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

2022-01-20 Thread David Laight
... > One example of software that runs into virtual memory size limitations is > the gnu linker when building large applications, but it's unlikely that you'll > actually need to run applications that run into this, while also needing to > build them natively. There are also database programs

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

2022-01-20 Thread Arnd Bergmann
On Thu, Jan 20, 2022 at 2:27 PM Guo Ren wrote: > On Thu, Jan 20, 2022 at 8:53 PM David Laight wrote: > > I think the x86-64 32bit compat code even puts the boundary at 4GB. > Yes, we could give rv32 compat for 4GB with some effort. But it's unnecessary. > > There are no history issues for rv32,

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

2022-01-20 Thread Guo Ren
On Thu, Jan 20, 2022 at 8:53 PM David Laight wrote: > > > > 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

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

2022-01-20 Thread David Laight
> > 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

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

2022-01-20 Thread Arnd Bergmann
On Thu, Jan 20, 2022 at 8:39 AM wrote: > > From: Guo Ren > > Make TASK_SIZE from const to dynamic detect TIF_32BIT flag > function. Refer to arm64 to implement DEFAULT_MAP_WINDOW_64 for > efi-stub. > > Limit 32-bit compatible process in 0-2GB virtual address range > (which is enough for real