2013/04/15 18:03, Tang Chen wrote:
>
> Reviewed-by: Tang Chen <tangchen@xxxxxxxxxxxxxx>
Thank you for your review.
Thanks,
Yasuaki Ishimatsu
>
> Thanks. :)
>
> On 04/15/2013 01:48 PM, Yasuaki Ishimatsu wrote:
>> When hot removing a memory, a firmware_map_entry which has memory range
>> of the memory is released by release_firmware_map_entry(). If the entry
>> is allocated by bootmem, release_firmware_map_entry() adds the entry to
>> map_entires_bootmem list when firmware_map_find_entry() finds the entry
>> from map_entries list. But firmware_map_find_entry never find the entry
>> sicne map_entires list does not have the entry. So the entry just leaks.
>>
>> Here are steps of leaking firmware_map_entry:
>> firmware_map_remove()
>> -> firmware_map_find_entry()
>> Find released entry from map_entries list
>> -> firmware_map_remove_entry()
>> Delete the entry from map_entries list
>> -> remove_sysfs_fw_map_entry()
>> ...
>> -> release_firmware_map_entry()
>> -> firmware_map_find_entry()
>> Find the entry from map_entries list but the entry has been
>> deleted from map_entries list. So the entry is not added
>> to map_entries_bootmem. Thus the entry leaks
>>
>> release_firmware_map_entry() should not call firmware_map_find_entry()
>> since releaed entry has been deleted from map_entries list.
>> So the patch delete firmware_map_find_entry() from releae_firmware_map_entry()
>>
>> Signed-off-by: Yasuaki Ishimatsu<isimatu.yasuaki@xxxxxxxxxxxxxx>
>> ---
>> drivers/firmware/memmap.c | 9 +++------
>> 1 files changed, 3 insertions(+), 6 deletions(-)
>>
>> diff --git a/drivers/firmware/memmap.c b/drivers/firmware/memmap.c
>> index 0b5b5f6..e2e04b0 100644
>> --- a/drivers/firmware/memmap.c
>> +++ b/drivers/firmware/memmap.c
>> @@ -114,12 +114,9 @@ static void __meminit release_firmware_map_entry(struct kobject *kobj)
>> * map_entries_bootmem here, and deleted from&map_entries in
>> * firmware_map_remove_entry().
>> */
>> - if (firmware_map_find_entry(entry->start, entry->end,
>> - entry->type)) {
>> - spin_lock(&map_entries_bootmem_lock);
>> - list_add(&entry->list,&map_entries_bootmem);
>> - spin_unlock(&map_entries_bootmem_lock);
>> - }
>> + spin_lock(&map_entries_bootmem_lock);
>> + list_add(&entry->list,&map_entries_bootmem);
>> + spin_unlock(&map_entries_bootmem_lock);
>>
>> return;
>> }
>>
>>
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