Re: [PATCH] x86, efi: initial the local variable of DataSize tozero

From: joeyli
Date: Mon Apr 29 2013 - 06:36:03 EST


æ äï2013-04-29 æ 18:25 +0800ïjoeyli æåï
> æ åï2013-04-27 æ 01:19 +0800ïLee, Chun-Yi æåï
> > 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
> > ...
>
> After applied patch, the log of size like this:
>
> [ 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
> [ 82.452669] efi: size: 0
> [ 82.453128] efi: size': 1
> [ 82.454339] efi: size: 0
> [ 82.454843] efi: size': 1
> [ 82.456173] efi: size: 0
> [ 82.456764] efi: size': 8
> [ 82.458194] efi: size: 0
> [ 82.458905] efi: size': 4
>
> The size' is the return value of Acer BIOS, it return right size value
> then we feed zero DataSize.
^^^^^^^^^ when

Sorry for typo!
Joey Lee

>
>
> Thanks a lot!
> Joey Lee
>
> >
> > 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;
>
>
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