RE: [PATCH V3 07/17] riscv: compat: Re-implement TASK_SIZE for COMPAT_32BIT

From: David Laight
Date: Thu Jan 20 2022 - 07:54:20 EST


> > Limit 32-bit compatible process in 0-2GB virtual address range
> > (which is enough for real scenarios), because it could avoid
> > address sign extend problem when 32-bit enter 64-bit and ease
> > software design.

Eh?
I thought nearly all the other 32bit unix ports (of any flavour)
put the user-kernel boundary at 3GB.
(Apart from some very old sparc ones that use 3.5GB.)

2GB is used by Windows.

I think the x86-64 32bit compat code even puts the boundary at 4GB.

David

-
Registered Address Lakeside, Bramley Road, Mount Farm, Milton Keynes, MK1 1PT, UK
Registration No: 1397386 (Wales)