[PATCH 0/2] Restrict address space for sv39,sv48,sv57

[Charles Jenkins]

I talked to Atish, he's not sure what's going on here either. I am going
to add him to the CC list.

On Tue, Jun 27, 2023 at 11:24 AM Conor Dooley <conor at kernel.org> wrote:

> Hey Charlie,
>
> On Mon, Jun 26, 2023 at 11:36:02AM -0700, Charlie Jenkins wrote:
> > Make sv39 the default address space for mmap as some applications
> > currently depend on this assumption. The RISC-V specification enforces
> > that bits outside of the virtual address range are not used, so
> > restricting the size of the default address space as such should be
> > temporary. A hint address passed to mmap will cause the largest address
> > space that fits entirely into the hint to be used. If the hint is less
> > than or equal to 1<<38, a 39-bit address will be used. After an address
> > space is completely full, the next smallest address space will be used.
> > 
> > Documentation is also added to the RISC-V virtual memory section to 
> explain
> > these changes.
>
> I don't know what went wrong here, but this never ended up in patchwork
> for some reason, although it has appeared on lore. That seems to be via
> the docs mailing list, rather than linux-riscv. Could you speak to Atish
> and see if he knows what went wrong?
>
> Cheers,
> Conor.
>
> > 
> > Charlie Jenkins (2):
> >   RISC-V: mm: Restrict address space for sv39,sv48,sv57
> >   RISC-V: mm: Update documentation and include test
> > 
> >  Documentation/riscv/vm-layout.rst             | 20 ++++++++
> >  arch/riscv/include/asm/elf.h                  |  2 +-
> >  arch/riscv/include/asm/pgtable.h              | 21 ++++++--
> >  arch/riscv/include/asm/processor.h            | 41 +++++++++++++---
> >  tools/testing/selftests/riscv/Makefile        |  2 +-
> >  tools/testing/selftests/riscv/mm/Makefile     | 22 +++++++++
> >  .../selftests/riscv/mm/testcases/mmap.c       | 49 +++++++++++++++++++
> >  7 files changed, 144 insertions(+), 13 deletions(-)
> >  create mode 100644 tools/testing/selftests/riscv/mm/Makefile
> >  create mode 100644 tools/testing/selftests/riscv/mm/testcases/mmap.c
> > 
> > 
> > base-commit: eef509789cecdce895020682192d32e8bac790e8
> > -- 
> > 2.34.1
> > 
>