2013-05-02 14:08:27

by Chun-Yi Lee

Subject: [PATCH] x86, efi: initial the local variable of DataSize to zero

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 <[email protected]>
Cc: Matt Fleming <[email protected]>
Cc: H. Peter Anvin <[email protected]>
Signed-off-by: Lee, Chun-Yi <[email protected]>
---
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

2013-05-03 08:50:15

by Matt Fleming

Subject: Re: [PATCH] x86, efi: initial the local variable of DataSize to zero

On Thu, 02 May, at 10:07:01PM, Lee, Chun-Yi wrote:
> 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 <[email protected]>
> Cc: Matt Fleming <[email protected]>
> Cc: H. Peter Anvin <[email protected]>
> Signed-off-by: Lee, Chun-Yi <[email protected]>
> ---
> arch/x86/platform/efi/efi.c | 2 +-
> 1 files changed, 1 insertions(+), 1 deletions(-)

Applied, thanks.

--
Matt Fleming, Intel Open Source Technology Center