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 <mjg@xxxxxxxxxx> Cc: Matt Fleming <matt.fleming@xxxxxxxxx> Cc: H. Peter Anvin <hpa@xxxxxxxxx> Signed-off-by: Lee, Chun-Yi <jlee@xxxxxxxx> --- arch/x86/platform/efi/efi.c | 2 +- 1 files changed, 1 insertions(+), 1 deletions(-) diff --git a/arch/x86/platform/efi/efi.c b/arch/x86/platform/efi/efi.c index e4a86a6..cb59732 100644 --- a/arch/x86/platform/efi/efi.c +++ b/arch/x86/platform/efi/efi.c @@ -204,7 +204,7 @@ static efi_status_t virt_efi_get_next_variable(unsigned long *name_size, } if (boot_used_size && !finished) { - unsigned long size; + unsigned long size = 0; u32 attr; efi_status_t s; void *tmp; -- 1.6.0.2 -- To unsubscribe from this list: send the line "unsubscribe linux-efi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html