From: Wen Congyang <we...@cn.fujitsu.com> The memory device can be removed by 2 ways: 1. send eject request by SCI 2. echo 1 >/sys/bus/pci/devices/PNP0C80:XX/eject
This 2 events may happen at the same time, so we may touch acpi_memory_device.res_list at the same time. This patch introduce a lock to protect this list. CC: David Rientjes <rient...@google.com> CC: Jiang Liu <liu...@gmail.com> CC: Len Brown <len.br...@intel.com> CC: Christoph Lameter <c...@linux.com> Cc: Minchan Kim <minchan....@gmail.com> CC: Andrew Morton <a...@linux-foundation.org> CC: KOSAKI Motohiro <kosaki.motoh...@jp.fujitsu.com> CC: Yasuaki Ishimatsu <isimatu.yasu...@jp.fujitsu.com> Signed-off-by: Wen Congyang <we...@cn.fujitsu.com> --- drivers/acpi/acpi_memhotplug.c | 17 +++++++++++++++-- 1 files changed, 15 insertions(+), 2 deletions(-) diff --git a/drivers/acpi/acpi_memhotplug.c b/drivers/acpi/acpi_memhotplug.c index 1e90e8f..8ff2976 100644 --- a/drivers/acpi/acpi_memhotplug.c +++ b/drivers/acpi/acpi_memhotplug.c @@ -83,7 +83,8 @@ struct acpi_memory_info { struct acpi_memory_device { struct acpi_device * device; unsigned int state; /* State of the memory device */ - struct list_head res_list; + struct mutex lock; + struct list_head res_list; /* protected by lock */ }; static int acpi_hotmem_initialized; @@ -101,19 +102,23 @@ acpi_memory_get_resource(struct acpi_resource *resource, void *context) (address64.resource_type != ACPI_MEMORY_RANGE)) return AE_OK; + mutex_lock(&mem_device->lock); list_for_each_entry(info, &mem_device->res_list, list) { /* Can we combine the resource range information? */ if ((info->caching == address64.info.mem.caching) && (info->write_protect == address64.info.mem.write_protect) && (info->start_addr + info->length == address64.minimum)) { info->length += address64.address_length; + mutex_unlock(&mem_device->lock); return AE_OK; } } new = kzalloc(sizeof(struct acpi_memory_info), GFP_KERNEL); - if (!new) + if (!new) { + mutex_unlock(&mem_device->lock); return AE_ERROR; + } INIT_LIST_HEAD(&new->list); new->caching = address64.info.mem.caching; @@ -121,6 +126,7 @@ acpi_memory_get_resource(struct acpi_resource *resource, void *context) new->start_addr = address64.minimum; new->length = address64.address_length; list_add_tail(&new->list, &mem_device->res_list); + mutex_unlock(&mem_device->lock); return AE_OK; } @@ -138,9 +144,11 @@ acpi_memory_get_device_resources(struct acpi_memory_device *mem_device) status = acpi_walk_resources(mem_device->device->handle, METHOD_NAME__CRS, acpi_memory_get_resource, mem_device); if (ACPI_FAILURE(status)) { + mutex_lock(&mem_device->lock); list_for_each_entry_safe(info, n, &mem_device->res_list, list) kfree(info); INIT_LIST_HEAD(&mem_device->res_list); + mutex_unlock(&mem_device->lock); return -EINVAL; } @@ -236,6 +244,7 @@ static int acpi_memory_enable_device(struct acpi_memory_device *mem_device) * We don't have memory-hot-add rollback function,now. * (i.e. memory-hot-remove function) */ + mutex_lock(&mem_device->lock); list_for_each_entry(info, &mem_device->res_list, list) { if (info->enabled) { /* just sanity check...*/ num_enabled++; @@ -256,6 +265,7 @@ static int acpi_memory_enable_device(struct acpi_memory_device *mem_device) info->enabled = 1; num_enabled++; } + mutex_unlock(&mem_device->lock); if (!num_enabled) { printk(KERN_ERR PREFIX "add_memory failed\n"); mem_device->state = MEMORY_INVALID_STATE; @@ -316,6 +326,7 @@ static int acpi_memory_disable_device(struct acpi_memory_device *mem_device) * Ask the VM to offline this memory range. * Note: Assume that this function returns zero on success */ + mutex_lock(&mem_device->lock); list_for_each_entry_safe(info, n, &mem_device->res_list, list) { if (info->enabled) { result = remove_memory(info->start_addr, info->length); @@ -324,6 +335,7 @@ static int acpi_memory_disable_device(struct acpi_memory_device *mem_device) } kfree(info); } + mutex_unlock(&mem_device->lock); /* Power-off and eject the device */ result = acpi_memory_powerdown_device(mem_device); @@ -438,6 +450,7 @@ static int acpi_memory_device_add(struct acpi_device *device) mem_device->device = device; sprintf(acpi_device_name(device), "%s", ACPI_MEMORY_DEVICE_NAME); sprintf(acpi_device_class(device), "%s", ACPI_MEMORY_DEVICE_CLASS); + mutex_init(&mem_device->lock); device->driver_data = mem_device; /* Get the range from the _CRS */ -- 1.7.1 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/