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authorWen Congyang <wency@cn.fujitsu.com>2012-11-16 02:10:37 +0100
committerRafael J. Wysocki <rafael.j.wysocki@intel.com>2012-11-16 02:10:37 +0100
commit65479472571fbf91502b7854be45ec0026b5229e (patch)
tree1f9e40f833838971398dae6c61471fdcc0adb654 /drivers/acpi
parente0b7b24dd9559fcda0f8bfd6acbcad81682c4fdd (diff)
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ACPI / memhotplug: don't allow to eject the memory device if it is being used
We eject the memory device even if it is in use. It is very dangerous, and it will cause the kernel to be panicked. Signed-off-by: Wen Congyang <wency@cn.fujitsu.com> Reviewed-by: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com> Acked-by: David Rientjes <rientjes@google.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Diffstat (limited to 'drivers/acpi')
-rw-r--r--drivers/acpi/acpi_memhotplug.c42
1 files changed, 33 insertions, 9 deletions
diff --git a/drivers/acpi/acpi_memhotplug.c b/drivers/acpi/acpi_memhotplug.c
index e52ad5d3792d..f7e300769966 100644
--- a/drivers/acpi/acpi_memhotplug.c
+++ b/drivers/acpi/acpi_memhotplug.c
@@ -78,6 +78,7 @@ struct acpi_memory_info {
unsigned short caching; /* memory cache attribute */
unsigned short write_protect; /* memory read/write attribute */
unsigned int enabled:1;
+ unsigned int failed:1;
};
struct acpi_memory_device {
@@ -257,9 +258,23 @@ static int acpi_memory_enable_device(struct acpi_memory_device *mem_device)
node = memory_add_physaddr_to_nid(info->start_addr);
result = add_memory(node, info->start_addr, info->length);
- if (result)
+
+ /*
+ * If the memory block has been used by the kernel, add_memory()
+ * returns -EEXIST. If add_memory() returns the other error, it
+ * means that this memory block is not used by the kernel.
+ */
+ if (result && result != -EEXIST) {
+ info->failed = 1;
continue;
- info->enabled = 1;
+ }
+
+ if (!result)
+ info->enabled = 1;
+ /*
+ * Add num_enable even if add_memory() returns -EEXIST, so the
+ * device is bound to this driver.
+ */
num_enabled++;
}
if (!num_enabled) {
@@ -280,21 +295,30 @@ static int acpi_memory_enable_device(struct acpi_memory_device *mem_device)
static int acpi_memory_remove_memory(struct acpi_memory_device *mem_device)
{
- int result;
+ int result = 0;
struct acpi_memory_info *info, *n;
list_for_each_entry_safe(info, n, &mem_device->res_list, list) {
- if (info->enabled) {
- result = remove_memory(info->start_addr, info->length);
- if (result)
- return result;
- }
+ if (info->failed)
+ /* The kernel does not use this memory block */
+ continue;
+
+ if (!info->enabled)
+ /*
+ * The kernel uses this memory block, but it may be not
+ * managed by us.
+ */
+ return -EBUSY;
+
+ result = remove_memory(info->start_addr, info->length);
+ if (result)
+ return result;
list_del(&info->list);
kfree(info);
}
- return 0;
+ return result;
}
static void acpi_memory_device_notify(acpi_handle handle, u32 event, void *data)