Re: [MdeModulePkg/Library v1 1/1] MdeModulePkg/UefiBootManangerLib: Fix exception issue

[Ming Huang <ming.huang@linaro.org>]

On 3/19/2019 10:25 AM, Wu, Hao A wrote:
>> -----Original Message-----
>> From: Leif Lindholm [mailto:leif.lindholm@linaro.org]
>> Sent: Monday, March 18, 2019 8:43 PM
>> To: Ming Huang
>> Cc: linaro-uefi@lists.linaro.org; edk2-devel@lists.01.org; Zeng, Star; Dong,
>> Eric; Ni, Ray; dann.frazier@canonical.com; ard.biesheuvel@linaro.org; Kinney,
>> Michael D; Gao, Liming; wanghuiqiang@huawei.com;
>> huangming23@huawei.com; zhangjinsong2@huawei.com;
>> huangdaode@hisilicon.com; waip23@126.com; Wang, Jian J; Wu, Hao A; Ni,
>> Ray
>> Subject: Re: [MdeModulePkg/Library v1 1/1]
>> MdeModulePkg/UefiBootManangerLib: Fix exception issue
>>
>> +MdeModulePkg maintainers (you added MdePkg maintainers to cc)
>>
>> This looks like an improvement to me.
>>
>> Am I correct in guessing this behaviour refers to some specific corner
>> case of a USB CDROM emulated from a BMC?
>>
>> On Mon, Feb 25, 2019 at 05:10:52PM +0800, Ming Huang wrote:
>>> The system environment: virtual-CDROM(USB interface) via BMC, insert a
>>> iso file to CDROM, like ubuntu-18.04.1-server-arm64.iso, change CDROM
>>> to first boot option.
>>> With release version bios, disconnecting CDROM when boot to
>>> "1 seconds left, Press Esc or F2 to enter Setup"
>>> then system will get a exception.
>>>
>>> The root cause is the EFI_BLOCK_IO_PROTOCOL for UsbMass will be
>> uninstalled
>>> in this situation after print some transfer error. The status will be
>>> invalid parameter. This line will get a exception for BlockIo not point
> 
> Do you mean 'EFI_INVALID_PARAMETER' is returned from:
>   Status = gBS->HandleProtocol (Handle, &gEfiBlockIoProtocolGuid, (VOID **) &BlockIo);

Yes.

> 
> If so, my guess is that 'Handle' is NULL at this point. An improvement can
> be adding a previous check for 'Status' after the ASSERT at: 
> 
>   Status = gBS->LocateDevicePath (&gEfiBlockIoProtocolGuid, &TempDevicePath, &Handle);
>   ASSERT_EFI_ERROR (Status);

As my debug output, this 'Status' is seccuss and Handle is not NULL, but
gBS->ConnectController return:Not Found

Debug output:
[BmExpandMediaDevicePath]:[1056L] Handle=3E3F3D18 BlockIo=3B2757B6 Media=AFAF6C617470AFAF Status=Success
EhcExecTransfer: transfer failed with 40
EhcBulkTransfer: error - Device Error, transfer - 40
.........
[UsbOnHubInterrupt]:[632L] SignalEvent (HubIf->HubNotify)
UsbBotExecCommand: UsbBotSendCommand (Device Error)
UsbBootExecCmd: Device Error to Exec 0x0 Cmd (Result = 1)
EhcExecTransfer: transfer failed with 40
...............
[USBMassDriverBindingStop]:[1010L] Uninstall USB block io, free: 3E44F218(F0)
[BmExpandMediaDevicePath]:[1064L] Connect Not Found
[BmExpandMediaDevicePath]:[1076L] Handle=3E3F3D18 BlockIo=3B2757B6 Media=AFAF6C617470AFAF Status=Invalid Parameter

Thanks

> 
> And leave:
> 
>   Status = gBS->HandleProtocol (Handle, &gEfiBlockIoProtocolGuid, (VOID **) &BlockIo);
>   ASSERT_EFI_ERROR (Status);
> 
> unchanged.



> 
> Best Regards,
> Hao Wu
> 
>>> to right address:
>>> AllocatePool (BlockIo->Media->BlockSize)
>>> So, here need to judge the status not using ASSERT_EFI_ERROR.
>>>
>>> Contributed-under: TianoCore Contribution Agreement 1.1
>>> Signed-off-by: Ming Huang <ming.huang@linaro.org>
>>> ---
>>>  MdeModulePkg/Library/UefiBootManagerLib/BmBoot.c | 4 +++-
>>>  1 file changed, 3 insertions(+), 1 deletion(-)
>>>
>>> diff --git a/MdeModulePkg/Library/UefiBootManagerLib/BmBoot.c
>> b/MdeModulePkg/Library/UefiBootManagerLib/BmBoot.c
>>> index d5957db610d9..c2f1c651b02f 100644
>>> --- a/MdeModulePkg/Library/UefiBootManagerLib/BmBoot.c
>>> +++ b/MdeModulePkg/Library/UefiBootManagerLib/BmBoot.c
>>> @@ -1068,7 +1068,9 @@ BmExpandMediaDevicePath (
>>>    // Block IO read/write will success.
>>>    //
>>>    Status = gBS->HandleProtocol (Handle, &gEfiBlockIoProtocolGuid, (VOID
>> **) &BlockIo);
>>> -  ASSERT_EFI_ERROR (Status);
>>> +  if (EFI_ERROR (Status)) {
>>
>> It would still be worth including an ASSERT here, to let DEBUG builds
>> report on point of failure rather than several steps up the chain.
>>
>> /
>>     Leif
>>
>>> +    return NULL;
>>> +  }
>>>    Buffer = AllocatePool (BlockIo->Media->BlockSize);
>>>    if (Buffer != NULL) {
>>>      BlockIo->ReadBlocks (
>>> --
>>> 2.9.5
>>>