diff options
| author | Liu Jinsong <jinsong.liu@intel.com> | 2013-02-16 16:59:03 +0800 |
|---|---|---|
| committer | Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> | 2013-02-25 07:44:21 -0500 |
| commit | 484400ffbf2dd33446d71c05b9cddf91932a882e (patch) | |
| tree | bb4d4650a246dadebe0eec93fac459876d67de46 /drivers/xen/xen-acpi-memhotplug.c | |
| parent | 77be36de8b07027a70fbc8f02703ccd76cd16d09 (diff) | |
| download | linux-484400ffbf2dd33446d71c05b9cddf91932a882e.tar.gz | |
xen/acpi: xen memory hotplug minor updates
Dan Carpenter found current xen memory hotplug logic
has potential issue: at func acpi_memory_get_device()
*mem_device = acpi_driver_data(device);
while the device may be NULL and then dereference.
At native side, Rafael recently updated acpi_memory_get_device(),
dropping acpi_bus_add, adding lock, and avoiding above issue.
This patch updates xen memory hotplug logic accordingly, removing
redundant logic, adding lock, and avoiding dereference.
Signed-off-by: Liu Jinsong <jinsong.liu@intel.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Diffstat (limited to 'drivers/xen/xen-acpi-memhotplug.c')
| -rw-r--r-- | drivers/xen/xen-acpi-memhotplug.c | 52 |
1 files changed, 26 insertions, 26 deletions
diff --git a/drivers/xen/xen-acpi-memhotplug.c b/drivers/xen/xen-acpi-memhotplug.c index 853b12dba5bb..faef5b396051 100644 --- a/drivers/xen/xen-acpi-memhotplug.c +++ b/drivers/xen/xen-acpi-memhotplug.c @@ -158,31 +158,17 @@ acpi_memory_get_device_resources(struct acpi_memory_device *mem_device) return 0; } -static int -acpi_memory_get_device(acpi_handle handle, - struct acpi_memory_device **mem_device) +static int acpi_memory_get_device(acpi_handle handle, + struct acpi_memory_device **mem_device) { - acpi_status status; - acpi_handle phandle; struct acpi_device *device = NULL; - struct acpi_device *pdevice = NULL; - int result; + int result = 0; - if (!acpi_bus_get_device(handle, &device) && device) - goto end; + acpi_scan_lock_acquire(); - status = acpi_get_parent(handle, &phandle); - if (ACPI_FAILURE(status)) { - pr_warn(PREFIX "Cannot find acpi parent\n"); - return -EINVAL; - } - - /* Get the parent device */ - result = acpi_bus_get_device(phandle, &pdevice); - if (result) { - pr_warn(PREFIX "Cannot get acpi bus device\n"); - return -EINVAL; - } + acpi_bus_get_device(handle, &device); + if (device) + goto end; /* * Now add the notified device. This creates the acpi_device @@ -190,18 +176,28 @@ acpi_memory_get_device(acpi_handle handle, */ result = acpi_bus_scan(handle); if (result) { - pr_warn(PREFIX "Cannot add acpi bus\n"); - return -EINVAL; + pr_warn(PREFIX "ACPI namespace scan failed\n"); + result = -EINVAL; + goto out; + } + result = acpi_bus_get_device(handle, &device); + if (result) { + pr_warn(PREFIX "Missing device object\n"); + result = -EINVAL; + goto out; } end: *mem_device = acpi_driver_data(device); if (!(*mem_device)) { - pr_err(PREFIX "Driver data not found\n"); - return -ENODEV; + pr_err(PREFIX "driver data not found\n"); + result = -ENODEV; + goto out; } - return 0; +out: + acpi_scan_lock_release(); + return result; } static int acpi_memory_check_device(struct acpi_memory_device *mem_device) @@ -259,12 +255,15 @@ static void acpi_memory_device_notify(acpi_handle handle, u32 event, void *data) ACPI_DEBUG_PRINT((ACPI_DB_INFO, "\nReceived EJECT REQUEST notification for device\n")); + acpi_scan_lock_acquire(); if (acpi_bus_get_device(handle, &device)) { + acpi_scan_lock_release(); pr_err(PREFIX "Device doesn't exist\n"); break; } mem_device = acpi_driver_data(device); if (!mem_device) { + acpi_scan_lock_release(); pr_err(PREFIX "Driver Data is NULL\n"); break; } @@ -274,6 +273,7 @@ static void acpi_memory_device_notify(acpi_handle handle, u32 event, void *data) * acpi_bus_remove if Xen support hotremove in the future */ acpi_memory_disable_device(mem_device); + acpi_scan_lock_release(); break; default: |