Re: [PATCH v12 05/13] x86/sgx: architectural structures

From: Jarkko Sakkinen
Date: Thu Jul 05 2018 - 16:09:24 EST


On Thu, Jul 05, 2018 at 08:31:42AM -0700, Dave Hansen wrote:
> On 07/03/2018 11:19 AM, Jarkko Sakkinen wrote:
> > +struct sgx_secs {
> > + uint64_t size;
> > + uint64_t base;
> > + uint32_t ssaframesize;
> > + uint32_t miscselect;
> > + uint8_t reserved1[SGX_SECS_RESERVED1_SIZE];
> > + uint64_t attributes;
> > + uint64_t xfrm;
> > + uint32_t mrenclave[8];
> > + uint8_t reserved2[SGX_SECS_RESERVED2_SIZE];
> > + uint32_t mrsigner[8];
> > + uint8_t reserved3[SGX_SECS_RESERVED3_SIZE];
> > + uint16_t isvvprodid;
> > + uint16_t isvsvn;
> > + uint8_t reserved4[SGX_SECS_RESERVED4_SIZE];
> > +} __packed __aligned(4096);
>
> Why are the uint* versions in use here? Those are for userspace ABI,
> but this is entirely for in-kernel-use, right?
>
> We've used u8/16/32/64 in arch code in a bunch of places. They're at
> least a bit more compact and easier to read. It's this:
>
> u8 foo;
> u64 bar;
>
> vs. this:
>
> uint8_t foo;
> uint64_t bar;

The reason was that with in-kernel LE these were in fact used by
user space code. Now they can be changed to those that you
suggested.

/Jarkko