RE: [PATCH v2 1/8] efi: Fix IA32/X64 Processor Error Record definition

[Ghannam, Yazen]

> -----Original Message-----
> From: Borislav Petkov [mailto:bp@xxxxxxx]
> Sent: Tuesday, February 27, 2018 5:47 AM
> To: Ghannam, Yazen <Yazen.Ghannam@xxxxxxx>
> Cc: linux-efi@xxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx;
> ard.biesheuvel@xxxxxxxxxx; x86@xxxxxxxxxx
> Subject: Re: [PATCH v2 1/8] efi: Fix IA32/X64 Processor Error Record
> definition
> 
> On Mon, Feb 26, 2018 at 01:38:57PM -0600, Yazen Ghannam wrote:
> > From: Yazen Ghannam <yazen.ghannam@xxxxxxx>
> >
> > Based on UEFI 2.7 Table 255. Processor Error Record, the "Local APIC_ID"
> 
> My pdf says this is table 252.
> 

Right. I'm using the latest which is UEFI 2.7 Errata A. It turns out that the table
numbering is different between the base and the errata specs. I can change this.

> > field is 8 bytes but Linux defines this field as 1 byte.
> >
> > Fix this in the struct cper_sec_proc_ia definition.
> >
> > Signed-off-by: Yazen Ghannam <yazen.ghannam@xxxxxxx>
> > ---
> > Link:
> > https://lkml.kernel.org/r/20180223200333.6410-2-
> Yazen.Ghannam@xxxxxxx
> >
> > v1->v2:
> > * No changes.
> >
> >  include/linux/cper.h | 2 +-
> >  1 file changed, 1 insertion(+), 1 deletion(-)
> >
> > diff --git a/include/linux/cper.h b/include/linux/cper.h
> > index d14ef4e77c8a..4b5f8459b403 100644
> > --- a/include/linux/cper.h
> > +++ b/include/linux/cper.h
> > @@ -381,7 +381,7 @@ struct cper_sec_proc_generic {
> >  /* IA32/X64 Processor Error Section */
> >  struct cper_sec_proc_ia {
> >  	__u64	validation_bits;
> > -	__u8	lapic_id;
> > +	__u64	lapic_id;
> >  	__u8	cpuid[48];
> 
> Ok, that processor error record has a variable length structure at byte
> offset 64 and we don't have it in this struct.
> 
> I guess I'll see it in the following patches but right now it looks
> like that "Processor Error Info" thing is simply situated after that
> Processor Error Record so we are supposed to simply find the info at
> offset 64...
> 
> /me continues reading...

The error and context info tables are defined in other structs and we
access them by offsetting from the previous table.

Thanks,
Yazen