acpi_video_bus) { pr_warn("No ACPI video bus found\n"); return; diff --git a/drivers/gpu/drm/nouveau/nouveau_acpi.c b/drivers/gpu/drm/nouveau/nouveau_acpi.c index fc841e8..f83efe3 100644 --- a/drivers/gpu/drm/nouveau/nouveau_acpi.c +++ b/drivers/gpu/drm/nouveau/nouveau_acpi.c @@ -423,6 +423,7 @@ nouveau_acpi_edid(struct drm_device *dev, struct drm_connector *connector) return -ENODEV; ret = acpi_video_get_edid(acpidev, type, -1, &edid); + acpi_device_put(acpidev); if (ret < 0) return ret; diff --git a/drivers/pci/hotplug/acpiphp_glue.c b/drivers/pci/hotplug/acpiphp_glue.c index 806c44f..78cffba4 100644 --- a/drivers/pci/hotplug/acpiphp_glue.c +++ b/drivers/pci/hotplug/acpiphp_glue.c @@ -724,11 +724,13 @@ static int acpiphp_bus_add(struct acpiphp_func *func) * the bus then re-add it... */ ret_val = acpi_bus_trim(device, 1); + acpi_device_put(device); dbg("acpi_bus_trim return %x\n", ret_val); } ret_val = acpi_bus_add(&device, pdevice, func->handle, ACPI_BUS_TYPE_DEVICE); + acpi_device_put(pdevice); if (ret_val) { dbg("error adding bus, %x\n", -ret_val); @@ -760,6 +762,8 @@ static int acpiphp_bus_trim(acpi_handle handle) if (retval) err("cannot remove from acpi list\n"); + acpi_device_put(device); + return retval; } @@ -1114,8 +1118,10 @@ static void handle_bridge_insertion(acpi_handle handle, u32 type) } if (acpi_bus_add(&device, pdevice, handle, ACPI_BUS_TYPE_DEVICE)) { err("cannot add bridge to acpi list\n"); + acpi_device_put(pdevice); return; } + acpi_device_put(pdevice); if (!acpiphp_configure_bridge(handle) && !acpi_bus_start(device)) add_bridge(handle); @@ -1192,7 +1198,6 @@ static void _handle_hotplug_event_bridge(struct work_struct *work) char objname[64]; struct acpi_buffer buffer = { .length = sizeof(objname), .pointer = objname }; - struct acpi_device *device; int num_sub_bridges = 0; struct acpiphp_hp_work *hp_work; acpi_handle handle; @@ -1202,7 +1207,7 @@ static void _handle_hotplug_event_bridge(struct work_struct *work) handle = hp_work->handle; type = hp_work->type; - if (acpi_bus_get_device(handle, &device)) { + if (!acpi_bus_has_device(handle)) { /* This bridge must have just been physically inserted */ handle_bridge_insertion(handle, type); goto out; diff --git a/drivers/pci/hotplug/acpiphp_ibm.c b/drivers/pci/hotplug/acpiphp_ibm.c index c35e8ad..ecd4b8d 100644 --- a/drivers/pci/hotplug/acpiphp_ibm.c +++ b/drivers/pci/hotplug/acpiphp_ibm.c @@ -450,7 +450,7 @@ static int __init ibm_acpiphp_init(void) } if (acpiphp_register_attention(&ibm_attention_info)) { retval = -ENODEV; - goto init_return; + goto put_device; } ibm_note.device = device; @@ -471,6 +471,8 @@ static int __init ibm_acpiphp_init(void) init_cleanup: acpiphp_unregister_attention(&ibm_attention_info); +put_device: + acpi_device_put(device); init_return: return retval; } @@ -493,6 +495,7 @@ static void __exit ibm_acpiphp_exit(void) err("%s: Notification handler removal failed\n", __func__); /* remove the /sys entries */ sysfs_remove_bin_file(sysdir, &ibm_apci_table_attr); + acpi_device_put(ibm_note.device); } module_init(ibm_acpiphp_init); diff --git a/drivers/pci/hotplug/sgi_hotplug.c b/drivers/pci/hotplug/sgi_hotplug.c index de57311..ad120f1 100644 --- a/drivers/pci/hotplug/sgi_hotplug.c +++ b/drivers/pci/hotplug/sgi_hotplug.c @@ -464,6 +464,8 @@ static int enable_slot(struct hotplug_slot *bss_hotplug_slot) } } } + + acpi_device_put(pdevice); } /* Call the driver for the new device */ @@ -540,8 +542,10 @@ static int disable_slot(struct hotplug_slot *bss_hotplug_slot) ret = acpi_bus_get_device(chandle, &device); - if (ACPI_SUCCESS(ret)) + if (ACPI_SUCCESS(ret)) { acpi_bus_trim(device, 1); + acpi_device_put(device); + } } } diff --git a/drivers/platform/x86/thinkpad_acpi.c b/drivers/platform/x86/thinkpad_acpi.c index 8b5610d..285eac5f 100644 --- a/drivers/platform/x86/thinkpad_acpi.c +++ b/drivers/platform/x86/thinkpad_acpi.c @@ -782,6 +782,7 @@ static int __init setup_acpi_notify(struct ibm_struct *ibm) pr_err("acpi_install_notify_handler(%s) failed: %s\n", ibm->name, acpi_format_exception(status)); } + acpi_device_put(ibm->acpi->device); return -ENODEV; } ibm->flags.acpi_notify_installed = 1; @@ -8461,6 +8462,7 @@ static void ibm_exit(struct ibm_struct *ibm) acpi_remove_notify_handler(*ibm->acpi->handle, ibm->acpi->type, dispatch_acpi_notify); + acpi_device_put(ibm->acpi->device); ibm->flags.acpi_notify_installed = 0; } diff --git a/drivers/pnp/pnpacpi/core.c b/drivers/pnp/pnpacpi/core.c index d21e8f5..684b462 100644 --- a/drivers/pnp/pnpacpi/core.c +++ b/drivers/pnp/pnpacpi/core.c @@ -82,7 +82,6 @@ static int pnpacpi_get_resources(struct pnp_dev *dev) static int pnpacpi_set_resources(struct pnp_dev *dev) { - struct acpi_device *acpi_dev; acpi_handle handle; struct acpi_buffer buffer; int ret; @@ -90,7 +89,7 @@ static int pnpacpi_set_resources(struct pnp_dev *dev) pnp_dbg(&dev->dev, "set resources\n"); handle = DEVICE_ACPI_HANDLE(&dev->dev); - if (!handle || ACPI_FAILURE(acpi_bus_get_device(handle, &acpi_dev))) { + if (!handle || !acpi_bus_has_device(handle)) { dev_dbg(&dev->dev, "ACPI device not found in %s!\n", __func__); return -ENODEV; } @@ -113,14 +112,13 @@ static int pnpacpi_set_resources(struct pnp_dev *dev) static int pnpacpi_disable_resources(struct pnp_dev *dev) { - struct acpi_device *acpi_dev; acpi_handle handle; int ret; dev_dbg(&dev->dev, "disable resources\n"); handle = DEVICE_ACPI_HANDLE(&dev->dev); - if (!handle || ACPI_FAILURE(acpi_bus_get_device(handle, &acpi_dev))) { + if (!handle || !acpi_bus_has_device(handle)) { dev_dbg(&dev->dev, "ACPI device not found in %s!\n", __func__); return 0; } @@ -138,11 +136,10 @@ static int pnpacpi_disable_resources(struct pnp_dev *dev) #ifdef CONFIG_ACPI_SLEEP static bool pnpacpi_can_wakeup(struct pnp_dev *dev) { - struct acpi_device *acpi_dev; acpi_handle handle; handle = DEVICE_ACPI_HANDLE(&dev->dev); - if (!handle || ACPI_FAILURE(acpi_bus_get_device(handle, &acpi_dev))) { + if (!handle || !acpi_bus_has_device(handle)) { dev_dbg(&dev->dev, "ACPI device not found in %s!\n", __func__); return false; } @@ -152,12 +149,11 @@ static bool pnpacpi_can_wakeup(struct pnp_dev *dev) static int pnpacpi_suspend(struct pnp_dev *dev, pm_message_t state) { - struct acpi_device *acpi_dev; acpi_handle handle; int error = 0; handle = DEVICE_ACPI_HANDLE(&dev->dev); - if (!handle || ACPI_FAILURE(acpi_bus_get_device(handle, &acpi_dev))) { + if (!handle || !acpi_bus_has_device(handle)) { dev_dbg(&dev->dev, "ACPI device not found in %s!\n", __func__); return 0; } @@ -190,11 +186,10 @@ static int pnpacpi_suspend(struct pnp_dev *dev, pm_message_t state) static int pnpacpi_resume(struct pnp_dev *dev) { - struct acpi_device *acpi_dev; acpi_handle handle = DEVICE_ACPI_HANDLE(&dev->dev); int error = 0; - if (!handle || ACPI_FAILURE(acpi_bus_get_device(handle, &acpi_dev))) { + if (!handle || !acpi_bus_has_device(handle)) { dev_dbg(&dev->dev, "ACPI device not found in %s!\n", __func__); return -ENODEV; } @@ -310,10 +305,12 @@ static acpi_status __init pnpacpi_add_device_handler(acpi_handle handle, { struct acpi_device *device; - if (!acpi_bus_get_device(handle, &device)) - pnpacpi_add_device(device); - else + if (acpi_bus_get_device(handle, &device)) return AE_CTRL_DEPTH; + + pnpacpi_add_device(device); + acpi_device_put(device); + return AE_OK; } diff --git a/include/acpi/acpi_bus.h b/include/acpi/acpi_bus.h index 9e6e1c6..e2a3eb0 100644 --- a/include/acpi/acpi_bus.h +++ b/include/acpi/acpi_bus.h @@ -345,8 +345,22 @@ extern void unregister_acpi_bus_notifier(struct notifier_block *nb); * External Functions */ +static inline struct acpi_device *acpi_device_get(struct acpi_device *d) +{ + if (d) + get_device(&d->dev); + + return d; +} + +static inline void acpi_device_put(struct acpi_device *d) +{ + if (d) + put_device(&d->dev); +} + +bool acpi_bus_has_device(acpi_handle handle); int acpi_bus_get_device(acpi_handle handle, struct acpi_device **device); -void acpi_bus_data_handler(acpi_handle handle, void *context); acpi_status acpi_bus_get_status_handle(acpi_handle handle, unsigned long long *sta); int acpi_bus_get_status(struct acpi_device *device); -- 1.7.9.5 -- To unsubscribe from this list: send the line "unsubscribe linux-pci" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html