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

[Leif Lindholm <leif.lindholm@linaro.org>]

+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
> 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
>