Re: [PATCH v2 1/4] mm: Add optional close() to struct vm_special_mapping

[Rob Landley <rob@landley.net>]

On 8/20/24 10:31, Linus Torvalds wrote:
> On Mon, 19 Aug 2024 at 23:26, Michael Ellerman <mpe@ellerman.id.au> wrote:
>>
>> Linus Torvalds <torvalds@linux-foundation.org> writes:
>> > +static struct vm_special_mapping vdso_mapping = {
>> > +     .name = "[vdso]",
>> > +     .pages = syscall_pages;
>>                               ^
>>                               should be ,
> 
> Ack. Changed here locally.

Hexagon also has &&vdso_page which I don't understand (but have a toolchain for
somewhere to at least smoketest...)

> But I assume you also don't actually test sh...

But I do.

Aside: arch/sh smoketests easily under qemu, here's a relocatable binary toolchain:

  wget https://landley.net/bin/toolchains/latest/sh4-linux-musl-cross.tar.xz
  tar xvf sh4-linux-musl-cross-tar.xz
  CROSS_COMPILE=$PWD/sh4-linux-musl-cross/bin/sh4-linux-musl-

And https://landley.net/bin/mkroot/latest/sh4.tgz is a tiny qemu-system-sh4
system with kernel + initramfs.cpio.gz + run-qemu.sh with the config used to
build it under docs/ and as the first three lines of docs/linux-miniconfig
record, the kernel is arch/sh/boot/zImage.

You can keep the initramfs.cpio.gz and run-qemu.sh and swap out the kernel for a
quick boot to shell prompt under qemu. Serial console is qemu's stdin/stdout,
"exit" to shut down the emulator.

The build script, if you care, is 400 lines of bash:

  https://github.com/landley/toybox/blob/master/mkroot/mkroot.sh

> It would be good to get acks from the architectures that still used
> the legacy interface.

I'll give arch/sh a whirl. Can somebody answer my above hexagon question?

>               Linus

Rob