Re: [edk2-devel] [PATCH v1 1/1] RamDiskDxe: Initialize list head before registering RAM disk protocol

["Daniel Schaefer" <daniel.schaefer@hpe.com>]

On 7/13/21 11:44 AM, Wu, Hao A wrote:
>> -----Original Message-----
>> From: devel@edk2.groups.io <devel@edk2.groups.io> On Behalf Of Daniel
>> Schaefer
>> Sent: Tuesday, July 13, 2021 9:10 AM
>> To: devel@edk2.groups.io
>> Cc: Trammell Hudson <hudson@trmm.net>; Daniel Schaefer
>> <daniel.schaefer@hpe.com>; Wang, Jian J <jian.j.wang@intel.com>; Wu,
>> Hao A <hao.a.wu@intel.com>; Ni, Ray <ray.ni@intel.com>; Gao, Zhichao
>> <zhichao.gao@intel.com>
>> Subject: [edk2-devel] [PATCH v1 1/1] RamDiskDxe: Initialize list head before
>> registering RAM disk protocol
>>
>> From: Trammell Hudson <hudson@trmm.net>
>>
>> This patch initializes the linked list RegisteredRamDisks in
>> RamDiskDxeEntryPoint before the registration of gEfiRamDiskProtocolGuid
>> with InstallMultipleProtocolInterfaces, allowing ramdisks to be created via a
>> callback installed with RegisterProtocolNotify as soon as the protocol is
>> registered.
>>
>> Without this, calling RamDisk->Register() in the callback causes a crash:
>>
>> ASSERT [RamDiskDxe] MdePkg/Library/BaseLib/LinkedList.c(75): List-
>>> ForwardLink != ((void *) 0)
>>
>> Signed-off-by: Trammell Hudson <hudson@trmm.net>
>> Cc: Daniel Schaefer <daniel.schaefer@hpe.com>
>> Cc: Jian J Wang <jian.j.wang@intel.com>
>> Cc: Hao A Wu <hao.a.wu@intel.com>
>> Cc: Ray Ni <ray.ni@intel.com>
>> Cc: Zhichao Gao <zhichao.gao@intel.com>
> 
> 
> Thanks a lot for the fix.
> Reviewed-by: Hao A Wu <hao.a.wu@intel.com>
> 
> I will modify the subject a little bit when merging:
> MdeModulePkg/RamDiskDxe: Init list head before registering RamDisk protocol

Sure, that's good. Thanks!

> 
> Best Regards,
> Hao Wu
> 
> 
>>
>> ---
>>   MdeModulePkg/Universal/Disk/RamDiskDxe/RamDiskDriver.c | 11 ++++++-
>> ----
>>   1 file changed, 6 insertions(+), 5 deletions(-)
>>
>> diff --git a/MdeModulePkg/Universal/Disk/RamDiskDxe/RamDiskDriver.c
>> b/MdeModulePkg/Universal/Disk/RamDiskDxe/RamDiskDriver.c
>> index fcbf4f117dc6..13e2aed87cef 100644
>> --- a/MdeModulePkg/Universal/Disk/RamDiskDxe/RamDiskDriver.c
>> +++ b/MdeModulePkg/Universal/Disk/RamDiskDxe/RamDiskDriver.c
>> @@ -154,6 +154,12 @@ RamDiskDxeEntryPoint (
>>       goto ErrorExit;
>>     }
>>
>> +  //
>> +  // Initialize the list of registered RAM disks maintained by the
>> + driver  // before installing the protocol  //  InitializeListHead
>> + (&RegisteredRamDisks);
>> +
>>     //
>>     // Install the EFI_RAM_DISK_PROTOCOL and RAM disk private data onto a
>>     // new handle
>> @@ -170,11 +176,6 @@ RamDiskDxeEntryPoint (
>>       goto ErrorExit;
>>     }
>>
>> -  //
>> -  // Initialize the list of registered RAM disks maintained by the driver
>> -  //
>> -  InitializeListHead (&RegisteredRamDisks);
>> -
>>     Status = EfiCreateEventReadyToBootEx (
>>                TPL_CALLBACK,
>>                RamDiskAcpiCheck,
>> --
>> 2.31.1
>>
>>
>>
>> 
>>
>