Re: [edk2-devel] [PATCH 35/35] UefiPayloadPkg/BlSupportDxe: fix ReserveResourceInGcd() calls

["Laszlo Ersek" <lersek@redhat.com>]

On 09/23/19 17:08, Philippe Mathieu-Daudé wrote:
> On 9/17/19 9:49 PM, Laszlo Ersek wrote:
>> The last parameter of ReserveResourceInGcd() is "ImageHandle", forwarded
>> in turn to gDS->AllocateMemorySpace() or gDS->AllocateIoSpace() as "owner"
>> image handle.
>>
>> But BlDxeEntryPoint() passes "SystemTable" as "ImageHandle".
>>
>> Compilers have not flagged it because EFI_HANDLE (the type of
>> "ImageHandle") is unfortunately specified as (VOID*), and
>> (EFI_SYSTEM_TABLE*) converts to (VOID*) silently.
>>
>> Hand the entry point function's "ImageHandle" parameter to
>> ReserveResourceInGcd(). This fixes an actual bug.
> 
> Wow very buggy, so I assume this is mostly dead code, right?

Not necessarily; as long as noone tries to use the "owner" image handle
in practice, the issue may remain dormant.

Thanks
Laszlo

>> Cc: Benjamin You <benjamin.you@intel.com>
>> Cc: Guo Dong <guo.dong@intel.com>
>> Cc: Maurice Ma <maurice.ma@intel.com>
>> Signed-off-by: Laszlo Ersek <lersek@redhat.com>
>> ---
>>
>> Notes:
>>     build-tested only
>>
>>  UefiPayloadPkg/BlSupportDxe/BlSupportDxe.c | 4 ++--
>>  1 file changed, 2 insertions(+), 2 deletions(-)
>>
>> diff --git a/UefiPayloadPkg/BlSupportDxe/BlSupportDxe.c b/UefiPayloadPkg/BlSupportDxe/BlSupportDxe.c
>> index bcee4cd9bc41..28dfc8fc5545 100644
>> --- a/UefiPayloadPkg/BlSupportDxe/BlSupportDxe.c
>> +++ b/UefiPayloadPkg/BlSupportDxe/BlSupportDxe.c
>> @@ -106,10 +106,10 @@ BlDxeEntryPoint (
>>    //
>>    // Report MMIO/IO Resources
>>    //
>> -  Status = ReserveResourceInGcd (TRUE, EfiGcdMemoryTypeMemoryMappedIo, 0xFEC00000, SIZE_4KB, 0, SystemTable); // IOAPIC
>> +  Status = ReserveResourceInGcd (TRUE, EfiGcdMemoryTypeMemoryMappedIo, 0xFEC00000, SIZE_4KB, 0, ImageHandle); // IOAPIC
>>    ASSERT_EFI_ERROR (Status);
>>  
>> -  Status = ReserveResourceInGcd (TRUE, EfiGcdMemoryTypeMemoryMappedIo, 0xFED00000, SIZE_1KB, 0, SystemTable); // HPET
>> +  Status = ReserveResourceInGcd (TRUE, EfiGcdMemoryTypeMemoryMappedIo, 0xFED00000, SIZE_1KB, 0, ImageHandle); // HPET
>>    ASSERT_EFI_ERROR (Status);
>>  
>>    //
>>
> 
> Reviewed-by: Philippe Mathieu-Daude <philmd@redhat.com>
>