Re: [PATCH 22/24] ARM64:ILP32: Use a seperate syscall table as a few syscalls need to be using the compat syscalls.

From: Catalin Marinas
Date: Tue Jul 01 2014 - 12:49:36 EST


On Tue, Jul 01, 2014 at 04:30:51PM +0100, Pinski, Andrew wrote:
> On Jul 1, 2014, at 8:07 AM, "Catalin Marinas" <catalin.marinas@xxxxxxx> wrote:
> > On Sat, May 24, 2014 at 12:02:17AM -0700, Andrew Pinski wrote:
> >> +/* Using Compat syscalls where necessary */
> >> +#define sys_ioctl compat_sys_ioctl
> >> +/* iovec */
> >> +#define sys_readv compat_sys_readv
> >> +#define sys_writev compat_sys_writev
> >> +#define sys_preadv compat_sys_preadv64
> >> +#define sys_pwritev compat_sys_pwritev64
> >> +#define sys_vmsplice compat_sys_vmsplice
> >
> > Do these actually work? compat_iovec has two members of 32-bit each
> > while the ILP32 iovec has a void * (32-bit) and a __kernel_size_t which
> > is 64-bit.
>
> size_t should be unsigned long in ilp32 so a 32bit unsigned integer
> type. That part of the abi was already defined in the arm abi
> documents. Now are saying we should pass size_t different between
> user and kernel space?

OK, I think you are right here. The ILP32 would not see __kernel_size_t
defined as __kernel_ulong_t because __BITS_PER_LONG != 64.

> >> +/* Pointer in struct */
> >> +#define sys_mount compat_sys_mount
> >
> > Which structure is this?
>
> NFS structure, I can expand out the comment if needed.

That would be good for future reference.

Thanks.

--
Catalin
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