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

["Wu, Hao A" <hao.a.wu@intel.com>]

> -----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

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
> 
> 
> 
> 
>