That will be better initial the value of DataSize to zero for the input of
GetVariable(), otherwise we will feed a random value. The debug log of input
DataSize like this:
...
[ 195.915612] EFI Variables Facility v0.08 2004-May-17
[ 195.915819] efi: size: 18446744071581821342
[ 195.915969] efi: size': 18446744071581821342
[ 195.916324] efi: size: 18446612150714306560
[ 195.916632] efi: size': 18446612150714306560
[ 195.917159] efi: size: 18446612150714306560
[ 195.917453] efi: size': 18446612150714306560
...
The size' is value that was returned by BIOS.
After applied this patch:
[ 82.442042] EFI Variables Facility v0.08 2004-May-17
[ 82.442202] efi: size: 0
[ 82.442360] efi: size': 1039
[ 82.443828] efi: size: 0
[ 82.444127] efi: size': 2616
[ 82.447057] efi: size: 0
[ 82.447356] efi: size': 5832
...
Found on Acer Aspire V3 BIOS, it will not return the size of data if we input a
non-zero DataSize.
Cc: Matthew Garrett <mjg59@srcf.ucam.org>
Cc: H. Peter Anvin <hpa@zytor.com>
Signed-off-by: Lee, Chun-Yi <jlee@suse.com>
Signed-off-by: Matt Fleming <matt.fleming@intel.com>
eccaf52fee